1
|
Chetty LC, Kruger HG, Arvidsson PI, Naicker T, Govender T. Investigating the efficacy of green solvents and solvent-free conditions in hydrogen-bonding mediated organocatalyzed model reactions. RSC Adv 2024; 14:7992-7998. [PMID: 38454950 PMCID: PMC10918449 DOI: 10.1039/d4ra00679h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 02/25/2024] [Indexed: 03/09/2024] Open
Abstract
In this study, we have delved into various reactions conducted using green solvents or under solvent-free conditions, employing hydrogen bonding organocatalysis to advance more sustainable practices in chemical synthesis. The outcomes suggest that cyclopentyl methyl ether could potentially replace non-polar organic solvents such as hexane and toluene with comparable enantioselectivity and yields. The non-polar nature of liquefied or supercritical CO2 restricts its application to reactions that require non-polar solvents. Furthermore, pursuing solvent-free conditions, even without liquid substrates, might result in similar conversion rates with reduced catalyst loading. These findings highlight the potential of exploring solvent-free conditions when enantioselectivity is not of concern. Based on the results, solvent-free conditions and bio-based solvents can serve as viable alternatives to conventional organic solvents without compromising performance. This is expected to influence the way chemists approach reaction optimisation within method development in the field, fostering a broader adoption of environmentally friendly approaches.
Collapse
Affiliation(s)
- Lloyd C Chetty
- Catalysis and Peptide Research Unit, University of KwaZulu Natal Durban 4001 South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, University of KwaZulu Natal Durban 4001 South Africa
| | - Per I Arvidsson
- Catalysis and Peptide Research Unit, University of KwaZulu Natal Durban 4001 South Africa
- Science for Life Laboratory, Drug Discovery & Development Platform & Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet Stockholm Sweden
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZulu Natal Durban 4001 South Africa
| | - Thavendran Govender
- Department of Chemistry, University of Zululand Private Bag X1001 KwaDlangezwa 3886 South Africa
| |
Collapse
|
2
|
Naidoo V, Mdanda S, Ntshangase S, Naicker T, Kruger HG, Govender T, Naidoo P, Baijnath S. Corrigendum to "Brain penetration of ketamine: Intranasal delivery VS parenteral routes of administration" [J. Psychiatr. Res. 112 (2019) 7-11]. J Psychiatr Res 2023; 165:254. [PMID: 37536188 DOI: 10.1016/j.jpsychires.2023.07.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/05/2023]
Affiliation(s)
- Vivian Naidoo
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Sipho Mdanda
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Sphamandla Ntshangase
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Panjasaram Naidoo
- Discipline of Pharmaceutical Sciences, Westville Campus, University of KwaZulu-Natal, Durban, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa.
| |
Collapse
|
3
|
Shungube M, Hlophe AK, Girdhari L, Sabe VT, Peters BB, Reddy N, Omolabi KF, Chetty L, Arumugam T, Chuturgoon A, Kruger HG, Arvidsson PI, Qin HL, Naicker T, Govender T. Synthesis and biological evaluation of novel β-lactam-metallo β-lactamase inhibitors. RSC Adv 2023; 13:18991-19001. [PMID: 37362332 PMCID: PMC10285615 DOI: 10.1039/d3ra02490c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 06/09/2023] [Indexed: 06/28/2023] Open
Abstract
β-lactamases are enzymes that deactivate β-lactam antibiotics through a hydrolysis mechanism. There are two known types of β-lactamases: serine β-lactamases (SBLs) and metallo β-lactamases (MBLs). The two existing strategies to overcome β-lactamase-mediated resistance are (a) to develop novel β-lactam antibiotics that are not susceptible to hydrolysis by these enzymes; or (b) to develop β-lactamase inhibitors that deactivate the enzyme and thereby restore the efficacy of the co-administered antibiotics. Many commercially available SBL inhibitors are used in combination therapy with antibiotics to treat antimicrobial resistant infections; however, there are only a handful of MBL inhibitors undergoing clinical trials. In this study, we present 11 novel potential MBL inhibitors (via multi-step chemical synthesis), that have shown to completely restore the efficacy of meropenem (≤2 mg L-1) against New Delhi metallo-β-lactamase (NDM) producing Klebsiella pneumoniae in vitro. These compounds contain a cyclic amino acid zinc chelator conjugated to various commercially available β-lactam antibiotic scaffolds with the aim to improve the overall drug transport, lipophilicity, and pharmacokinetic/pharmacodynamic properties as compared to the chelator alone. Biological evaluation of compounds 24b and 24c has further highlighted the downstream application of these MBLs, since they are non-toxic at the selected doses. Time-kill assays indicate that compounds 24b and 24c exhibit sterilizing activity towards NDM producing Klebsiella pneumoniae in vitro using minimal concentrations of meropenem. Furthermore, 24b and 24c proved to be promising inhibitors of VIM-2 (Ki = 0.85 and 1.87, respectively). This study has revealed a novel series of β-lactam MBLIs that are potent, efficacious, and safe leads with the potential to develop into therapeutic MBLIs.
Collapse
Affiliation(s)
- Mbongeni Shungube
- Catalysis and Peptide Research Unit, University of KwaZulu Natal Durban 4001 South Africa +27 312601845
| | - Ayanda K Hlophe
- Catalysis and Peptide Research Unit, University of KwaZulu Natal Durban 4001 South Africa +27 312601845
| | - Letisha Girdhari
- Catalysis and Peptide Research Unit, University of KwaZulu Natal Durban 4001 South Africa +27 312601845
| | - Victor T Sabe
- Catalysis and Peptide Research Unit, University of KwaZulu Natal Durban 4001 South Africa +27 312601845
| | - Byron B Peters
- Catalysis and Peptide Research Unit, University of KwaZulu Natal Durban 4001 South Africa +27 312601845
| | - Nakita Reddy
- Catalysis and Peptide Research Unit, University of KwaZulu Natal Durban 4001 South Africa +27 312601845
| | - Kehinde F Omolabi
- Catalysis and Peptide Research Unit, University of KwaZulu Natal Durban 4001 South Africa +27 312601845
| | - Lloyd Chetty
- Catalysis and Peptide Research Unit, University of KwaZulu Natal Durban 4001 South Africa +27 312601845
| | - Thilona Arumugam
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal Durban South Africa
| | - Anil Chuturgoon
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal Durban South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, University of KwaZulu Natal Durban 4001 South Africa +27 312601845
| | - Per I Arvidsson
- Catalysis and Peptide Research Unit, University of KwaZulu Natal Durban 4001 South Africa +27 312601845
- Science for Life Laboratory, Drug Discovery & Development Platform & Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet Stockholm Sweden
| | - Hua-Li Qin
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology 205 Luoshi Road Wuhan 430070 P. R. China
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZulu Natal Durban 4001 South Africa +27 312601845
| | - Thavendran Govender
- Department of Chemistry, University of Zululand Private Bag X1001 KwaDlangezwa 3886 South Africa
| |
Collapse
|
4
|
Reddy N, Girdhari L, Shungube M, Gouws AC, Peters BK, Rajbongshi KK, Baijnath S, Mdanda S, Ntombela T, Arumugam T, Bester LA, Singh SD, Chuturgoon A, Arvidsson PI, Maguire GEM, Kruger HG, Govender T, Naicker T. Neutralizing Carbapenem Resistance by Co-Administering Meropenem with Novel β-Lactam-Metallo-β-Lactamase Inhibitors. Antibiotics (Basel) 2023; 12:antibiotics12040633. [PMID: 37106995 PMCID: PMC10135050 DOI: 10.3390/antibiotics12040633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 03/17/2023] [Accepted: 03/20/2023] [Indexed: 04/29/2023] Open
Abstract
Virulent Enterobacterale strains expressing serine and metallo-β-lactamases (MBL) genes have emerged responsible for conferring resistance to hard-to-treat infectious diseases. One strategy that exists is to develop β-lactamase inhibitors to counter this resistance. Currently, serine β-lactamase inhibitors (SBLIs) are in therapeutic use. However, an urgent global need for clinical metallo-β-lactamase inhibitors (MBLIs) has become dire. To address this problem, this study evaluated BP2, a novel beta-lactam-derived β-lactamase inhibitor, co-administered with meropenem. According to the antimicrobial susceptibility results, BP2 potentiates the synergistic activity of meropenem to a minimum inhibitory concentration (MIC) of ≤1 mg/L. In addition, BP2 is bactericidal over 24 h and safe to administer at the selected concentrations. Enzyme inhibition kinetics showed that BP2 had an apparent inhibitory constant (Kiapp) of 35.3 µM and 30.9 µM against New Delhi Metallo-β-lactamase (NDM-1) and Verona Integron-encoded Metallo-β-lactamase (VIM-2), respectively. BP2 did not interact with glyoxylase II enzyme up to 500 µM, indicating specific (MBL) binding. In a murine infection model, BP2 co-administered with meropenem was efficacious, observed by the >3 log10 reduction in K. pneumoniae NDM cfu/thigh. Given the promising pre-clinical results, BP2 is a suitable candidate for further research and development as an (MBLI).
Collapse
Affiliation(s)
- Nakita Reddy
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Letisha Girdhari
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Mbongeni Shungube
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Arnoldus C Gouws
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Byron K Peters
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Kamal K Rajbongshi
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
- School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2020, South Africa
| | - Sipho Mdanda
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Thandokuhle Ntombela
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Thilona Arumugam
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa
| | - Linda A Bester
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa
| | - Sanil D Singh
- Department of Pharmaceutical Sciences, University of KwaZulu-Natal, Westville Campus, Durban 3629, South Africa
| | - Anil Chuturgoon
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa
| | - Per I Arvidsson
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
- Science for Life Laboratory, Drug Discovery & Development Platform & Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Glenn E M Maguire
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
- School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Thavendran Govender
- Department of Chemistry, University of Zululand, Private Bag X1001, KwaDlangezwa 3886, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
| |
Collapse
|
5
|
Peters BK, Reddy N, Shungube M, Girdhari L, Baijnath S, Mdanda S, Chetty L, Ntombela T, Arumugam T, Bester LA, Singh SD, Chuturgoon A, Arvidsson PI, Maguire GEM, Kruger HG, Naicker T, Govender T. In Vitro and In Vivo Development of a β-Lactam-Metallo-β-Lactamase Inhibitor: Targeting Carbapenem-Resistant Enterobacterales. ACS Infect Dis 2023; 9:486-496. [PMID: 36786013 PMCID: PMC10012271 DOI: 10.1021/acsinfecdis.2c00485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
β-lactams are the most prescribed class of antibiotics due to their potent, broad-spectrum antimicrobial activities. However, alarming rates of antimicrobial resistance now threaten the clinical relevance of these drugs, especially for the carbapenem-resistant Enterobacterales expressing metallo-β-lactamases (MBLs). Antimicrobial agents that specifically target these enzymes to restore the efficacy of last resort β-lactam drugs, that is, carbapenems, are therefore desperately needed. Herein, we present a cyclic zinc chelator covalently attached to a β-lactam scaffold (cephalosporin), that is, BP1. Observations from in vitro assays (with seven MBL expressing bacteria from different geographies) have indicated that BP1 restored the efficacy of meropenem to ≤ 0.5 mg/L, with sterilizing activity occurring from 8 h postinoculation. Furthermore, BP1 was nontoxic against human hepatocarcinoma cells (IC50 > 1000 mg/L) and exhibited a potency of (Kiapp) 24.8 and 97.4 μM against Verona integron-encoded MBL (VIM-2) and New Delhi metallo β-lactamase (NDM-1), respectively. There was no inhibition observed from BP1 with the human zinc-containing enzyme glyoxylase II up to 500 μM. Preliminary molecular docking of BP1 with NDM-1 and VIM-2 sheds light on BP1's mode of action. In Klebsiella pneumoniae NDM infected mice, BP1 coadministered with meropenem was efficacious in reducing the bacterial load by >3 log10 units' postinfection. The findings herein propose a favorable therapeutic combination strategy that restores the activity of the carbapenem antibiotic class and complements the few MBL inhibitors under development, with the ultimate goal of curbing antimicrobial resistance.
Collapse
Affiliation(s)
- Byron K Peters
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | - Nakita Reddy
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | - Mbongeni Shungube
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | - Letisha Girdhari
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa.,School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Gauteng 2193, South Africa
| | - Sipho Mdanda
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | - Lloyd Chetty
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | - Thandokuhle Ntombela
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | - Thilona Arumugam
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Linda A Bester
- Biomedical Research Unit, School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa
| | - Sanil D Singh
- Department of Pharmaceutical Science, University of KwaZulu-Natal, Westville Campus, Durban 3629, South Africa
| | - Anil Chuturgoon
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Per I Arvidsson
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa.,Science for Life Laboratory, Drug Discovery & Development Platform & Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden
| | - Glenn E M Maguire
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa.,School of Chemistry and Physics, University of KwaZulu Natal, Durban 4001, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | - Thavendran Govender
- Department of Chemistry, University of Zululand, Private Bag X1001, KwaDlangezwa, Empangeni 3886, South Africa
| |
Collapse
|
6
|
Omolabi KF, Reddy N, Mdanda S, Ntshangase S, Singh SD, Kruger HG, Naicker T, Govender T, Bajinath S. The in vitro and in vivo potential of metal-chelating agents as metallo-beta-lactamase inhibitors against carbapenem-resistant Enterobacterales. FEMS Microbiol Lett 2023; 370:6912242. [PMID: 36521842 DOI: 10.1093/femsle/fnac122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 11/28/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022] Open
Abstract
The recent surge in beta-lactamase resistance has created superbugs, which pose a current and significant threat to public healthcare. This has created an urgent need to keep pace with the discovery of inhibitors that can inactivate these beta-lactamase producers. In this study, the in vitro and in vivo activity of 1,4,7-triazacyclononane-1,4,7 triacetic acid (NOTA)-a potential metallo-beta-lactamase (MBL) inhibitor was evaluated in combination with meropenem against MBL producing bacteria. Time-kill studies showed that NOTA restored the efficacy of meropenem against all bacterial strains tested. A murine infection model was then used to study the in vivo pharmacokinetics and efficacy of this metal chelator. The coadministration of NOTA and meropenem (100 mg/kg.bw each) resulted in a significant decrease in the colony-forming units of Klebsiella pneumoniae NDM-1 over an 8-h treatment period (>3 log10 units). The findings suggest that chelators, such as NOTA, hold strong potential for use as a MBL inhibitor in treating carbapenem-resistant Enterobacterale infections.
Collapse
Affiliation(s)
- Kehinde F Omolabi
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Private Bag X54001,Durban 4000, South Africa
| | - Nakita Reddy
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Private Bag X54001,Durban 4000, South Africa
| | - Sipho Mdanda
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Private Bag X54001,Durban 4000, South Africa
| | - Sphamandla Ntshangase
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Private Bag X54001,Durban 4000, South Africa
| | - Sanil D Singh
- Department of Pharmaceutical Sciences, University of KwaZulu-Natal, Westville Campus, Durban, 4000, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Private Bag X54001,Durban 4000, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Private Bag X54001,Durban 4000, South Africa
| | - Thavendran Govender
- Department of Chemistry, University of Zululand, Private Bag X1001, KwaDlangezwa 3886, South Africa
| | - Sooraj Bajinath
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Private Bag X54001,Durban 4000, South Africa.,Department of Pharmaceutical Sciences, University of KwaZulu-Natal, Westville Campus, Durban, 4000, South Africa.,School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa
| |
Collapse
|
7
|
Martins LS, Kruger HG, Naicker T, Alves CN, Lameira J, Araújo Silva JR. Computational insights for predicting the binding and selectivity of peptidomimetic plasmepsin IV inhibitors against cathepsin D. RSC Adv 2022; 13:602-614. [PMID: 36605626 PMCID: PMC9773328 DOI: 10.1039/d2ra06246a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022] Open
Abstract
Plasmepsins (Plms) are aspartic proteases involved in the degradation of human hemoglobin by P. falciparum and are essential for the survival and growth of the parasite. Therefore, Plm enzymes are reported as an important antimalarial drug target. Herein, we have applied molecular docking, molecular dynamics (MD) simulations, and binding free energy with the Linear Interaction Energy (LIE) approach to investigate the binding of peptidomimetic PlmIV inhibitors with a particular focus on understanding their selectivity against the human Asp protease cathepsin D (CatD). The residual decomposition analysis results suggest that amino acid differences in the subsite S3 of PlmIV and CatD are responsible for the higher selectivity of the 5a inhibitor. These findings yield excellent agreement with experimental binding data and provide new details regarding van der Waals and electrostatic interactions of subsite residues as well as structural properties of the PlmIV and CatD systems.
Collapse
Affiliation(s)
- Lucas Sousa Martins
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais, Universidade Federal do ParáBelémPará 66075-110Brazil
| | | | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZulu-NatalDurban 4000South Africa
| | - Cláudio Nahum Alves
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais, Universidade Federal do ParáBelémPará 66075-110Brazil
| | - Jerônimo Lameira
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais, Universidade Federal do ParáBelémPará 66075-110Brazil
| | - José Rogério Araújo Silva
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais, Universidade Federal do ParáBelémPará 66075-110Brazil
| |
Collapse
|
8
|
Gouws AC, Kruger HG, Gheysens O, Zeevaart JR, Govender T, Naicker T, Ebenhan T. Antibiotic-Derived Radiotracers for Positron Emission Tomography: Nuclear or "Unclear" Infection Imaging? Angew Chem Int Ed Engl 2022; 61:e202204955. [PMID: 35834311 PMCID: PMC9826354 DOI: 10.1002/anie.202204955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Indexed: 01/11/2023]
Abstract
The excellent features of non-invasive molecular imaging, its progressive technology (real-time, whole-body imaging and quantification), and global impact by a growing infrastructure for positron emission tomography (PET) scanners are encouraging prospects to investigate new concepts, which could transform clinical care of complex infectious diseases. Researchers are aiming towards the extension beyond the routinely available radiopharmaceuticals and are looking for more effective tools that interact directly with causative pathogens. We reviewed and critically evaluated (challenges or pitfalls) antibiotic-derived PET radiopharmaceutical development efforts aimed at infection imaging. We considered both radiotracer development for infection imaging and radio-antibiotic PET imaging supplementing other tools for pharmacologic drug characterization; overall, a total of 20 original PET radiotracers derived from eleven approved antibiotics.
Collapse
Affiliation(s)
- Arno Christiaan Gouws
- Catalysis and Peptide Research UnitUniversity of KwaZulu-NatalDurban4000South Africa
| | | | - Olivier Gheysens
- Department of Nuclear MedicineCliniques Universitaires Saint-Luc, and Institute of Clinical and Experimental ResearchUniversité Catholique de LouvainBrusselsBelgium
| | - Jan Rijn Zeevaart
- Nuclear Medicine Research Infrastructure NPCPretoria0001South Africa
- RadiochemistryThe South African Nuclear Energy CorporationBrits0420South Africa
- Preclinical Drug Development PlatformNorth West UniversityPotchefstroom2520South Africa
| | | | - Tricia Naicker
- Catalysis and Peptide Research UnitUniversity of KwaZulu-NatalDurban4000South Africa
| | - Thomas Ebenhan
- Nuclear Medicine Research Infrastructure NPCPretoria0001South Africa
- Preclinical Drug Development PlatformNorth West UniversityPotchefstroom2520South Africa
- Department of Nuclear MedicineUniversity of PretoriaPretoria0001South Africa
| |
Collapse
|
9
|
Ramphal S, Govender N, Singh S, Khaliq OP, Naicker T. Histopathological features in advanced abdominal pregnancies co-infected with SARS-CoV-2 and HIV-1 infections: A case evaluation. Eur J Obstet Gynecol Reprod Biol X 2022; 15:100153. [PMID: 35600136 PMCID: PMC9106399 DOI: 10.1016/j.eurox.2022.100153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/27/2022] [Accepted: 05/11/2022] [Indexed: 11/25/2022] Open
Abstract
Objectives This study aims to provide a semi-qualitative histopathological report of the dual SARS-CoV-2 and HIV infected placentae in the third trimester of Advanced Abdominal Pregnancy (AAP). Study design Four AAP placentae in the third trimester of pregnancy (two positive for HIV-1 and two positives for SARS-CoV-2) were histologically examined. Results The SARS-CoV-2+ HIV+ placentae were dysmorphic in shape compared to the flattened disc-like shape noted in the SARS-CoV-2+HIV-, SARS-CoV-2-HIV+and SARS-CoV-2-HIV- placentae. Diffused syncytial knots and syncytial degeneration were observed in all placentae. Intermittent cytotrophoblast increase, perivillous and intravillous fibrin deposition, mononuclear inflammatory cells with widespread degeneration/necrosis of the syncytiotrophoblast and microcalcification were pronounced in the SARS-CoV-2+HIV+ compared to the SARS-CoV-2+HIV- placentae. Vascular pathological changes included thrombi, ectasis, mural hypertrophy and atherotic vessels. Conclusion Elevated syncytial trophoblast injury, villitis, microcalcifications and mineralisation of the syncytial basement membrane in the AAP placentae may be due to SARS-CoV-2 viral transgression instead of HIV infection alone. Vascular malperfusion is suggestive of a hypoxic insult arising from a compensatory response to meet the fetal oxygen and nutrient demands of an AAP. Placentae from HIV infected women on antiretroviral treatment were characterised by vascular malperfusion.
Collapse
|
10
|
Gowans LJJ, Comnick CL, Mossey PA, Eshete MA, Adeyemo WL, Naicker T, Awotoye WA, Petrin A, Adeleke C, Donkor P, Busch TD, James O, Ogunlewe MO, Li M, Olotu J, Hassan M, Adeniyan OA, Obiri-Yeboah S, Arthur FKN, Agbenorku P, Oti AA, Olatosi O, Adamson OO, Fashina AA, Zeng E, Marazita ML, Adeyemo AA, Murray JC, Butali A. Genome-Wide Scan for Parent-of-Origin Effects in a sub-Saharan African Cohort With Nonsyndromic Cleft Lip and/or Cleft Palate (CL/P). Cleft Palate Craniofac J 2022; 59:841-851. [PMID: 34382870 PMCID: PMC9884465 DOI: 10.1177/10556656211036316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
OBJECTIVE Nonsyndromic cleft lip and/or cleft palate (NSCL/P) have multifactorial etiology where genetic factors, gene-environment interactions, stochastic factors, gene-gene interactions, and parent-of-origin effects (POEs) play cardinal roles. POEs arise when the parental origin of alleles differentially impacts the phenotype of the offspring. The aim of this study was to identify POEs that can increase risk for NSCL/P in humans using a genome-wide dataset. METHODS The samples (174 case-parent trios from Ghana, Ethiopia, and Nigeria) included in this study were from the African only genome wide association studies (GWAS) that was published in 2019. Genotyping of individual DNA using over 2 million multiethnic and African ancestry-specific single-nucleotide polymorphisms from the Illumina Multi-Ethnic Genotyping Array v2 15070954 A2 (genome build GRCh37/hg19) was done at the Center for Inherited Diseases Research. After quality control checks, PLINK was employed to carry out POE analysis employing the pooled subphenotypes of NSCL/P. RESULTS We observed possible hints of POEs at a cluster of genes at a 1 mega base pair window at the major histocompatibility complex class 1 locus on chromosome 6, as well as at other loci encompassing candidate genes such as ASB18, ANKEF1, AGAP1, GABRD, HHAT, CCT7, DNMT3A, EPHA7, FOXO3, lncRNAs, microRNA, antisense RNAs, ZNRD1, ZFAT, and ZBTB16. CONCLUSION Findings from our study suggest that some loci may increase the risk for NSCL/P through POEs. Additional studies are required to confirm these suggestive loci in NSCL/P etiology.
Collapse
Affiliation(s)
- LJJ Gowans
- Department of Biochemistry and Biotechnology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana,School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana,Department of Oral Pathology, Radiology and Medicine, College of Dentistry, University of Iowa, Iowa, IA, USA
| | - CL Comnick
- Division of Biostatistics and Computational Biology, College of Dentistry, University of Iowa, Iowa City, IA, USA
| | - PA Mossey
- Department of Orthodontics, University of Dundee, Dundee, UK
| | - MA Eshete
- Department of Surgery, School of Medicine, Addis Ababa University, Addis Ababa, Ethiopia
| | - WL Adeyemo
- Department of Oral and Maxillofacial Surgery, University of Lagos, Akoka, Lagos, Nigeria
| | - T Naicker
- Department of Pediatrics, University of KwaZulu-Natal and Inkosi Albert Luthuli Central Hospital, South Africa
| | - WA Awotoye
- Department of Oral Pathology, Radiology and Medicine, College of Dentistry, University of Iowa, Iowa, IA, USA
| | - A Petrin
- Department of Oral Pathology, Radiology and Medicine, College of Dentistry, University of Iowa, Iowa, IA, USA
| | - C Adeleke
- Department of Oral Pathology, Radiology and Medicine, College of Dentistry, University of Iowa, Iowa, IA, USA
| | - P Donkor
- School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - TD Busch
- Department of Oral Pathology, Radiology and Medicine, College of Dentistry, University of Iowa, Iowa, IA, USA
| | - O James
- Department of Oral and Maxillofacial Surgery, University of Lagos, Akoka, Lagos, Nigeria
| | - MO Ogunlewe
- Department of Oral and Maxillofacial Surgery, University of Lagos, Akoka, Lagos, Nigeria
| | - M Li
- Department of Oral Pathology, Radiology and Medicine, College of Dentistry, University of Iowa, Iowa, IA, USA
| | - J Olotu
- Department of Anatomy, University of Port Harcourt, Nigeria
| | - M Hassan
- Department of Oral Pathology, Radiology and Medicine, College of Dentistry, University of Iowa, Iowa, IA, USA
| | - OA Adeniyan
- NHS Foundation Trust (Queens Hospital, Belvedere Road, Burton-On-Trent), Staffordshire, UK
| | - S Obiri-Yeboah
- School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - FKN Arthur
- Department of Biochemistry and Biotechnology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - P Agbenorku
- School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - AA Oti
- School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - O Olatosi
- Center for Craniofacial and Dental Genetics, School of Dental Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - OO Adamson
- Department of Oral and Maxillofacial Surgery, University of Lagos, Akoka, Lagos, Nigeria
| | - AA Fashina
- Department of Oral and Maxillofacial Surgery, University of Lagos, Akoka, Lagos, Nigeria
| | - E Zeng
- Division of Biostatistics and Computational Biology, College of Dentistry, University of Iowa, Iowa City, IA, USA
| | - ML Marazita
- Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA,Clinical and Translational Science Institute, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - AA Adeyemo
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, Bethesda, MD, USA
| | - JC Murray
- Department of Pediatrics, University of Iowa, Iowa, IA, USA
| | - A Butali
- Department of Oral Pathology, Radiology and Medicine, College of Dentistry, University of Iowa, Iowa, IA, USA
| |
Collapse
|
11
|
Govender K, Mdanda S, Baijnath S, Kruger HG, Govender T, Naicker T. The analysis of alcohol content in hand sanitisers (in the Durban region) using gas chromatography-mass spectrometry during the COVID-19 pandemic. S Afr j chem 2022. [DOI: 10.17159/0379-4350/2022/v76a04] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
ABSTRACT The COVID-19 pandemic has resulted in an unprecedented surge in the demand for alcohol-based hand sanitisers (ABHS). The Centre for Disease Control (CDC) and World Health Organisation (WHO) recommend alcohol, i.e., isopropanol or ethanol, at a 60-95% concentration in ABHS for sufficient antiviral protection. Consumers need to be vigilant of substandard hand sanitisers being marketed to the public. The frequent exposure of microorganisms to alcohol concentrations below the recommended range for infection prevention may lead to resistant mutations, and above the range may be ineffective. Therefore, this study aimed to verify the stated alcohol content in hand sanitisers from their respective labels. We analysed 50 hand sanitiser samples available to our region in Durban, KwaZulu-Natal, South Africa, using a Shimadzu GC-MS-QP2010 Ultra equipped with a Zebron ZB-wax capillary column. The hand sanitisers analysed had a range of 44-93% alcohol content. The data from our study also revealed that 32% (16) of hand sanitisers did not adhere to the stated alcohol indicated on their labels. 16% (8) contained >80% and 12% (6) contained <60%, while 6% (3) of the ABHS contained 1-propanol and ethyl acetate as contaminants, respectively. This study clearly emphasises manufacturers' exploitation of the pandemic and the need for stricter guidelines and regulations for consistency amongst ABHS manufacturers. The public should also be more alert to the % alcohol stated (ideal range 60-80%) on the sanitizer bottle and note one needs to rub their hands together until it feels dry. Keywords: alcohol-content, ethanol, gas chromatography-mass spectrometry, hand sanitiser, 2-propanol (isopropanol)
Collapse
|
12
|
Awotoye W, Comnick C, Pendleton C, Zeng E, Alade A, Mossey PA, Gowans LJJ, Eshete MA, Adeyemo WL, Naicker T, Adeleke C, Busch T, Li M, Petrin A, Olotu J, Hassan M, Pape J, Miller SE, Donkor P, Anand D, Lachke SA, Marazita ML, Adeyemo AA, Murray JC, Albokhari D, Sobreira N, Butali A. Genome-wide Gene-by-Sex Interaction Studies Identify Novel Nonsyndromic Orofacial Clefts Risk Locus. J Dent Res 2021; 101:465-472. [PMID: 34689653 DOI: 10.1177/00220345211046614] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Risk loci identified through genome-wide association studies have explained about 25% of the phenotypic variations in nonsyndromic orofacial clefts (nsOFCs) on the liability scale. Despite the notable sex differences in the incidences of the different cleft types, investigation of loci for sex-specific effects has been understudied. To explore the sex-specific effects in genetic etiology of nsOFCs, we conducted a genome-wide gene × sex (GxSex) interaction study in a sub-Saharan African orofacial cleft cohort. The sample included 1,019 nonsyndromic orofacial cleft cases (814 cleft lip with or without cleft palate and 205 cleft palate only) and 2,159 controls recruited from 3 sites (Ethiopia, Ghana, and Nigeria). An additive logistic model was used to examine the joint effects of the genotype and GxSex interaction. Furthermore, we examined loci with suggestive significance (P < 1E-5) in the additive model for the effect of the GxSex interaction only. We identified a novel risk locus on chromosome 8p22 with genome-wide significant joint and GxSex interaction effects (rs2720555, p2df = 1.16E-08, pGxSex = 1.49E-09, odds ratio [OR] = 0.44, 95% CI = 0.34 to 0.57). For males, the risk of cleft lip with or without cleft palate at this locus decreases with additional copies of the minor allele (p < 0.0001, OR = 0.60, 95% CI = 0.48 to 0.74), but the effect is reversed for females (p = 0.0004, OR = 1.36, 95% CI = 1.15 to 1.60). We replicated the female-specific effect of this locus in an independent cohort (p = 0.037, OR = 1.30, 95% CI = 1.02 to 1.65), but no significant effect was found for the males (p = 0.29, OR = 0.86, 95% CI = 0.65 to 1.14). This locus is in topologically associating domain with craniofacially expressed and enriched genes during embryonic development. Rare coding mutations of some of these genes were identified in nsOFC cohorts through whole exome sequencing analysis. Our study is additional proof that genome-wide GxSex interaction analysis provides an opportunity for novel findings of loci and genes that contribute to the risk of nsOFCs.
Collapse
Affiliation(s)
- W Awotoye
- Iowa Institute for Oral Health Research, University of Iowa, Iowa City, IA, USA
| | - C Comnick
- Division of Biostatistics and Computational Biology, College of Dentistry, University of Iowa, Iowa City, IA, USA
| | - C Pendleton
- Division of Biostatistics and Computational Biology, College of Dentistry, University of Iowa, Iowa City, IA, USA
| | - E Zeng
- Division of Biostatistics and Computational Biology, College of Dentistry, University of Iowa, Iowa City, IA, USA
| | - A Alade
- Department of Oral Pathology, Radiology and Medicine, College of Dentistry, University of Iowa, Iowa City, IA, USA.,Department of Epidemiology, College of Public Health, University of Iowa, Iowa City, IA, USA
| | - P A Mossey
- Department of Orthodontics, University of Dundee, Dundee, UK
| | - L J J Gowans
- Komfo Anokye Teaching Hospital and Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - M A Eshete
- Department of Surgery, School of Medicine, Addis Ababa University, Addis Ababa, Ethiopia
| | - W L Adeyemo
- Department of Oral and Maxillofacial Surgery, University of Lagos, Lagos, Nigeria
| | - T Naicker
- Department of Pediatrics, University of KwaZulu-Natal, Durban, South Africa
| | - C Adeleke
- Department of Oral Pathology, Radiology and Medicine, College of Dentistry, University of Iowa, Iowa City, IA, USA
| | - T Busch
- Department of Oral Pathology, Radiology and Medicine, College of Dentistry, University of Iowa, Iowa City, IA, USA
| | - M Li
- Department of Oral Pathology, Radiology and Medicine, College of Dentistry, University of Iowa, Iowa City, IA, USA
| | - A Petrin
- Iowa Institute for Oral Health Research, University of Iowa, Iowa City, IA, USA
| | - J Olotu
- Department of Anatomy, University of Port Harcourt, Choba, Nigeria
| | - M Hassan
- Department of Orthodontics, University of Dundee, Dundee, UK
| | - J Pape
- Department of Oral Pathology, Radiology and Medicine, College of Dentistry, University of Iowa, Iowa City, IA, USA
| | - S E Miller
- Iowa Institute for Oral Health Research, University of Iowa, Iowa City, IA, USA
| | - P Donkor
- Department of Orthodontics, University of Dundee, Dundee, UK
| | - D Anand
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - S A Lachke
- Department of Biological Sciences, University of Delaware, Newark, DE, USA.,Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE, USA
| | - M L Marazita
- Center for Craniofacial and Dental Genetics, Departments of Oral Biology and Human Genetics, University of Pittsburgh, Pittsburgh, PA, USA
| | - A A Adeyemo
- National Human Genomic Research Institute, Bethesda, MD, USA
| | - J C Murray
- Department of Pediatrics, University of Iowa, Iowa City, IA, USA
| | - D Albokhari
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - N Sobreira
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - A Butali
- Iowa Institute for Oral Health Research, University of Iowa, Iowa City, IA, USA.,Department of Oral Pathology, Radiology and Medicine, College of Dentistry, University of Iowa, Iowa City, IA, USA
| |
Collapse
|
13
|
Sabe VT, Ntombela T, Jhamba LA, Maguire GEM, Govender T, Naicker T, Kruger HG. Current trends in computer aided drug design and a highlight of drugs discovered via computational techniques: A review. Eur J Med Chem 2021; 224:113705. [PMID: 34303871 DOI: 10.1016/j.ejmech.2021.113705] [Citation(s) in RCA: 147] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 07/12/2021] [Accepted: 07/12/2021] [Indexed: 12/30/2022]
Abstract
Computer-aided drug design (CADD) is one of the pivotal approaches to contemporary pre-clinical drug discovery, and various computational techniques and software programs are typically used in combination, in a bid to achieve the desired outcome. Several approved drugs have been developed with the aid of CADD. On SciFinder®, we evaluated more than 600 publications through systematic searching and refining, using the terms, virtual screening; software methods; computational studies and publication year, in order to obtain data concerning particular aspects of CADD. The primary focus of this review was on the databases screened, virtual screening and/or molecular docking software program used. Furthermore, we evaluated the studies that subsequently performed molecular dynamics (MD) simulations and we reviewed the software programs applied, the application of density functional theory (DFT) calculations and experimental assays. To represent the latest trends, the most recent data obtained was between 2015 and 2020, consequently the most frequently employed techniques and software programs were recorded. Among these, the ZINC database was the most widely preferred with an average use of 31.2%. Structure-based virtual screening (SBVS) was the most prominently used type of virtual screening and it accounted for an average of 57.6%, with AutoDock being the preferred virtual screening/molecular docking program with 41.8% usage. Following the screening process, 38.5% of the studies performed MD simulations to complement the virtual screening and GROMACS with 39.3% usage, was the popular MD software program. Among the computational techniques, DFT was the least applied whereby it only accounts for 0.02% average use. An average of 36.5% of the studies included reports on experimental evaluations following virtual screening. Ultimately, since the inception and application of CADD in pre-clinical drug discovery, more than 70 approved drugs have been discovered, and this number is steadily increasing over time.
Collapse
Affiliation(s)
- Victor T Sabe
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa.
| | - Thandokuhle Ntombela
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa.
| | - Lindiwe A Jhamba
- HIV Pathogenesis Program, School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Glenn E M Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa; School of Chemistry and Physics, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Thavendran Govender
- Faculty of Science and Agriculture, Department of Chemistry, University of Zululand, KwaDlangezwa, 3886, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa.
| |
Collapse
|
14
|
Xhakaza SP, Khoza LJ, Haripershad AM, Ghazi T, Dhani S, Mutsimhu C, Molopa MJ, Madurai NP, Madurai L, Singh SD, Gopal ND, Kruger HG, Govender T, Chuturgoon A, Naicker T, Baijnath S. Alterations in neurotransmitter levels and transcription factor expression following intranasal buprenorphine administration. Biomed Pharmacother 2021; 138:111515. [PMID: 33752062 DOI: 10.1016/j.biopha.2021.111515] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 03/12/2021] [Accepted: 03/14/2021] [Indexed: 11/28/2022] Open
Abstract
Buprenorphine is an opioid drug used in the management of pain and the treatment opioid addiction. Like other opioids, it is believed that it achieves these effects by altering functional neurotransmitter pathways and the expression of important transcription factors; cyclic AMP response element-binding protein (CREB) and brain-derived neurotrophic factor (BDNF) in the brain. However, there is a lack of scientific evidence to support these theories. This study investigated the pharmacodynamic effects of BUP administration by assessing neurotransmitter and molecular changes in the healthy rodent brain. Sprague-Dawley rats (150-200 g) were intranasally administered buprenorphine (0.3 mg/mL) and sacrificed at different time points: 0.25, 0.5, 1, 2, 4, 6, 8 and 24 h post drug administration. LC-MS was used to quantify BUP and neurotransmitters (GABA, GLUT, DA, NE and 5-HT) in the brain, while CREB and BDNF gene expression was determined using qPCR. Results showed that BUP reached a Cmax of 1.21 ± 0.0523 ng/mL after 2 h, with all neurotransmitters showing an increase in their concentration over time, with GABA, GLUT and NE reaching their maximum concentration after 8 h. DA and 5-HT reached their maximum concentrations at 1 h and 24 h, respectively post drug administration. Treatment with BUP resulted in significant upregulation in BDNF expression throughout the treatment period while CREB showed patterns of significant upregulation at 2 and 8 h, and downregulation at 1 and 6 h. This study contributes to the understanding of the pharmacodynamic effects of BUP in opioid addiction by proving that the drug significantly influences NT pathways that are implicated in opioid addiction.
Collapse
Affiliation(s)
- Sanelisiwe P Xhakaza
- Catalysis and Peptide Research Unit, Department of Pharmaceutical Sciences, College of Health Science, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Leon J Khoza
- Catalysis and Peptide Research Unit, Department of Pharmaceutical Sciences, College of Health Science, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Advaitaa M Haripershad
- Catalysis and Peptide Research Unit, Department of Pharmaceutical Sciences, College of Health Science, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Terisha Ghazi
- Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Science, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Shanel Dhani
- Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Science, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Cosmas Mutsimhu
- Viro Care (SA) Pty Ltd, 12 The Avenue East, Prospecton, Durban 4113, South Africa
| | - Molopa J Molopa
- Viro Care (SA) Pty Ltd, 12 The Avenue East, Prospecton, Durban 4113, South Africa
| | - Nithia P Madurai
- Viro Care (SA) Pty Ltd, 12 The Avenue East, Prospecton, Durban 4113, South Africa
| | - Lorna Madurai
- Viro Care (SA) Pty Ltd, 12 The Avenue East, Prospecton, Durban 4113, South Africa
| | - Sanil D Singh
- Catalysis and Peptide Research Unit, Department of Pharmaceutical Sciences, College of Health Science, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Nirmala D Gopal
- Department of Criminology, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, Department of Pharmaceutical Sciences, College of Health Science, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Thavendran Govender
- Department of Chemistry, University of Zululand, Private Bag X1001, KwaDlangezwa 3886, South Africa
| | - Anil Chuturgoon
- Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Science, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, Department of Pharmaceutical Sciences, College of Health Science, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, Department of Pharmaceutical Sciences, College of Health Science, University of KwaZulu-Natal, Durban, 4001, South Africa.
| |
Collapse
|
15
|
Natarajan S, Govender K, Shobo A, Baijnath S, Arvidsson PI, Govender T, Lin J, Maguire GE, Naicker T, Kruger HG. Potential of brain mast cells for therapeutic application in the immune response to bacterial and viral infections. Brain Res 2021; 1767:147524. [PMID: 34015358 DOI: 10.1016/j.brainres.2021.147524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/21/2021] [Accepted: 05/11/2021] [Indexed: 10/21/2022]
Abstract
A wide range of microorganisms can infect the central nervous system (CNS). The immune response of the CNS provides limited protection against microbes penetrating the blood-brain barrier. This results in a neurological deficit and sometimes leads to high morbidity and mortality rates despite advanced therapies. For the last two decades, different studies have expanded our understanding of the molecular basis of human neuroinfectious diseases, especially concerning the contributions of mast cell interactions with other central nervous system compartments. Brain mast cells are multifunctional cells derived from the bone marrow and reside in the brain. Their proximity to blood vessels, their role as "first responders" their unique receptors systems and their ability to rapidly release pathogen responsive mediators enable them to exert a crucial defensive role in the host-defense system. This review describes key biological and physiological functions of mast cells, concerning their ability to recognize pathogens via various receptor systems, followed by a coordinated and selective mediator release upon specific interactions with pathogenic stimulating factors. The goal of this review is to direct attention to the possibilities for therapeutic applications of mast cells against bacterial and viral related infections. We also focus on opportunities for future research activating mast cells via adjuvants.
Collapse
Affiliation(s)
- Satheesh Natarajan
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa
| | - Kamini Govender
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa
| | - Adeola Shobo
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa
| | - Per I Arvidsson
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa; Science for Life Laboratory, Drug Discovery and Development, Platform and Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
| | - Thavendran Govender
- Department of Chemistry, University of Zululand, Private Bag X1001, KwaDlangezwa 3886, South Africa
| | - Johnson Lin
- School of Life Sciences, University of KwaZulu-Natal, Durban 4001, South Africa; School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Glenn Em Maguire
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa.
| |
Collapse
|
16
|
Olatosi OO, Alade AA, Naicker T, Busch T, Oyapero A, Li M, Pape J, Olotu J, Awotoye W, Hassan M, Adeleke C, Adeyemo WL, Shaffer J, Marazita ML, Butali A. Dental Caries Severity and Nutritional Status of Nigerian Preschool Children. JDR Clin Trans Res 2021; 7:154-162. [PMID: 33764218 DOI: 10.1177/23800844211002108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
INTRODUCTION Malnutrition in children is one of the most prevalent global health challenges, and malnourished children have a higher risk of death from childhood diseases. Early childhood caries (ECC) is the most common chronic disease of childhood. Complications from ECC such as pain, loss of tooth/teeth, and infection can undermine a child's nutrition and growth. AIM This study aims to evaluate the severity of decay, missing, and filled tooth (dmft) by nutritional status using the z scores of the anthropometric measurements: height for age (HFA), weight for age (WFA), weight for height (WFH), and body mass index for age (BMIA) among children with ECC in Nigeria. STUDY DESIGN This is a cross-sectional study conducted in 5 local government areas (LGAs) in Lagos State, Nigeria. A multistage sampling technique was used. RESULTS A total of 273 cases of ECC were included in the analyses (mean age 4.19 ± 0.96 y). Overall, the mean dmft was 3.04 ± 2.28, and most (96%) were accounted for by untreated decay. The distribution of dmft within the different z score categories of BMIA (<-3 = severely wasted, -2 to -3 = wasted, -2 to +2 = normal, +2 to +3 = overweight and >+3 = obese) showed the highest dmft scores among the combined severely wasted and wasted groups, lowest among children with normal z scores, and intermediate in the overweight and obese groups. There was a significant negative correlation between BMIA z score, WFH z score, and dmft (r = -0.181, P < 0.05 and r = -0.143, P < 0.05, respectively). However, the correlations between HFA z score, WFA z score, and dmft were positive but not significant (r = 0.048, P = 0.44 and r = 0.022, P = 0.77, respectively). CONCLUSION Our study showed an increased severity of dental caries among severely wasted or wasted children with ECC compared to those of normal or overweight. KNOWLEDGE TRANSFER STATEMENT The results from this study will raise awareness among clinicians and policy makers on the need for a primary prevention program for early childhood caries in countries with high burden of malnutrition and limited resources. Also, it will help draw the attention of clinicians to the caries status of malnourished children that can be managed to improve the nutritional outcomes.
Collapse
Affiliation(s)
- O O Olatosi
- Department of Child Dental Health, Faculty of Dental Sciences, College of Medicine University of Lagos, Lagos, Nigeria
| | - A A Alade
- Department of Oral Pathology, Radiology and Medicine, College of Dentistry, University of Iowa, Iowa City, IA, USA.,Iowa Institute of Oral Health Research, University of Iowa, Iowa City, IA, USA.,Department of Epidemiology, College of Public Health, University of Iowa, Iowa City, IA, USA
| | - T Naicker
- Department of Paediatrics, University of KwaZulu-Natal, Durban, South Africa
| | - T Busch
- Iowa Institute of Oral Health Research, University of Iowa, Iowa City, IA, USA
| | - A Oyapero
- Department of Preventive Dentistry, Faculty of Dentistry, Lagos State University College of Medicine, Lagos, Nigeria
| | - M Li
- Iowa Institute of Oral Health Research, University of Iowa, Iowa City, IA, USA
| | - J Pape
- Iowa Institute of Oral Health Research, University of Iowa, Iowa City, IA, USA
| | - J Olotu
- Department of Anatomy, University of Port Harcourt, Port Harcourt, Nigeria
| | - W Awotoye
- Department of Oral Pathology, Radiology and Medicine, College of Dentistry, University of Iowa, Iowa City, IA, USA.,Iowa Institute of Oral Health Research, University of Iowa, Iowa City, IA, USA
| | - M Hassan
- Iowa Institute of Oral Health Research, University of Iowa, Iowa City, IA, USA
| | - C Adeleke
- Iowa Institute of Oral Health Research, University of Iowa, Iowa City, IA, USA
| | - W L Adeyemo
- Department of Oral and Maxillofacial Surgery, University of Lagos, Lagos, Nigeria
| | - J Shaffer
- Center for Craniofacial and Dental Genetics, Department of Oral Biology, School of Dental Medicine, University of Pittsburgh, Pittsburgh, PA, USA.,Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - M L Marazita
- Center for Craniofacial and Dental Genetics, Department of Oral Biology, School of Dental Medicine, University of Pittsburgh, Pittsburgh, PA, USA.,Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - A Butali
- Department of Oral Pathology, Radiology and Medicine, College of Dentistry, University of Iowa, Iowa City, IA, USA.,Iowa Institute of Oral Health Research, University of Iowa, Iowa City, IA, USA
| |
Collapse
|
17
|
Ntombela T, Seupersad A, Maseko S, Ibeji CU, Tolufashe G, Maphumulo SI, Naicker T, Baijnath S, Maguire GEM, Govender T, Lamichhane G, Honarparvar B, Kruger HG. Mechanistic insight on the inhibition of D, D-carboxypeptidase from Mycobacterium tuberculosis by β-lactam antibiotics: an ONIOM acylation study. J Biomol Struct Dyn 2021; 40:7645-7655. [PMID: 33719919 DOI: 10.1080/07391102.2021.1899052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Mycobacterium tuberculosis cell wall is intricate and impermeable to many agents. A D, D-carboxypeptidase (DacB1) is one of the enzymes involved in the biosynthesis of cell wall peptidoglycan and catalyzes the terminal D-alanine cleavage from pentapeptide precursors. Catalytic activity and mechanism by which DacB1 functions is poorly understood. Herein, we investigated the acylation mechanism of DacB1 by β-lactams using a 6-membered ring transition state model that involves a catalytic water molecule in the reaction pathway. The full transition states (TS) optimization plus frequency were achieved using the ONIOM (B3LYP/6-31 + G(d): AMBER) method. Subsequently, the activation free energies were computed via single-point calculations on fully optimized structures using B3LYP/6-311++(d,p): AMBER and M06-2X/6-311++(d,p): AMBER with an electronic embedding scheme. The 6-membered ring transition state is an effective model to examine the inactivation of DacB1 via acylation by β-lactams antibiotics (imipenem, meropenem, and faropenem) in the presence of the catalytic water. The ΔG# values obtained suggest that the nucleophilic attack on the carbonyl carbon is the rate-limiting step with 13.62, 19.60 and 30.29 kcal mol-1 for Imi-DacB1, Mero-DacB1 and Faro-DacB1, respectively. The electrostatic potential (ESP) and natural bond orbital (NBO) analysis provided significant electronic details of the electron-rich region and charge delocalization, respectively, based on the concerted 6-membered ring transition state. The stabilization energies of charge transfer within the catalytic reaction pathway concurred with the obtained activation free energies. The outcomes of this study provide important molecular insight into the inactivation of D, D-carboxypeptidase by β-lactams.
Collapse
Affiliation(s)
- Thandokuhle Ntombela
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Anya Seupersad
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Sibusiso Maseko
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Collins U Ibeji
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Gideon Tolufashe
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Siyabonga Innocent Maphumulo
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Glenn E M Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa.,School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Thavendran Govender
- Faculty of Science and Agriculture, Department of Chemistry, University of Zululand, Richards Bay, South Africa
| | - Gyanu Lamichhane
- Center for Tuberculosis Research, Division of Infectious Diseases, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Bahareh Honarparvar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| |
Collapse
|
18
|
Kelani MT, Dieudonné D, Skowron KJ, Pedigo C, Govender T, Kruger HG, Naicker T, Onajole OK. Trends in NMR Structural Elucidation Of Polycyclic Cages, Namely: Adamantane, Pentacycloundecane and Trishomocubane. S Afr j chem 2021. [DOI: 10.17159/0379-4350/2021/v75a14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
ABSTRACT Advances in Nuclear Magnetic Resonance (NMR) spectroscopy is a cornerstone in structure elucidation of polycyclic 'cage' scaffolds. Due to the compactness of these compounds, much overlap, as well as unique through-space and bond NMR interactions are frequently observed. This review serves as a guide for the NMR elucidation of future derivatives by providing some of the typical and relevant aspects of the characteristic trends, substituent patterns and chemical shift behaviour for the identification of the polycyclic structures, namely adamantane, pentacycloundecane and trishomocubane derivatives. Keywords: adamantane, NMR elucidation, pentacycloundecane, polycyclic compounds, trishomocubane
Collapse
|
19
|
Aung M, Konoshita T, Moodley J, Naicker T, Connolly C, Khaliq OP, Gathiram P. Aminopeptidase A (ENPEP) gene polymorphisms and preeclampsia: Descriptive analysis. Eur J Obstet Gynecol Reprod Biol 2020; 258:70-74. [PMID: 33421813 DOI: 10.1016/j.ejogrb.2020.12.051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 12/28/2020] [Indexed: 10/22/2022]
Abstract
OBJECTIVE The etiology of preeclampsia (PE) remains elusive. Recent genome-wide association studies have identified a number of genetic variants associated with blood pressure variations in east Asians. One of the genetic variants is the aminopeptidase A (ENPEP) gene, which converts angiotensin II to angiotensin III. The C allele of rs6825911 is a risk for hypertension. The current study investigated whether genetic variants of ENPEP play a role in the pathogenesis of preeclampsia. STUDY DESIGN The study was a descriptive analysis of gene polymorphisms of ENPEP; 602 pregnant women of African ancestry [normotensive (n = 245) and PE (n = 357)] were recruited. The two groups were divided according to their HIV status. The PE group consisted of early- and late-onset sub-categories. A single nucleotide polymorphism of rs6825911 was analyzed using the TaqMan® Probe mix and by means of real time polymerase chain reaction. RESULTS The risk of C allele for PE was 1.07 (95 % CI 0.83-1.38, P = 0.589) for allele comparison and the risk for preeclampsia CC to CT/TT was 1.33 (95 % CI 0.96-1.85, P = 0.086). The sub analysis for the PE group without HIV infection the risk of C allele was 1.25 (95 % CI 0.838-1.78, P = 0.199) and the risk of PE of CC to CT/TT was 1.51 (95 %CI: 0.96-2.35, P = 0.071). CONCLUSION This is the first study in a homogenous South African population of African ancestry to show that the variant of ENPEP gene does not play a role in pathogenesis of preeclampsia.
Collapse
Affiliation(s)
- M Aung
- Department of Family Medicine, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - T Konoshita
- The Third Department of Internal Medicine, University of Fukui Faculty of Medicine Sciences, Fukui, Japan
| | - J Moodley
- Department of Women's Health and HIV Research Group, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - T Naicker
- Department of Optics & Imaging, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - C Connolly
- Department of Public Health Medicine & Biostatistics, College of Health Science, University of KwaZulu-Natal, Durban. South Africa
| | - O P Khaliq
- Department of Women's Health and HIV Research Group, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa.
| | - P Gathiram
- Department of Family Medicine, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| |
Collapse
|
20
|
Sanusi ZK, Lawal MM, Gupta PL, Govender T, Baijnath S, Naicker T, Maguire GEM, Honarparvar B, Roitberg AE, Kruger HG. Exploring the concerted mechanistic pathway for HIV-1 PR-substrate revealed by umbrella sampling simulation. J Biomol Struct Dyn 2020; 40:1736-1747. [PMID: 33073714 DOI: 10.1080/07391102.2020.1832578] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
HIV-1 protease (HIV-1 PR) is an essential enzyme for the replication process of its virus, and therefore considered an important target for the development of drugs against the acquired immunodeficiency syndrome (AIDS). Our previous study shows that the catalytic mechanism of subtype B/C-SA HIV-1 PR follows a one-step concerted acyclic hydrolysis reaction process using a two-layered ONIOM B3LYP/6-31++G(d,p) method. This present work is aimed at exploring the proposed mechanism of the proteolysis catalyzed by HIV-1 PR and to ensure our proposed mechanism is not an artefact of a single theoretical technique. Hence, we present umbrella sampling method that is suitable for calculating potential mean force (PMF) for non-covalent ligand/substrate-enzyme association/dissociation interactions which provide thermodynamic details for molecular recognition. The free activation energy results were computed in terms of PMF analysis within the hybrid QM(DFTB)/MM approach. The theoretical findings suggest that the proposed mechanism corresponds in principle with experimental data. Given our observations, we suggest that the QM/MM MD method can be used as a reliable computational technique to rationalize lead compounds against specific targets such as the HIV-1 protease.
Collapse
Affiliation(s)
- Zainab K Sanusi
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Monsurat M Lawal
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Pancham Lal Gupta
- Department of Chemistry, University of Florida, Gainesville, Florida, USA
| | | | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Glenn E M Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa.,School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Bahareh Honarparvar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Adrian E Roitberg
- Department of Chemistry, University of Florida, Gainesville, Florida, USA
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| |
Collapse
|
21
|
Mhlongo NZ, Ebenhan T, Driver CHS, Maguire GEM, Kruger HG, Govender T, Naicker T. Microwave-assisted synthesis of meso-carboxyalkyl-BODIPYs and an application to fluorescence imaging. Org Biomol Chem 2020; 18:7876-7883. [PMID: 32986056 DOI: 10.1039/d0ob01415j] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In this study, a significantly improved method for the synthesis of modular meso-BODIPY (boron dipyrromethene) derivatives possessing a free carboxylic acid group (which was subsequently coupled to peptides), is disclosed. This method provides a vastly efficient synthetic route with a > threefold higher overall yield than other reports. The resultant meso-BODIPY acid allowed for further easy incorporation into peptides. The meso-BODIPY peptides showed absorption maxima from 495-498 nm and emission maxima from 504-506 nm, molar absorptivity coefficients from 33 383-80 434 M-1 cm-1 and fluorescent quantum yields from 0.508-0.849. The meso-BODIPY-c(RGDyK) peptide was evaluated for plasma stability and (proved to be durable even up to 4 h) was then assessed for its fluorescence imaging applicability in vivo and ex vivo. The optical imaging in vivo was limited due to autofluorescence, however, the ex vivo tissue analysis displayed BODIPY-c(RGDyK) internalization and cancer detection thereby making it a novel tumor-integrin associated fluorescent probe while displaying the lack of interference the dye has on the properties of this ligand to bind the receptor.
Collapse
Affiliation(s)
- Neliswa Z Mhlongo
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban, South Africa.
| | | | | | | | | | | | | |
Collapse
|
22
|
Govender K, Naicker T, Baijnath S, Chuturgoon AA, Abdul NS, Docrat T, Kruger HG, Govender T. Sub/supercritical fluid chromatography employing water-rich modifier enables the purification of biosynthesized human insulin. J Chromatogr B Analyt Technol Biomed Life Sci 2020; 1155:122126. [DOI: 10.1016/j.jchromb.2020.122126] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/21/2020] [Accepted: 04/23/2020] [Indexed: 10/24/2022]
|
23
|
Govender K, Naicker T, Baijnath S, Kruger HG, Govender T. The development of a sub/supercritical fluid chromatography based purification method for peptides. J Pharm Biomed Anal 2020; 190:113539. [DOI: 10.1016/j.jpba.2020.113539] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 07/28/2020] [Accepted: 08/05/2020] [Indexed: 11/24/2022]
|
24
|
Lubanyana H, Arvidsson PI, Govender T, Kruger HG, Naicker T. Correction to "Improved Synthesis and Isolation of Bedaquiline". ACS Omega 2020; 5:24154. [PMID: 32984738 PMCID: PMC7513548 DOI: 10.1021/acsomega.0c03922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Indexed: 06/11/2023]
Abstract
[This corrects the article DOI: 10.1021/acsomega.9b04037.].
Collapse
|
25
|
Ijomone OK, Erukainure OL, Shallie P, Naicker T. Neurotoxicity in pre-eclampsia involves oxidative injury, exacerbated cholinergic activity and impaired proteolytic and purinergic activities in cortex and cerebellum. Hum Exp Toxicol 2020; 40:158-171. [PMID: 32772714 DOI: 10.1177/0960327120946477] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Women with a history of pre-eclampsia (PE) tend to have a higher risk of developing cardiovascular and neurological diseases later in life. Imbalance in oxidative markers and purinergic enzymes have been implicated in the pathogenesis of neurological disease. This study investigated the effect of PE on oxidative imbalance, purinergic enzyme inhibitory activity, acetylcholinesterase and chymotrypsin activities in the brain of PE rat model at post-partum/post-natal day (PP/PND) 60. Pregnant rats divided into early-onset and late-onset groups were administered with Nω-nitro-l-arginine methyl through drinking water at gestational days 8-17. Rats were allowed free access to water throughout the pregnancy and allowed to deliver on their own. The mother and the pups were euthanized at PP and PND 60, respectively, the cortex and the cerebellum excised, homogenized and stored for analyses of the enzymes. Results showed an increase in nitric oxide and malondialdehyde with a concomitant decrease in reduced glutathione and superoxide dismutase, an indication of oxidative damage. Also, there was an increase in acetylcholinesterase activity with a decrease in chymotrypsin, adenylpyrophosphatase and ecto-nucleoside triphosphate diphosphohydrolase activities in both the cortex and the cerebellum of the mother and the pups at PND 60. These results indicate the involvement of oxidative stress, increased cholinergic activity and depleted proteolytic and purinergic activities in PE-induced neurotoxicity.
Collapse
Affiliation(s)
- O K Ijomone
- Optics and Imaging Centre, Doris Duke Medical Research Institute, College of Health Sciences, 72753University of KwaZulu-Natal, Durban, South Africa
- Department of Anatomy, Faculty of Basic Medical Sciences, University of Medical Sciences, Ondo, Ondo State, Nigeria
| | - O L Erukainure
- Department of Pharmacology, University of the Free State, Bloemfontein, South Africa
| | - P Shallie
- Department of Anatomy, 361901Olabisi Onabanjo University, Ikenne, Ogun State, Nigeria
| | - T Naicker
- Optics and Imaging Centre, Doris Duke Medical Research Institute, College of Health Sciences, 72753University of KwaZulu-Natal, Durban, South Africa
| |
Collapse
|
26
|
Mdanda S, Ntshangase S, Singh SD, Naicker T, Kruger HG, Baijnath S, Govender T. Zidovudine and Lamivudine as Potential Agents to Combat HIV-Associated Neurocognitive Disorder. Assay Drug Dev Technol 2020; 17:322-329. [PMID: 31634020 DOI: 10.1089/adt.2019.941] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The central nervous system has been identified as an anatomical reservoir for HIV due the difficulties in delivering therapeutic agents into the brain and this complication results in HIV-associated neurocognitive disorder that persists in infected patients. The brain regions that are potentially exposed to tissue deficits due to HIV have been reported in previous reports; therefore, it is important to determine the drugs that can enter and localize in brain regions that are known to be susceptible to HIV neurodegeneration. Sprague-Dawley rats received intraperitoneal doses of zidovudine and lamivudine (50 mg kg-1). Mass spectrometry methods were used to determine the pharmacokinetics, of zidovudine and lamivudine, in the brain using liquid chromatography tandem mass spectrometry and mass spectrometry imaging (MSI), respectively. Zidovudine and lamivudine displayed complementary pharmacokinetic curves indicating a rapid absorption and blood-brain barrier penetration of both drugs reaching Cmax at 0.5 h after single dose. MSI of coronal brain sections showed that zidovudine and lamivudine are mostly distributed in corpus callosum, globus pallidus, striatum, and the neocortex region. Mass spectrometry techniques were used to demonstrate that zidovudine and lamivudine drugs are able to reach and localize in brain regions that are targets of HIV neurodegeneration in the brain.
Collapse
Affiliation(s)
- Sipho Mdanda
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Sphamandla Ntshangase
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Sanil D Singh
- Biomedical Resource Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa.,AnSynth Pty Ltd., Durban, South Africa
| |
Collapse
|
27
|
Sebitloane HM, Naicker T, Moodley J. The impact of the duration of HAART on cytokine profiles in pregnancy. Inflamm Res 2020; 69:1053-1058. [PMID: 32638065 DOI: 10.1007/s00011-020-01375-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 06/23/2020] [Accepted: 07/02/2020] [Indexed: 10/23/2022] Open
Abstract
OBJECTIVE To determine the cytokine profile of HIV infected women treated with highly active anti-retroviral therapy (HAART) of variable duration in pregnancy. METHODS HIV infected women were enrolled at a large tertiary hospital in Durban, South Africa in their antenatal period and stratified into those that initiated HAART before pregnancy (pre-pregnancy HAART or PPH group) and those who initiated HAART during pregnancy (in-pregnancy HAART or IPH group). These were compared with HIV negative women (HN group), matched for gestational age at the time of enrolment. Serum was obtained and Th1 and Th2 cytokines expression determined using the Bio-Plex Pro™ Human Cytokine Treg Panels. RESULTS The overall cytokine profile of the cohort was pro-inflammatory as a result of significant IL-6 and TNF alpha expression. The anti-inflammatory markers (i.e. Th2 cytokines, namely IL4 and IL10) were poorly expressed by the whole cohort, with IL 4 seen almost exclusively in the IPH group, thus counter-balancing the predominantly pro-inflammatory milieu only in this group. PPH group had a pro-inflammatory milieu comparable to the HN control. IL 6 was the predominant cytokine in all groups, and as expected, it increased with advancing gestation in all the groups. This highly pro-inflammatory milieu was unexpected and needs further review CONCLUSION: Long use of HAART suppresses the anti-inflammatory markers previously reported to be conducive for the wellbeing of pregnancy. This effect needs further review as it was similarly observed in our HIV uninfected controls.
Collapse
Affiliation(s)
- H M Sebitloane
- Discipline of Obstetrics and Gynaecology, School of Clinical Medicine, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa.
| | - T Naicker
- Optics and Imaging Centre, Doris Duke Medical Research Institute, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - J Moodley
- Women's Health and HIV Research Unit, Discipline of Obstetrics and Gynaecology, Nelson R. Mandela School of Medicine, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| |
Collapse
|
28
|
Teklezgi B, Pamreddy A, Ntshangase S, Mdanda S, Singh SD, Gopal ND, Naicker T, Kruger HG, Govender T, Baijnath S. Mass Spectrometric Imaging of the Brain Demonstrates the Regional Displacement of 6-Monoacetylmorphine by Naloxone. ACS Omega 2020; 5:12596-12602. [PMID: 32548443 PMCID: PMC7288357 DOI: 10.1021/acsomega.9b03570] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 05/04/2020] [Indexed: 06/11/2023]
Abstract
Overdose is the main cause of mortality among heroin users. Many of these overdose-induced deaths can be prevented through the timely administration of naloxone (NLX), a nonselective mu (μ)-, kappa (κ)-, and delta (δ)-opioid receptor antagonist. NLX competitively inhibits opioid-overdose-induced respiratory depression without eliciting any narcotic effect itself. The aim of this study was to investigate the antagonistic action of NLX by comparing its distribution to that of 6-monacetylmorphine (6-MAM), heroin's major metabolite, in a rodent model using mass spectrometric imaging (MSI) in combination with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Male Sprague-Dawley rats (n = 5) received heroin (10 mg kg-1) intraperitoneally, NLX (10 mg kg-1) intranasally, and NLX injected intranasally 5 min after heroin administration. The animals were sacrificed 15 min after dose and brain tissues were harvested. The MSI image analysis showed a region-specific distribution of 6-MAM in the brain regions including the corpus callosum, hippocampal formation, cerebral cortex, corticospinal tracts, caudate putamen, thalamus, globus pallidus, hypothalamus, and basal forebrain regions of the brain. The antagonist had a similar biodistribution throughout the brain in both groups of animals that received NLX or NLX after heroin administration. The MSI analysis demonstrated that the intensity of 6-MAM in these brain regions was reduced following NLX treatment. The decrease in 6-MAM intensity was caused by its displacement by the antagonist and its binding to these receptors in these specific brain regions, consequently enhancing the opioid elimination. These findings will contribute to the evaluation of other narcotic antagonists that might be considered for use in the treatment of drug overdose via MSI.
Collapse
Affiliation(s)
- Belin
G. Teklezgi
- Catalysis
and Peptide Research Unit, University of
KwaZulu-Natal, Westville Campus, Durban 3629, South Africa
| | - Annapurna Pamreddy
- Catalysis
and Peptide Research Unit, University of
KwaZulu-Natal, Westville Campus, Durban 3629, South Africa
| | - Sphamandla Ntshangase
- Catalysis
and Peptide Research Unit, University of
KwaZulu-Natal, Westville Campus, Durban 3629, South Africa
| | - Sipho Mdanda
- Catalysis
and Peptide Research Unit, University of
KwaZulu-Natal, Westville Campus, Durban 3629, South Africa
| | - Sanil D. Singh
- Department
of Pharmaceutical Science, University of
KwaZulu-Natal, Westville
Campus, Durban 3629, South Africa
| | - Nirmala D. Gopal
- Department
of Criminology, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Tricia Naicker
- Catalysis
and Peptide Research Unit, University of
KwaZulu-Natal, Westville Campus, Durban 3629, South Africa
| | - Hendrik G. Kruger
- Catalysis
and Peptide Research Unit, University of
KwaZulu-Natal, Westville Campus, Durban 3629, South Africa
| | - Thavendran Govender
- Department
of Chemistry, University of Zululand, Richards Bay 3900, South Africa
| | - Sooraj Baijnath
- Catalysis
and Peptide Research Unit, University of
KwaZulu-Natal, Westville Campus, Durban 3629, South Africa
| |
Collapse
|
29
|
Reddy N, Shungube M, Arvidsson PI, Baijnath S, Kruger HG, Govender T, Naicker T. A 2018–2019 patent review of metallo beta-lactamase inhibitors. Expert Opin Ther Pat 2020; 30:541-555. [DOI: 10.1080/13543776.2020.1767070] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Nakita Reddy
- Catalysis and Peptide Research Unit, Westville Campus, University of KwaZulu-Natal, Durban, South Africa
| | - Mbongeni Shungube
- Catalysis and Peptide Research Unit, Westville Campus, University of KwaZulu-Natal, Durban, South Africa
| | - Per I Arvidsson
- Catalysis and Peptide Research Unit, Westville Campus, University of KwaZulu-Natal, Durban, South Africa
- Science for Life Laboratory, Karolinska Institutet, Stockhlom, Sweden
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, Westville Campus, University of KwaZulu-Natal, Durban, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, Westville Campus, University of KwaZulu-Natal, Durban, South Africa
| | | | - Tricia Naicker
- Catalysis and Peptide Research Unit, Westville Campus, University of KwaZulu-Natal, Durban, South Africa
| |
Collapse
|
30
|
Govender K, Naicker T, Lin J, Baijnath S, Chuturgoon AA, Abdul NS, Docrat T, Kruger HG, Govender T. A novel and more efficient biosynthesis approach for human insulin production in Escherichia coli (E. coli). AMB Express 2020; 10:43. [PMID: 32152803 PMCID: PMC7062966 DOI: 10.1186/s13568-020-00969-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 02/05/2020] [Indexed: 11/10/2022] Open
Abstract
Insulin has captured researchers' attention worldwide. There is a rapid global rise in the number of diabetic patients, which increases the demand for insulin. Current methods of insulin production are expensive and time-consuming. A PCR-based strategy was employed for the cloning and verification of human insulin. The human insulin protein was then overexpressed in E. coli on a laboratory scale. Thereafter, optimisation of human insulin expression was conducted. The yield of human insulin produced was approximately 520.92 (mg/L), located in the intracellular fraction. Human insulin was detected using the MALDI-TOF-MS and LC-MS methods. The crude biosynthesised protein sequence was verified using protein sequencing, which had a 100% similarity to the human insulin sequence. The biological activity of human insulin was tested in vitro using a MTT assay, which revealed that the crude biosynthesised human insulin displayed a similar degree of efficacy to the standard human insulin. This study eliminated the use of affinity tags since an untagged pET21b expression vector was employed. Tedious protein renaturation, inclusion body recovery steps, and the expensive enzymatic cleavage of the C-peptide of insulin were eliminated, thereby making this method of biosynthesising human insulin a novel and more efficient method.
Collapse
|
31
|
|
32
|
Lubanyana H, Arvidsson PI, Govender T, Kruger HG, Naicker T. Improved Synthesis and Isolation of Bedaquiline. ACS Omega 2020; 5:3607-3611. [PMID: 32118176 PMCID: PMC7045498 DOI: 10.1021/acsomega.9b04037] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 01/10/2020] [Indexed: 05/02/2023]
Abstract
Bedaquiline (BDQ) is the most critical pharmaceutical in the world for treating multidrug-resistant Mycobacterium tuberculosis. Despite it being highly effective, BDQ asymmetric synthesis remains a challenge. Herein, the influence of chiral bases, namely, bis(1-phenylethyl)amine, bisoxazoline, and sparteine on the diastereoselective lithiation reaction to obtain BDQ was investigated. The highest diastereoselective ratio (dr) emerged as 90:10 from the (+)-bis[(R)-1-phenylethyl] lithium amide. This is a significant improvement from the 50:50 dr achieved from the commercial synthesis. Thereafter, the desired (90:10 RS, SR) diastereomeric mixture was easily isolated via a gravity column and subjected to chiral supercritical fluid chromatography (SFC) to access the desired enantiomer (1R, 2S)-BDQ. The advantages of this procedure are enhanced diastereoselection as well as a greener, faster way to achieve excellent enantioseparation (up to 1.0 g scale).
Collapse
Affiliation(s)
- Hlengekile Lubanyana
- Catalysis
and Peptide Research Unit, University of
KwaZulu-Natal, Durban 4000, South Africa
| | - Per I. Arvidsson
- Catalysis
and Peptide Research Unit, University of
KwaZulu-Natal, Durban 4000, South Africa
- Science
for Life Laboratory, Drug Discovery & Development Platform &
Division of Translational Medicine, and Chemical Biology, Department
of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden
| | - Thavendran Govender
- Catalysis
and Peptide Research Unit, University of
KwaZulu-Natal, Durban 4000, South Africa
| | - Hendrik G. Kruger
- Catalysis
and Peptide Research Unit, University of
KwaZulu-Natal, Durban 4000, South Africa
| | - Tricia Naicker
- Catalysis
and Peptide Research Unit, University of
KwaZulu-Natal, Durban 4000, South Africa
| |
Collapse
|
33
|
Anand K, Naicker T, Baijnath S, Mphahlele MJ, Katari NK, Zamisa SJ, Balakumar C, Vijayakumar K, Palanisamy S, Saravanan M, Boomi P, Chuturgoon A. TPGS-mediated one-pot synthesis, XRD structural analysis, antimicrobial evaluation and molecular docking of novel heterocycles as potential inhibitors of p53-MDM2 protein. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2019.127252] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
|
34
|
Rajbongshi KK, Ambala S, Govender T, Kruger HG, Arvidsson PI, Naicker T. Microwave-Accelerated N-Acylation of Sulfoximines with Aldehydes under Catalyst-Free Conditions. SYNTHESIS-STUTTGART 2020. [DOI: 10.1055/s-0039-1691589] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
An efficient catalyst-free radical cross-coupling reaction between aromatic aldehydes and sulfoximines was developed. The reaction took place in the presence of N-bromosuccinimide as the radical initiator under microwave irradiation to afford the corresponding acylated sulfoximines in moderate to excellent yields (27 examples). This protocol proved to be rapid, easy to handle, and applicable to a broad scope of substrates.
Collapse
Affiliation(s)
| | - Srinivas Ambala
- Catalysis and Peptide Research Unit, University of KwaZuluNatal
| | | | | | - Per I. Arvidsson
- Catalysis and Peptide Research Unit, University of KwaZuluNatal
- Science for Life Laboratory, Drug Discovery & Development Platform & Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZuluNatal
| |
Collapse
|
35
|
Sanusi ZK, Lawal MM, Govender T, Baijnath S, Naicker T, Maguire GEM, Honarparvar B, Kruger HG. Concerted hydrolysis mechanism of HIV-1 natural substrate against subtypes B and C-SA PR: insight through molecular dynamics and hybrid QM/MM studies. Phys Chem Chem Phys 2020; 22:2530-2539. [PMID: 31942584 DOI: 10.1039/c9cp05639d] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
It is well known that understanding the catalytic mechanism of HIV-1 PR is the rationale on which its inhibitors were developed; therefore, a better understanding of the mechanism of natural substrate hydrolysis is important. Herein, the reaction mechanism of HIV-1 natural substrates with subtypes B and common mutant in South Africa (subtype C-SA) protease were studied through transition state modelling, using a general acid-general base (GA-GB) one-step concerted process. The activation free energies of enzyme-substrate complexes were compared based on their rate of hydrolysis using a two-layered ONIOM (B3LYP/6-31++G(d,p):AMBER) method. We expanded our computational model to obtain a better understanding of the mechanism of hydrolysis as well as how the enzyme recognises or chooses the cleavage site of the scissile bonds. Using this model, a potential substrate-based inhibitor could be developed with better potency. The calculated activation energies of natural substrates in our previous study correlated well with experimental data. A similar trend was observed for the Gag and Gag-Pol natural substrates in the present work for both enzyme complexes except for the PR-RT substrate. Natural bond orbital (NBO) analysis was also applied to determine the extent of charge transfer within the QM part of both enzymes considered and the PR-RT natural substrate. The result of this study shows that the method can be utilized as a dependable computational technique to rationalize lead compounds against specific targets.
Collapse
Affiliation(s)
- Zainab K Sanusi
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa.
| | - Monsurat M Lawal
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa.
| | | | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa.
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa.
| | - Glenn E M Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa. and School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Bahareh Honarparvar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa.
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa.
| |
Collapse
|
36
|
Ntshangase S, Mdanda S, Singh SD, Naicker T, Kruger HG, Baijnath S, Govender T. Mass Spectrometry Imaging Demonstrates the Regional Brain Distribution Patterns of Three First-Line Antiretroviral Drugs. ACS Omega 2019; 4:21169-21177. [PMID: 31867510 PMCID: PMC6921606 DOI: 10.1021/acsomega.9b02582] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 11/06/2019] [Indexed: 05/04/2023]
Abstract
HIV in the central nervous system (CNS) contributes to the development of HIV-associated neurological disorders (HAND), even with chronic antiretroviral therapy. In order for antiretroviral therapy to be effective in protecting the CNS, these drugs should have the ability to localize in brain areas known to be affected by HIV. Consequently, this study aimed to investigate the localization patterns of three first-line antiretroviral drugs, namely, efavirenz, tenofovir, and emtricitabine, in the rat brain. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) and matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) were utilized to assess the pharmacokinetics and brain spatial distribution of the three drugs. Each drug was administered (50 mg/kg) to healthy female Sprague-Dawley rats via intraperitoneal administration. LC-MS/MS results showed that all three drugs could be delivered into the brain, although they varied in blood-brain barrier permeability. MALDI-MSI showed a high degree of efavirenz localization across the entire brain, while tenofovir localized mainly in the cortex. Emtricitabine distributed heterogeneously mainly in the thalamus, corpus callosum, and hypothalamus. This study showed that efavirenz, tenofovir, and emtricitabine might be a potential drug combination antiretroviral therapy for CNS protection against HAND.
Collapse
Affiliation(s)
- Sphamandla Ntshangase
- Catalysis
and Peptide Research Unit and Biomedical Resource Unit, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa
| | - Sipho Mdanda
- Catalysis
and Peptide Research Unit and Biomedical Resource Unit, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa
| | - Sanil D. Singh
- Catalysis
and Peptide Research Unit and Biomedical Resource Unit, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa
| | - Tricia Naicker
- Catalysis
and Peptide Research Unit and Biomedical Resource Unit, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa
| | - Hendrik G. Kruger
- Catalysis
and Peptide Research Unit and Biomedical Resource Unit, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa
| | - Sooraj Baijnath
- Catalysis
and Peptide Research Unit and Biomedical Resource Unit, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa
- E-mail: . Tel: +27 31 260 81799. Cell: +27 84 562 1530(S.B.)
| | - Thavendran Govender
- AnSynth
Pty Ltd., 498 Grove End
Drive, Durban 4000, South Africa
- E-mail: (T.G.)
| |
Collapse
|
37
|
Ntshangase S, Mdanda S, Naicker T, Kruger HG, Baijnath S, Govender T. Spatial distribution of elvitegravir and tenofovir in rat brain tissue: Application of matrix-assisted laser desorption/ionization mass spectrometry imaging and liquid chromatography/tandem mass spectrometry. Rapid Commun Mass Spectrom 2019; 33:1643-1651. [PMID: 31240777 DOI: 10.1002/rcm.8510] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 06/10/2019] [Accepted: 06/18/2019] [Indexed: 05/21/2023]
Abstract
RATIONALE The complexity of central nervous system (CNS) drug delivery is the main obstacle with the blood-brain barrier (BBB) known to restrict access of most pharmaceutical drugs into the brain. Mass spectrometry imaging (MSI) offers possibilities for studying drug deposition into the CNS. METHODS The deposition and spatial distribution of the two antiretroviral drugs elvitegravir and tenofovir in the brain were investigated in healthy female Sprague-Dawley rats following a single intraperitoneal administration (50 mg/kg). This was achieved by the utilization of quantitative liquid chromatography/tandem mass spectrometry (LC/MS/MS) and matrix-assisted laser desorption/ionization (MALDI) MSI. RESULTS LC/MS/MS showed that elvitegravir has better BBB penetration, reaching maximum concentration in the brain (Cmax brain) of 976.5 ng/g. In contrast, tenofovir displayed relatively lower BBB penetration, reaching Cmax brain of 54.5 ng/g. MALDI-MSI showed the heterogeneous distribution of both drugs in various brain regions including the cerebral cortex. CONCLUSIONS LC/MS/MS and MALDI-MSI provided valuable information about the relative concentration and the spatial distribution of the two common antiretroviral drugs. This study has also shown the capability of MALDI-MSI for direct visualization of pharmaceutical drugs in situ.
Collapse
Affiliation(s)
- Sphamandla Ntshangase
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Sipho Mdanda
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | | |
Collapse
|
38
|
Mkhize PZ, Naicker T, Onyangunga OA, Moodley J. Adherence to iron prophylactic therapy during pregnancy in an urban regional hospital in South Africa. S Afr Fam Pract (2004) 2019. [DOI: 10.4102/safp.v61i5.4937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Background: Iron and folic acid supplementation plays a major role in the prevention and control of iron-deficiency anaemia in pregnancy. Therefore, this study assesses adherence to prophylactic iron supplementation during the antenatal period in South Africa.Methods: An observational study was conducted in a regional hospital from January to December 2016. HIV-uninfected (n = 100) and HIV-infected (n = 100)] women were enrolled and subdivided into three groups: (a) ≤ 34 weeks (n = 33), (b) 34–36 weeks (n = 34) and (c) ≥ 37 weeks (n = 33) gestational age respectively. A structured questionnaire was used for data collection. Data were coded and statistically analysed using SPSS software. Pill count and self-reported data from women (n = 24) at ≤ 34 weeks and 34–36 weeks reflected 50% adherence and 46% non-adherence, being higher in the HIV-infected women (75%). Nausea was the commonest side effect across all trimesters (79. 2%). Adherence (27.8%) and non-adherence (72.1%) to iron, folic acid and calcium supplementation were found in 88% of women.Conclusion: This study found that adherence to micronutrient supplementation is low in pregnancy, albeit higher in HIV-infected women receiving antenatal care at a regional hospital in Durban, South Africa.Abbreviations: Haemoglobin (Hb), Human Immune Deficiency Virus (HIV), antiretroviral therapy (ARV), zidovudine (ZDV), tuberculosis (TB), low to middle- income countries (LMICs), World Health Organization (WHO), antenatal clinic (ANC).
Collapse
|
39
|
Thota N, Makam P, Rajbongshi KK, Nagiah S, Abdul NS, Chuturgoon AA, Kaushik A, Lamichhane G, Somboro AM, Kruger HG, Govender T, Naicker T, Arvidsson PI. N-Trifluoromethylthiolated Sulfonimidamides and Sulfoximines: Anti-microbial, Anti-mycobacterial, and Cytotoxic Activity. ACS Med Chem Lett 2019; 10:1457-1461. [PMID: 31620233 DOI: 10.1021/acsmedchemlett.9b00285] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 09/11/2019] [Indexed: 01/27/2023] Open
Abstract
Herein we demonstrate the expanded utility of a recently described N-trifluoromethylthiolation protocol to sulfonimidamide containing substances. The novel N-trifluoromethylthio sulfonimidamide derivatives thus obtained were evaluated for antibacterial activity against Mycobacterium tuberculosis (M. tb.) and Mycobacterium abscessus and Gram + Ve (Streptococcus aureus, Bacillus subtilis), and Gram - Ve (Escherichia coli, Pseudomonas aeruginosa) bacteria. Two compounds, 13 and 15 showed high antimycobacterial activity with MIC value of 4-8 μg/mL; i.e. comparable to WHO recommended first line antibiotic for TB infection ethambutol. The same compounds were also found to be cytotoxic in HepG2 cells (compound 13 IC50 = 15 μg/mL; compound 15 IC50 = 65 μg/mL). A structure activity relationship, using matched pair analysis, gave the unexpected conclusion that the trifluoromethylthio moiety was responsible for the cellular and bacterial toxicity. Given the increasing use of the trifluoromethylthio group in contemporary medicinal chemistry, this observation calls for considerations before implementation of the functionality in drug design.
Collapse
Affiliation(s)
- Niranjan Thota
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | - Parameshwar Makam
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | - Kamal K. Rajbongshi
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | - Savania Nagiah
- Discipline of Medical Biochemistry, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Naeem Sheik Abdul
- Discipline of Medical Biochemistry, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Anil A Chuturgoon
- Discipline of Medical Biochemistry, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Amit Kaushik
- Division of Infectious Diseases, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205, United States
| | - Gyanu Lamichhane
- Division of Infectious Diseases, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205, United States
| | - Anou M. Somboro
- Biomedical Resource Unit, College of Health Science, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Hendrik G. Kruger
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | | | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | - Per I Arvidsson
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
- Science for Life Laboratory Drug Discovery and Development Platform and Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 171 77, Sweden
| |
Collapse
|
40
|
Mkhize PZ, Naicker T, Onyangunga OA, Moodley J. Adherence to iron prophylactic therapy during pregnancy in an urban regional hospital in South Africa. S Afr Fam Pract (2004) 2019. [DOI: 10.1080/20786190.2019.1654705] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Affiliation(s)
- Princess Z Mkhize
- Women’s Health and HIV Research Group, Department of Obstetrics and Gynaecology
| | - T Naicker
- Optics and Imaging Centre, University of KwaZulu-Natal, South Africa
| | - OA Onyangunga
- Optics and Imaging Centre, University of KwaZulu-Natal, South Africa
| | - J Moodley
- Women’s Health and HIV Research Group, Department of Obstetrics and Gynaecology
| |
Collapse
|
41
|
Mdanda S, Ntshangase S, Singh SD, Naicker T, Kruger HG, Baijnath S, Govender T. Mass spectrometric investigations into the brain delivery of abacavir, stavudine and didanosine in a rodent model. Xenobiotica 2019; 50:570-579. [PMID: 31403353 DOI: 10.1080/00498254.2019.1655605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
HIV replication in the brain is unopposed due to reduced antiretroviral drug penetration into the central nervous system (CNS). Prevalence of HIV-associated neurocognitive disorder (HAND) has increased severely in patients living with HIV despite current treatments. The aims of this study were to evaluate the brain bio-distribution of alternative nucleoside reverse transcriptase inhibitors, abacavir, stavudine and didanosine in the CNS and to determine their localization patterns in the brain.Sprague-Dawley rats received 50 mg kg-1 single i.p dose of each drug. Mass spectrometric techniques were then used to investigate the pharmacokinetics and localization patterns of these drugs in the brain using LC-MS/MS and mass spectrometric imaging (MSI), respectively.Abacavir, stavudine and didanosine reached the Brain Cmax with concentration of 831.2, 1300 and 43.37 ngmL-1, respectively. Based on MSI analysis Abacavir and Stavudine were located in brain regions that are strongly implicated in the progression of HAND.Abacavir and Stavudine penetrated into CNS, reaching a Cmax that was above the IC50 for HIV (457.6 and 112.0 ngmL-1, respectively), however, it was noted ddI showed poor entry within the brain, therefore, it is recommended that this drug cannot be considered for treating CNS-HIV.
Collapse
Affiliation(s)
- Sipho Mdanda
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Sphamandla Ntshangase
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | | | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa.,Biomedical Resource Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| |
Collapse
|
42
|
Maseko S, Padayachee E, Maphumulo S, Govender T, Sayed Y, Maguire G, Lin J, Naicker T, Baijnath S, Gerhardus KH. Kinetic and thermodynamic characterisation of HIV-protease inhibitors against E35D↑G↑S mutant in the South African HIV-1 subtype C protease. J Enzyme Inhib Med Chem 2019; 34:1451-1456. [PMID: 31409143 PMCID: PMC6713120 DOI: 10.1080/14756366.2019.1636234] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Herein, we report the effect of nine FDA approved protease inhibitor drugs against a new HIV-1 subtype C mutant protease, E35D↑G↑S. The mutant has five mutations, E35D, two insertions, position 36 (G and S), and D60E. Kinetics, inhibition constants, vitality, Gibbs free binding energies are reported. The variant showed a decreased affinity for substrate and low catalytic efficiency compared to the wild type. There was a significant decrease in the binding of seven FDA approved protease inhibitors against the mutant (p < .0001). Amprenavir and ritonavir showed the least decrease, but still significant reduced activity in comparison to the wildtype (4 and 5 folds, respectively, p = .0021 and .003, respectively). Nelfinavir and atazanavir were the worst inhibitors against the variant as seen from the IC50, with values of 1401 ± 3.0 and 685 ± 3.0 nM, respectively. Thermodynamics data showed less favourable Gibbs free binding energies for the protease inhibitors to the mutant.
Collapse
Affiliation(s)
- Sibusiso Maseko
- a Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal , Durban , South Africa
| | - Eden Padayachee
- a Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal , Durban , South Africa
| | - Siyabonga Maphumulo
- a Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal , Durban , South Africa
| | - Thavendran Govender
- a Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal , Durban , South Africa
| | - Yasien Sayed
- b Protein Structure-Function Research Unit, School of Molecular and Cell Biology, University of the Witwatersrand , Wits , South Africa
| | - Glenn Maguire
- a Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal , Durban , South Africa.,c School of Chemistry and Physics, University of KwaZulu-Natal , Durban , South Africa
| | - Johnson Lin
- d School of Life Sciences, University of KwaZulu-Natal , Durban , South Africa
| | - Tricia Naicker
- a Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal , Durban , South Africa
| | - Sooraj Baijnath
- a Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal , Durban , South Africa
| | - Kruger Hendrik Gerhardus
- a Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal , Durban , South Africa
| |
Collapse
|
43
|
Soobramoney C, Maduray K, Moodley J, Moodley R, Naicker T. The Screening of Nails for Selected Essential and Toxic Elements in Normotensive and Pre-Eclamptic Women. Biol Trace Elem Res 2019; 189:28-33. [PMID: 30073457 DOI: 10.1007/s12011-018-1465-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 07/27/2018] [Indexed: 11/26/2022]
Abstract
To compare the concentrations of 13 different elements in nail samples from pre-eclamptic and normotensive pregnant women. The study site was a regional hospital in Durban, KwaZulu Natal. Nail samples were collected from normotensive (n = 33) and pre-eclamptic (n = 33) pregnant women. Approximately 0.02 g of nail samples were digested in 70% nitric acid and analyzed using inductively coupled plasma-optical emission spectrometry. Analytes of interest were the following essential elements calcium (Ca), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), nickel (Ni), selenium (Se) and Zinc (Zn) as well as toxic elements, arsenic (As), cadmium (Cd) and lead (Pb). The observed concentrations of bioelements (mean, μg/g), Ca: normotensive (N) 3467 ± 197 vs (PE) 2897 ± 190; Mg: (N) 736 ± 61 vs (PE) 695 ± 59, were lower in pre-eclampsia albeit not statistically significant. Similarly, the observed concentrations of bioelements (mean, μg/g), Cd: (N) 3 ± 0.3 vs (PE) 2 ± 0.4; Co: (N) 3 ± 0.3 (PE) not detected; Mn: (N) 7 ± 1 (PE) 4 ± 0.8, were significantly lower in pre-eclampsia (p = 0.004, 0.0001 and 0.022, respectively). Therefore, this study demonstrated significantly lower levels of Cd, Co and Mn in pre-eclampsia which justifies the need for further research on these elements towards the effective management or prevention of pre-eclampsia which could ultimately also aid in establishing its pathogenesis.
Collapse
Affiliation(s)
- C Soobramoney
- Inkosi Albert Luthuli Hospital and School of Laboratory Medicine and Medical Science, College of Health Sciences, University of KwaZulu Natal, Durban, South Africa
| | - K Maduray
- Department of Human Physiology, Faculty of Health Sciences, School of Laboratory Medicine and Medical Sciences, University of KwaZulu Natal, E- Block, Westville Campus, Durban, 3629, South Africa.
| | - J Moodley
- Women Health and HIV Research Group, School of Clinical Medicine, College of Health Sciences, University of KwaZulu Natal, Durban, South Africa
| | - R Moodley
- School of Chemistry and Physics, College of Agriculture, Engineering and Science, University of KwaZulu Natal, Durban, South Africa
| | - T Naicker
- Optics and Imaging Centre, School of Laboratory Medicine and Medical Science, College of Health Sciences, University of KwaZulu Natal, Durban, South Africa
| |
Collapse
|
44
|
Teklezgi BG, Pamreddy A, Baijnath S, Kruger HG, Naicker T, Gopal ND, Govender T. Time-dependent regional brain distribution of methadone and naltrexone in the treatment of opioid addiction. Addict Biol 2019; 24:438-446. [PMID: 29441714 DOI: 10.1111/adb.12609] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 12/01/2017] [Accepted: 01/17/2018] [Indexed: 12/15/2022]
Abstract
Opioid addiction is a serious public health concern with severe health and social implications; therefore, extensive therapeutic efforts are required to keep users drug free. The two main pharmacological interventions, in the treatment of addiction, involve management with methadone an mu (μ)-opioid agonist and treatment with naltrexone, μ-opioid, kappa (κ)-opioid and delta (δ)-opioid antagonist. MET and NAL are believed to help individuals to derive maximum benefit from treatment and undergo a full recovery. The aim of this study was to determine the localization and distribution of MET and NAL, over a 24-hour period in rodent brain, in order to investigate the differences in their respective regional brain distributions. This would provide a better understanding of the role of each individual drug in the treatment of addiction, especially NAL, whose efficacy is controversial. Tissue distribution was determined by using mass spectrometric imaging (MSI), in combination with quantification via liquid chromatography tandem mass spectrometry. MSI image analysis showed that MET was highly localized in the striatal and hippocampal regions, including the nucleus caudate, putamen and the upper cortex. NAL was distributed with high intensities in the mesocorticolimbic system including areas of the cortex, caudate putamen and ventral pallidum regions. Our results demonstrate that MET and NAL are highly localized in the brain regions with a high density of μ-receptors, the primary sites of heroin binding. These areas are strongly implicated in the development of addiction and are the major pathways that mediate brain stimulation during reward.
Collapse
Affiliation(s)
- Belin G. Teklezgi
- Catalysis and Peptide Research UnitUniversity of KwaZulu‐Natal South Africa
| | - Annapurna Pamreddy
- Catalysis and Peptide Research UnitUniversity of KwaZulu‐Natal South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research UnitUniversity of KwaZulu‐Natal South Africa
| | - Hendrik G. Kruger
- Catalysis and Peptide Research UnitUniversity of KwaZulu‐Natal South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research UnitUniversity of KwaZulu‐Natal South Africa
| | - Nirmala D. Gopal
- Department of CriminologyUniversity of KwaZulu‐Natal South Africa
| | | |
Collapse
|
45
|
Ntshangase S, Mdanda S, Naicker T, Kruger HG, Govender T, Baijnath S. Rilpivirine as a potential candidate for the treatment of HIV-associated neurocognitive disorders (HAND). J Mol Histol 2019; 50:295-303. [PMID: 31011919 DOI: 10.1007/s10735-019-09826-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 04/17/2019] [Indexed: 12/20/2022]
Abstract
As the HIV epidemic continues to contribute to global morbidity and mortality, the prevalence of HIV-associated neurological disorders (HAND) also continues to be a major concern in infected individuals, despite the widespread use of combination antiretroviral therapy. Therefore, current antiretroviral drugs should be able to reach therapeutic levels in the brain for the treatment of HAND. The brain distribution of the next-generation non-nucleoside reverse transcriptase inhibitor, rilpivirine (RPV) was investigated in healthy female Sprague-Dawley (SD) rats. The presented study involves the use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) to estimate the concentrations of RPV in plasma and brain homogenate samples. The use of matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) provided regional spatial distribution of RPV in brain tissue sections. The localization of RPV was found to be relatively high in the hypothalamus, thalamus and corpus callosum, brain regions known to be associated with neurodegeneration during HAND (including the cerebral cortex). This study has shown that RPV has an excellent blood-brain barrier penetrability. Thus, in combination with other antiretroviral drugs, better central nervous system (CNS) protection against HAND can possibly be achieved.
Collapse
Affiliation(s)
- Sphamandla Ntshangase
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-block, 6th floor, Room E1-06-016, Durban, South Africa
| | - Sipho Mdanda
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-block, 6th floor, Room E1-06-016, Durban, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-block, 6th floor, Room E1-06-016, Durban, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-block, 6th floor, Room E1-06-016, Durban, South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-block, 6th floor, Room E1-06-016, Durban, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-block, 6th floor, Room E1-06-016, Durban, South Africa.
| |
Collapse
|
46
|
Ibeji CU, Lawal MM, Tolufashe GF, Govender T, Naicker T, Maguire GEM, Lamichhane G, Kruger HG, Honarparvar B. The Driving Force for the Acylation of β-Lactam Antibiotics by L,D-Transpeptidase 2: Quantum Mechanics/Molecular Mechanics (QM/MM) Study. Chemphyschem 2019; 20:1126-1134. [PMID: 30969480 DOI: 10.1002/cphc.201900173] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 03/13/2019] [Indexed: 11/06/2022]
Abstract
β-lactam antibiotics, which are used to treat infectious diseases, are currently the most widely used class of antibiotics. This study focused on the chemical reactivity of five- and six-membered ring systems attached to the β-lactam ring. The ring strain energy (RSE), force constant (FC) of amide (C-N), acylation transition states and second-order perturbation stabilization energies of 13 basic structural units of β-lactam derivatives were computed using the M06-2X and G3/B3LYP multistep method. In the ring strain calculations, an isodesmic reaction scheme was used to obtain the total energies. RSE is relatively greater in the five-(1a-2c) compared to the six-membered ring systems except for 4b, which gives a RSE that is comparable to five-membered ring lactams. These variations were also observed in the calculated inter-atomic amide bond distances (C-N), which is why the six-membered ring lactams C-N bond are more rigid than those with five-membered ring lactams. The calculated ΔG# values from the acylation reaction of the lactams (involving the S-H group of the cysteine active residue from L,D transpeptidase 2) revealed a faster rate of C-N cleavage in the five-membered ring lactams especially in the 1-2 derivatives (17.58 kcal mol-1 ). This observation is also reflected in the calculated amide bond force constant (1.26 mDyn/A) indicating a weaker bond strength, suggesting that electronic factors (electron delocalization) play more of a role on reactivity of the β-lactam ring, than ring strain.
Collapse
Affiliation(s)
- Collins U Ibeji
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa.,Department of Pure and Industrial Chemistry, Faculty of Physical Sciences, University of Nigeria, Nsukka, 410001, Enugu State, Nigeria
| | - Monsurat M Lawal
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa
| | - Gideon F Tolufashe
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa
| | - Glenn E M Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa.,School of Chemistry and Physics, University of KwaZulu-Natal, Durban, 4041, South Africa
| | - Gyanu Lamichhane
- Center for Tuberculosis Research, Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa
| | - Bahareh Honarparvar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa
| |
Collapse
|
47
|
Govender KB, Samipillai M, Govender T, Kruger HG, Naicker T. Crystal structure of 2-(bis(3,5-dimethylphenyl) ((methyldiphenylsilyl)oxy)methyl) pyrrolidine, C 34H 39NOSi. Z KRIST-NEW CRYST ST 2019. [DOI: 10.1515/ncrs-2018-0422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C34H39NOSi, triclinic, P1̅ (no. 2), a = 10.0901(2) Å, b = 11.5016(2) Å, c = 14.4098(3) Å, α = 69.207(1)°, β = 86.555(2)°, γ = 65.579(3)°, V = 1416.10(6) Å3, Z = 2, R
gt(F) = 0.0463, wR
ref(F
2) = 0.1200, T = 100(2) K.
Collapse
Affiliation(s)
- Kimberleigh B. Govender
- University of KwaZulu Natal, Catalysis and Peptide Research Unit , Durban 4000 , South Africa
| | - Marivel Samipillai
- University of KwaZulu Natal, Catalysis and Peptide Research Unit , Durban 4000 , South Africa
| | - Thavendran Govender
- University of KwaZulu Natal, Catalysis and Peptide Research Unit , Durban 4000 , South Africa
| | - Hendrik G. Kruger
- University of KwaZulu Natal, Catalysis and Peptide Research Unit , Durban 4000 , South Africa
| | - Tricia Naicker
- University of KwaZulu Natal, Catalysis and Peptide Research Unit , Durban 4000 , South Africa
| |
Collapse
|
48
|
Brasil E, Samipillai M, Govender T, Kruger HG, Naicker T. Crystal structure of ( E)-2-(4-cyanophenyl)ethenesulfonyl fluoride, C 9H 6FNO 2S. Z KRIST-NEW CRYST ST 2019. [DOI: 10.1515/ncrs-2018-0449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
C9H6FNO2S, triclinic, P1̄ (no. 2), a = 7.2786(2) Å, b = 8.1014(3) Å, c = 16.1084(5) Å, α = 76.320(1)°, β = 87.918(1)°, γ = 80.784(1)°, V = 911.00(5) Å3, Z = 4, R
gt(F) = 0.0298, wR
ref(F
2) = 0.0857, T = 100(2) K.
Collapse
Affiliation(s)
- Edikarlos Brasil
- University of KwaZulu Natal, Catalysis and Peptide Research Unit , Durban 4000 , South Africa
| | - Marivel Samipillai
- University of KwaZulu Natal, Catalysis and Peptide Research Unit , Durban 4000 , South Africa
| | - Thavendran Govender
- University of KwaZulu Natal, Catalysis and Peptide Research Unit , Durban 4000 , South Africa
| | - Hendrik G. Kruger
- University of KwaZulu Natal, Catalysis and Peptide Research Unit , Durban 4000 , South Africa
| | - Tricia Naicker
- University of KwaZulu Natal, Catalysis and Peptide Research Unit , Durban 4000 , South Africa
| |
Collapse
|
49
|
Maseko SB, Govender D, Govender T, Naicker T, Lin J, Maguire GEM, Kruger HG. Optimized Procedure for Recovering HIV-1 Protease (C-SA) from Inclusion Bodies. Protein J 2019; 38:30-36. [PMID: 30666487 DOI: 10.1007/s10930-018-9805-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
HIV-1 is an infectious virus that causes acquired immunodeficiency syndrome (AIDS) and it is one of the major causes of deaths worldwide. The production of HIV-1 protease (PR) on a large scale has been a problem for scientists due to its cytotoxicity, low yield, insolubility, and low activity. HIV-1 C-SA protease has been cloned, expressed, and purified previously, however, with low recovery (0.25 mg/L). Herein we report an optimal expression and solubilisation procedure to recover active HIV-1 C-SA protease enzyme from inclusion bodies. The HIV protease was expressed in seven different vectors (pET11b, pET15b, pET28a pET32a, pET39b, pET41b and pGEX 6P-1). The highest expression was achieved when the vector pET32a (Trx tag) was employed. A total of 19.5 mg of fusion protein was refolded of which 5.5 mg of active protease was obtained after cleavage. The free protease had a high specific activity of 2.81 µmoles/min/mg. Interestingly the Trx-fusion protein also showed activity closer (1.24 µmoles/min/mg) to that of the free protease suggesting that the pET32a vector (Trx tag) expressed in BL21(DE3) pLysS provides a more efficient way to obtain HIV-1 protease.
Collapse
Affiliation(s)
- Sibusiso B Maseko
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Deidre Govender
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Johnson Lin
- School of Life Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Glenn E M Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa.,School of Chemistry and Physics, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa.
| |
Collapse
|
50
|
Naicker T, Brasil E, Samipillai M, Govender T, Baijnath S. Crystal structure of 2-(4-fluorophenyl)-N-phenyl-2-(phenylamino)ethanesulfonamide – toluene (1/0.5), C23.5H23FN2O2S. Z KRIST-NEW CRYST ST 2018. [DOI: 10.1515/ncrs-2018-0253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractC23.5H23FN2O2S, Mr = 416.50, monoclinic, C2/c (no. 15), a = 27.2594(19) Å, b = 5.7351(4) Å, c = 26.1139(18) Å, β = 102.009(2)°, V = 3993.2(5) Å3, Z = 8, Rgt(F) = 0.0358, wRref(F2) = 0.0958 T = 100(2) K.
Collapse
Affiliation(s)
- Tricia Naicker
- University of KwaZulu Natal, Catalysis and Peptide Research Unit, Durban 4000, South Africa
| | - Edikarlos Brasil
- University of KwaZulu Natal, Catalysis and Peptide Research Unit, Durban 4000, South Africa
| | - Marivel Samipillai
- University of KwaZulu Natal, Catalysis and Peptide Research Unit, Durban 4000, South Africa
| | - Thavendran Govender
- University of KwaZulu Natal, Catalysis and Peptide Research Unit, Durban 4000, South Africa
| | - Sooraj Baijnath
- University of KwaZulu Natal, Catalysis and Peptide Research Unit, Durban 4000, South Africa
| |
Collapse
|