1
|
Sukhran Y, Alshanski I, Filiba O, Mackintosh MJ, Schapiro I, Hurevich M. Unexpected Nucleophile Masking in Acyl Transfer to Sterically Crowded and Conformationally Restricted Galactosides. J Org Chem 2023. [PMID: 37269328 DOI: 10.1021/acs.joc.3c00878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Design and synthesis of orthogonally protected monosaccharide building blocks are crucial for the preparation of well-defined oligosaccharides in a stereo- and regiocontrolled manner. Selective introduction of protecting groups to partially protected monosaccharides is nontrivial due to the often unpredictable electronic, steric, and conformational effects of the substituents. Abolished reactivity toward a commonly used Lewis base-catalyzed acylation of O-2 was observed in conformationally restricted 4,6-O-benzylidene-3-O-Nap galactoside. Investigation of analogous systems, crystallographic characterization, and quantum chemical calculations highlighted the overlooked conformational and steric considerations, the combination of which produces a unique passivity of the 2-OH nucleophile. Evaluating the role of electrophile counterion and auxiliary base in the acylation of the sterically crowded and conformationally restricted galactoside system revealed an alternative Brønsted base-driven reaction pathway via nucleophilic activation. Insights gained from this model system were utilized to access the target galactoside intermediate within the envisioned synthetic route. The acylation strategy described herein can be implemented in future syntheses of key monomeric building blocks with unique protecting group hierarchies.
Collapse
Affiliation(s)
- Yonatan Sukhran
- The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Israel Alshanski
- The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Ofer Filiba
- Fritz Haber Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Megan J Mackintosh
- Fritz Haber Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Igor Schapiro
- Fritz Haber Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Mattan Hurevich
- The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| |
Collapse
|
2
|
Zhao MM, Zhang H, Iimura S, Bednarz MS, Song QL, Lim NK, Yan J, Wu W, Dai K, Gu X, Wang Y. Process Development of Sotagliflozin, a Dual Inhibitor of Sodium–Glucose Cotransporter-1/2 for the Treatment of Diabetes. Org Process Res Dev 2020. [DOI: 10.1021/acs.oprd.0c00359] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Matthew M. Zhao
- Chemical Development, Lexicon Pharmaceuticals Incorporation, 110 Allen Road, Basking Ridge, New Jersey 07920, United States
| | - Haiming Zhang
- Chemical Development, Lexicon Pharmaceuticals Incorporation, 110 Allen Road, Basking Ridge, New Jersey 07920, United States
| | - Shinya Iimura
- Chemical Development, Lexicon Pharmaceuticals Incorporation, 110 Allen Road, Basking Ridge, New Jersey 07920, United States
| | - Mark S. Bednarz
- Chemical Development, Lexicon Pharmaceuticals Incorporation, 110 Allen Road, Basking Ridge, New Jersey 07920, United States
| | - Qiu-Ling Song
- Chemical Development, Lexicon Pharmaceuticals Incorporation, 110 Allen Road, Basking Ridge, New Jersey 07920, United States
| | - Ngiap-Kie Lim
- Chemical Development, Lexicon Pharmaceuticals Incorporation, 110 Allen Road, Basking Ridge, New Jersey 07920, United States
| | - Jie Yan
- Chemical Development, Lexicon Pharmaceuticals Incorporation, 110 Allen Road, Basking Ridge, New Jersey 07920, United States
| | - Wenxue Wu
- Chemical Development, Lexicon Pharmaceuticals Incorporation, 110 Allen Road, Basking Ridge, New Jersey 07920, United States
| | - Kuangchu Dai
- Process R&D, WuXi Apptec, 288 Fute Zhong Road, Waigaoqiao Free Trade Zone, Shanghai 200131, China
| | - Xiaodong Gu
- Process R&D, WuXi Apptec, 288 Fute Zhong Road, Waigaoqiao Free Trade Zone, Shanghai 200131, China
| | - Youchu Wang
- Process R&D, WuXi Apptec, 288 Fute Zhong Road, Waigaoqiao Free Trade Zone, Shanghai 200131, China
| |
Collapse
|
3
|
Synthesis, spectral, structure and computational studies of novel transition Metal(II) complexes of (Z)-((dimethylcarbamothioyl)thio) ((1,1,1-trifluoro-4-(naphthalen-2-yl)-4-oxobut-2-en-2-yl)oxy). J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2020.128057] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
4
|
Lawal MM, Sanusi ZK, Govender T, Maguire GE, Honarparvar B, Kruger HG. From Recognition to Reaction Mechanism: An Overview on the Interactions between HIV-1 Protease and its Natural Targets. Curr Med Chem 2020; 27:2514-2549. [DOI: 10.2174/0929867325666181113122900] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 11/04/2018] [Accepted: 11/07/2018] [Indexed: 12/28/2022]
Abstract
Current investigations on the Human Immunodeficiency Virus Protease (HIV-1
PR) as a druggable target towards the treatment of AIDS require an update to facilitate further
development of promising inhibitors with improved inhibitory activities. For the past two
decades, up to 100 scholarly reports appeared annually on the inhibition and catalytic mechanism
of HIV-1 PR. A fundamental literature review on the prerequisite of HIV-1 PR action
leading to the release of the infectious virion is absent. Herein, recent advances (both computationally
and experimentally) on the recognition mode and reaction mechanism of HIV-1 PR
involving its natural targets are provided. This review features more than 80 articles from
reputable journals. Recognition of the natural Gag and Gag-Pol cleavage junctions by this
enzyme and its mutant analogs was first addressed. Thereafter, a comprehensive dissect of
the enzymatic mechanism of HIV-1 PR on its natural polypeptide sequences from literature
was put together. In addition, we highlighted ongoing research topics in which in silico
methods could be harnessed to provide deeper insights into the catalytic mechanism of the
HIV-1 protease in the presence of its natural substrates at the molecular level. Understanding
the recognition and catalytic mechanism of HIV-1 PR leading to the release of an infective
virion, which advertently affects the immune system, will assist in designing mechanismbased
inhibitors with improved bioactivity.
Collapse
Affiliation(s)
- Monsurat M. Lawal
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Zainab K. Sanusi
- 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
| | - Glenn E.M. Maguire
- 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
| | - Hendrik G. Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
| |
Collapse
|
5
|
Chioma F, Ibeji CU, Okpareke O. Novel 3d divalent metallic complexes of 3-[(2-hydroxy-5-methyl-phenylimino)-methyl]-napthalen-2-ol: Synthesis, spectral characterization, antimicrobial and computational studies. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2020.128017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
6
|
Ashush N, Fallek R, Fallek A, Dobrovetsky R, Portnoy M. Base- and Catalyst-Induced Orthogonal Site Selectivities in Acylation of Amphiphilic Diols. Org Lett 2020; 22:3749-3754. [PMID: 32330055 DOI: 10.1021/acs.orglett.0c00830] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Seeking to selectively functionalize natural and synthetic amphiphiles, we explored acylation of model amphiphilic diols. The use of a nucleophilic catalyst enabled a remarkable shift of the site selectivity from the polar site, preferred in background noncatalyzed or base-promoted reactions, to the apolar site. This tendency was significantly enhanced for organocatalysts comprising an imidazole active site surrounded by long/branched tails. An explanation of these orthogonal modes of selectivity is supported by competitive experiments with monoalcohol substrates.
Collapse
Affiliation(s)
- Natali Ashush
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Reut Fallek
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Amit Fallek
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Roman Dobrovetsky
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Moshe Portnoy
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| |
Collapse
|
7
|
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] [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
|
8
|
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] [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
|
9
|
Lawal MM, Sanusi ZK, Govender T, Tolufashe GF, Maguire GEM, Honarparvar B, Kruger HG. Unraveling the concerted catalytic mechanism of the human immunodeficiency virus type 1 (HIV-1) protease: a hybrid QM/MM study. Struct Chem 2018. [DOI: 10.1007/s11224-018-1251-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
|
10
|
Sharma A, Zamisa SJ, Noki S, Almarhoon Z, El-Faham A, Torre BGDL, Albericio F. Crystal structure, spectroscopic studies and theoretical studies of thiobarbituric acid derivatives: understanding the hydrogen-bonding patterns. ACTA CRYSTALLOGRAPHICA SECTION C-STRUCTURAL CHEMISTRY 2018; 74:1703-1714. [PMID: 30516155 DOI: 10.1107/s2053229618015516] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 11/02/2018] [Indexed: 11/10/2022]
Abstract
In addition to their wide-ranging applications in the pharmaceutical industry, thiobarbituric acid (TBA) derivatives are also known to possess applications in engineering and materials science. 20 TBA derivatives, with diversity at the N and C-5 positions through acylation, Schiff base formation, Knoevenagel condensation, thioamide and enamine formation, were studied. The absolute configurations for six derivatives, namely 5-acetyl-1,3-diethyl-2-thioxodihydropyrimidine-4,6(1H,5H)-dione, C10H14N2O3S, A01, 1,3-diethyl-5-propionyl-2-thioxodihydropyrimidine-4,6(1H,5H)-dione, C11H16N2O3S, A02, tert-butyl [1-(1,3-diethyl-4,6-dioxo-2-thioxohexahydropyrimidin-5-yl)-3-methyl-1-oxobutan-2-yl]carbamate, C18H29N3O5S, A06, 1,3-diethyl-4,6-dioxo-2-thioxo-N-(p-tolyl)hexahydropyrimidine-5-carbothioamide, C16H19N3O2S2, A13, 5-(1-aminoethylidene)-1,3-diethyl-2-thioxodihydropyrimidine-4,6(1H,5H)-dione, C10H15N3O2S, A17, and 5-(1-aminopropylidene)-1,3-diethyl-2-thioxodihydropyrimidine-4,6(1H,5H)-dione, C11H17N3O2S, A18, were confirmed by single-crystal X-ray crystallography, which indicates the formation of intramolecular hydrogen bonding in all six cases and intermolecular hydrogen bonding for A17. In A13, the presence of two intramolecular hydrogen bonds was observed. The stabilization of the enol form over the keto form was confirmed by computation. In order to convert the keto form to the enol form, an energy barrier of 55.05 kcal mol-1 needs to be overcome, as confirmed by transition-state calculations.
Collapse
Affiliation(s)
- Anamika Sharma
- School of Health Sciences, University of KwaZulu Natal, University Road, Westville, Durban, 4000, South Africa
| | - Sizwe J Zamisa
- School of Chemistry and Physics, University of KwaZulu Natal, Private bag X54001, Westville campus, Durban, 4000, South Africa
| | - Sikabwe Noki
- School of Chemistry and Physics, University of KwaZulu Natal, Private bag X54001, Westville campus, Durban, 4000, South Africa
| | - Zainab Almarhoon
- Department of Chemistry, College of Science, King Saud University, 2455 Riyadh, 11451, Saudi Arabia
| | - Ayman El-Faham
- Department of Chemistry, College of Science, King Saud University, 2455 Riyadh, 11451, Saudi Arabia
| | - Beatriz G de la Torre
- KRISP, College of Health Sciences, University of KwaZulu Natal, Durban, 4001, South Africa
| | - Fernando Albericio
- School of Chemistry and Physics, University of KwaZulu Natal, Private bag X54001, Westville campus, Durban, 4000, South Africa
| |
Collapse
|
11
|
Ibeji CU, Tolufashe GF, Ntombela T, Govender T, Maguire GEM, Lamichhane G, Kruger HG, Honarparvar B. The catalytic role of water in the binding site of l,d-transpeptidase 2 within acylation mechanism: A QM/MM (ONIOM) modelling. Tuberculosis (Edinb) 2018; 113:222-230. [PMID: 30514506 DOI: 10.1016/j.tube.2018.10.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 10/11/2018] [Accepted: 10/14/2018] [Indexed: 01/13/2023]
Abstract
Mycobacterium tuberculosis is the causative agent of Tuberculosis. Formation of 3 → 3 crosslinks in the peptidoglycan layer of M. tuberculosis is catalyzed by l,d-transpeptidases. These enzymes can confer resistance against classical β-lactams that inhibit enzymes that generate 4 → 3 peptidoglycan crosslinks. The focus of this study is to investigate the catalytic role of water molecules in the acylation mechanism of the β-lactam ring within two models; 4- and 6-membered ring systems using two-layered our Own N-layer integrated Molecular Mechanics ONIOM (B3LYP/6-311++G(2d,2p): AMBER) model. The obtained thermochemical parameters revealed that the 6-membered ring model best describes the inhibition mechanism of acylation which indicates the role of water in the preference of 6-membered ring reaction pathway. This finding is in accordance with experimental data for the rate-limiting step of cysteine protease with the same class of inhibitor and binding affinity for both inhibitors. As expected, the ΔG# results also reveal that the 6-membered ring reaction pathway is the most favourable. The electrostatic potential (ESP) and the natural bond orbital analysis (NBO) showed stronger interactions in 6-membered ring transition state (TS-6) mechanism involving water in the active site of the enzyme. This study could be helpful in the development of novel antibiotics against l,d-transpeptidase.
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
| | - Gideon F Tolufashe
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa
| | - Thandokuhle Ntombela
- 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
| | - 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, 21287, 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
|
12
|
Synthesis, Crystal Structure and DFT Studies of 1,3-Dimethyl-5-propionylpyrimidine-2,4,6(1H,3H,5H)-trione. CRYSTALS 2017. [DOI: 10.3390/cryst7010031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
13
|
Fakhar Z, Govender T, Lamichhane G, Maguire GE, Kruger HG, Honarparvar B. Computational model for the acylation step of the β-lactam ring: Potential application for l,d-transpeptidase 2 in mycobacterium tuberculosis. J Mol Struct 2017. [DOI: 10.1016/j.molstruc.2016.08.049] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
|
14
|
Lawal MM, Govender T, Maguire GEM, Honarparvar B, Kruger HG. Mechanistic investigation of the uncatalyzed esterification reaction of acetic acid and acid halides with methanol: a DFT study. J Mol Model 2016; 22:235. [PMID: 27604278 DOI: 10.1007/s00894-016-3084-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 08/05/2016] [Indexed: 11/29/2022]
Abstract
Implementation of catalysts to drive reactions from reactants to products remains a burden to synthetic and organic chemists. In spite of investigations into the kinetics and mechanism of catalyzed esterification reactions, less effort has been made to explore the possibility of an uncatalyzed esterification process. Therefore, a comprehensive mechanistic perspective for the uncatalyzed mechanism at the molecular level is presented. Herein, we describe the non-catalyzed esterification reaction of acetic acid and its halide derivatives (XAc, where X= OH, F, Cl, Br, I) with methanol (MeOH) through a concerted process. The reaction in vacuum and methanol was performed using the density functional theory (DFT) method at M06-2X level with def2-TZVP basis set after a careful literature survey and computations. Esterification through cyclic 4- or 6-membered transition state structures in one- or two-step concerted mechanisms were investigated. The present study outlines the possible cyclic geometry conformations that may occur during experiments at simple ratio of reactants. The free energy of activation for acetic acid and acetyl chloride are 36 kcal mol(-1) and 21 kcal mol(-1), respectively. These are in good agreement with available experimental results from the literature. The selected quantum chemical descriptors proved to be useful tools in chemical reactivity prediction for the reaction mechanism. This quantum mechanics study can serve as a necessary step towards revisiting uncatalyzed reaction mechanisms in some classical organic reactions.
Collapse
Affiliation(s)
- Monsurat M Lawal
- 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
| | - 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
| | - 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
|
15
|
Honarparvar B, Pawar SA, Alves CN, Lameira J, Maguire GE, Silva JRA, Govender T, Kruger HG. Pentacycloundecane lactam vs lactone norstatine type protease HIV inhibitors: binding energy calculations and DFT study. J Biomed Sci 2015; 22:15. [PMID: 25889635 PMCID: PMC4387594 DOI: 10.1186/s12929-015-0115-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 01/16/2015] [Indexed: 01/12/2023] Open
Abstract
Background Novel pentacycloundecane (PCU)-lactone-CO-EAIS peptide inhibitors were designed, synthesized, and evaluated against wild-type C-South African (C-SA) HIV-1 protease. Three compounds are reported herein, two of which displayed IC50 values of less than 1.00 μM. A comparative MM-PB(GB)SA binding free energy of solvation values of PCU-lactam and lactone models and their enantiomers as well as the PCU-lactam-NH-EAIS and lactone-CO-EAIS peptide inhibitors and their corresponding diastereomers complexed with South African HIV protease (C-SA) was performed. This will enable us to rationalize the considerable difference between inhibitory concentration (IC50) of PCU-lactam-NH-EAIS and PCU-lactone-CO-EAIS peptides. Results The PCU-lactam model exhibited more negative calculated binding free energies of solvation than the PCU-lactone model. The same trend was observed for the PCU-peptide inhibitors, which correspond to the experimental activities for the PCU-lactam-NH-EAIS peptide (IC50 = 0.076 μM) and the PCU-lactone-CO-EAIS peptide inhibitors (IC50 = 0.850 μM). Furthermore, a density functional theory (DFT) study on the natural atomic charges of the nitrogen and oxygen atoms of the three PCU-lactam, PCU-lactim and PCU-lactone models were performed using natural bond orbital (NBO) analysis. Electrostatic potential maps were also used to visualize the electron density around electron-rich regions. The asymmetry parameter (η) and quadrupole coupling constant (χ) values of the nitrogen and oxygen nuclei of the model compounds were calculated at the same level of theory. Electronic molecular properties including polarizability and electric dipole moments were also calculated and compared. The Gibbs theoretical free solvation energies of solvation (∆Gsolv) were also considered. Conclusions A general trend is observed that the lactam species appears to have a larger negative charge distribution around the heteroatoms, larger quadrupole constant, dipole moment and better solvation energy, in comparison to the PCU-lactone model. It can be argued that these characteristics will ensure better eletronic interaction between the lactam and the receptor, corresponding to the observed HIV protease activities in terms of experimental IC50 data. Electronic supplementary material The online version of this article (doi:10.1186/s12929-015-0115-5) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Bahareh Honarparvar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa.
| | - Sachin A Pawar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa.
| | - Cláudio Nahum Alves
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais, Universidade Federal do Pará, CP 11101, 66075-110, Belém, PA, Brazil.
| | - Jerônimo Lameira
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais, Universidade Federal do Pará, CP 11101, 66075-110, Belém, PA, Brazil.
| | - Glenn Em Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa.
| | - José Rogério A Silva
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais, Universidade Federal do Pará, CP 11101, 66075-110, Belém, PA, Brazil.
| | - Thavendran Govender
- 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
|
16
|
Md. Abdur Rauf S, Arvidsson PI, Albericio F, Govender T, Maguire GEM, Kruger HG, Honarparvar B. The effect of N-methylation of amino acids (Ac-X-OMe) on solubility and conformation: a DFT study. Org Biomol Chem 2015; 13:9993-10006. [DOI: 10.1039/c5ob01565k] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
N-Methylation of amino acid derivatives (Ac-X-OMe, X = Gly, Val, Leu, Ile, Phe, Met, Cys, Ser, Asp and His) leads to an increase in aqueous solubility, lipophilicity and lowering of the cis/trans amide conformational energy barrier (EA).
Collapse
Affiliation(s)
- Shah Md. Abdur Rauf
- Catalysis and Peptide Research Unit
- School of Health Sciences
- University of KwaZulu-Natal
- Durban 4001
- South Africa
| | - Per I. Arvidsson
- Catalysis and Peptide Research Unit
- School of Health Sciences
- University of KwaZulu-Natal
- Durban 4001
- South Africa
| | - Fernando Albericio
- 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
| | - Glenn E. M. Maguire
- 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
| | - Bahareh Honarparvar
- Catalysis and Peptide Research Unit
- School of Health Sciences
- University of KwaZulu-Natal
- Durban 4001
- South Africa
| |
Collapse
|
17
|
Farahani MD, Honarparvar B, Albericio F, Maguire GEM, Govender T, Arvidsson PI, Kruger HG. Proline N-oxides: modulators of the 3D conformation of linear peptides through “NO-turns”. Org Biomol Chem 2014; 12:4479-90. [DOI: 10.1039/c4ob00433g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
18
|
Larionov E, Zipse H. Organocatalysis: acylation catalysts. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2011. [DOI: 10.1002/wcms.48] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
19
|
Asano Y, Togashi S. A Study of Solvent Effects on Reaction Rates Using a Microreactor. JOURNAL OF CHEMICAL ENGINEERING OF JAPAN 2010. [DOI: 10.1252/jcej.09we240] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yukako Asano
- Mechanical Engineering Research Laboratory, Hitachi, Ltd
| | | |
Collapse
|
20
|
Zhang H, Chen D, Zhang G, Mi S, Lu N. Mechanism of the aminolysis of dimethyl phenylphosphinate: A DFT study. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.theochem.2009.04.039] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
21
|
Petrova T, Okovytyy S, Gorb L, Leszczynski J. Computational Study of the Aminolysis of Anhydrides: Effect of the Catalysis to the Reaction of Succinic Anhydride with Methylamine in Gas Phase and Nonpolar Solution. J Phys Chem A 2008; 112:5224-35. [DOI: 10.1021/jp7102897] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tetyana Petrova
- Department of Chemistry, Computational Center for Molecular Structure and Interactions, Jackson State University, 1400 J.R. Lynch Street, P.O. Box 17910, Jackson, Mississippi 39217-0510, and Department of Organic Chemistry, Dnepropetrovsk National University, Dnepropetrovsk 49625, Ukraine
| | - Sergiy Okovytyy
- Department of Chemistry, Computational Center for Molecular Structure and Interactions, Jackson State University, 1400 J.R. Lynch Street, P.O. Box 17910, Jackson, Mississippi 39217-0510, and Department of Organic Chemistry, Dnepropetrovsk National University, Dnepropetrovsk 49625, Ukraine
| | - Leonid Gorb
- Department of Chemistry, Computational Center for Molecular Structure and Interactions, Jackson State University, 1400 J.R. Lynch Street, P.O. Box 17910, Jackson, Mississippi 39217-0510, and Department of Organic Chemistry, Dnepropetrovsk National University, Dnepropetrovsk 49625, Ukraine
| | - Jerzy Leszczynski
- Department of Chemistry, Computational Center for Molecular Structure and Interactions, Jackson State University, 1400 J.R. Lynch Street, P.O. Box 17910, Jackson, Mississippi 39217-0510, and Department of Organic Chemistry, Dnepropetrovsk National University, Dnepropetrovsk 49625, Ukraine
| |
Collapse
|
22
|
Sato M, Matsushima K, Kawanami H, Ikuhsima Y. A Highly Selective, High-Speed, and Hydrolysis-Free O-Acylation in Subcritical Water in the Absence of a Catalyst. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200700180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
23
|
Sato M, Matsushima K, Kawanami H, Ikuhsima Y. A Highly Selective, High-Speed, and Hydrolysis-Free O-Acylation in Subcritical Water in the Absence of a Catalyst. Angew Chem Int Ed Engl 2007; 46:6284-8. [PMID: 17640027 DOI: 10.1002/anie.200700180] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Masahiro Sato
- National Institute of Advanced Industrial Science and Technology (AIST), Research Center for Compact Chemical Process, Nigatake 4-2-1, Miyagino-ku, Sendai 983-8551, Japan.
| | | | | | | |
Collapse
|
24
|
Kruger HG, Mdluli P, Power TD, Raasch T, Singh A. Experimental and computational studies of the regioselective protection of hydantoins using anhydride. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.theochem.2006.03.037] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
25
|
Regioselective protection of hydantoins – essential for hydantoin based anti-epileptic drugs. Struct Chem 2006. [DOI: 10.1007/s11224-006-9006-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
26
|
Govender T, Kruger HG, Raasch T. Complete NMR Elucidation of Two N-Protected Trishomocubane Hydantoins and the Ethyl Ester of the Corresponding Amino Acid. Struct Chem 2005. [DOI: 10.1007/s11224-005-2836-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
27
|
An ab initio mechanistic understanding of the regioselective acetylation of 8,11-dihydroxy-pentacyclo[5.4.0.02,6.03,10.05,9] undecane-8,11-lactam. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.theochem.2003.11.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|