1
|
Parveen S, Maurya N, Meena A, Luqman S. Cinchonine: A Versatile Pharmacological Agent Derived from Natural Cinchona Alkaloids. Curr Top Med Chem 2024; 24:343-363. [PMID: 38031797 DOI: 10.2174/0115680266270796231109171808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 09/13/2023] [Accepted: 09/20/2023] [Indexed: 12/01/2023]
Abstract
BACKGROUND Cinchonine is one of the Cinchona alkaloids that is commercially extracted from the Peruvian bark of Cinchona officinalis L. (Family: Rubiaceae). It is also obtained in much lower quantities from other species of Cinchona, such as Cinchona calisaya, Cinchona succirubra, and Cinchona pubescens, and in some other plants, such as Remijia peruviana. Cinchonine has been historically used as an anti-malarial agent. It also has a wide range of other biological properties, including anti-cancer, anti-obesity, anti-inflammatory, anti-parasitic, antimicrobial, anti-platelet aggregation, and anti-osteoclast differentiation. AIM AND OBJECTIVE This review discusses the pharmacological activity of cinchonine under different experimental conditions, including in silico, in vitro, and in vivo. It also covers the compound's physicochemical properties, toxicological aspects, and pharmacokinetics. METHODOLOGY A comprehensive literature search was conducted on multiple online databases, such as PubMed, Scopus, and Google Scholar. The aim was to retrieve a wide range of review/research papers and bibliographic sources. The process involved applying exclusion and inclusion criteria to ensure the selection of relevant and high-quality papers. RESULTS Cinchonine has numerous pharmacological properties, making it a promising compound for various therapeutic applications. It induces anti-cancer activity by activating caspase-3 and PARP-1, and triggers the endoplasmic reticulum stress response. It up-regulates GRP78 and promotes the phosphorylation of PERK and ETIF-2α. Cinchonine also inhibits osteoclastogenesis, inhibiting TAK1 activation and suppressing NFATc1 expression by regulating AP-1 and NF-κB. Its potential anti-inflammatory effects reduce the impact of high-fat diets, making it suitable for targeting obesity-related diseases. However, research on cinchonine is limited, and further studies are needed to fully understand its therapeutic potential. Further investigation is needed to ensure its safety and efficacy in clinical applications. CONCLUSION Overall, this review article explains the pharmacological activity of cinchonine, its synthesis, and physicochemical properties, toxicological aspects, and pharmacokinetics.
Collapse
Affiliation(s)
- Shahnaz Parveen
- Bioprospection and Product Development Division, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, 226015, Uttar Pradesh, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, Uttar Pradesh, India
| | - Nidhi Maurya
- Bioprospection and Product Development Division, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, 226015, Uttar Pradesh, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, Uttar Pradesh, India
| | - Abha Meena
- Bioprospection and Product Development Division, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, 226015, Uttar Pradesh, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, Uttar Pradesh, India
| | - Suaib Luqman
- Bioprospection and Product Development Division, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, 226015, Uttar Pradesh, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, Uttar Pradesh, India
| |
Collapse
|
2
|
Duay SS, Yap RCY, Gaitano AL, Santos JAA, Macalino SJY. Roles of Virtual Screening and Molecular Dynamics Simulations in Discovering and Understanding Antimalarial Drugs. Int J Mol Sci 2023; 24:ijms24119289. [PMID: 37298256 DOI: 10.3390/ijms24119289] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 05/16/2023] [Accepted: 05/23/2023] [Indexed: 06/12/2023] Open
Abstract
Malaria continues to be a global health threat, with approximately 247 million cases worldwide. Despite therapeutic interventions being available, patient compliance is a problem due to the length of treatment. Moreover, drug-resistant strains have emerged over the years, necessitating urgent identification of novel and more potent treatments. Given that traditional drug discovery often requires a great deal of time and resources, most drug discovery efforts now use computational methods. In silico techniques such as quantitative structure-activity relationship (QSAR), docking, and molecular dynamics (MD) can be used to study protein-ligand interactions and determine the potency and safety profile of a set of candidate compounds to help prioritize those tested using assays and animal models. This paper provides an overview of antimalarial drug discovery and the application of computational methods in identifying candidate inhibitors and elucidating their potential mechanisms of action. We conclude with the continued challenges and future perspectives in the field of antimalarial drug discovery.
Collapse
Affiliation(s)
- Searle S Duay
- Department of Chemistry, De La Salle University, Manila 0922, Philippines
| | - Rianne Casey Y Yap
- Department of Chemistry, De La Salle University, Manila 0922, Philippines
| | - Arturo L Gaitano
- Chemistry Department, Adamson University, Manila 1000, Philippines
| | | | | |
Collapse
|
3
|
Domes R, Frosch T. Investigations on the Novel Antimalarial Ferroquine in Biomimetic Solutions Using Deep UV Resonance Raman Spectroscopy and Density Functional Theory. Anal Chem 2023; 95:7630-7639. [PMID: 37141178 DOI: 10.1021/acs.analchem.3c00539] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Deep ultraviolet (DUV) resonance Raman experiments are performed, investigating the novel, promising antimalarial ferroquine (FQ). Two buffered aqueous solutions with pH values of 5.13 and 7.00 are used, simulating the acidic and neutral conditions inside a parasite's digestive vacuole and cytosol, respectively. To imitate the different polarities of the membranes and interior, the buffer's 1,4-dioxane content was increased. These experimental conditions should mimic the transport of the drug inside malaria-infected erythrocytes through parasitophorous membranes. Supporting density functional theory (DFT) calculations on the drug's micro-speciation were performed, which could be nicely assigned to shifts in the peak positions of resonantly enhanced high-wavenumber Raman signals at λexc = 257 nm. FQ is fully protonated in polar mixtures like the host interior and the parasite's cytoplasm or digestive vacuole (DV) and is only present as a free base in nonpolar ones, such as the host's and parasitophorous membranes. Additionally, the limit of detection (LoD) of FQ at vacuolic pH values was determined using DUV excitation wavelengths at 244 and 257 nm. By applying the resonant laser line at λexc = 257 nm, a minimal FQ concentration of 3.1 μM was detected, whereas the pre-resonant excitation wavelength 244 nm provides an LoD of 6.9 μM. These values were all up to one order of magnitude lower than the concentration found for the food vacuole of a parasitized erythrocyte.
Collapse
Affiliation(s)
- Robert Domes
- Leibniz Institute of Photonic Technology, Albert-Einstein Strasse 9, 07751 Jena, Germany
| | - Torsten Frosch
- Leibniz Institute of Photonic Technology, Albert-Einstein Strasse 9, 07751 Jena, Germany
- Biophotonics and Biomedical Engineering Group, Technical University Darmstadt, Merckstrasse 25, 64283 Darmstadt, Germany
| |
Collapse
|
4
|
D’Acquarica I, Agranat I. The Quest for Secondary Pharmaceuticals: Drug Repurposing/Chiral-Switches Combination Strategy. ACS Pharmacol Transl Sci 2023; 6:201-219. [PMID: 36798472 PMCID: PMC9926527 DOI: 10.1021/acsptsci.2c00151] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Indexed: 01/19/2023]
Abstract
Drug repurposing toward new medical uses and chiral switches are elements of secondary pharmaceuticals. The drug repurposing and chiral-switches strategies have mostly been applied independently in drug discovery. Drug repurposing has peaked in the search for therapeutic treatments of the Coronavirus Disease 2019 pandemic, whereas chiral switches have been overlooked. The current Perspective introduces the drug repurposing/chiral-switches combination strategy, overviewing representative cases of chiral drugs that have undergone this combination: ketamine, flurbiprofen, fenfluramine, and milnacipran. The deuterium-enabled chiral switches of racemic thalidomide analogs, a variation of the repurposing/chiral-switch combination strategy, is also included. Patenting and regulatory-exclusivity considerations of the combination strategy in the discovery of new medical uses are considered. The proposed combination creates a new synergy of its two elements, overcoming arguments against chiral switches, with better prospects for validation of patents and regulatory exclusivities. The combination strategy may be applied to chiral switches to paired enantiomers. Repurposing/chiral-switch drugs may be 'obvious-to-try'; however, their inventions may be unexpected and their patents nonobvious. Patenting repurposing/chiral-switch combination drugs is not 'evergreening', 'product hopping', and 'me-too'. The expected benefits and opportunities of the combined repurposing/chiral-switch strategy vis-à-vis its two elements are superior pharmacological properties, overcoming arguments against patent validities, challenges of chiral-switch patents, reduced expenses, shortened approval procedures, and higher expectations of regulatory exclusivities.
Collapse
Affiliation(s)
- Ilaria D’Acquarica
- Dipartimento
di Chimica e Tecnologie del Farmaco, Sapienza
Università di Roma, 00185 Rome, Italy
| | - Israel Agranat
- Organic
Chemistry, Institute of Chemistry, The Hebrew
University of Jerusalem, Edmond J. Safra Campus, Jerusalem 9190401, Israel
| |
Collapse
|
5
|
Virendra SA, Sahu C, Kumar A, Chawla PA. Natural Antioxidants as Additional Weapons in the Fight against Malarial Parasite. Curr Top Med Chem 2022; 22:2045-2067. [PMID: 35524663 DOI: 10.2174/1568026622666220504172655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 03/17/2022] [Accepted: 03/18/2022] [Indexed: 12/15/2022]
Abstract
BACKGROUND All currently available antimalarial drugs are developed from natural product lineages that may be traced back to herbal medicines, including quinine, lapachol, and artemisinin. Natural products that primarily target free radicals or reactive oxygen species, play an important role in treating malaria. OBJECTIVES This review analyses the role of antioxidative therapy in treating malaria by scavenging or countering free radicals and reviews the importance of natural plant extracts as antioxidants in oxidative therapy of malaria treatment. METHODS The search for natural antioxidants was conducted using the following databases: ResearchGate, ScienceDirect, Google Scholar, and Bentham Science with the keywords malaria, reactive oxygen species, natural antioxidants, and antiplasmodial. CONCLUSION This study reviewed various literature sources related to natural products employed in antimalarial therapy directly or indirectly by countering/scavenging reactive oxygen species published between 2016 till date. The literature survey made it possible to summarize the natural products used in treating malaria, emphasizing botanical extracts as a single component and in association with other botanical extracts. Natural antioxidants like polyphenols, flavonoids, and alkaloids, have a broad range of biological effects against malaria. This review is pivoted around natural antioxidants obtained from food and medicinal plants and explores their application in restraining reactive oxygen species (ROS). We anticipate this article will provide information for future research on the role of antioxidant therapy in malaria infection.
Collapse
Affiliation(s)
- Sharma Arvind Virendra
- Department of Pharmaceutical Chemistry, ISF College of Pharmacy, Moga-142001, Punjab, India
| | - Chandrakant Sahu
- Department of Pharmaceutical Chemistry, ISF College of Pharmacy, Moga-142001, Punjab, India
| | - Ankur Kumar
- Department of Pharmaceutical Chemistry, ISF College of Pharmacy, Moga-142001, Punjab, India
| | - Pooja Abrol Chawla
- Department of Pharmaceutical Chemistry, ISF College of Pharmacy, Moga-142001, Punjab, India
| |
Collapse
|
6
|
4-Aminoquinoline-Based Adamantanes as Potential Anticholinesterase Agents in Symptomatic Treatment of Alzheimer's Disease. Pharmaceutics 2022; 14:pharmaceutics14061305. [PMID: 35745878 PMCID: PMC9229919 DOI: 10.3390/pharmaceutics14061305] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 06/14/2022] [Accepted: 06/16/2022] [Indexed: 12/03/2022] Open
Abstract
Considering that acetylcholinesterase (AChE) inhibition is the most important mode of action expected of a potential drug used for the treatment of symptoms of Alzheimer’s disease (AD), our previous pilot study of 4-aminoquinolines as potential human cholinesterase inhibitors was extended to twenty-two new structurally distinct 4-aminoquinolines bearing an adamantane moiety. Inhibition studies revealed that all of the compounds were very potent inhibitors of AChE and butyrylcholinesterase (BChE), with inhibition constants (Ki) ranging between 0.075 and 25 µM. The tested compounds exhibited a modest selectivity between the two cholinesterases; the most selective for BChE was compound 14, which displayed a 10 times higher preference, while compound 19 was a 5.8 times more potent inhibitor of AChE. Most of the compounds were estimated to be able to cross the blood–brain barrier (BBB) by passive transport. Evaluation of druglikeness singled out fourteen compounds with possible oral route of administration. The tested compounds displayed modest but generally higher antioxidant activity than the structurally similar AD drug tacrine. Compound 19 showed the highest reducing power, comparable to those of standard antioxidants. Considering their simple structure, high inhibition of AChE and BChE, and ability to cross the BBB, 4-aminoquinoline-based adamantanes show promise as structural scaffolds for further design of novel central nervous system drugs. Among them, two compounds stand out: compound 5 as the most potent inhibitor of both cholinesterases with a Ki constant in low nano molar range and the potential to cross the BBB, and compound 8, which met all our requirements, including high cholinesterase inhibition, good oral bioavailability, and antioxidative effect. The QSAR model revealed that AChE and BChE inhibition was mainly influenced by the ring and topological descriptors MCD, Nnum, RP, and RSIpw3, which defined the shape, conformational flexibility, and surface properties of the molecules.
Collapse
|
7
|
Divya IS, Amrutha S, SeethaLekshmi S, Varughese S. Molecular salts of quinine: a crystal engineering route to enhance the aqueous solubility. CrystEngComm 2021. [DOI: 10.1039/d1ce00791b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Salts of quinine, with α,ω-aliphatic dicarboxylic acids, and aromatic coformers, show superior aqueous solubility. The structural, thermal and microscopy data provide structural, compositional, and stability profiles of the salts.
Collapse
Affiliation(s)
- Indira S. Divya
- Chemical Science and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Trivandrum 695019, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Surendran Amrutha
- Chemical Science and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Trivandrum 695019, India
| | - Sunil SeethaLekshmi
- Chemical Science and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Trivandrum 695019, India
| | - Sunil Varughese
- Chemical Science and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Trivandrum 695019, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| |
Collapse
|
8
|
El‐Mesery M, Seher A, El‐Shafey M, El‐Dosoky M, Badria FA. Repurposing of quinoline alkaloids identifies their ability to enhance doxorubicin‐induced sub‐G0/G1 phase cell cycle arrest and apoptosis in cervical and hepatocellular carcinoma cells. Biotechnol Appl Biochem 2020; 68:832-840. [DOI: 10.1002/bab.1999] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/27/2020] [Indexed: 12/24/2022]
Affiliation(s)
- Mohamed El‐Mesery
- Department of Biochemistry, Faculty of Pharmacy Mansoura University Mansoura Egypt
| | - Axel Seher
- Department of Oral and Maxillofacial Plastic Surgery University Hospital Wuerzburg Wuerzburg Germany
| | - Mohamed El‐Shafey
- Department of Anatomy and Embryology, Faculty of Medicine Mansoura University Egypt
- Physiological Sciences Department Fakeeh College for Medical Sciences Jeddah Saudi Arabia
| | - Mohamed El‐Dosoky
- Department of Neuroscience Technology, College of Applied Medical Science in Jubail Imam Abdulalrahman Bin Faisal University Dammam Saudi Arabia
| | - Farid A Badria
- Department of Pharmacognosy, Faculty of Pharmacy Mansoura University Egypt
| |
Collapse
|
9
|
Joshi MC, Egan TJ. Quinoline Containing Side-chain Antimalarial Analogs: Recent Advances and Therapeutic Application. Curr Top Med Chem 2020; 20:617-697. [DOI: 10.2174/1568026620666200127141550] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 10/25/2019] [Accepted: 10/30/2019] [Indexed: 01/16/2023]
Abstract
The side-chains of quinoline antimalarial agents are the major concern of focus to build
novel and efficaciaous bioactive and clinical antimalarials. Bioative antimalarial analogs may play a
critical role in pH trapping in the food vacuole of RBC’s with the help of fragmented amino acid, thus
lead to β-hematin inhibition. Here, the authors tried to summarize a useful, comprehensive compilation
of side-chain modified ACQs along with their synthesis, biophysical and therapeutic applications etc.
of potent antiplasmodial agents and therefore, opening the door towards the potential clinical status.
Collapse
Affiliation(s)
- Mukesh C. Joshi
- Department of Chemistry, Motilal Nehru College, Benito Juarez Marg, South Campus, University of Delhi, New Delhi- 110021, India
| | - Timothy J. Egan
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| |
Collapse
|
10
|
Alia JD, Karl S, Kelly TD. Quantum Chemical Lipophilicities of Antimalarial Drugs in Relation to Terminal Half-Life. ACS OMEGA 2020; 5:6500-6515. [PMID: 32258886 PMCID: PMC7114756 DOI: 10.1021/acsomega.9b04140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 03/09/2020] [Indexed: 06/11/2023]
Abstract
According to the WHO, artemisinin-based combination therapies (ACTs) have been integral to the recent reduction in deaths due to Plasmodium falciparum malaria. ACT-resistant strains are an emerging problem and have evolved altered developmental stages, reducing exposure of the most susceptible stages to artemisinin drugs in popular ACTs. Lipophilicity, log K ow, is a guide in understanding and predicting pharmacokinetic properties such as terminal half-life which alters drug exposure. Consistent log K ow values are not necessarily available for artemisinin derivatives designed to extend terminal half-life, increase bioavailability, and reduce neurotoxicity. For other drugs used in ACTs, an assortment of experimental and computational log K ow values are available in the literature and in some cases, do not account for subtle but important differences between closely related structures such as between diastereomers. Quantum chemical methods such as density functional theory (DFT) used with an implicit solvent model allow for consistent comparison of physical properties including log K ow and distinguish between closely related structures. To this end, DFT, B3LYP/6-31G(d), with an implicit solvent model (SMD) was used to compute ΔG ow o and ΔG vow o for 1-octanol-water and olive oil-water partitions, respectively, for 21 antimalarial drugs: 12 artemisinin-based, 4 4-aminoquinolines and structurally similar pyronaridine, and 4 amino alcohols. The computed ΔG ow o was close to ΔG ow o calculated from experimental log K ow values from the literature where available, with a mean signed error of 2.3 kJ/mol and mean unsigned error of 3.7 kJ/mol. The results allow assignment of log K ow for α-and β-diastereomers of arteether, and prediction of log K ow for β-DHA and five experimental drugs. Linear least square analysis of log K ow and log K vow versus terminal elimination half-life showed strong linear relationships, once the data points for the 4-aminoquinoline drugs, mefloquine and pyronaridine were found to follow their own linear relationship, which is consistent with their different plasma protein binding. The linear relationship between the computed log K vow and terminal elimination half-life was particularly strong, R 2 = 0.99 and F = 467, and can be interpreted in terms of a simple pharmacokinetic model. Terminal elimination half-life for β-DHA and four experimental artemisinin drugs were estimated based on this linear relationship between log K vow and terminal t 1/2. The computed log K ow and log K vow values for epimers α- and β-DHA and α and β-arteether provide physical data that may be helpful in understanding their different pharmacokinetics and activity based on their different molecular geometries. Relative solubility of quinine and quinidine are found to be sensitive to thermal corrections to enthalpy and to vibrational entropy and do not follow the general trend of longer terminal t 1/2 with greater predicted log K ow. Geometric relaxation of α- and β-DHA in solvent and inclusion of thermal correction for enthalpy and entropy results in correct prediction that α-DHA is favored in aqueous environments compared to β-DHA. Predictions made regarding experimental drugs have implications regarding their potential use in response to artemisinin drug-resistant strains.
Collapse
Affiliation(s)
- Joseph D. Alia
- Division of Science and Mathematics, University of Minnesota Morris, 600 E 4th Street, Morris, Minnesota 56267, United States
| | - Sheila Karl
- Division of Science and Mathematics, University of Minnesota Morris, 600 E 4th Street, Morris, Minnesota 56267, United States
| | - Tyler D. Kelly
- Division of Science and Mathematics, University of Minnesota Morris, 600 E 4th Street, Morris, Minnesota 56267, United States
| |
Collapse
|
11
|
Moles E, Kavallaris M, Fernàndez-Busquets X. Modeling the Distribution of Diprotic Basic Drugs in Liposomal Systems: Perspectives on Malaria Nanotherapy. Front Pharmacol 2019; 10:1064. [PMID: 31611785 PMCID: PMC6773836 DOI: 10.3389/fphar.2019.01064] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 08/20/2019] [Indexed: 01/16/2023] Open
Abstract
Understanding how polyprotic compounds distribute within liposome (LP) suspensions is of major importance to design effective drug delivery strategies. Advances in this research field led to the definition of LP-based active drug encapsulation methods driven by transmembrane pH gradients with evidenced efficacy in the management of cancer and infectious diseases. An accurate modeling of membrane-solution drug partitioning is also fundamental when designing drug delivery systems for poorly endocytic cells, such as red blood cells (RBCs), in which the delivered payloads rely mostly on the passive diffusion of drug molecules across the cell membrane. Several experimental models have been proposed so far to predict the partitioning of polyprotic basic/acid drugs in artificial membranes. Nevertheless, the definition of a model in which the membrane-solution partitioning of each individual drug microspecies is studied relative to each other is still a topic of ongoing research. We present here a novel experimental approach based on mathematical modeling of drug encapsulation efficiency (EE) data in liposomal systems by which microspecies-specific partition coefficients are reported as a function of pH and phospholipid compositions replicating the RBC membrane in a simple and highly translatable manner. This approach has been applied to the study of several diprotic basic antimalarials of major clinical importance (quinine, primaquine, tafenoquine, quinacrine, and chloroquine) describing their respective microspecies distribution in phosphatidylcholine-LP suspensions. Estimated EE data according to the model described here closely fitted experimental values with no significant differences obtained in 75% of all pH/lipid composition-dependent conditions assayed. Additional applications studied include modeling drug EE in LPs in response to transmembrane pH gradients and lipid bilayer asymmetric charge, conditions of potential interest reflected in our previously reported RBC-targeted antimalarial nanotherapeutics.
Collapse
Affiliation(s)
- Ernest Moles
- Children's Cancer Institute, Lowy Cancer Research Centre, UNSW Sydney, Randwick, NSW, Australia.,School of Women's and Children's Health, UNSW Sydney, Sydney, NSW, Australia.,ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Australian Centre for NanoMedicine, UNSW Sydney, Sydney, NSW, Australia
| | - Maria Kavallaris
- Children's Cancer Institute, Lowy Cancer Research Centre, UNSW Sydney, Randwick, NSW, Australia.,School of Women's and Children's Health, UNSW Sydney, Sydney, NSW, Australia.,ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Australian Centre for NanoMedicine, UNSW Sydney, Sydney, NSW, Australia
| | - Xavier Fernàndez-Busquets
- Nanomalaria Group, Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Barcelona, Spain.,Barcelona Institute for Global Health (ISGlobal, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain.,Nanoscience and Nanotechnology Institute (IN2UB), University of Barcelona, Barcelona, Spain
| |
Collapse
|
12
|
Tripathi M, Taylor D, Khan SI, Tekwani BL, Ponnan P, Das US, Velpandian T, Rawat DS. Hybridization of Fluoro-amodiaquine (FAQ) with Pyrimidines: Synthesis and Antimalarial Efficacy of FAQ-Pyrimidines. ACS Med Chem Lett 2019; 10:714-719. [PMID: 31097988 DOI: 10.1021/acsmedchemlett.8b00496] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 03/13/2019] [Indexed: 01/25/2023] Open
Abstract
To evade the possible toxicity associated with the formation of quinone-imine metabolite in amodiaquine (AQ), the para-hydroxyl group was replaced with a -F atom, and the resulting 4'-fluoro-amodiaquine (FAQ) was hybridized with substituted pyrimidines. The synthesized FAQ-pyrimidines displayed better in vitro potency than chloroquine (CQ) against the resistant P. falciparum strain (Dd2), exhibiting up to 47.3-fold better activity (IC50: 4.69 nM) than CQ (IC50: 222 nM) and 2.8-fold better potency than artesunate (IC50: 13.0 nM). Twelve compounds exhibited better antiplasmodial activity than CQ against the CQ-sensitive (NF54) strain. Two compounds were evaluated in vivo against a P. berghei-mouse malaria model. Mechanistic heme-binding studies, computational docking studies against Pf-DHFR and in vitro microsomal stability studies were performed for the representative molecules of the series to assess their antimalarial efficacy.
Collapse
Affiliation(s)
- Mohit Tripathi
- Department of Chemistry, University of Delhi, Delhi 110007, India
| | - Dale Taylor
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Rondebosch 7700, South Africa
| | - Shabana I. Khan
- National Center for Natural Products Research, University of Mississippi, Oxford, Mississippi 38677, United States
| | - Babu L. Tekwani
- National Center for Natural Products Research, University of Mississippi, Oxford, Mississippi 38677, United States
| | - Prija Ponnan
- Department of Chemistry, University of Delhi, Delhi 110007, India
| | - Ujjalkumar Subhash Das
- Department of Ocular Pharmacology, Dr. R.P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar East, Aurobindo Marg, New Delhi 110029, India
| | - Thirumurthy Velpandian
- Department of Ocular Pharmacology, Dr. R.P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar East, Aurobindo Marg, New Delhi 110029, India
| | - Diwan S. Rawat
- Department of Chemistry, University of Delhi, Delhi 110007, India
| |
Collapse
|
13
|
Abdalla MA, McGaw LJ. Bioprospecting of South African Plants as a Unique Resource for Bioactive Endophytic Microbes. Front Pharmacol 2018; 9:456. [PMID: 29867466 PMCID: PMC5966565 DOI: 10.3389/fphar.2018.00456] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 04/18/2018] [Indexed: 01/02/2023] Open
Abstract
South Africa has a long history and strong belief in traditional herbal medicines. Using ethnobotanical knowledge as a lead, a large number of South African medicinal plants have been discovered to possess a wide spectrum of pharmacological properties. In this review, bioprospecting of endophytes is highlighted by following the advantages of the ethnomedicinal approach together with identifying unique medicinal plants where biological activity may be due to endophytes. This review focuses on the current status of South African medicinal plants to motivate the research community to harness the benefits of ethnobotanical knowledge to investigate the presence of endophytic microbes from the most potent South African medicinal plants. The potential chemical diversity and subsequent putative medicinal value of endophytes is deserving of further research. A timely and comprehensive review of literature on recently isolated endophytes and their metabolites was conducted. Worldwide literature from the last 2 years demonstrating the importance of ethnobotanical knowledge as a useful approach to discover endophytic microbes was documented. Information was obtained from scientific databases such as Pubmed, Scopus, Scirus, Google Scholar, Dictionary of Natural Products, Chemical Abstracts Services, official websites, and scientific databases on ethnomedicines. Primary sources such as books, reports, dissertations, and thesises were accessed where available. Recently published information on isolated endophytes with promising bioactivity and their bioactive natural products worldwide (2015-2017) was summarized. The potential value of South African medicinal plants as sources of endophytes is discussed. The insights provided through this study indicate that medicinal plants in South Africa are highly under-investigated sources of potentially useful endophytic microbes. New approaches may be used by medicinal plant scientists for further exploration of natural products from endophytic fungi and bacteria in southern Africa.
Collapse
Affiliation(s)
| | - Lyndy J. McGaw
- Phytomedicine Programme, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| |
Collapse
|
14
|
Murauer A, Ganzera M. Quantitative determination of major alkaloids in Cinchona bark by Supercritical Fluid Chromatography. J Chromatogr A 2018; 1554:117-122. [PMID: 29699870 PMCID: PMC6193530 DOI: 10.1016/j.chroma.2018.04.038] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 04/12/2018] [Accepted: 04/15/2018] [Indexed: 12/21/2022]
Abstract
Chinoline alkaloids found in Cinchona bark still play an important role in medicine, for example as antimalarial and antiarrhythmic drugs. For the first time Supercritical Fluid Chromatography has been utilized for their separation. Six respective derivatives (dihydroquinidine, dihydroquinine, quinidine, quinine, cinchonine and cinchonidine) could be resolved in less than 7 min, and three of them quantified in crude plant extracts. The optimum stationary phase showed to be an Acquity UPC2 Torus DEA 1.7 μm column, the mobile phase comprised of CO2, acetonitrile, methanol and diethylamine. Method validation confirmed that the procedure is selective, accurate (recovery rates from 97.2% to 103.7%), precise (intra-day ≤2.2%, inter-day ≤3.0%) and linear (R2 ≥ 0.999); at 275 nm the observed detection limits were always below 2.5 μg/ml. In all of the samples analyzed cinchonine dominated (1.87%-2.30%), followed by quinine and cinchonidine. Their total content ranged from 4.75% to 5.20%. These values are in good agreement with published data, so that due to unmatched speed and environmental friendly character SFC is definitely an excellent alternative for the analysis of these important natural products.
Collapse
Affiliation(s)
- Adele Murauer
- Institute of Pharmacy, Pharmacognosy, Center for Molecular Biosciences (CMBI), University of Innsbruck, Innsbruck, Austria
| | - Markus Ganzera
- Institute of Pharmacy, Pharmacognosy, Center for Molecular Biosciences (CMBI), University of Innsbruck, Innsbruck, Austria.
| |
Collapse
|
15
|
Chopra R, Chibale K, Singh K. Pyrimidine-chloroquinoline hybrids: Synthesis and antiplasmodial activity. Eur J Med Chem 2018; 148:39-53. [DOI: 10.1016/j.ejmech.2018.02.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Revised: 01/27/2018] [Accepted: 02/06/2018] [Indexed: 10/18/2022]
|
16
|
Joshi MC, Okombo J, Nsumiwa S, Ndove J, Taylor D, Wiesner L, Hunter R, Chibale K, Egan TJ. 4-Aminoquinoline Antimalarials Containing a Benzylmethylpyridylmethylamine Group Are Active against Drug Resistant Plasmodium falciparum and Exhibit Oral Activity in Mice. J Med Chem 2017; 60:10245-10256. [PMID: 29185748 DOI: 10.1021/acs.jmedchem.7b01537] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Emergence of drug resistant Plasmodium falciparum including artemisinin-tolerant parasites highlights the need for new antimalarials. We have previously shown that dibemequines, 4-amino-7-chloroquinolines with dibenzylmethylamine (dibemethin) side chains, are efficacious. In this study, analogues in which the terminal phenyl group of the dibemethin was replaced with a 2-pyridyl group and in which the 4-amino-7-chloroquinoline was either maintained or replaced with a 4-aminoquinoline-7-carbonitrile were synthesized in an effort to improve druglikeness. These compounds exhibited significantly improved solubility and decreased lipophilicity and were potent against chloroquine-sensitive (NF54) and -resistant (Dd2 and 7G8) P. falciparum strains with 5/6 having IC50 < 100 nM against the NF54 strain. All inhibited both β-hematin (synthetic hemozoin) formation and hemozoin formation in the parasite. Parasitemia was reduced by over 90% in P. berghei infected mice in 3/6 derivatives following oral dosing at 4 × 30 mg/kg, with microsomal metabolic stability data suggesting that this could be attributed to highly active metabolites.
Collapse
Affiliation(s)
- Mukesh C Joshi
- Department of Chemistry, University of Cape Town , Rondebosch 7701, South Africa
| | - John Okombo
- Department of Chemistry, University of Cape Town , Rondebosch 7701, South Africa
| | - Samkele Nsumiwa
- Department of Chemistry, University of Cape Town , Rondebosch 7701, South Africa
| | - Jeffrey Ndove
- Department of Medicine, Division of Clinical Pharmacology, University of Cape Town , Observatory 7925, South Africa
| | - Dale Taylor
- Department of Medicine, Division of Clinical Pharmacology, University of Cape Town , Observatory 7925, South Africa
| | - Lubbe Wiesner
- Department of Medicine, Division of Clinical Pharmacology, University of Cape Town , Observatory 7925, South Africa
| | - Roger Hunter
- Department of Chemistry, University of Cape Town , Rondebosch 7701, South Africa
| | - Kelly Chibale
- Department of Chemistry, University of Cape Town , Rondebosch 7701, South Africa.,South African Medical Research Council Drug Discovery and Development Research Unit, Department of Chemistry and Institute of Infectious Disease and Molecular Medicine, University of Cape Town , Rondebosch 7701, South Africa
| | - Timothy J Egan
- Department of Chemistry, University of Cape Town , Rondebosch 7701, South Africa
| |
Collapse
|
17
|
Reddy D, Choonara YE, Kumar P, Govender M, Indermun S, du Toit LC, Meyer LC, Pillay V. In vivo evaluation of an Ultra-fast Disintegrating Wafer matrix: A molecular simulation approach to the ora-mucoadhesivity. J Drug Deliv Sci Technol 2017. [DOI: 10.1016/j.jddst.2016.12.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
18
|
Zahari A, Ablat A, Sivasothy Y, Mohamad J, Choudhary MI, Awang K. In vitro antiplasmodial and antioxidant activities of bisbenzylisoquinoline alkaloids from Alseodaphne corneri Kosterm. ASIAN PAC J TROP MED 2016; 9:328-332. [DOI: 10.1016/j.apjtm.2016.03.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 02/20/2016] [Accepted: 03/01/2016] [Indexed: 10/22/2022] Open
|
19
|
Ekengard E, Kumar K, Fogeron T, de Kock C, Smith PJ, Haukka M, Monari M, Nordlander E. Pentamethylcyclopentadienyl-rhodium and iridium complexes containing (N^N and N^O) bound chloroquine analogue ligands: synthesis, characterization and antimalarial properties. Dalton Trans 2016; 45:3905-17. [DOI: 10.1039/c5dt03739e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Rhodium and iridium cyclopentadienyl complexes have been examined for anti-malarial activity. Three rhodium complexes are especially active.
Collapse
Affiliation(s)
- Erik Ekengard
- Inorganic Chemistry Research Group
- Chemical Physics
- Center for Chemistry and Chemical Engineering
- Lund University
- SE-221 00 Lund
| | - Kamlesh Kumar
- Inorganic Chemistry Research Group
- Chemical Physics
- Center for Chemistry and Chemical Engineering
- Lund University
- SE-221 00 Lund
| | - Thibault Fogeron
- Inorganic Chemistry Research Group
- Chemical Physics
- Center for Chemistry and Chemical Engineering
- Lund University
- SE-221 00 Lund
| | - Carmen de Kock
- Division of Pharmacology
- Department of Medicine
- University of Cape Town Medical School
- Observatory 7925
- South Africa
| | - Peter J. Smith
- Division of Pharmacology
- Department of Medicine
- University of Cape Town Medical School
- Observatory 7925
- South Africa
| | - Matti Haukka
- Department of Chemistry
- University of Jyväskylä
- Jyväskylä
- Finland
| | - Magda Monari
- Dipartimento di Chimica “G. Ciamician”
- Alma Mater Studiorum Università di Bologna
- 40126 Bologna
- Italy
| | - Ebbe Nordlander
- Inorganic Chemistry Research Group
- Chemical Physics
- Center for Chemistry and Chemical Engineering
- Lund University
- SE-221 00 Lund
| |
Collapse
|
20
|
Ngwuluka NC, Choonara YE, Kumar P, du Toit LC, Modi G, Pillay V. A Co-blended Locust Bean Gum and Polymethacrylate-NaCMC Matrix to Achieve Zero-Order Release via Hydro-Erosive Modulation. AAPS PharmSciTech 2015; 16:1377-89. [PMID: 25956484 DOI: 10.1208/s12249-015-0326-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 04/23/2015] [Indexed: 12/29/2022] Open
Abstract
Locust bean gum (LBG) was blended with a cellulose/methacrylate-based interpolyelectrolyte complex (IPEC) to assess the hydro-erosive influence of addition of a polysaccharide on the disposition and drug delivery properties inherent to IPEC matrix. The addition of LBG modulated the drug (levodopa) release characteristics of the IPEC by reducing excessive swelling and preventing bulk erosion. After 8 h in pH 4.5 dissolution medium, gravimetric analysis established that IPEC tablet matrix eroded by 30% of the initial weight due to bulk erosion while LBG-blended IPEC (LBG-b-IPEC) demonstrated surface erosion accounting to 62% of initial weight (596→226.8 mg). Mathematical modeling of the drug release data depicted a transformation from non-Fickian mechanism (IPEC matrices) to zero-order drug release pattern (LBG-b-IPEC matrices) with the linearity of release profile being close to 1 (R (2) = 0.99). Physicochemical characterizations employing Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) explicated that LBG interacted with IPEC by its hydrophilic groups associating with the existing water-holding bodies of IPEC to produce compact matrices. The lattice atomistic modeling elucidated that LBG acted as a linker with the formation of intra- and intermolecular hydrogen bonds generating a highly stabilized polysaccharide-polyelectrolytic structure which influenced the improved properties observed.
Collapse
|
21
|
Golden EB, Cho HY, Hofman FM, Louie SG, Schönthal AH, Chen TC. Quinoline-based antimalarial drugs: a novel class of autophagy inhibitors. Neurosurg Focus 2015; 38:E12. [PMID: 25727221 DOI: 10.3171/2014.12.focus14748] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Chloroquine (CQ) is a quinoline-based drug widely used for the prevention and treatment of malaria. More recent studies have provided evidence that this drug may also harbor antitumor properties, whereby CQ possesses the ability to accumulate in lysosomes and blocks the cellular process of autophagy. Therefore, the authors of this study set out to investigate whether CQ analogs, in particular clinically established antimalaria drugs, would also be able to exert antitumor properties, with a specific focus on glioma cells. METHODS Toward this goal, the authors treated different glioma cell lines with quinine (QN), quinacrine (QNX), mefloquine (MFQ), and hydroxychloroquine (HCQ) and investigated endoplasmic reticulum (ER) stress-induced cell death, autophagy, and cell death. RESULTS All agents blocked cellular autophagy and exerted cytotoxic effects on drug-sensitive and drug-resistant glioma cells with varying degrees of potency (QNX > MFQ > HCQ > CQ > QN). Furthermore, all quinoline-based drugs killed glioma cells that were highly resistant to temozolomide (TMZ), the current standard of care for patients with glioma. The cytotoxic mechanism involved the induction of apoptosis and ER stress, as indicated by poly(ADP-ribose) polymerase (PARP) cleavage and CHOP/GADD153. The induction of ER stress and resulting apoptosis could be confirmed in the in vivo setting, in which tumor tissues from animals treated with quinoline-based drugs showed increased expression of CHOP/GADD153, along with elevated TUNEL staining, a measure of apoptosis. CONCLUSIONS Thus, the antimalarial compounds investigated in this study hold promise as a novel class of autophagy inhibitors for the treatment of newly diagnosed TMZ-sensitive and recurrent TMZ-resistant gliomas.
Collapse
Affiliation(s)
- Encouse B Golden
- Department of Radiation Oncology, New York University School of Medicine, New York, New York
| | | | | | | | | | | |
Collapse
|
22
|
Alata I, Scuderi D, Lepere V, Steinmetz V, Gobert F, Thiao-Layel L, Le Barbu-Debus K, Zehnacker-Rentien A. Exotic Protonated Species Produced by UV-Induced Photofragmentation of a Protonated Dimer: Metastable Protonated Cinchonidine. J Phys Chem A 2015; 119:10007-15. [DOI: 10.1021/acs.jpca.5b06506] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ivan Alata
- Institut des Sciences
Moléculaires d’Orsay (ISMO), CNRS, Univ Paris-Sud, Université Paris Saclay, F-91405 Orsay, France
| | - Debora Scuderi
- Laboratoire de
Chimie Physique (LCP), CNRS, Univ Paris-Sud, Université Paris Saclay, F-91405 Orsay, France
| | - Valeria Lepere
- Institut des Sciences
Moléculaires d’Orsay (ISMO), CNRS, Univ Paris-Sud, Université Paris Saclay, F-91405 Orsay, France
| | - Vincent Steinmetz
- Laboratoire de
Chimie Physique (LCP), CNRS, Univ Paris-Sud, Université Paris Saclay, F-91405 Orsay, France
| | - Fabrice Gobert
- Laboratoire de
Chimie Physique (LCP), CNRS, Univ Paris-Sud, Université Paris Saclay, F-91405 Orsay, France
| | - Loïc Thiao-Layel
- Laboratoire de
Chimie Physique (LCP), CNRS, Univ Paris-Sud, Université Paris Saclay, F-91405 Orsay, France
| | - Katia Le Barbu-Debus
- Institut des Sciences
Moléculaires d’Orsay (ISMO), CNRS, Univ Paris-Sud, Université Paris Saclay, F-91405 Orsay, France
| | - Anne Zehnacker-Rentien
- Institut des Sciences
Moléculaires d’Orsay (ISMO), CNRS, Univ Paris-Sud, Université Paris Saclay, F-91405 Orsay, France
| |
Collapse
|
23
|
Gildenhuys J, Sammy CJ, Müller R, Streltsov VA, le Roex T, Kuter D, de Villiers KA. Alkoxide coordination of iron(III) protoporphyrin IX by antimalarial quinoline methanols: a key interaction observed in the solid-state and solution. Dalton Trans 2015; 44:16767-77. [PMID: 26335948 DOI: 10.1039/c5dt02671g] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The quinoline methanol antimalarial drug mefloquine is a structural analogue of the Cinchona alkaloids, quinine and quinidine. We have elucidated the single crystal X-ray diffraction structure of the complexes formed between racemic erythro mefloquine and ferriprotoporphyrin IX (Fe(iii)PPIX) and show that alkoxide coordination is a key interaction in the solid-state. Mass spectrometry confirms the existence of coordination complexes of quinine, quinidine and mefloquine to Fe(iii)PPIX in acetonitrile. The length of the iron(iii)-O bond in the quinine and quinidine complexes as determined by Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy unequivocally confirms that coordination of the quinoline methanol compounds to Fe(iii)PPIX occurs in non-aqueous aprotic solution via their benzylic alkoxide functional group. UV-visible spectrophotometric titrations of the low-spin bis-pyridyl-Fe(iii)PPIX complex with each of the quinoline methanol compounds results in the displacement of a single pyridine molecule and subsequent formation of a six-coordinate pyridine-Fe(iii)PPIX-drug complex. We propose that formation of the drug-Fe(iii)PPIX coordination complexes is favoured in a non-aqueous environment, such as that found in lipid bodies or membranes in the malaria parasite, and that their existence may contribute to the mechanism of haemozoin inhibition or other toxicity effects that lead ultimately to parasite death. In either case, coordination is a key interaction to be considered in the design of novel antimalarial drug candidates.
Collapse
Affiliation(s)
- Johandie Gildenhuys
- Stellenbosch University, Department of Chemistry and Polymer Science, Private Bag X1, Matieland, 7602, Stellenbosch, South Africa.
| | | | | | | | | | | | | |
Collapse
|
24
|
Bijukumar D, Choonara YE, Kumar P, du Toit LC, Pillay V. An electro-conductive fluid as a responsive implant for the controlled stimuli-release of diclofenac sodium. Pharm Dev Technol 2015; 21:875-886. [PMID: 26258651 DOI: 10.3109/10837450.2015.1073742] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The purpose of this study was to develop an electro-responsive co-polymeric (ERP) implantable gel from polyethylene glycol (PEG), sodium polystyrene sulphonate (NaPss), polyvinyl alcohol (PVA), and diethyl acetomidomalonate (DAA) for electro-liberation of the model drug diclofenac sodium. Various physicochemical and physicomechanical characterization tests were undertaken on the synthesized drug-free gel (ERP G1) and drug-loaded gel (ERP G2). The ability of the gel to release diclofenac sodium following electrical stimulation was evaluated using a galvanostat while Molecular Mechanics (MM) simulations were performed to elucidate the experimental mechanisms. A stable electro-active gel exhibiting superior cycling stability was produced with desirable rheological properties, rigidity (BHN = 35.4 N ± 0.33 N/mm2; resilience = 10.91 ± 0.11%), thermal properties (Tg ≈ 70 °C; Tc ≈ 200 °C) and homogeneous morphology. "ON-OFF" pursatile gradual drug release (37-94% from t30 min-t180 min) kinetics was observed upon applying electric stimulation intermittently, indicating that drug release from the gel was electrically controlled. Overall, the galvanometric and MM evaluation ascertained the suitability of the PEG/NaPss/PVA ERP-Gel for application as a subcutaneously injectable drug delivery implant.
Collapse
Affiliation(s)
- Divya Bijukumar
- a Wits Advanced Drug Delivery Platform Research Unit, Department of Pharmacy and Pharmacology, School of Therapeutic Sciences, Faculty of Health Sciences, University of the Witwatersrand , Parktown , South Africa
| | - Yahya E Choonara
- a Wits Advanced Drug Delivery Platform Research Unit, Department of Pharmacy and Pharmacology, School of Therapeutic Sciences, Faculty of Health Sciences, University of the Witwatersrand , Parktown , South Africa
| | - Pradeep Kumar
- a Wits Advanced Drug Delivery Platform Research Unit, Department of Pharmacy and Pharmacology, School of Therapeutic Sciences, Faculty of Health Sciences, University of the Witwatersrand , Parktown , South Africa
| | - Lisa C du Toit
- a Wits Advanced Drug Delivery Platform Research Unit, Department of Pharmacy and Pharmacology, School of Therapeutic Sciences, Faculty of Health Sciences, University of the Witwatersrand , Parktown , South Africa
| | - Viness Pillay
- a Wits Advanced Drug Delivery Platform Research Unit, Department of Pharmacy and Pharmacology, School of Therapeutic Sciences, Faculty of Health Sciences, University of the Witwatersrand , Parktown , South Africa
| |
Collapse
|
25
|
Chopra R, de Kock C, Smith P, Chibale K, Singh K. Ferrocene-pyrimidine conjugates: Synthesis, electrochemistry, physicochemical properties and antiplasmodial activities. Eur J Med Chem 2015; 100:1-9. [DOI: 10.1016/j.ejmech.2015.05.043] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 05/26/2015] [Accepted: 05/28/2015] [Indexed: 11/15/2022]
|
26
|
Synthesis, characterization and pharmacological evaluation of ferrocenyl azines and their rhodium(I) complexes. J Organomet Chem 2015. [DOI: 10.1016/j.jorganchem.2015.04.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
27
|
Poulsen CE, Wootton RCR, Wolff A, deMello AJ, Elvira KS. A Microfluidic Platform for the Rapid Determination of Distribution Coefficients by Gravity-Assisted Droplet-Based Liquid–Liquid Extraction. Anal Chem 2015; 87:6265-70. [DOI: 10.1021/acs.analchem.5b01061] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Carl Esben Poulsen
- Department
of Micro- and Nanotechnology, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Robert C. R. Wootton
- Institute
of Chemical and Bioengineering, Department of Chemistry and Applied
Biosciences, ETH Zurich, Zurich, Switzerland
| | - Anders Wolff
- Department
of Micro- and Nanotechnology, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Andrew J. deMello
- Institute
of Chemical and Bioengineering, Department of Chemistry and Applied
Biosciences, ETH Zurich, Zurich, Switzerland
| | - Katherine S. Elvira
- Institute
of Chemical and Bioengineering, Department of Chemistry and Applied
Biosciences, ETH Zurich, Zurich, Switzerland
| |
Collapse
|
28
|
Bouchet A, Klyne J, Piani G, Dopfer O, Zehnacker A. Diastereo-specific conformational properties of neutral, protonated and radical cation forms of (1R,2S)-cis- and (1R,2R)-trans-amino-indanol by gas phase spectroscopy. Phys Chem Chem Phys 2015; 17:25809-21. [DOI: 10.1039/c5cp00576k] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The effects of ionisation and protonation on the geometric and electronic structure of a prototypical aromatic amino-alcohol with two chiral centres are revealed by IR and UV spectroscopy.
Collapse
Affiliation(s)
- Aude Bouchet
- Institut für Optik und Atomare Physik
- Technische Universität Berlin
- D-10623 Berlin
- Germany
| | - Johanna Klyne
- Institut für Optik und Atomare Physik
- Technische Universität Berlin
- D-10623 Berlin
- Germany
| | - Giovanni Piani
- CNRS
- Institut des Sciences Moléculaires d’Orsay (ISMO/UMR8214) and Univ. Paris Sud
- Orsay
- France
- CLUPS (Centre Laser de l’Université Paris Sud/LUMAT FR 2764)
| | - Otto Dopfer
- Institut für Optik und Atomare Physik
- Technische Universität Berlin
- D-10623 Berlin
- Germany
| | - Anne Zehnacker
- CNRS
- Institut des Sciences Moléculaires d’Orsay (ISMO/UMR8214) and Univ. Paris Sud
- Orsay
- France
- CLUPS (Centre Laser de l’Université Paris Sud/LUMAT FR 2764)
| |
Collapse
|
29
|
Zehnacker A. Chirality effects in gas-phase spectroscopy and photophysics of molecular and ionic complexes: contribution of low and room temperature studies. INT REV PHYS CHEM 2014. [DOI: 10.1080/0144235x.2014.911548] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
30
|
Singh K, Kaur H, Smith P, de Kock C, Chibale K, Balzarini J. Quinoline–Pyrimidine Hybrids: Synthesis, Antiplasmodial Activity, SAR, and Mode of Action Studies. J Med Chem 2013; 57:435-48. [DOI: 10.1021/jm4014778] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kamaljit Singh
- Department
of Chemistry, UGC Centre of Advance Study-I, Guru Nanak Dev University, Amritsar, Punjab 143005, India
| | - Hardeep Kaur
- Department
of Chemistry, UGC Centre of Advance Study-I, Guru Nanak Dev University, Amritsar, Punjab 143005, India
| | - Peter Smith
- Division
of Pharmacology, Department of Medicine, University of Cape Town, Observatory 7925, South Africa
| | - Carmen de Kock
- Division
of Pharmacology, Department of Medicine, University of Cape Town, Observatory 7925, South Africa
| | - Kelly Chibale
- Department
of Chemistry, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 701, South Africa
| | - Jan Balzarini
- Rega
Institute for Medical Research, KU Leuven, Minderbroedersstraat 10, B-3000 Leuven, Belgium
| |
Collapse
|
31
|
Antimalarial efficacy of hydroxyethylapoquinine (SN-119) and its derivatives. Antimicrob Agents Chemother 2013; 58:820-7. [PMID: 24247136 DOI: 10.1128/aac.01704-13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Quinine and other cinchona-derived alkaloids, although recently supplanted by the artemisinins (ARTs), continue to be important for treatment of severe malaria. Quinine and quinidine have narrow therapeutic indices, and a safer quinine analog is desirable, particularly with the continued threat of antimalarial drug resistance. Hydroxyethylapoquinine (HEAQ), used at 8 g a day for dosing in humans in the 1930s and halving mortality from bacterial pneumonias, was shown to cure bird malaria in the 1940s and was also reported as treatment for human malaria cases. Here we describe synthesis of HEAQ and its novel stereoisomer hydroxyethylapoquinidine (HEAQD) along with two intermediates, hydroxyethylquinine (HEQ) and hydroxyethylquinidine (HEQD), and demonstrate comparable but elevated antimalarial 50% inhibitory concentrations (IC50) of 100 to 200 nM against Plasmodium falciparum quinine-sensitive strain 3D7 (IC50, 56 nM). Only HEAQD demonstrated activity against quinine-tolerant P. falciparum strains Dd2 and INDO with IC50s of 300 to 700 nM. HEQD had activity only against Dd2 with an IC50 of 313 nM. In the lethal mouse malaria model Plasmodium berghei ANKA, only HEQD had activity at 20 mg/kg of body weight comparable to that of the parent quinine or quinidine drugs measured by parasite inhibition and 30-day survival. In addition, HEQ, HEQD, and HEAQ (IC50 ≥ 90 μM) have little to no human ether-à-go-go-related gene (hERG) channel inhibition expressed in CHO cells compared to HEAQD, quinine, and quinidine (hERG IC50s of 27, 42, and 4 μM, respectively). HEQD more closely resembled quinine in vitro and in vivo for Plasmodium inhibition and demonstrated little hERG channel inhibition, suggesting that further optimization and preclinical studies are warranted for this molecule.
Collapse
|
32
|
A Hybrid Methacrylate-Sodium Carboxymethylcellulose Interpolyelectrolyte Complex: Rheometry and in Silico Disposition for Controlled Drug Release. MATERIALS 2013; 6:4284-4308. [PMID: 28788332 PMCID: PMC5452861 DOI: 10.3390/ma6104284] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 08/13/2013] [Accepted: 08/16/2013] [Indexed: 11/23/2022]
Abstract
The rheological behavioral changes that occurred during the synthesis of an interpolyelectrolyte complex (IPEC) of methacrylate copolymer and sodium carboxymethylcellulose were assessed. These changes were compared with the rheological behavior of the individual polymers employing basic viscosity, yield stress, stress sweep, frequency sweep, temperature ramp as well as creep and recovery testing. The rheological studies demonstrated that the end-product of the complexation of low viscous methacrylate copolymer and entangled solution of sodium carboxymethylcellulose generated a polymer, which exhibited a solid-like behavior with a three-dimensional network. Additionally, the rheological profile of the sodium carboxymethylcellulose and methacrylate copolymer with respect to the effect of various concentrations of acetic acid on the synthesis of the IPEC was elucidated using molecular mechanics energy relationships (MMER) by exploring the spatial disposition of carboxymethylcellulose and methacrylate copolymer with respect to each other and acetic acid. The computational results corroborated well with the experimental in vitro drug release data. Results have shown that the IPEC may be suitable polymeric material for achieving controlled zero-order drug delivery.
Collapse
|
33
|
Sen A, Lepere V, Le Barbu-Debus K, Zehnacker A. How do Pseudoenantiomers Structurally Differ in the Gas Phase? An IR/UV Spectroscopy Study of Jet-Cooled Hydroquinine and Hydroquinidine. Chemphyschem 2013; 14:3559-68. [DOI: 10.1002/cphc.201300643] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Indexed: 11/11/2022]
|
34
|
du Toit LC, Carmichael T, Govender T, Kumar P, Choonara YE, Pillay V. In Vitro, In Vivo, and In Silico Evaluation of the Bioresponsive Behavior of an Intelligent Intraocular Implant. Pharm Res 2013; 31:607-34. [DOI: 10.1007/s11095-013-1184-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 08/09/2013] [Indexed: 11/29/2022]
|
35
|
Mashingaidze F, Choonara YE, Kumar P, du Toit LC, Maharaj V, Buchmann E, Ndesendo VMK, Pillay V. Exploration of the biomacromolecular interactions of an interpenetrating proteo-saccharide hydrogel network at the mucosal interface. J Biomed Mater Res A 2013; 101:3616-29. [PMID: 23996781 DOI: 10.1002/jbm.a.34664] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Revised: 02/01/2013] [Accepted: 02/05/2013] [Indexed: 11/07/2022]
Abstract
The relationship between mucin (MUC) and pectin (PEC) was explored in an attempt to understand the biomacromolecular interactions that occur at mucosal surfaces when mucus membranes are exposed to PEC-based materials. These interactions were explored through techniques, such as attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, SEM imagery of lyophilized MUC-PEC blends, thermodynamic analysis, rheology investigations, and in silico static lattice atomistic simulations using a molecular mechanics energy relationships (MMER) approach. Three types of PEC that had different degrees of esterification and degrees of amidation were investigated at different MUC-PEC mass ratios (1:0, 1:1, 1:4, 1:9, and 0:1). The effect PEG 400 and Ca(2 +) in the MUC-PEC interactions were also studied. ATR-FTIR spectroscopy revealed broadening and strengthening of FTIR peaks at 3363 cm(-1) and between 3000-3650 cm(-1) due to stretching vibrations of the -OH, -COOH groups on MUC and PEC as well as the -N-H group on MUC. This suggested significant intra- and inter-molecular H-bonding. Morphologically, MUC-rich scaffolds were porous, thin, and multidirectional compared with the smooth, rigid, and unidirectional PEC-rich scaffolds. The Flory-Huggins interaction parameter (χ12 ) for all MUC-PEC mass ratios was negative, thus confirming MUC-PEC miscibility and interactions. UV absorbance increased with increasing relative concentration of PEC in the aqueous MUC-PEC dispersions. Furthermore, rheology investigations demonstrated synergistic enhancement in viscosity (η) and dynamic moduli upon the addition of PEG 400 and Ca(2 +) . MMER analysis revealed several key MUC-PEC interactions that corroborated well with the experimental data. Notably, higher esterification and larger mass ratios of PEC yielded greater MUC-PEC interactions.
Collapse
Affiliation(s)
- Felix Mashingaidze
- University of the Witwatersrand, Faculty of Health Sciences, Department of Pharmacy and Pharmacology, 7 York Road, Parktown, 2193, Johannesburg, South Africa
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Du Toit LC, Govender T, Carmichael T, Kumar P, Choonara YE, Pillay V. Design of an Anti-Inflammatory Composite Nanosystem and Evaluation of Its Potential for Ocular Drug Delivery. J Pharm Sci 2013; 102:2780-805. [DOI: 10.1002/jps.23650] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 05/17/2013] [Accepted: 06/10/2013] [Indexed: 12/31/2022]
|
37
|
Johnston D, Kumar P, Choonara YE, du Toit LC, Pillay V. Modulation of the nano-tensile mechanical properties of co-blended amphiphilic alginate fibers as oradurable biomaterials for specialized biomedical application. J Mech Behav Biomed Mater 2013; 23:80-102. [PMID: 23665485 DOI: 10.1016/j.jmbbm.2013.03.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 03/26/2013] [Accepted: 03/28/2013] [Indexed: 01/22/2023]
Abstract
The modulation of the mechanical properties of monolithic fibers by plasticizing and crosslinking enables the dynamic control of the nano-tensile forces, thereby obtaining optimized Young's modulus and ultimate strain for specialized application in the treatment of periodontal disease. In this work, drug-loaded crosslinked and plasticized alginate fibers (cl-PAFs) were prepared by extrusion-gelification with the aim of designing oradurable biomaterials for placement within the periodontal pocket and provide prolonged drug delivery. Mechanical properties of drug-free cl-PAFs were determined using a nanoTensile™ 5000 instrument and subsequently optimized versus the quantity of plasticizer and crosslinker as formulation variables employing a Box-Behnken experimental design strategy. Mechanically optimized fibers obtained (Young's Modulus=314.04 MPa, yield stress=5.80 MPa, ultimate strength=10.05 MPa, ultimate strain=0.29 MPa and toughness=2.39 J cm(-3)) were loaded with the model drugs ciprofloxacin and diclofenac both individually and simultaneously. The Young's modulus of cl-PAFs loaded with either drug individually exhibited a steep decline. However, in the case of cl-PAFs loaded with both drugs simultaneously, Young's modulus regained the original value which may be attributed to the cohesive energy density, porosity and space filling. The effect of various formulation variables on the drug entrapment and release characteristics of the alginate fibers was elucidated at pH 4.0 and pH 6.8. Furthermore, a previously established atomistic computational model based on energy refinements was employed to mechanistically describe the fiber performance. The effect of varying the plasticizer and crosslinking ion concentration on Young's modulus and ultimate strain of the linear elastic polymer matrix and the performance of the ciprofloxacin and/or diclofenac loaded optimized fiber was elucidated and conceptualized using molecular mechanics energy relationships (MMER) via the geometrical conformation and positioning of the molecular architectures.
Collapse
Affiliation(s)
- Deanne Johnston
- University of the Witwatersrand, Faculty of Health Sciences, Department of Pharmacy and Pharmacology, 7 York Road, Parktown, 2193 Johannesburg, South Africa
| | | | | | | | | |
Collapse
|
38
|
Kumar P, Choonara YE, Toit LC, Pillay V. In silico elucidation of the inclusion phenomenon and permeation behavior of a zidovudine–cyclodextrin complex via static lattice atomistic simulation. J INCL PHENOM MACRO 2013. [DOI: 10.1007/s10847-013-0316-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
39
|
Affiliation(s)
- Paloma F. Salas
- Medicinal Inorganic Chemistry
Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia
V6T 1Z1, Canada
| | - Christoph Herrmann
- Medicinal Inorganic Chemistry
Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia
V6T 1Z1, Canada
- Advanced
Applied Physics Solutions, TRIUMF, 4004
Wesbrook Mall, Vancouver, British Columbia
V6T 2A3, Canada
| | - Chris Orvig
- Medicinal Inorganic Chemistry
Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia
V6T 1Z1, Canada
| |
Collapse
|
40
|
Tomar L, Tyagi C, Kumar M, Kumar P, Singh H, Choonara YE, Pillay V. In vivo evaluation of a conjugated poly(lactide-ethylene glycol) nanoparticle depot formulation for prolonged insulin delivery in the diabetic rabbit model. Int J Nanomedicine 2013; 8:505-20. [PMID: 23429428 PMCID: PMC3575164 DOI: 10.2147/ijn.s38011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Indexed: 11/23/2022] Open
Abstract
Poly(ethylene glycol) (PEG) and polylactic acid (PLA)-based copolymeric nanoparticles were synthesized and investigated as a carrier for prolonged delivery of insulin via the parenteral route. Insulin loading was simultaneously achieved with particle synthesis using a double emulsion solvent evaporation technique, and the effect of varied PEG chain lengths on particle size and insulin loading efficiency was determined. The synthesized copolymer and nanoparticles were analyzed by standard polymer characterization techniques of gel permeation chromatography, dynamic light scattering, nuclear magnetic resonance, and transmission electron microscopy. In vitro insulin release studies performed under simulated conditions provided a near zero-order release pattern up to 10 days. In vivo animal studies were undertaken with varied insulin loads of nanoparticles administered subcutaneously to fed diabetic rabbits and, of all doses administered, nanoparticles containing 50 IU of insulin load per kg body weight controlled the blood glucose level within the physiologically normal range of 90-140 mg/dL, and had a prolonged effect for more than 7 days. Histopathological evaluation of tissue samples from the site of injection showed no signs of inflammation or aggregation, and established the nontoxic nature of the prepared copolymeric nanoparticles. Further, the reaction profiles for PLA-COOH and NH(2)-PEGDA-NH(2) were elucidated using molecular mechanics energy relationships in vacuum and in a solvated system by exploring the spatial disposition of various concentrations of polymers with respect to each other. Incorporation of insulin within the polymeric matrix was modeled using Connolly molecular surfaces. The computational results corroborated the experimental and analytical data. The ability to control blood glucose levels effectively coupled with the nontoxic behavior of the nanoparticles indicates that these nanoparticles are a potential candidate for insulin delivery.
Collapse
Affiliation(s)
- Lomas Tomar
- University of the Witwatersrand, Faculty of Health Sciences, Department of Pharmacy and Pharmacology, Johannesburg, Gauteng, South Africa
- Centre for Biomedical Engineering, Indian Institute of Technology, Delhi, India
| | - Charu Tyagi
- University of the Witwatersrand, Faculty of Health Sciences, Department of Pharmacy and Pharmacology, Johannesburg, Gauteng, South Africa
- VSPG College, Chaudhary Charan Singh University, Meerut, India
| | - Manoj Kumar
- Centre for Biomedical Engineering, Indian Institute of Technology, Delhi, India
| | - Pradeep Kumar
- University of the Witwatersrand, Faculty of Health Sciences, Department of Pharmacy and Pharmacology, Johannesburg, Gauteng, South Africa
| | - Harpal Singh
- Centre for Biomedical Engineering, Indian Institute of Technology, Delhi, India
| | - Yahya E Choonara
- University of the Witwatersrand, Faculty of Health Sciences, Department of Pharmacy and Pharmacology, Johannesburg, Gauteng, South Africa
| | - Viness Pillay
- University of the Witwatersrand, Faculty of Health Sciences, Department of Pharmacy and Pharmacology, Johannesburg, Gauteng, South Africa
| |
Collapse
|
41
|
Relative to quinine and quinidine, their 9-epimers exhibit decreased cytostatic activity and altered heme binding but similar cytocidal activity versus Plasmodium falciparum. Antimicrob Agents Chemother 2012; 57:365-74. [PMID: 23114754 DOI: 10.1128/aac.01234-12] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The 9-epimers of quinine (QN) and quinidine (QD) are known to exhibit poor cytostatic potency against P. falciparum (Karle JM, Karle IL, Gerena L, Milhous WK, Antimicrob. Agents Chemother. 36:1538-1544, 1992). We synthesized 9-epi-QN (eQN) and 9-epi-QD (eQD) via Mitsunobu esterification-saponification and evaluated both cytostatic and cytocidal antimalarial activities. Relative to the cytostatic activity of QN and QD, we observed a large decrease in cytostatic activity (higher 50% inhibitory concentration [IC(50)s]) against QN-sensitive strain HB3, QN-resistant strain Dd2, and QN-hypersensitive strain K76I, consistent with previous work. However, we observed relatively small changes in cytocidal activity (the 50% lethal dose), similar to observations with chloroquine (CQ) analogues with a wide range of IC(50)s (see the accompanying paper [A. P. Gorka, J. N. Alumasa, K. S. Sherlach, L. M. Jacobs, K. B. Nickley, J. P. Brower, A. C. de Dios, and P. D. Roepe, Antimicrob. Agents Chemother. 57:356-364, 2013]). Compared to QN and QD, the 9-epimers had significantly reduced hemozoin inhibition efficiency and did not affect pH-dependent aggregation of ferriprotoporphyrin IX (FPIX) heme. Magnetic susceptibility measurements showed that the 9-epimers perturb FPIX monomer-dimer equilibrium in favor of monomer, and UV-visible (VIS) titrations showed that eQN and eQD bind monomer with similar affinity relative to QN and QD. However, unique ring proton shifts in the presence of zinc(II) protoporphyrin IX (ZnPIX) indicate that binding of the 9-epimers to monomeric heme is via a distinct geometry. We isolated eQN- and eQD-FPIX complexes formed under aqueous conditions and analyzed them by mass, fluorescence, and UV-VIS spectroscopies. The 9-epimers produced low-fluorescent adducts with a 2:1 stoichiometry (drug to FPIX) which did not survive electrospray ionization, in contrast to QN and QD complexes. The data offer important insight into the relevance of heme interactions as a drug target for cytostatic versus cytocidal dosages of quinoline antimalarial drugs and further elucidate a surprising structural diversity of quinoline antimalarial drug-heme complexes.
Collapse
|
42
|
Griffin CE, Hoke JM, Samarakoon U, Duan J, Mu J, Ferdig MT, Warhurst DC, Cooper RA. Mutation in the Plasmodium falciparum CRT protein determines the stereospecific activity of antimalarial cinchona alkaloids. Antimicrob Agents Chemother 2012; 56:5356-64. [PMID: 22869567 PMCID: PMC3457399 DOI: 10.1128/aac.05667-11] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Accepted: 07/30/2012] [Indexed: 11/20/2022] Open
Abstract
The Cinchona alkaloids are quinoline aminoalcohols that occur as diastereomer pairs, typified by (-)-quinine and (+)-quinidine. The potency of (+)-isomers is greater than the (-)-isomers in vitro and in vivo against Plasmodium falciparum malaria parasites. They may act by the inhibition of heme crystallization within the parasite digestive vacuole in a manner similar to chloroquine. Earlier studies showed that a K76I mutation in the digestive vacuole-associated protein, PfCRT (P. falciparum chloroquine resistance transporter), reversed the normal potency order of quinine and quinidine toward P. falciparum. To further explore PfCRT-alkaloid interactions in the malaria parasite, we measured the in vitro susceptibility of eight clonal lines of P. falciparum derived from the 106/1 strain, each containing a unique pfcrt allele, to four Cinchona stereoisomer pairs: quinine and quinidine; cinchonidine and cinchonine; hydroquinine and hydroquinidine; 9-epiquinine and 9-epiquinidine. Stereospecific potency of the Cinchona alkaloids was associated with changes in charge and hydrophobicity of mutable PfCRT amino acids. In isogenic chloroquine-resistant lines, the IC(50) ratio of (-)/(+) CA pairs correlated with side chain hydrophobicity of the position 76 residue. Second-site PfCRT mutations negated the K76I stereospecific effects: charge-change mutations C72R or Q352K/R restored potency patterns similar to the parent K76 line, while V369F increased susceptibility to the alkaloids and nullified stereospecific differences between alkaloid pairs. Interactions between key residues of the PfCRT channel/transporter with (-) and (+) alkaloids are stereospecifically determined, suggesting that PfCRT binding plays an important role in the antimalarial activity of quinine and other Cinchona alkaloids.
Collapse
Affiliation(s)
- Carol E. Griffin
- Department of Biological Sciences, Old Dominion University, Norfolk, Virginia, USA
| | - Jonathan M. Hoke
- Department of Biological Sciences, Old Dominion University, Norfolk, Virginia, USA
| | - Upeka Samarakoon
- Eck Institute for Global Health, Department of Biological Sciences, University of Notre Dame, South Bend, Indiana, USA
| | - Junhui Duan
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
| | - Jianbing Mu
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
| | - Michael T. Ferdig
- Eck Institute for Global Health, Department of Biological Sciences, University of Notre Dame, South Bend, Indiana, USA
| | - David C. Warhurst
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Disease, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Roland A. Cooper
- Department of Biological Sciences, Old Dominion University, Norfolk, Virginia, USA
- Department of Natural Sciences and Mathematics, Dominican University of California, San Rafael, California, USA
| |
Collapse
|
43
|
Casagrande M, Barteselli A, Basilico N, Parapini S, Taramelli D, Sparatore A. Synthesis and antiplasmodial activity of new heteroaryl derivatives of 7-chloro-4-aminoquinoline. Bioorg Med Chem 2012; 20:5965-79. [DOI: 10.1016/j.bmc.2012.07.040] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 07/18/2012] [Accepted: 07/22/2012] [Indexed: 10/28/2022]
|
44
|
Mahapatra RK, Behera N, Naik PK. Molecular modeling and evaluation of binding mode and affinity of artemisinin-quinine hybrid and its congeners with Fe-protoporphyrin-IX as a putative receptor. Bioinformation 2012; 8:369-80. [PMID: 22570518 PMCID: PMC3346024 DOI: 10.6026/97320630008369] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 04/16/2012] [Indexed: 11/23/2022] Open
Abstract
A recent rational approach to anti-malarial drug design is characterized as "covalent biotherapy" involves linking of two molecules with individual intrinsic activity into a single agent, thus packaging dual activity into a single hybrid molecule. In view of this background and reported anti malaria synergism between artemisinin and quinine; we describe the computer-assisted docking to predict molecular interaction and binding affinity of Artemisinin-Quinine hybrid and its derivatives with the intraparasitic haeme group of human haemoglobin. Starting from a crystallographic structure of Fe-protoporphyrin-IX, binding modes, orientation of peroxide bridge (Fe-O distance), docking score and interaction energy are predicted using the docking molecular mechanics based on generalized Born/surface area (MM-GBSA) solvation model. Seven new ligands were identified with a favourable glide score (XP score) and binding free energy (ΔG) with reference to the experimental structure from a data set of thirty four hybrid derivatives. The result shows the conformational property of the drug-receptor interaction and may lead to rational design and synthesis of improved potent artemisinin based hybrid antimalarial that target haemozoin formation.
Collapse
Affiliation(s)
- Rajani Kanta Mahapatra
- School of Life Sciences, Sambalpur University, Burla, Odisha-768019, India; School of Biotechnology, KIIT University, Bhubaneswar, Odisha-751024, India.
| | | | | |
Collapse
|
45
|
de Villiers KA, Gildenhuys J, le Roex T. Iron(III) protoporphyrin IX complexes of the antimalarial Cinchona alkaloids quinine and quinidine. ACS Chem Biol 2012; 7:666-71. [PMID: 22276975 DOI: 10.1021/cb200528z] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The antimalarial properties of the Cinchona alkaloids quinine and quinidine have been known for decades. Surprisingly, 9-epiquinine and 9-epiquinidine are almost inactive. A lack of definitive structural information has precluded a clear understanding of the relationship between molecular structure and biological activity. In the current study, we have determined by single crystal X-ray diffraction the structures of the complexes formed between quinine and quinidine and iron(III) protoporphyrin IX (Fe(III)PPIX). Coordination of the alkaloid to the Fe(III) center is a key feature of both complexes, and further stability is provided by an intramolecular hydrogen bond formed between a propionate side chain of Fe(III)PPIX and the protonated quinuclidine nitrogen atom of either alkaloid. These interactions are believed to be responsible for inhibiting the incorporation of Fe(III)PPIX into crystalline hemozoin during its in vivo detoxification. It is also possible to rationalize the greater activity of quinidine compared to that of quinine.
Collapse
Affiliation(s)
- Katherine A. de Villiers
- Department of Chemistry and Polymer Science, Stellenbosch University, Private Bag X1, Stellenbosch
7602, South Africa
| | - Johandie Gildenhuys
- Department of Chemistry and Polymer Science, Stellenbosch University, Private Bag X1, Stellenbosch
7602, South Africa
| | - Tanya le Roex
- Department of Chemistry and Polymer Science, Stellenbosch University, Private Bag X1, Stellenbosch
7602, South Africa
| |
Collapse
|
46
|
Shaikh RP, Kumar P, Choonara YE, du Toit LC, Pillay V. Crosslinked electrospun PVA nanofibrous membranes: elucidation of their physicochemical, physicomechanical and molecular disposition. Biofabrication 2012; 4:025002. [DOI: 10.1088/1758-5082/4/2/025002] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
47
|
Glans L, Ehnbom A, de Kock C, Martínez A, Estrada J, Smith PJ, Haukka M, Sánchez-Delgado RA, Nordlander E. Ruthenium(II) arene complexes with chelating chloroquine analogue ligands: synthesis, characterization and in vitro antimalarial activity. Dalton Trans 2012; 41:2764-73. [PMID: 22249579 PMCID: PMC3303165 DOI: 10.1039/c2dt12083f] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Three new ruthenium complexes with bidentate chloroquine analogue ligands, [Ru(η(6)-cym)(L(1))Cl]Cl (1, cym = p-cymene, L(1) = N-(2-((pyridin-2-yl)methylamino)ethyl)-7-chloroquinolin-4-amine), [Ru(η(6)-cym)(L(2))Cl]Cl (2, L(2) = N-(2-((1-methyl-1H-imidazol-2-yl)methylamino)ethyl)-7-chloroquinolin-4-amine) and [Ru(η(6)-cym)(L(3))Cl] (3, L(3) = N-(2-((2-hydroxyphenyl)methylimino)ethyl)-7-chloroquinolin-4-amine) have been synthesized and characterized. In addition, the X-ray crystal structure of 2 is reported. The antimalarial activity of complexes 1-3 and ligands L(1), L(2) and L(3), as well as the compound N-(2-(bis((pyridin-2-yl)methyl)amino)ethyl)-7-chloroquinolin-4-amine (L(4)), against chloroquine sensitive and chloroquine resistant Plasmodium falciparum malaria strains was evaluated. While 1 and 2 are less active than the corresponding ligands, 3 exhibits high antimalarial activity. The chloroquine analogue L(2) also shows good activity against both the chloroquine sensitive and the chloroquine resistant strains. Heme aggregation inhibition activity (HAIA) at an aqueous buffer/n-octanol interface (HAIR(50)) and lipophilicity (D, as measured by water/n-octanol distribution coefficients) have been measured for all ligands and metal complexes. A direct correlation between the D and HAIR(50) properties cannot be made because of the relative structural diversity of the complexes, but it may be noted that these properties are enhanced upon complexation of the inactive ligand L(3) to ruthenium, to give a metal complex (3) with promising antimalarial activity.
Collapse
Affiliation(s)
- Lotta Glans
- Inorganic Chemistry Research Group, Chemical Physics, Center for Chemistry and Chemical Engineering, Lund University, Box 124, SE-221 00 Lund, Sweden
| | - Andreas Ehnbom
- Inorganic Chemistry Research Group, Chemical Physics, Center for Chemistry and Chemical Engineering, Lund University, Box 124, SE-221 00 Lund, Sweden
| | - Carmen de Kock
- Division of Pharmacology, Department of Medicine, University of Cape Town Medical School, Observatory 7925, South Africa
| | - Alberto Martínez
- Department of Chemistry, Brooklyn College and The Graduate Center, The City University of New York, CUNY, 2900 Bedford Avenue, Brooklyn, New York 11210, U.S.A
| | - Jesús Estrada
- Department of Chemistry, Brooklyn College and The Graduate Center, The City University of New York, CUNY, 2900 Bedford Avenue, Brooklyn, New York 11210, U.S.A
| | - Peter J. Smith
- Division of Pharmacology, Department of Medicine, University of Cape Town Medical School, Observatory 7925, South Africa
| | - Matti Haukka
- Department of Chemistry, University of Eastern Finland, Box 111, FIN-80101 Joensuu, Finland
| | - Roberto A. Sánchez-Delgado
- Department of Chemistry, Brooklyn College and The Graduate Center, The City University of New York, CUNY, 2900 Bedford Avenue, Brooklyn, New York 11210, U.S.A
| | - Ebbe Nordlander
- Inorganic Chemistry Research Group, Chemical Physics, Center for Chemistry and Chemical Engineering, Lund University, Box 124, SE-221 00 Lund, Sweden
| |
Collapse
|
48
|
Abstract
Binding of alkaloids by different hosts (native and modified cyclodextrins, cucurbiturils, calixarenes, and metal complexes of porphyrin and Salphen-type ligands), as well as receptor properties of alkaloid based hosts are reviewed. With alkaloids as guests, the largest binding constants and most significant spectral changes, in particular strong fluorescence enhancements induced by complexation with isoquinoline alkaloids, are observed with cucurbituril hosts. Cyclodextrins are successfully employed for improvement of solubility and for chiral separation of alkaloids of different types. Receptor properties of native and modified cinchona and bisbenzylisoquinoline alkaloids have attracted considerable attention for development of chiral selectors for analysis and separation.
Collapse
|
49
|
Yu XM, Ramiandrasoa F, Guetzoyan L, Pradines B, Quintino E, Gadelle D, Forterre P, Cresteil T, Mahy JP, Pethe S. Synthesis and biological evaluation of acridine derivatives as antimalarial agents. ChemMedChem 2012; 7:587-605. [PMID: 22331612 DOI: 10.1002/cmdc.201100554] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Revised: 01/13/2012] [Indexed: 11/11/2022]
Abstract
New N-alkylaminoacridine derivatives attached to nitrogen heterocycles were synthesized, and their antimalarial potency was examined. They were tested in vitro against the growth of Plasmodium falciparum, including chloroquine (CQ)-susceptible and CQ-resistant strains. This biological evaluation has shown that the presence of a heterocyclic ring significantly increases the activity against P. falciparum. The best compound shows a nanomolar IC(50) value toward parasite proliferation on both CQ-susceptible and CQ-resistant strains. The antimalarial activity of these new acridine derivatives can be explained by the two mechanisms studied in this work. First, we showed the capacity of these compounds to inhibit heme biocrystallization, a detoxification process specific to the parasite and essential for its survival. Second, in our search for alternative targets, we evaluated the in vitro inhibitory activity of these compounds toward Sulfolobus shibatae topoisomerase VI-mediated DNA relaxation. The preliminary results obtained reveal that all tested compounds are potent DNA intercalators, and significantly inhibit the activity of S. shibatae topoisomerase VI at concentrations ranging between 2.0 and 2.5 μM.
Collapse
Affiliation(s)
- Xiao-Min Yu
- Université Paris-Sud 11, Institut de Chimie Moléculaire et des Matériaux d'Orsay, Equipe de Chimie Bioorganique et Bioinorganique, Orsay 91405 CEDEX, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Dos Santos SC, Sá-Correia I. A genome-wide screen identifies yeast genes required for protection against or enhanced cytotoxicity of the antimalarial drug quinine. Mol Genet Genomics 2011; 286:333-46. [PMID: 21960436 DOI: 10.1007/s00438-011-0649-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Accepted: 09/16/2011] [Indexed: 11/28/2022]
Abstract
Quinine is used in the treatment of Plasmodium falciparum severe malaria. However, both the drug's mode of action and mechanisms of resistance are still poorly understood and subject to debate. In an effort to clarify these questions, we used the yeast Saccharomyces cerevisiae as a model for pharmacological studies with quinine. Following on a previous work that examined the yeast genomic expression program in response to quinine, we now explore a genome-wide screen for altered susceptibility to quinine using the EUROSCARF collection of yeast deletion strains. We identified 279 quinine-susceptible strains, among which 112 conferred a hyper-susceptibility phenotype. The expression of these genes, mainly involved in carbohydrate metabolism, iron uptake and ion homeostasis functions, is required for quinine resistance in yeast. Sixty-two genes whose deletion leads to increased quinine resistance were also identified in this screen, including several genes encoding ribosome protein subunits. These well-known potential drug targets in Plasmodium are associated with quinine action for the first time in this study. The suggested involvement of phosphate signaling and transport in quinine tolerance was also studied, and activation of phosphate starvation-responsive genes was observed under a mild-induced quinine stress. Finally, P. falciparum homology searches were performed for a selected group of 41 genes. Thirty-two encoded proteins possess homologs in the parasite, including subunits of a parasitic vacuolar H(+)-ATPase complex, ion and phosphate importers, and several ribosome protein subunits, suggesting that the results obtained in yeast are good candidates to be transposed and explored in a P. falciparum context.
Collapse
Affiliation(s)
- Sandra C Dos Santos
- IBB - Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001, Lisbon, Portugal
| | | |
Collapse
|