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Mambwe D, Coertzen D, Leshabane M, Mulubwa M, Njoroge M, Gibhard L, Girling G, Wicht KJ, Lee MCS, Wittlin S, Moreira DRM, Birkholtz LM, Chibale K. hERG, Plasmodium Life Cycle, and Cross Resistance Profiling of New Azabenzimidazole Analogues of Astemizole. ACS Med Chem Lett 2024; 15:463-469. [PMID: 38628794 PMCID: PMC11017395 DOI: 10.1021/acsmedchemlett.3c00496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 03/01/2024] [Accepted: 03/06/2024] [Indexed: 04/19/2024] Open
Abstract
Toward addressing the cardiotoxicity liability associated with the antimalarial drug astemizole (AST, hERG IC50 = 0.0042 μM) and its derivatives, we designed and synthesized analogues based on compound 1 (Pf NF54 IC50 = 0.012 μM; hERG IC50 = 0.63 μM), our previously identified 3-trifluoromethyl-1,2,4-oxadiazole AST analogue. Compound 11 retained in vitro multistage antiplasmodium activity (ABS PfNF54 IC50 = 0.017 μM; gametocytes PfiGc/PfLGc IC50 = 1.24/1.39 μM, and liver-stage PbHepG2 IC50 = 2.30 μM), good microsomal metabolic stability (MLM CLint < 11 μL·min-1·mg-1, EH < 0.33), and solubility (150 μM). It shows a ∼6-fold and >6000-fold higher selectivity against human ether-á-go-go-related gene higher selectively potential over hERG relative to 1 and AST, respectively. Despite the excellent in vitro antiplasmodium activity profile, in vivo efficacy in the Plasmodium berghei mouse infection model was diminished, attributable to suboptimal oral bioavailability (F = 14.9%) at 10 mg·kg-1 resulting from poor permeability (log D7.4 = -0.82). No cross-resistance was observed against 44 common Pf mutant lines, suggesting activity via a novel mechanism of action.
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Affiliation(s)
- Dickson Mambwe
- Department
of Chemistry, University of Cape Town, Rondebosch, 7701 Cape Town, South Africa
| | - Dina Coertzen
- Department
of Biochemistry, Genetics & Microbiology, Institute for Sustainable
Malaria Control, University of Pretoria, Private Bag X20, Hatfield, 0028 Pretoria, South Africa
| | - Meta Leshabane
- Department
of Biochemistry, Genetics & Microbiology, Institute for Sustainable
Malaria Control, University of Pretoria, Private Bag X20, Hatfield, 0028 Pretoria, South Africa
| | - Mwila Mulubwa
- Drug
Discovery and Development Centre (H3D), DMPK & Pharmacology, University of Cape Town, Observatory, 7925 Cape Town, South Africa
| | - Mathew Njoroge
- Drug
Discovery and Development Centre (H3D), DMPK & Pharmacology, University of Cape Town, Observatory, 7925 Cape Town, South Africa
| | - Liezl Gibhard
- Drug
Discovery and Development Centre (H3D), DMPK & Pharmacology, University of Cape Town, Observatory, 7925 Cape Town, South Africa
| | - Gareth Girling
- Wellcome
Sanger Institute, Wellcome
Trust Genome Campus, Hinxton CB10 1SA, United Kingdom
| | - Kathryn J. Wicht
- Department
of Chemistry, University of Cape Town, Rondebosch, 7701 Cape Town, South Africa
| | - Marcus C. S. Lee
- Wellcome
Sanger Institute, Wellcome
Trust Genome Campus, Hinxton CB10 1SA, United Kingdom
- Biological
Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee DD1 4HN, Scotland, United Kingdom
| | - Sergio Wittlin
- Swiss
Tropical and Public Health Institute, Socinstrasse 57, 4002 Basel, Switzerland
- University
of Basel, 4003 Basel, Switzerland
| | | | - Lyn-Marie Birkholtz
- Department
of Biochemistry, Genetics & Microbiology, Institute for Sustainable
Malaria Control, University of Pretoria, Private Bag X20, Hatfield, 0028 Pretoria, South Africa
| | - Kelly Chibale
- Department
of Chemistry, University of Cape Town, Rondebosch, 7701 Cape Town, South Africa
- Drug
Discovery and Development Centre (H3D), DMPK & Pharmacology, University of Cape Town, Observatory, 7925 Cape Town, South Africa
- South
African Medical Research Council Drug Discovery and Development Research
Unit, University of Cape Town, Rondebosch, 7701 Cape Town, South Africa
- Institute
of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch, 7701 Cape Town, South Africa
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2
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Redhi D, Mulubwa M, Gibhard L, Chibale K. Integrating Pharmacokinetic-Pharmacodynamic Modeling and Physiologically Based Pharmacokinetic Modeling to Optimize Human Dose Predictions for Plasmodium falciparum Malaria: a Chloroquine Case Study. Antimicrob Agents Chemother 2023; 67:e0134522. [PMID: 37010410 PMCID: PMC10190664 DOI: 10.1128/aac.01345-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Accepted: 03/05/2023] [Indexed: 04/04/2023] Open
Abstract
The translation of a preclinical antimalarial drug development candidate to the clinical phases should be supported by rational human dose selection. A model-informed strategy based on preclinical data, which incorporates pharmacokinetic-pharmacodynamic (PK-PD) properties with physiologically based pharmacokinetic (PBPK) modeling, is proposed to optimally predict an efficacious human dose and dosage regimen for the treatment of Plasmodium falciparum malaria. The viability of this approach was explored using chloroquine, which has an extensive clinical history for malaria treatment. First, the PK-PD parameters and the PK-PD driver of efficacy for chloroquine were determined through a dose fractionation study in the P. falciparum-infected humanized mouse model. A PBPK model for chloroquine was then developed for predicting the drug's PK profiles in a human population, from which the human PK parameters were determined. Lastly, the PK-PD parameters estimated in the P. falciparum-infected mouse model and the human PK parameters derived from the PBPK model were integrated to simulate the human dose-response relationships against P. falciparum, which subsequently allowed the determination of an optimized treatment. The predicted efficacious human dose and dosage regimen for chloroquine were comparable to those recommended clinically for the treatment of uncomplicated, drug-sensitive malaria, which provided supportive evidence for the proposed model-based approach to antimalarial human dose predictions.
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Affiliation(s)
- Devasha Redhi
- 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, Cape Town, South Africa
| | - Mwila Mulubwa
- Holistic Drug Discovery and Development (H3D) Centre, University of Cape Town, Cape Town, South Africa
| | - Liezl Gibhard
- Holistic Drug Discovery and Development (H3D) Centre, University of Cape Town, Cape Town, South Africa
| | - Kelly Chibale
- 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, Cape Town, South Africa
- Holistic Drug Discovery and Development (H3D) Centre, University of Cape Town, Cape Town, South Africa
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3
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Matshe WMR, Tshweu LL, Mvango S, Cele ZED, Chetty AS, Pilcher LA, Famuyide IM, McGaw LJ, Taylor D, Gibhard L, Basarab GS, Balogun MO. A Water-Soluble Polymer-Lumefantrine Conjugate for the Intravenous Treatment of Severe Malaria. Macromol Biosci 2023; 23:e2200518. [PMID: 36999404 DOI: 10.1002/mabi.202200518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 03/10/2023] [Indexed: 04/01/2023]
Abstract
Uncomplicated malaria is effectively treated with oral artemisinin-based combination therapy (ACT). Yet, there is an unmet clinical need for the intravenous treatment of the more fatal severe malaria. There is no combination intravenous therapy for uncomplicated due to the nonavailability of a water-soluble partner drug for the artemisinin, artesunate. The currently available treatment is a two-part regimen split into an intravenous artesunate followed by the conventional oral ACT . In a novel application of polymer therapeutics, the aqueous insoluble antimalarial lumefantrine is conjugated to a carrier polymer to create a new water-soluble chemical entity suitable for intravenous administration in a clinically relevant formulation . The conjugate is characterized by spectroscopic and analytical techniques, and the aqueous solubility of lumefantrine is determined to have increased by three orders of magnitude. Pharmacokinetic studies in mice indicate that there is a significant plasma release of lumefantrine and production its metabolite desbutyl-lumefantrine (area under the curve of metabolite is ≈10% that of the parent). In a Plasmodium falciparum malaria mouse model, parasitemia clearance is 50% higher than that of reference unconjugated lumefantrine. The polymer-lumefantrine shows potential for entering the clinic to meet the need for a one-course combination treatment for severe malaria.
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Affiliation(s)
- William M R Matshe
- Bio-Polymer Modification and Therapeutics Laboratory, Centre for Nanostructures and Advanced Materials, CSIR, Pretoria, 0001, South Africa
| | - Lesego L Tshweu
- Bio-Polymer Modification and Therapeutics Laboratory, Centre for Nanostructures and Advanced Materials, CSIR, Pretoria, 0001, South Africa
| | - Sindisiwe Mvango
- Bio-Polymer Modification and Therapeutics Laboratory, Centre for Nanostructures and Advanced Materials, CSIR, Pretoria, 0001, South Africa
- Department of Chemistry, University of Pretoria, Lynnwood Road, Hatfield, Pretoria, 0002, South Africa
| | - Zamani E D Cele
- Bio-Polymer Modification and Therapeutics Laboratory, Centre for Nanostructures and Advanced Materials, CSIR, Pretoria, 0001, South Africa
| | - Avashnee S Chetty
- Bio-Polymer Modification and Therapeutics Laboratory, Centre for Nanostructures and Advanced Materials, CSIR, Pretoria, 0001, South Africa
| | - Lynne A Pilcher
- Department of Chemistry, University of Pretoria, Lynnwood Road, Hatfield, Pretoria, 0002, South Africa
| | - Ibukun M Famuyide
- Phytomedicine Programme, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, Pretoria, 0110, South Africa
| | - Lyndy J McGaw
- Phytomedicine Programme, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, Pretoria, 0110, South Africa
| | - Dale Taylor
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch, Cape Town, 7701, South Africa
| | - Liezl Gibhard
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch, Cape Town, 7701, South Africa
| | - Gregory S Basarab
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch, Cape Town, 7701, South Africa
| | - Mohammed O Balogun
- Bio-Polymer Modification and Therapeutics Laboratory, Centre for Nanostructures and Advanced Materials, CSIR, Pretoria, 0001, South Africa
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4
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Mambwe D, Korkor CM, Mabhula A, Ngqumba Z, Cloete C, Kumar M, Barros PL, Leshabane M, Coertzen D, Taylor D, Gibhard L, Njoroge M, Lawrence N, Reader J, Moreira DR, Birkholtz LM, Wittlin S, Egan TJ, Chibale K. Novel 3-Trifluoromethyl-1,2,4-oxadiazole Analogues of Astemizole with Multi-stage Antiplasmodium Activity and In Vivo Efficacy in a Plasmodium berghei Mouse Malaria Infection Model. J Med Chem 2022; 65:16695-16715. [PMID: 36507890 DOI: 10.1021/acs.jmedchem.2c01516] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Iterative medicinal chemistry optimization of an ester-containing astemizole (AST) analogue 1 with an associated metabolic instability liability led to the identification of a highly potent 3-trifluoromethyl-1,2,4-oxadiazole analogue 23 (PfNF54 IC50 = 0.012 μM; PfK1 IC50 = 0.040 μM) displaying high microsomal metabolic stability (HLM CLint < 11.6 μL·min-1·mg-1) and > 1000-fold higher selectivity over hERG compared to AST. In addition to asexual blood stage activity, the compound also shows activity against liver and gametocyte life cycle stages and demonstrates in vivo efficacy in Plasmodium berghei-infected mice at 4 × 50 mg·kg-1 oral dose. Preliminary interrogation of the mode of action using live-cell microscopy and cellular heme speciation revealed that 23 could be affecting multiple processes in the parasitic digestive vacuole, with the possibility of a novel target at play in the organelles associated with it.
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Affiliation(s)
- Dickson Mambwe
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Constance M Korkor
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Amanda Mabhula
- Drug Discovery and Development Centre (H3D), DMPK & Pharmacology, University of Cape Town, Observatory 7925, South Africa
| | - Zama Ngqumba
- Drug Discovery and Development Centre (H3D), DMPK & Pharmacology, University of Cape Town, Observatory 7925, South Africa
| | - Cleavon Cloete
- Drug Discovery and Development Centre (H3D), DMPK & Pharmacology, University of Cape Town, Observatory 7925, South Africa
| | - Malkeet Kumar
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Paula Ladeia Barros
- Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz (Fiocruz), Instituto Gonçalo Moniz, CEP 40296-710 Salvador, Brazil
| | - Meta Leshabane
- Department of Biochemistry, Genetics & Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield, 0028 Pretoria, South Africa
| | - Dina Coertzen
- Department of Biochemistry, Genetics & Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield, 0028 Pretoria, South Africa
| | - Dale Taylor
- Drug Discovery and Development Centre (H3D), DMPK & Pharmacology, University of Cape Town, Observatory 7925, South Africa
| | - Liezl Gibhard
- Drug Discovery and Development Centre (H3D), DMPK & Pharmacology, University of Cape Town, Observatory 7925, South Africa
| | - Mathew Njoroge
- Drug Discovery and Development Centre (H3D), DMPK & Pharmacology, University of Cape Town, Observatory 7925, South Africa
| | - Nina Lawrence
- Drug Discovery and Development Centre (H3D), DMPK & Pharmacology, University of Cape Town, Observatory 7925, South Africa
| | - Janette Reader
- Department of Biochemistry, Genetics & Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield, 0028 Pretoria, South Africa
| | - Diogo Rodrigo Moreira
- Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz (Fiocruz), Instituto Gonçalo Moniz, CEP 40296-710 Salvador, Brazil
| | - Lyn-Marie Birkholtz
- Department of Biochemistry, Genetics & Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield, 0028 Pretoria, South Africa
| | - Sergio Wittlin
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002 Basel, Switzerland.,University of Basel, 4003 Basel, Switzerland
| | - Timothy J Egan
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa.,Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa
| | - Kelly Chibale
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa.,Drug Discovery and Development Centre (H3D), DMPK & Pharmacology, University of Cape Town, Observatory 7925, South Africa.,South African Medical Research Council Drug Discovery and Development Research Unit, University of Cape Town, Rondebosch 7701, South Africa.,Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa
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5
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Arendse LB, Murithi JM, Qahash T, Pasaje CFA, Godoy LC, Dey S, Gibhard L, Ghidelli-Disse S, Drewes G, Bantscheff M, Lafuente-Monasterio MJ, Fienberg S, Wambua L, Gachuhi S, Coertzen D, van der Watt M, Reader J, Aswat AS, Erlank E, Venter N, Mittal N, Luth MR, Ottilie S, Winzeler EA, Koekemoer LL, Birkholtz LM, Niles JC, Llinás M, Fidock DA, Chibale K. The anticancer human mTOR inhibitor sapanisertib potently inhibits multiple Plasmodium kinases and life cycle stages. Sci Transl Med 2022; 14:eabo7219. [PMID: 36260689 PMCID: PMC9951552 DOI: 10.1126/scitranslmed.abo7219] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Compounds acting on multiple targets are critical to combating antimalarial drug resistance. Here, we report that the human "mammalian target of rapamycin" (mTOR) inhibitor sapanisertib has potent prophylactic liver stage activity, in vitro and in vivo asexual blood stage (ABS) activity, and transmission-blocking activity against the protozoan parasite Plasmodium spp. Chemoproteomics studies revealed multiple potential Plasmodium kinase targets, and potent inhibition of Plasmodium phosphatidylinositol 4-kinase type III beta (PI4Kβ) and cyclic guanosine monophosphate-dependent protein kinase (PKG) was confirmed in vitro. Conditional knockdown of PI4Kβ in ABS cultures modulated parasite sensitivity to sapanisertib, and laboratory-generated P. falciparum sapanisertib resistance was mediated by mutations in PI4Kβ. Parasite metabolomic perturbation profiles associated with sapanisertib and other known PI4Kβ and/or PKG inhibitors revealed similarities and differences between chemotypes, potentially caused by sapanisertib targeting multiple parasite kinases. The multistage activity of sapanisertib and its in vivo antimalarial efficacy, coupled with potent inhibition of at least two promising drug targets, provides an opportunity to reposition this pyrazolopyrimidine for malaria.
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Affiliation(s)
- Lauren B. Arendse
- Drug Discovery and Development Centre (H3D), University of Cape Town, Rondebosch, Cape Town 7701, South Africa
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Observatory, Cape Town 7925, South Africa
- South African Medical Research Council Drug Discovery and Development Research Unit, University of Cape Town, Rondebosch, Cape Town 7701, South Africa
| | - James M. Murithi
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Tarrick Qahash
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
- Huck Center for Malaria Research, Pennsylvania State University, University Park, PA 16802, USA
| | | | - Luiz C. Godoy
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Sumanta Dey
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Liezl Gibhard
- Drug Discovery and Development Centre (H3D), University of Cape Town, Rondebosch, Cape Town 7701, South Africa
| | | | - Gerard Drewes
- Cellzome GmbH, a GSK Company, Heidelberg 69117, Germany
| | | | - Maria J. Lafuente-Monasterio
- Tres Cantos Medicines Development Campus-Diseases of the Developing World, GlaxoSmithKline, Tres Cantos, Madrid 28760, Spain
| | - Stephen Fienberg
- Drug Discovery and Development Centre (H3D), University of Cape Town, Rondebosch, Cape Town 7701, South Africa
- Department of Chemistry, University of Cape Town, Rondebosch, Cape Town 7701, South Africa
| | - Lynn Wambua
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Observatory, Cape Town 7925, South Africa
- Department of Chemistry, University of Cape Town, Rondebosch, Cape Town 7701, South Africa
| | - Samuel Gachuhi
- Department of Chemistry, University of Cape Town, Rondebosch, Cape Town 7701, South Africa
| | - Dina Coertzen
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield 0028, South Africa
| | - Mariëtte van der Watt
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield 0028, South Africa
| | - Janette Reader
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield 0028, South Africa
| | - Ayesha S. Aswat
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg 2193, South Africa
| | - Erica Erlank
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg 2193, South Africa
| | - Nelius Venter
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg 2193, South Africa
| | - Nimisha Mittal
- School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Madeline R. Luth
- School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Sabine Ottilie
- School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | | | - Lizette L. Koekemoer
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg 2193, South Africa
| | - Lyn-Marie Birkholtz
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield 0028, South Africa
| | - Jacquin C. Niles
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Manuel Llinás
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
- Huck Center for Malaria Research, Pennsylvania State University, University Park, PA 16802, USA
- Department of Chemistry, Pennsylvania State University, University Park, PA 16802, USA
| | - David A. Fidock
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY 10032, USA
- Center for Malaria Therapeutics and Antimicrobial Resistance, Division of Infectious Diseases, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Kelly Chibale
- Drug Discovery and Development Centre (H3D), University of Cape Town, Rondebosch, Cape Town 7701, South Africa
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Observatory, Cape Town 7925, South Africa
- South African Medical Research Council Drug Discovery and Development Research Unit, University of Cape Town, Rondebosch, Cape Town 7701, South Africa
- Department of Chemistry, University of Cape Town, Rondebosch, Cape Town 7701, South Africa
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6
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Watson DJ, Laing L, Beteck RM, Gibhard L, Haynes RK, Wiesner L. The evaluation of ADME and pharmacokinetic properties of decoquinate derivatives for the treatment of malaria. Front Pharmacol 2022; 13:957690. [PMID: 36091789 PMCID: PMC9450014 DOI: 10.3389/fphar.2022.957690] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 07/18/2022] [Indexed: 12/03/2022] Open
Abstract
The emergence of Plasmodium falciparum (Pf) parasite strains tolerant of the artemisinin component and resistant to the other drug component in artemisinin combination therapies (ACTs) used for treatment now markedly complicates malaria control. Thus, development of new combination therapies are urgently required. For the non-artemisinin component, the quinolone ester decoquinate (DQ) that possesses potent activities against blood stage Pf and acts on a distinct target, namely the Pf cytochrome bc1 complex, was first considered. However, DQ has poor drug properties including high lipophilicity and exceedingly poor aqueous solubility (0.06 μg/ml), rendering it difficult to administer. Thus, DQ was chemically modified to provide the secondary amide derivative RMB005 and the quinoline O-carbamate derivatives RMB059 and RMB060. The last possesses sub-nanomolar activities against multidrug resistant blood stages of Pf, and P. berghei sporozoite liver stages. Here we present the results of ADME analyses in vitro and pharmacokinetic analyses using C57BL/6 mice. The amide RMB005 had a maximum mean whole blood concentration of 0.49 ± 0.02 µM following oral administration; however, the area under the curve (AUC), elimination half-life (t1/2) and bioavailability (BA) were not significantly better than those of DQ. Surprisingly, the quinoline O-carbamates which can be recrystallized without decomposition were rapidly converted into DQ in human plasma and blood samples. The maximum concentrations of DQ reached after oral administration of RMB059 and RMB060 were 0.23 ± 0.05 and 0.11 ± 0.01 µM, the DQ elimination half-lives were 4.79 ± 1.66 and 4.66 ± 1.16 h, and the DQ clearance were 19.40 ± 3.14 and 21.50 ± 3.38 respectively. Under these assay conditions, the BA of DQ could not be calculated Overall although RMB059 and -060 are labile in physiological medium with respect to the DQ parent, the potential to apply these as prodrugs is apparent from the current data coupled with their ease of preparation.
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Affiliation(s)
- Daniel J. Watson
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Lizahn Laing
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Richard M. Beteck
- Centre of Excellence for Pharmaceutical Sciences, School of Health Sciences, North-West University, Potchefstroom, South Africa
| | - Liezl Gibhard
- Department of Chemistry, University of Cape Town, Cape Town, South Africa
| | - Richard K. Haynes
- Centre of Excellence for Pharmaceutical Sciences, School of Health Sciences, North-West University, Potchefstroom, South Africa
| | - Lubbe Wiesner
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
- *Correspondence: Lubbe Wiesner,
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7
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Watson DJ, Laing L, Gibhard L, Wong HN, Haynes RK, Wiesner L. Toward New Transmission-Blocking Combination Therapies: Pharmacokinetics of 10-Amino-Artemisinins and 11-Aza-Artemisinin and Comparison with Dihydroartemisinin and Artemether. Antimicrob Agents Chemother 2021; 65:e0099021. [PMID: 34097488 PMCID: PMC8284440 DOI: 10.1128/aac.00990-21] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Accepted: 05/17/2021] [Indexed: 11/20/2022] Open
Abstract
As artemisinin combination therapies (ACTs) are compromised by resistance, we are evaluating triple combination therapies (TACTs) comprising an amino-artemisinin, a redox drug, and a third drug with a different mode of action. Thus, here we briefly review efficacy data on artemisone, artemiside, other amino-artemisinins, and 11-aza-artemisinin and conduct absorption, distribution, and metabolism and excretion (ADME) profiling in vitro and pharmacokinetic (PK) profiling in vivo via intravenous (i.v.) and oral (p.o.) administration to mice. The sulfamide derivative has a notably long murine microsomal half-life (t1/2 > 150 min), low intrinsic liver clearance and total plasma clearance rates (CLint 189.4, CLtot 32.2 ml/min/kg), and high relative bioavailability (F = 59%). Kinetics are somewhat similar for 11-aza-artemisinin (t1/2 > 150 min, CLint = 576.9, CLtot = 75.0 ml/min/kg), although bioavailability is lower (F = 14%). In contrast, artemether is rapidly metabolized to dihydroartemisinin (DHA) (t1/2 = 17.4 min) and eliminated (CLint = 855.0, CLtot = 119.7 ml/min/kg) and has low oral bioavailability (F) of 2%. While artemisone displays low t1/2 of <10 min and high CLint of 302.1, it displays a low CLtot of 42.3 ml/min/kg and moderate bioavailability (F) of 32%. Its active metabolite M1 displays a much-improved t1/2 of >150 min and a reduced CLint of 37.4 ml/min/kg. Artemiside has t1/2 of 12.4 min, CLint of 673.9, and CLtot of 129.7 ml/kg/min, likely a reflection of its surprisingly rapid metabolism to artemisone, reported here for the first time. DHA is not formed from any amino-artemisinin. Overall, the efficacy and PK data strongly support the development of selected amino-artemisinins as components of new TACTs.
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Affiliation(s)
- Daniel J. Watson
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Lizahn Laing
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Liezl Gibhard
- H3D, Department of Chemistry, University of Cape Town, Cape Town, South Africa
| | - Ho Ning Wong
- Centre of Excellence for Pharmaceutical Sciences, Faculty of Health Sciences, North-West University, Potchefstroom, South Africa
| | - Richard K. Haynes
- Centre of Excellence for Pharmaceutical Sciences, Faculty of Health Sciences, North-West University, Potchefstroom, South Africa
| | - Lubbe Wiesner
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
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8
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Dziwornu GA, Coertzen D, Leshabane M, Korkor CM, Cloete CK, Njoroge M, Gibhard L, Lawrence N, Reader J, van der Watt M, Wittlin S, Birkholtz LM, Chibale K. Antimalarial Benzimidazole Derivatives Incorporating Phenolic Mannich Base Side Chains Inhibit Microtubule and Hemozoin Formation: Structure-Activity Relationship and In Vivo Oral Efficacy Studies. J Med Chem 2021; 64:5198-5215. [PMID: 33844521 DOI: 10.1021/acs.jmedchem.1c00354] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
A novel series of antimalarial benzimidazole derivatives incorporating phenolic Mannich base side chains at the C2 position, which possess dual asexual blood and sexual stage activities, is presented. Structure-activity relationship studies revealed that the 1-benzylbenzimidazole analogues possessed submicromolar asexual blood and sexual stage activities in contrast to the 1H-benzimidazole analogues, which were only active against asexual blood stage (ABS) parasites. Further, the former demonstrated microtubule inhibitory activity in ABS parasites but more significantly in stage II/III gametocytes. In addition to being bona fide inhibitors of hemozoin formation, the 1H-benzimidazole analogues also showed inhibitory effects on microtubules. In vivo efficacy studies in Plasmodium berghei-infected mice revealed that the frontrunner compound 41 exhibited high efficacy (98% reduction in parasitemia) when dosed orally at 4 × 50 mg/kg. Generally, the compounds were noncytotoxic to mammalian cells.
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Affiliation(s)
| | - Dina Coertzen
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Meta Leshabane
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Constance M Korkor
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Cleavon K Cloete
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Mathew Njoroge
- Drug Discovery and Development Centre (H3D), Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory, Cape Town 7925, South Africa
| | - Liezl Gibhard
- Drug Discovery and Development Centre (H3D), Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory, Cape Town 7925, South Africa
| | - Nina Lawrence
- Drug Discovery and Development Centre (H3D), Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory, Cape Town 7925, South Africa
| | - Janette Reader
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Mariëtte van der Watt
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Sergio Wittlin
- Swiss Tropical and Public Health Institute, Socinstrasse 57, Basel 4002, Switzerland.,University of Basel, Basel 4003, Switzerland
| | - Lyn-Marie Birkholtz
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Kelly Chibale
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa.,Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa.,South African Medical Research Council Drug Discovery and Development Research Unit, University of Cape Town, Rondebosch 7701, South Africa
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9
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Le Manach C, Dam J, Woodland JG, Kaur G, Khonde LP, Brunschwig C, Njoroge M, Wicht KJ, Horatscheck A, Paquet T, Boyle GA, Gibhard L, Taylor D, Lawrence N, Yeo T, Mok S, Eastman RT, Dorjsuren D, Talley DC, Guo H, Simeonov A, Reader J, van der Watt M, Erlank E, Venter N, Zawada JW, Aswat A, Nardini L, Coetzer TL, Lauterbach SB, Bezuidenhout BC, Theron A, Mancama D, Koekemoer LL, Birkholtz LM, Wittlin S, Delves M, Ottilie S, Winzeler EA, von Geldern TW, Smith D, Fidock DA, Street LJ, Basarab GS, Duffy J, Chibale K. Identification and Profiling of a Novel Diazaspiro[3.4]octane Chemical Series Active against Multiple Stages of the Human Malaria Parasite Plasmodium falciparum and Optimization Efforts. J Med Chem 2021; 64:2291-2309. [PMID: 33573376 DOI: 10.1021/acs.jmedchem.1c00034] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A novel diazaspiro[3.4]octane series was identified from a Plasmodium falciparum whole-cell high-throughput screening campaign. Hits displayed activity against multiple stages of the parasite lifecycle, which together with a novel sp3-rich scaffold provided an attractive starting point for a hit-to-lead medicinal chemistry optimization and biological profiling program. Structure-activity-relationship studies led to the identification of compounds that showed low nanomolar asexual blood-stage activity (<50 nM) together with strong gametocyte sterilizing properties that translated to transmission-blocking activity in the standard membrane feeding assay. Mechanistic studies through resistance selection with one of the analogues followed by whole-genome sequencing implicated the P. falciparum cyclic amine resistance locus in the mode of resistance.
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Affiliation(s)
- Claire Le Manach
- Drug Discovery and Development Center (H3D), University of Cape Town, Rondebosch 7701, South Africa
| | - Jean Dam
- Drug Discovery and Development Center (H3D), University of Cape Town, Rondebosch 7701, South Africa
| | - John G Woodland
- Drug Discovery and Development Center (H3D), University of Cape Town, Rondebosch 7701, South Africa
| | - Gurminder Kaur
- Drug Discovery and Development Center (H3D), University of Cape Town, Rondebosch 7701, South Africa
| | - Lutete P Khonde
- Drug Discovery and Development Center (H3D), University of Cape Town, Rondebosch 7701, South Africa
| | - Christel Brunschwig
- Drug Discovery and Development Center (H3D), Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory 7925, South Africa
| | - Mathew Njoroge
- Drug Discovery and Development Center (H3D), Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory 7925, South Africa
| | - Kathryn J Wicht
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, New York 10032, United States
| | - André Horatscheck
- Drug Discovery and Development Center (H3D), University of Cape Town, Rondebosch 7701, South Africa
| | - Tanya Paquet
- Drug Discovery and Development Center (H3D), University of Cape Town, Rondebosch 7701, South Africa
| | - Grant A Boyle
- Drug Discovery and Development Center (H3D), University of Cape Town, Rondebosch 7701, South Africa
| | - Liezl Gibhard
- Drug Discovery and Development Center (H3D), Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory 7925, South Africa
| | - Dale Taylor
- Drug Discovery and Development Center (H3D), Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory 7925, South Africa
| | - Nina Lawrence
- Drug Discovery and Development Center (H3D), Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory 7925, South Africa
| | - Tomas Yeo
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, New York 10032, United States
| | - Sachel Mok
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, New York 10032, United States
| | - Richard T Eastman
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Dorjbal Dorjsuren
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Daniel C Talley
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Hui Guo
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Anton Simeonov
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Janette Reader
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, Pretoria 0028, South Africa
| | - Mariëtte van der Watt
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, Pretoria 0028, South Africa
| | - Erica Erlank
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa.,Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg 2192, South Africa
| | - Nelius Venter
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa.,Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg 2192, South Africa
| | - Jacek W Zawada
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa.,Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg 2192, South Africa
| | - Ayesha Aswat
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa.,Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg 2192, South Africa
| | - Luisa Nardini
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa.,Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg 2192, South Africa
| | - Theresa L Coetzer
- Wits Research Institute for Malaria, School of Pathology, Department of Molecular Medicine and Haematology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa
| | - Sonja B Lauterbach
- Wits Research Institute for Malaria, School of Pathology, Department of Molecular Medicine and Haematology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa
| | - Belinda C Bezuidenhout
- Wits Research Institute for Malaria, School of Pathology, Department of Molecular Medicine and Haematology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa
| | - Anjo Theron
- Biosciences, Council for Scientific and Industrial Research, P.O. Box 395, Pretoria 0001, South Africa
| | - Dalu Mancama
- Biosciences, Council for Scientific and Industrial Research, P.O. Box 395, Pretoria 0001, South Africa
| | - Lizette L Koekemoer
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa.,Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg 2192, South Africa
| | - Lyn-Marie Birkholtz
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, Pretoria 0028, South Africa
| | - Sergio Wittlin
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002 Basel, Switzerland.,University of Basel, 4003 Basel, Switzerland
| | - Michael Delves
- Imperial College London, South Kensington, London SW7 2AZ, U.K.,London School of Hygiene and Tropical Medicine, London WC1E 7HT, U.K
| | - Sabine Ottilie
- Division of Host-Microbe Systems & Therapeutics, Department of Pediatrics, University of California San Diego, La Jolla, California 92093-076, United States
| | - Elizabeth A Winzeler
- Division of Host-Microbe Systems & Therapeutics, Department of Pediatrics, University of California San Diego, La Jolla, California 92093-076, United States
| | | | | | - David A Fidock
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, New York 10032, United States.,Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, New York, New York 10032, United States
| | - Leslie J Street
- Drug Discovery and Development Center (H3D), University of Cape Town, Rondebosch 7701, South Africa
| | - Gregory S Basarab
- Drug Discovery and Development Center (H3D), University of Cape Town, Rondebosch 7701, South Africa
| | - James Duffy
- Medicines for Malaria Venture, ICC, Route de Pré-Bois 20, P.O. Box 1826, 1215 Geneva, Switzerland
| | - Kelly Chibale
- Drug Discovery and Development Center (H3D), 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
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10
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Horatscheck A, Andrijevic A, Nchinda AT, Le Manach C, Paquet T, Khonde LP, Dam J, Pawar K, Taylor D, Lawrence N, Brunschwig C, Gibhard L, Njoroge M, Reader J, van der Watt M, Wicht K, de Sousa ACC, Okombo J, Maepa K, Egan TJ, Birkholtz LM, Basarab GS, Wittlin S, Fish PV, Street LJ, Duffy J, Chibale K. Correction to "Identification of 2,4-Disubstituted Imidazopyridines as Hemozoin Formation Inhibitors with Fast-Killing Kinetics and In Vivo Efficacy in the Plasmodium falciparum NSG Mouse Model". J Med Chem 2021; 64:1762. [PMID: 33508187 DOI: 10.1021/acs.jmedchem.1c00064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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11
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Horatscheck A, Andrijevic A, Nchinda AT, Le Manach C, Paquet T, Khonde LP, Dam J, Pawar K, Taylor D, Lawrence N, Brunschwig C, Gibhard L, Njoroge M, Reader J, van der Watt M, Wicht K, de Sousa ACC, Okombo J, Maepa K, Egan TJ, Birkholtz LM, Basarab GS, Wittlin S, Fish PV, Street LJ, Duffy J, Chibale K. Identification of 2,4-Disubstituted Imidazopyridines as Hemozoin Formation Inhibitors with Fast-Killing Kinetics and In Vivo Efficacy in the Plasmodium falciparum NSG Mouse Model. J Med Chem 2020; 63:13013-13030. [PMID: 33103428 DOI: 10.1021/acs.jmedchem.0c01411] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
A series of 2,4-disubstituted imidazopyridines, originating from a SoftFocus Kinase library, was identified from a high throughput phenotypic screen against the human malaria parasite Plasmodium falciparum. Hit compounds showed moderate asexual blood stage activity. During lead optimization, several issues were flagged such as cross-resistance against the multidrug-resistant K1 strain, in vitro cytotoxicity, and cardiotoxicity and were addressed through structure-activity and structure-property relationship studies. Pharmacokinetic properties were assessed in mice for compounds showing desirable in vitro activity, a selectivity window over cytotoxicity, and microsomal metabolic stability. Frontrunner compound 37 showed good exposure in mice combined with good in vitro activity against the malaria parasite, which translated into in vivo efficacy in the P. falciparum NOD-scid IL-2Rγnull (NSG) mouse model. Preliminary mechanistic studies suggest inhibition of hemozoin formation as a contributing mode of action.
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Affiliation(s)
- André Horatscheck
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Ana Andrijevic
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Aloysius T Nchinda
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Claire Le Manach
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Tanya Paquet
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Lutete Peguy Khonde
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Jean Dam
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Kailash Pawar
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Dale Taylor
- Drug Discovery and Development Centre (H3D), Division of Clinical Pharmacology, University of Cape Town, Rondebosch 7701, South Africa
| | - Nina Lawrence
- Drug Discovery and Development Centre (H3D), Division of Clinical Pharmacology, University of Cape Town, Rondebosch 7701, South Africa
| | - Christel Brunschwig
- Drug Discovery and Development Centre (H3D), Division of Clinical Pharmacology, University of Cape Town, Rondebosch 7701, South Africa
| | - Liezl Gibhard
- Drug Discovery and Development Centre (H3D), Division of Clinical Pharmacology, University of Cape Town, Rondebosch 7701, South Africa
| | - Mathew Njoroge
- Drug Discovery and Development Centre (H3D), Division of Clinical Pharmacology, University of Cape Town, Rondebosch 7701, South Africa
| | - Janette Reader
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, Pretoria 0028, South Africa
| | - Mariëtte van der Watt
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, Pretoria 0028, South Africa
| | - Kathryn Wicht
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | | | - John Okombo
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Keletso Maepa
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Timothy J Egan
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa.,Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa
| | - Lyn-Marie Birkholtz
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, Pretoria 0028, South Africa
| | - Gregory S Basarab
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Sergio Wittlin
- Swiss Tropical and Public Health Institute ,Socinstrasse 57, 4002 Basel, Switzerland.,University of Basel, 4002 Basel, Switzerland
| | - Paul V Fish
- Alzheimer's Research UK, UCL Drug Discovery Institute, The Cruciform Building, University College London, Gower Street, London WC1E 6BT, U.K
| | - Leslie J Street
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - James Duffy
- Medicines for Malaria Venture, ICC, Route de Pré-Bois 20, P.O. Box 1826, 1215 Geneva, Switzerland
| | - Kelly Chibale
- South African Medical Research Council, Drug Discovery and Development Research Unit, Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa.,Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa
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12
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Bleloch JS, du Toit A, Gibhard L, Kimani S, Ballim RD, Lee M, Blanckenberg A, Mapolie S, Wiesner L, Loos B, Prince S. The palladacycle complex AJ-5 induces apoptotic cell death while reducing autophagic flux in rhabdomyosarcoma cells. Cell Death Discov 2019; 5:60. [PMID: 30701092 PMCID: PMC6349869 DOI: 10.1038/s41420-019-0139-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 12/19/2018] [Accepted: 01/02/2019] [Indexed: 12/16/2022] Open
Abstract
Rhabdomyosarcoma (RMS) forms in skeletal muscle and is the most common soft tissue sarcoma in children and adolescents. Current treatment is associated with debilitating side effects and treatment outcomes for patients with metastatic disease are dismal. Recently, a novel binuclear palladacycle, AJ-5, was shown to exert potent cytotoxicity in melanoma and breast cancer and to present with negligible adverse effects in mice. This study investigates the anti-cancer activity of AJ-5 in alveolar and embryonal RMS. IC50 values of ≤ 0.2 µM were determined for AJ-5 and it displayed a favourable selectivity index of >2. Clonogenic and migration assays showed that AJ-5 inhibited the ability of RMS cells to survive and migrate, respectively. Western blotting revealed that AJ-5 induced levels of key DNA damage response proteins (γH2AX, p-ATM and p-Chk2) and the p38/MAPK stress pathway. This correlated with an upregulation of p21 and a G1 cell cycle arrest. Annexin V-FITC/propidium iodide staining revealed that AJ-5 induced apoptosis and necrosis. Apoptosis was confirmed by the detection of cleaved PARP and increased levels and activity of cleaved caspases-3, -7, -8 and -9. Furthermore, AJ-5 reduced autophagic flux as shown by reduced LC3II accumulation in the presence of bafilomycin A1 and a significant reduction in autophagosome flux J. Finally, pharmacokinetic studies in mice show that AJ-5 has a promising half-life and that its volume of distribution is high, its clearance low and its intraperitoneal absorption is good. Together these findings suggest that AJ-5 may be an effective chemotherapeutic with a desirable mechanism of action for treating drug-resistant and advanced sarcomas.
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Affiliation(s)
- Jenna Susan Bleloch
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, Western Cape South Africa
| | - André du Toit
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, Western Cape South Africa
| | - Liezl Gibhard
- Division of Clinical Pharmacology, Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, Western Cape South Africa
| | - Serah Kimani
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, Western Cape South Africa
| | - Reyna Deeya Ballim
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, Western Cape South Africa
| | - Minkyu Lee
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, Western Cape South Africa
| | - Angelique Blanckenberg
- Department of Chemistry and Polymer Science, Stellenbosch University, Stellenbosch, Western Cape South Africa
| | - Selwyn Mapolie
- Department of Chemistry and Polymer Science, Stellenbosch University, Stellenbosch, Western Cape South Africa
| | - Lubbe Wiesner
- Division of Clinical Pharmacology, Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, Western Cape South Africa
| | - Ben Loos
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, Western Cape South Africa
| | - Sharon Prince
- Division of Cell Biology, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, Western Cape South Africa
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13
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Mayoka G, Njoroge M, Okombo J, Gibhard L, Sanches-Vaz M, Fontinha D, Birkholtz LM, Reader J, van der Watt M, Coetzer TL, Lauterbach S, Churchyard A, Bezuidenhout B, Egan TJ, Yeates C, Wittlin S, Prudêncio M, Chibale K. Structure–Activity Relationship Studies and Plasmodium Life Cycle Profiling Identifies Pan-Active N-Aryl-3-trifluoromethyl Pyrido[1,2-a]benzimidazoles Which Are Efficacious in an in Vivo Mouse Model of Malaria. J Med Chem 2018; 62:1022-1035. [DOI: 10.1021/acs.jmedchem.8b01769] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Godfrey Mayoka
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Mathew Njoroge
- Drug Discovery and Development Centre (H3D), Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory, Cape Town 7925, South Africa
| | - John Okombo
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Liezl Gibhard
- Drug Discovery and Development Centre (H3D), Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory, Cape Town 7925, South Africa
| | - Margarida Sanches-Vaz
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisbon, Portugal
| | - Diana Fontinha
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisbon, Portugal
| | - Lyn-Marie Birkholtz
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Janette Reader
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Mariëtte van der Watt
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Theresa L. Coetzer
- Wits Research Institute for Malaria, Faculty of Health Sciences, University of the Witwatersrand and National Health Laboratory Service, Johannesburg 2193, South Africa
| | - Sonja Lauterbach
- Wits Research Institute for Malaria, Faculty of Health Sciences, University of the Witwatersrand and National Health Laboratory Service, Johannesburg 2193, South Africa
| | - Alisje Churchyard
- Wits Research Institute for Malaria, Faculty of Health Sciences, University of the Witwatersrand and National Health Laboratory Service, Johannesburg 2193, South Africa
| | - Belinda Bezuidenhout
- Wits Research Institute for Malaria, Faculty of Health Sciences, University of the Witwatersrand and National Health Laboratory Service, Johannesburg 2193, South Africa
| | - Timothy J. Egan
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa
| | - Clive Yeates
- Inpharma
Consultancy, 6 Dudley Hill Close, Welwyn, Hertfordshire AL60QQ, U.K
| | - Sergio Wittlin
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Miguel Prudêncio
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisbon, Portugal
| | - Kelly Chibale
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
- South African Medical Research Council, Drug Discovery and Development Research Unit, University of Cape Town, Rondebosch 7701, South Africa
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa
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14
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Le Manach C, Paquet T, Wicht K, Nchinda AT, Brunschwig C, Njoroge M, Gibhard L, Taylor D, Lawrence N, Wittlin S, Eyermann CJ, Basarab GS, Duffy J, Fish PV, Street LJ, Chibale K. Antimalarial Lead-Optimization Studies on a 2,6-Imidazopyridine Series within a Constrained Chemical Space To Circumvent Atypical Dose–Response Curves against Multidrug Resistant Parasite Strains. J Med Chem 2018; 61:9371-9385. [DOI: 10.1021/acs.jmedchem.8b01333] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Claire Le Manach
- Drug Discovery and Development Center (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Tanya Paquet
- Drug Discovery and Development Center (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Kathryn Wicht
- Drug Discovery and Development Center (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Aloysius T. Nchinda
- Drug Discovery and Development Center (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Christel Brunschwig
- H3D, Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory 7925, South Africa
| | - Mathew Njoroge
- H3D, Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory 7925, South Africa
| | - Liezl Gibhard
- H3D, Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory 7925, South Africa
| | - Dale Taylor
- H3D, Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory 7925, South Africa
| | - Nina Lawrence
- H3D, Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory 7925, South Africa
| | - Sergio Wittlin
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002 Basel, Switzerland
- University of Basel, 4003 Basel, Switzerland
| | - Charles J. Eyermann
- Drug Discovery and Development Center (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Gregory S. Basarab
- Drug Discovery and Development Center (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - James Duffy
- Medicines for Malaria Venture, ICC, Route de Pré-Bois 20, PO Box 1826, 1215 Geneva, Switzerland
| | - Paul V. Fish
- Alzheimer’s Research UK, UCL Drug Discovery Institute, The Cruciform Building, University College London, Gower Street, London WC1E 6BT, U.K
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, U.K
| | - Leslie J. Street
- Drug Discovery and Development Center (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Kelly Chibale
- Drug Discovery and Development Center (H3D), 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
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15
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Kandepedu N, Gonzàlez Cabrera D, Eedubilli S, Taylor D, Brunschwig C, Gibhard L, Njoroge M, Lawrence N, Paquet T, Eyermann CJ, Spangenberg T, Basarab GS, Street LJ, Chibale K. Identification, Characterization, and Optimization of 2,8-Disubstituted-1,5-naphthyridines as Novel Plasmodium falciparum Phosphatidylinositol-4-kinase Inhibitors with in Vivo Efficacy in a Humanized Mouse Model of Malaria. J Med Chem 2018; 61:5692-5703. [DOI: 10.1021/acs.jmedchem.8b00648] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Nishanth Kandepedu
- Drug Discovery and Development Centre (H3D), University of Cape Town, Rondebosch 7701, South Africa
| | - Diego Gonzàlez Cabrera
- Drug Discovery and Development Centre (H3D), University of Cape Town, Rondebosch 7701, South Africa
| | - Srinivas Eedubilli
- Drug Discovery and Development Centre (H3D), University of Cape Town, Rondebosch 7701, South Africa
| | - Dale Taylor
- Drug Discovery and Development Centre (H3D), DMPK/Pharmacology, University of Cape Town, Observatory 7925, South Africa
| | - Christel Brunschwig
- Drug Discovery and Development Centre (H3D), DMPK/Pharmacology, University of Cape Town, Observatory 7925, South Africa
| | - Liezl Gibhard
- Drug Discovery and Development Centre (H3D), DMPK/Pharmacology, University of Cape Town, Observatory 7925, South Africa
| | - Mathew Njoroge
- Drug Discovery and Development Centre (H3D), DMPK/Pharmacology, University of Cape Town, Observatory 7925, South Africa
| | - Nina Lawrence
- Drug Discovery and Development Centre (H3D), DMPK/Pharmacology, University of Cape Town, Observatory 7925, South Africa
| | - Tanya Paquet
- Drug Discovery and Development Centre (H3D), University of Cape Town, Rondebosch 7701, South Africa
| | - Charles J. Eyermann
- Drug Discovery and Development Centre (H3D), University of Cape Town, Rondebosch 7701, South Africa
| | - Thomas Spangenberg
- Merck Global Health Institute, Ares Trading S.A., a subsidiary of Merck KGaA (Darmstadt, Germany), Coinsins 1267, Switzerland
| | - Gregory S. Basarab
- Drug Discovery and Development Centre (H3D), University of Cape Town, Rondebosch 7701, South Africa
| | - Leslie J. Street
- Drug Discovery and Development Centre (H3D), University of Cape Town, Rondebosch 7701, South Africa
| | - Kelly Chibale
- Drug Discovery and Development Centre (H3D), 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
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16
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Okombo J, Singh K, Mayoka G, Ndubi F, Barnard L, Njogu PM, Njoroge M, Gibhard L, Brunschwig C, Vargas M, Keiser J, Egan TJ, Chibale K. Antischistosomal Activity of Pyrido[1,2-a]benzimidazole Derivatives and Correlation with Inhibition of β-Hematin Formation. ACS Infect Dis 2017; 3:411-420. [PMID: 28440625 DOI: 10.1021/acsinfecdis.6b00205] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The extensive use of praziquantel against schistosomiasis raises concerns about drug resistance. New therapeutic alternatives targeting critical pathways within the parasite are therefore urgently needed. Hemozoin formation in Schistosoma presents one such target. We assessed the in vitro antischistosomal activity of pyrido[1,2-a]benzimidazoles (PBIs) and investigated correlations with their ability to inhibit β-hematin formation. We further evaluated the in vivo efficacy of representative compounds in experimental mice and conducted pharmacokinetic analysis on the most potent. At 10 μM, 48/57 compounds resulted in >70% mortality of newly transformed schistosomula, whereas 37 of these maintained >60% mortality of adult S. mansoni. No correlations were observed between β-hematin inhibitory and antischistosomal activities against both larval and adult parasites, suggesting possible presence of other target(s) or a mode of inhibition of crystal formation that is not adequately modeled by the assay. The most active compound in vivo showed 58.7 and 61.3% total and female worm burden reduction, respectively. Pharmacokinetic analysis suggested solubility-limited absorption and high hepatic clearance as possible contributors to the modest efficacy despite good in vitro activity. The PBIs evaluated in this report thus merit further optimization to improve their efficacy and to elucidate their possible mode of action.
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Affiliation(s)
- John Okombo
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Kawaljit Singh
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Godfrey Mayoka
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Ferdinand Ndubi
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Linley Barnard
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Peter M. Njogu
- Department of Pharmaceutical Chemistry, University of Nairobi, P.O. Box 19676, Nairobi 00202, Kenya
| | - Mathew Njoroge
- Drug Discovery and Development Centre (H3D),
Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory 7925, South Africa
| | - Liezl Gibhard
- Drug Discovery and Development Centre (H3D),
Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory 7925, South Africa
| | - Christel Brunschwig
- Drug Discovery and Development Centre (H3D),
Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory 7925, South Africa
| | - Mireille Vargas
- Department of Medical Parasitology and
Infection Biology, Swiss Tropical and Public Health Institute, 4051 Basel, Switzerland
- University of Basel, 4003 Basel, Switzerland
| | - Jennifer Keiser
- Department of Medical Parasitology and
Infection Biology, Swiss Tropical and Public Health Institute, 4051 Basel, Switzerland
- University of Basel, 4003 Basel, Switzerland
| | - Timothy J. Egan
- 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, University of Cape Town, Rondebosch 7701, South Africa
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa
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17
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Combrinck JM, Fong KY, Gibhard L, Smith PJ, Wright DW, Egan TJ. Optimization of a multi-well colorimetric assay to determine haem species in Plasmodium falciparum in the presence of anti-malarials. Malar J 2015; 14:253. [PMID: 26099266 PMCID: PMC4484700 DOI: 10.1186/s12936-015-0729-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 05/07/2015] [Indexed: 11/24/2022] Open
Abstract
Background The activity of several well-known anti-malarials, including chloroquine (CQ), is attributed to their ability to inhibit the formation of haemozoin (Hz) in the malaria parasite. The formation of inert Hz, or malaria pigment, from toxic haem acquired from the host red blood cell of the parasite during haemoglobin digestion represents a pathway essential for parasite survival. Inhibition of this critical pathway therefore remains a desirable target for novel anti-malarials. A recent publication described the results of a haem fractionation assay used to directly determine haemoglobin, free haem and Hz in Plasmodium falciparum inoculated with CQ. CQ was shown to cause a dose-dependent increase in cellular-free haem that was correlated with decreased parasite survival. The method provided valuable information but was limited due to its low throughput and high demand on parasite starting material. Here, this haem fractionation assay has been successfully adapted to a higher throughput method in 24-well plates, significantly reducing lead times and starting material volumes. Methods All major haem species in P. falciparum trophozoites, isolated through a series of cellular fractionation steps were determined spectrophotometrically in aqueous pyridine (5 % v/v, pH 7.5) as a low spin complex with haematin. Cell counts were determined using a haemocytometer and a rapid novel fluorescent flow cytometry method. Results A higher throughput haem fractionation assay in 24-well plates, containing at most ten million trophozoites was validated against the original published method using CQ and its robustness was confirmed. It provided a minimum six-fold improvement in productivity and 24-fold reduction in starting material volume. The assay was successfully applied to amodiaquine (AQ), which was shown to inhibit Hz formation, while the antifolate pyrimethamine (PYR) and the mitochondrial electron transporter inhibitor atovaquone (Atov) demonstrated no increase in toxic cellular free haem. Conclusions This higher throughput cellular haem fractionation assay can easily be applied to novel anti-malarials with a significantly decreased lead time, providing a valuable tool with which to probe the mechanisms of action of both new and established anti-malarials.
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Affiliation(s)
- Jill M Combrinck
- Division of Pharmacology, Department of Medicine, University of Cape Town, Observatory 7925, Cape Town, South Africa.
| | - Kim Y Fong
- Department of Chemistry, Vanderbilt University, Station B 351822, Nashville, TN, 37235, USA.
| | - Liezl Gibhard
- Division of Pharmacology, Department of Medicine, University of Cape Town, Observatory 7925, Cape Town, South Africa.
| | - Peter J Smith
- Division of Pharmacology, Department of Medicine, University of Cape Town, Observatory 7925, Cape Town, South Africa.
| | - David W Wright
- Department of Chemistry, Vanderbilt University, Station B 351822, Nashville, TN, 37235, USA.
| | - Timothy J Egan
- Department of Chemistry, University of Cape Town, Private Bag, Rondebosch, 7701, South Africa.
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18
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Govender K, Gibhard L, Du Plessis L, Wiesner L. Development and validation of a LC–MS/MS method for the quantitation of lumefantrine in mouse whole blood and plasma. J Chromatogr B Analyt Technol Biomed Life Sci 2015; 985:6-13. [DOI: 10.1016/j.jchromb.2015.01.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 01/13/2015] [Accepted: 01/15/2015] [Indexed: 10/24/2022]
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19
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Melariri P, Kalombo L, Nkuna P, Dube A, Hayeshi R, Ogutu B, Gibhard L, deKock C, Smith P, Wiesner L, Swai H. Oral lipid-based nanoformulation of tafenoquine enhanced bioavailability and blood stage antimalarial efficacy and led to a reduction in human red blood cell loss in mice. Int J Nanomedicine 2015; 10:1493-503. [PMID: 25759576 PMCID: PMC4346002 DOI: 10.2147/ijn.s76317] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Tafenoquine (TQ), a new synthetic analog of primaquine, has relatively poor bioavailability and associated toxicity in glucose-6-phosphate dehydrogenase (G6PD)-deficient individuals. A microemulsion formulation of TQ (MTQ) with sizes <20 nm improved the solubility of TQ and enhanced the oral bioavailability from 55% to 99% in healthy mice (area under the curve 0 to infinity: 11,368±1,232 and 23,842±872 min·μmol/L) for reference TQ and MTQ, respectively. Average parasitemia in Plasmodium berghei-infected mice was four- to tenfold lower in the MTQ-treated group. In vitro antiplasmodial activities against chloroquine-sensitive and chloroquine-resistant strains of Plasmodium falciparum indicated no change in half maximal inhibitory concentration, suggesting that the microemulsion did not affect the inherent activity of TQ. In a humanized mouse model of G6PD deficiency, we observed reduction in toxicity of TQ as delivered by MTQ at low but efficacious concentrations of TQ. We hereby report an enhancement in the solubility, bioavailibility, and efficacy of TQ against blood stages of Plasmodium parasites without a corresponding increase in toxicity.
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Affiliation(s)
- Paula Melariri
- Polymers and Composites, Material Science and Manufacturing, Council for Scientific and Industrial Research, Port Elizabeth, South Africa
| | - Lonji Kalombo
- Polymer and Composites, Material Science and Manufacturing, Council for Scientific and Industrial Research, Pretoria, South Africa
| | - Patric Nkuna
- Polymer and Composites, Material Science and Manufacturing, Council for Scientific and Industrial Research, Pretoria, South Africa
| | - Admire Dube
- Polymer and Composites, Material Science and Manufacturing, Council for Scientific and Industrial Research, Pretoria, South Africa ; School of Pharmacy, University of the Western Cape, Bellville, South Africa
| | - Rose Hayeshi
- Polymer and Composites, Material Science and Manufacturing, Council for Scientific and Industrial Research, Pretoria, South Africa
| | - Benhards Ogutu
- Centre for Research in Therapeutic Sciences, Strathmore University, Nairobi, Kenya ; Centre for Clinical Research, Kenya Medical Research Institute, Nairobi, Kenya
| | - Liezl Gibhard
- Division of Pharmacology, University of Cape Town Medical School, Groote Schuur Hospital, Cape Town, South Africa
| | - Carmen deKock
- Division of Pharmacology, University of Cape Town Medical School, Groote Schuur Hospital, Cape Town, South Africa
| | - Peter Smith
- Division of Pharmacology, University of Cape Town Medical School, Groote Schuur Hospital, Cape Town, South Africa
| | - Lubbe Wiesner
- Division of Pharmacology, University of Cape Town Medical School, Groote Schuur Hospital, Cape Town, South Africa
| | - Hulda Swai
- Polymer and Composites, Material Science and Manufacturing, Council for Scientific and Industrial Research, Pretoria, South Africa
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20
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Abay ET, van der Westuizen JH, Swart KJ, Gibhard L, Lawrence N, Dambuza N, Wilhelm A, Pravin K, Wiesner L. Efficacy and pharmacokinetic evaluation of a novel anti-malarial compound (NP046) in a mouse model. Malar J 2015; 14:8. [PMID: 25563929 PMCID: PMC4326489 DOI: 10.1186/1475-2875-14-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 12/17/2014] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Even though malaria is a completely preventable and treatable disease, it remains a threat to human life and a burden to the global economy due to the emergence of multiple-drug resistant malaria parasites. According to the World Malaria Report 2013, in 2012 there were an estimated 207 million malaria cases and 627,000 deaths. Thus, the discovery and development of new, effective anti-malarial drugs are required. To achieve this goal, the Department of Chemistry at the University of the Free State has synthesized a number of novel amino-alkylated chalcones and analogues, which showed in vitro anti-malarial activity against both chloroquine-sensitive and chloroquine-resistant Plasmodium falciparum strains. The lead compound (NP046) was selected for a comprehensive pharmacokinetic (PK) and in vivo efficacy evaluation in a mouse model. METHODS In vivo efficacy: Water solutions of NP046 were administered orally at 50 and 10 mg/kg using oral gavage and IV at 5 and 1 mg/kg via the dorsal penile vein to Plasmodium berghei (ANKA strain) infected male C57BL/6 mice (n = 5), once a day for four days. Blood samples were collected via tail bleeding in tubes containing phosphate buffer saline (PBS) on day five to determine the % parasitaemia by flow cytometry.In vivo PK: NP046 solutions in water were administered orally (50 and 10 mg/kg) and IV (5 mg/kg) to male C57BL/6 mice (n = 5). Blood samples were collected via tail bleeding into heparinized tubes and analysed using a validated LC-MS/MS assay. Data obtained from the concentration-time profile was evaluated using Summit PK software to determine the PK parameters of NP046. RESULTS NP046 inhibited parasite growth for the oral and IV groups. Better parasite growth inhibition was observed for the IV group. The PK evaluation of NP046 showed low oral bioavailability (3.2% and 6% at 50 mg/kg and 10 mg/kg dose, respectively and a moderate mean half-life ranging from 3.1 to 4.4 hours. CONCLUSION Even though the oral bioavailability of NP046 is low, its percentage parasite growth inhibition is promising, but in order to improve the oral bioavailability, structure-activity-relationship (SAR) optimization studies are currently being conducted.
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Affiliation(s)
- Efrem T Abay
- />Department of Medicine, Division of Clinical Pharmacology, University of Cape Town, Observatory, 7925 Cape Town, South Africa
- />PAREXEL® International Clinical Research Organization, Private Bag X09, Brandhof, 9324 Bloemfontein, South Africa
| | - Jan H van der Westuizen
- />Research Development, University of the Free State, PO Box 339, Bloemfontein, 9300 South Africa
| | - Kenneth J Swart
- />PAREXEL® International Clinical Research Organization, Private Bag X09, Brandhof, 9324 Bloemfontein, South Africa
- />Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein, 9300 South Africa
| | - Liezl Gibhard
- />Department of Medicine, Division of Clinical Pharmacology, University of Cape Town, Observatory, 7925 Cape Town, South Africa
| | - Nina Lawrence
- />Department of Medicine, Division of Clinical Pharmacology, University of Cape Town, Observatory, 7925 Cape Town, South Africa
| | - Ntokozo Dambuza
- />Department of Medicine, Division of Clinical Pharmacology, University of Cape Town, Observatory, 7925 Cape Town, South Africa
| | - Anke Wilhelm
- />Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein, 9300 South Africa
| | - Kendrekar Pravin
- />Research Development, University of the Free State, PO Box 339, Bloemfontein, 9300 South Africa
| | - Lubbe Wiesner
- />Department of Medicine, Division of Clinical Pharmacology, University of Cape Town, Observatory, 7925 Cape Town, South Africa
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21
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Abay ET, van der Westhuizen JH, Swart KJ, Gibhard L, Tukulula M, Chibale K, Wiesner L. The development and validation of an LC-MS/MS method for the determination of a new anti-malarial compound (TK900D) in human whole blood and its application to pharmacokinetic studies in mice. Malar J 2014; 13:42. [PMID: 24484513 PMCID: PMC3916804 DOI: 10.1186/1475-2875-13-42] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 01/28/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malaria is one of the most lethal and life-threatening killer infectious diseases in the world, and account for the deaths of more than half a million people annually. Despite the remarkable achievement made in preventing and eradicating malaria, it still remains a threat to the public health and a burden to the global economy due to the emergence of multiple-drug resistant malaria parasites. Therefore, the need to develop new anti-malarial drugs is crucial. The chemistry department at the University of Cape Town synthesized a number of new CQ-like derivatives (TK-series), and evaluated them for in vitro activity against both CQ-sensitive and -resistant Plasmodium falciparum strains, and for general cytotoxicity against a Chinese Hamster Ovarian (CHO) mammalian cell line. The lead compounds from the TK-series were selected for a comprehensive pharmacokinetic (PK) evaluation in a mouse model. METHODS A sensitive LC-MS/MS assay was developed for the quantitative determination of TK900D. Multiple reaction monitoring (MRM) in the positive ionization mode was used for detection. The analyte and the internal standard (TK900E) were isolated from blood samples by liquid-liquid extraction with ethyl acetate. Chromatographic separation was achieved with a Phenomenex® Kinetex C18 (100 × 2.0 mm id, 2.6 μm) analytical column, using a mixture of 0.1% formic acid and acetonitrile (50:50; v/v) as the mobile phase. The method was fully validated over concentrations that ranged from 3.910 to 1000 ng/ml, and used to evaluate the PK properties of the lead compounds in a mouse model. RESULTS The assay was robust, with deviation not exceeding 11% for the intra- and inter-run precision and accuracy. Extraction recovery was consistent and more than 60%. PK evaluation showed that TK900D and TK900E have moderate oral bioavailability of 30.8% and 25.9%, respectively. The apparent half-life ranged between 4 to 6 h for TK900D and 3.6 to 4 h for TK900E. CONCLUSION The assay was sensitive and able to measure accurately low drug levels from a small sample volume (20 μl). PK evaluation showed that the oral bioavailability was moderate. Therefore, from a PK perspective, the compounds look promising and can be taken further in the drug development process.
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Affiliation(s)
- Efrem T Abay
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory, 7925 Cape Town, South Africa
- PAREXEL® International Clinical Research Organisation, Private Bag X09, Brandhof 9300, Bloemfontein, South Africa
| | - Jan H van der Westhuizen
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa
| | - Kenneth J Swart
- PAREXEL® International Clinical Research Organisation, Private Bag X09, Brandhof 9300, Bloemfontein, South Africa
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa
| | - Liezl Gibhard
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory, 7925 Cape Town, South Africa
| | - Matshawandile Tukulula
- Department of Chemistry, University of Cape Town, Rondebosch 7701, Cape Town, South Africa
| | - Kelly Chibale
- Department of Chemistry, University of Cape Town, Rondebosch 7701, Cape Town, South Africa
- Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Rondebosch 7701, Cape Town, South Africa
| | - Lubbe Wiesner
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory, 7925 Cape Town, South Africa
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22
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Tukulula M, Njoroge M, Abay ET, Mugumbate GC, Wiesner L, Taylor D, Gibhard L, Norman J, Swart KJ, Gut J, Rosenthal PJ, Barteau S, Streckfuss J, Kameni-Tcheudji J, Chibale K. Synthesis and in vitro and in vivo pharmacological evaluation of new 4-aminoquinoline-based compounds. ACS Med Chem Lett 2013; 4:1198-202. [PMID: 24900630 DOI: 10.1021/ml400311r] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 10/01/2013] [Indexed: 11/28/2022] Open
Abstract
A new class of 4-aminoquinolines was synthesized and evaluated in vitro for antiplasmodial activity against both the chloroquine-sensitive (3D7) and -resistant (K1 and W2) strains. The most active compounds 3c-3e had acceptable cytotoxicity but showed strong inhibition toward a panel of cytochrome P450 enzymes in vitro. Pharmacokinetic studies on 3d and 3e in mice showed that they had moderate half-life (4-6 h) and low oral bioavailability. The front runner compound 3d exhibited moderate inhibition of the malaria parasite on P. berghei infected mice following oral administration (5 mg/kg), achieving reduction of parasitemia population by 47% on day 7.
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Affiliation(s)
| | - Mathew Njoroge
- Department
of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Efrem T. Abay
- Department
of Chemistry (48), University of the Free State, Bloemfontein 339, South Africa
- PAREXEL International Clinical Research Organization, Private Bag X09, Brandhof 9324, Bloemfontein 339, South Africa
| | - Grace C. Mugumbate
- Department
of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Lubbe Wiesner
- Department
of Pharmacology, University of Cape Town, Medical School, Observatory 7925, South Africa
| | - Dale Taylor
- Department
of Pharmacology, University of Cape Town, Medical School, Observatory 7925, South Africa
| | - Liezl Gibhard
- Department
of Pharmacology, University of Cape Town, Medical School, Observatory 7925, South Africa
| | - Jennifer Norman
- Department
of Pharmacology, University of Cape Town, Medical School, Observatory 7925, South Africa
| | - Kenneth J. Swart
- PAREXEL International Clinical Research Organization, Private Bag X09, Brandhof 9324, Bloemfontein 339, South Africa
| | - Jiri Gut
- Department
of Medicine, San Francisco General Hospital, University of San Francisco, San
Francisco, California 94143, United States
| | - Philip J. Rosenthal
- Department
of Medicine, San Francisco General Hospital, University of San Francisco, San
Francisco, California 94143, United States
| | - Samuel Barteau
- Drug Metabolism
and Pharmacokinetics, Novartis Institutes for BioMedical Research, Basel CH-4057, Switzerland
| | - Judith Streckfuss
- Drug Metabolism
and Pharmacokinetics, Novartis Institutes for BioMedical Research, Basel CH-4057, Switzerland
| | - Jacques Kameni-Tcheudji
- Drug Metabolism
and Pharmacokinetics, Novartis Institutes for BioMedical Research, Basel CH-4057, Switzerland
| | - Kelly Chibale
- Department
of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
- Institute
of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa
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