1. Academic Validation
  2. 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

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. 2019 Jan 24;62(2):1022-1035. doi: 10.1021/acs.jmedchem.8b01769.
Godfrey Mayoka 1 Mathew Njoroge 2 John Okombo 1 Liezl Gibhard 2 Margarida Sanches-Vaz 3 Diana Fontinha 3 Lyn-Marie Birkholtz 4 Janette Reader 4 Mariëtte van der Watt 4 Theresa L Coetzer 5 Sonja Lauterbach 5 Alisje Churchyard 5 Belinda Bezuidenhout 5 Timothy J Egan 1 6 Clive Yeates 7 Sergio Wittlin 8 9 Miguel Prudêncio 3 Kelly Chibale 1 10 6
Affiliations

Affiliations

  • 1 Department of Chemistry , University of Cape Town , Rondebosch 7701 , South Africa.
  • 2 Drug Discovery and Development Centre (H3D), Division of Clinical Pharmacology, Department of Medicine , University of Cape Town , Observatory , Cape Town 7925 , South Africa.
  • 3 Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina , Universidade de Lisboa , Av. Prof. Egas Moniz , 1649-028 Lisbon , Portugal.
  • 4 Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control , University of Pretoria , Private Bag X20 , Hatfield 0028 , South Africa.
  • 5 Wits Research Institute for Malaria, Faculty of Health Sciences , University of the Witwatersrand and National Health Laboratory Service , Johannesburg 2193 , South Africa.
  • 6 Institute of Infectious Disease and Molecular Medicine , University of Cape Town , Rondebosch 7701 , South Africa.
  • 7 Inpharma Consultancy, 6 Dudley Hill Close , Welwyn , Hertfordshire AL60QQ , U.K.
  • 8 Department of Medical Parasitology and Infection Biology , Swiss Tropical and Public Health Institute , Basel , Switzerland.
  • 9 University of Basel , Basel , Switzerland.
  • 10 South African Medical Research Council, Drug Discovery and Development Research Unit , University of Cape Town , Rondebosch 7701 , South Africa.
Abstract

Structure-activity relationship studies involving N-aryl-3-trifluoromethyl pyrido[1,2- a]benzimidazoles (PBI) identified several compounds possessing potent in vitro activities against the asexual blood, liver, and gametocyte stages of the Plasmodium parasite with no cross-resistance to chloroquine. Frontrunner lead compounds with good in vitro absorption, distribution, metabolism, and excretion (ADME) profiles were subjected to in vivo proof-of-concept studies in NMRI mice harboring the rodent P. berghei Infection. This led to the identification of compounds 10 and 49, effecting 98% and 99.93% reduction in parasitemia with mean survival days of 12 and 14, respectively, at an oral dose of 4 × 50 mg/kg. In vivo pharmacokinetics studies on 10 revealed slow absorption, low volume of distribution, and low clearance profiles. Furthermore, this series displayed a low propensity to inhibit the human ether-a-go-go-related gene (hERG) potassium ion channel whose inhibition is associated with cardiotoxicity.

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