Decaprenylphosphoryl-β-d-ribose 2'-epimerase (DprE1) is an essential enzyme in and has recently been studied as a potential drug target, with inhibitors progressing to clinical studies. Here we describe the identification of a novel series of morpholino-pyrimidine DprE1 inhibitors. These were derived from a phenotypic high-throughput screening (HTS) hit with suboptimal physicochemical properties.
View Article and Find Full Text PDFWe have targeted the Mycobacterium tuberculosis decaprenylphosphoryl-β-d-ribose oxidase (Mt-DprE1) for potential chemotherapeutic intervention of tuberculosis. A multicopy suppression strategy that overexpressed Mt-DprE1 in M. bovis BCG was used to profile the publically available GlaxoSmithKline antimycobacterial compound set, and one compound (GSK710) was identified that showed an 8-fold higher minimum inhibitory concentration relative to the control strain.
View Article and Find Full Text PDFDespite being one of the first antitubercular agents identified, isoniazid (INH) is still the most prescribed drug for prophylaxis and tuberculosis (TB) treatment and, together with rifampicin, the pillars of current chemotherapy. A high percentage of isoniazid resistance is linked to mutations in the pro-drug activating enzyme KatG, so the discovery of direct inhibitors (DI) of the enoyl-ACP reductase (InhA) has been pursued by many groups leading to the identification of different enzyme inhibitors, active against Mycobacterium tuberculosis (Mtb), but with poor physicochemical properties to be considered as preclinical candidates. Here, we present a series of InhA DI active against multidrug (MDR) and extensively (XDR) drug-resistant clinical isolates as well as in TB murine models when orally dosed that can be a promising foundation for a future treatment.
View Article and Find Full Text PDFIsoniazid (INH) remains one of the cornerstones of antitubercular chemotherapy for drug-sensitive strains of M. tuberculosis bacteria. However, the increasing prevalence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains containing mutations in the KatG enzyme, which is responsible for the activation of INH into its antitubercular form, have rendered this drug of little or no use in many cases of drug-resistant tuberculosis.
View Article and Find Full Text PDFTetrahydropyran derivative 1 was discovered in a high-throughput screening campaign to find new inhibitors of mycobacterial InhA. Following initial in-vitro profiling, a structure-activity relationship study was initiated and a focused library of analogs was synthesized and evaluated. This yielded compound 42 with improved antimycobacterial activity and low cytotoxicity.
View Article and Find Full Text PDFAs a follow up to the antimycobacterial screening exercise and the release of GSK´s first Tres Cantos Antimycobacterial Set (TCAMS-TB), this paper presents the results of a second antitubercular screening effort of two hundred and fifty thousand compounds recently added to the GSK collection. The compounds were further prioritized based on not only antitubercular potency but also on physicochemical characteristics. The 50 most attractive compounds were then progressed for evaluation in three different predictive computational biology algorithms based on structural similarity or GSK historical biological assay data in order to determine their possible mechanisms of action.
View Article and Find Full Text PDFTuberculosis (TB) is one of the world's oldest and deadliest diseases, killing a person every 20 s. InhA, the enoyl-ACP reductase from Mycobacterium tuberculosis, is the target of the frontline antitubercular drug isoniazid (INH). Compounds that directly target InhA and do not require activation by mycobacterial catalase peroxidase KatG are promising candidates for treating infections caused by INH resistant strains.
View Article and Find Full Text PDFRapid triaging of three series of related hits selected from the Tres Cantos Anti-Malarial Set (TCAMS) are described. A triazolopyrimidine series was deprioritized due to delayed inhibition of parasite growth. A lactic acid series has derivatives with IC50 < 500 nM in a standard Plasmodium falciparum in vitro whole cell assay (Pf assay) but shows half-lives of < 30 min in both human and murine microsomes.
View Article and Find Full Text PDFTwo new families of closely related selective, non-cytotoxic, and potent antitubercular agents were discovered: thioquinolines and thiazoloquinolines. The compounds were found to possess potent antitubercular properties in vitro, an activity that is dependent on experimental conditions of MIC determination (resazurin test and the presence or absence of Tween-80). To clarify the therapeutic potential of these compound families, a medicinal chemistry effort was undertaken to generate a lead-like structure that would enable murine efficacy studies and help elucidate the in vivo implications of the in vitro observations.
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