A new strategy for hit generation: Novel in cellulo active inhibitors of CYP121A1 from Mycobacterium tuberculosis via a combined X-ray crystallographic and phenotypic screening approach (XP screen)

• Published in: European journal of medicinal chemistry Vol. 230; p. 114105
• Main Authors: Frederickson, Martyn, Selvam, Irwin R., Evangelopoulos, Dimitrios, McLean, Kirsty J., Katariya, Mona M., Tunnicliffe, Richard B., Campbell, Bethany, Kavanagh, Madeline E., Charoensutthivarakul, Sitthivut, Blankley, Richard T., Levy, Colin W., de Carvalho, Luiz Pedro S., Leys, David, Munro, Andrew W., Coyne, Anthony G., Abell, Chris
• Format: Journal Article
• Language: English
• Published: ISSY-LES-MOULINEAUX Elsevier Masson SAS 15.02.2022; Elsevier; Editions Scientifiques Elsevier
• Subjects: Antitubercular Agents - pharmacology; Chemistry, Medicinal; CYP121; Drug Design; Drug discovery; Humans; Life Sciences & Biomedicine; Mycobacterium tuberculosis; Pharmacology & Pharmacy; Science & Technology; Tuberculosis; Tuberculosis - drug therapy; X-ray crystallography; X-Rays; X-ray crystallography; CYP121; Tuberculosis; Drug discovery; Mycobacterium tuberculosis; CYTOCHROME-P450; SITE; FLAVODOXIN; POTENT; INTEGRATION; DISCOVERY; FEATURES
• ISSN: 0223-5234; 1768-3254; 1768-3254
• DOI: 10.1016/j.ejmech.2022.114105

There is a pressing need for new drugs against tuberculosis (TB) to combat the growing resistance to current antituberculars. Herein a novel strategy is described for hit generation against promising TB targets involving X-ray crystallographic screening in combination with phenotypic screening. This combined approach (XP Screen) affords both a validation of target engagement as well as determination of in cellulo activity. The utility of this method is illustrated by way of an XP Screen against CYP121A1, a cytochrome P450 enzyme from Mycobacterium tuberculosis (Mtb) championed as a validated drug discovery target. A focused screening set was synthesized and tested by such means, with several members of the set showing promising activity against Mtb strain H37Rv. One compound was observed as an X-ray hit against CYP121A1 and showed improved activity against Mtb strain H37Rv under multiple assay conditions (pan-assay activity). Data obtained during X-ray crystallographic screening were utilized in a structure-based campaign to design a limited number of analogues (less than twenty), many of which also showed pan-assay activity against Mtb strain H37Rv. These included the benzo[b][1,4]oxazine derivative (MIC90 6.25 μM), a novel hit compound suitable as a starting point for a more involved hit to lead candidate medicinal chemistry campaign. [Display omitted] •CYP121 from M.tuberculosis has been previously shown to be a crucial target for the survival of the mycobacteria.•Strategies previously employed have identified high affinity inhibitors however these have lacked activity on M.tuberculosis.•The strategy reported here uses a combination of X-ray crystallography and phenotypic screening (XP Screen) to identify compounds.•The XP screen approach identified a number of compounds which show good affinity (up to 3.2 μM) and MIC against M.tuberculosis (up to 6.25 μM).