Reddyrajula, R.Perveen, S.Negi, A.Etikyala, U.Vijjulatha, V.Sharma, R.Udayakumar, D.2026-02-042024Bioorganic Chemistry, 2024, 151, , pp. -452068https://doi.org/10.1016/j.bioorg.2024.107702https://idr.nitk.ac.in/handle/123456789/20888The mycobacterial F-ATP synthase is responsible for the optimal growth, metabolism and viability of Mycobacteria, establishing it as a validated target for the development of anti-TB therapeutics. Herein, we report the discovery of an N-acyl phenothiazine derivative, termed PT6, targeting the mycobacterial F-ATP synthase. PT6 is bactericidal and active against the drug sensitive, Rifampicin-resistant as well as Multidrug-resistant tuberculosis strains. Compound PT6 showed noteworthy inhibition of F-ATP synthesis, exhibiting an IC<inf>50</inf> of 0.788 µM in M. smegmatis IMVs and was observed that it could deplete intracellular ATP levels, exhibiting an IC<inf>50</inf> of 30 µM. PT6 displayed a high selectivity towards mycobacterial ATP synthase compared to mitochondrial ATP synthase. Compound PT6 showed a minor synergistic effect in combination with Rifampicin and Isoniazid. PT6 demonstrated null cytotoxicity as confirmed by assessing its toxicity against VERO cell lines. Further, the binding mechanism and the activity profile of PT6 were validated by employing in silico techniques such as molecular docking, Prime MM/GBSA, DFT and ADMET analysis. These results suggest that PT6 presents an attractive lead for the discovery of a novel class of mycobacterial F-ATP synthase inhibitors. © 2024 Elsevier Inc.5 chloro 1 [1 [2 oxo 2 (10h phenothiazin 10 yl)ethyl]piperidin 4 yl] 1,3 dihydro 2h benzo[d]imidazol 2 one5 chloro 3 (4 fluorobenzyl) 1 [1 [2 oxo 2 (10h phenothiazin 10 yl)ethyl]piperidin 4 yl] 1,3 dihydro 2h benzo[d]imidazol 2 onebedaquilinedicyclohexylcarbodiimideisoniazidphenothiazinephenothiazine derivativeproton transporting adenosine triphosphate synthaseproton transporting adenosine triphosphate synthase inhibitorrifampicintuberculostatic agentunclassified drugenzyme inhibitorantibacterial activityArticlebinding affinitycell viabilitycomputer modelcontrolled studydrug bindingdrug designdrug efficacydrug potencydrug screeningdrug synthesiselectrophilicityenzyme inhibitionevaluation studyfractional inhibitory concentrationfractional inhibitory concentration indexhydrogen bondIC50in vitro studymembrane vesicleminimum inhibitory concentrationmolecular dockingmultidrug resistancemultidrug resistant tuberculosisMycobacterium smegmatisMycobacterium tuberculosisnonhumanoral absorptionpharmacophorerifampicin resistanceselectivity indexsynergistic effectVero cell lineanimalchemical structurechemistryChlorocebus aethiopsdose responsedrug effectdrug therapyenzymologymicrobial sensitivity teststructure activity relationsynthesisAnimalsAntitubercular AgentsDose-Response Relationship, DrugDrug DesignEnzyme InhibitorsMicrobial Sensitivity TestsMolecular Docking SimulationMolecular StructurePhenothiazinesStructure-Activity RelationshipTuberculosis, Multidrug-ResistantVero Cells