Benzothiazol clubbed imidazol-4-ones as anti-fungal, anti-tubercular and anti-HIV-1 agents: Their synthesis and molecular docking study

Background: The present work describes antimicrobial, antimycobacterium and anti HIV-1 evaluation of newly synthesized 5-(4-Substituted-benzylidene)-3-[4-(5-methyl-benzothiazol2-yl)-phenyl]-2-phenyl-3,5-dihydro-imidazol-4-one (4a-o). The docking studies were performed in order to predict the potential binding affinities. Objective: The major aim of this study is to develop the new class of bezylidine candidate clubbed with benzothiazole with less toxicity and improved potency as antimicrobial, antitubercular and anti HIV-1. Methods: The titled compounds were characterized by spectral studies (IR, 1H NMR, 13C NMR and Mass). In vitro antimycobacterium activity was carried out using Lowenstein-Jensen medium method and antimicrobial activity using the broth microdilution method. The anti HIV-1 reverse transcriptase activity was determined by the colorimetric MTT method and inhibition of virusinduced cytopathogenicity in MT-4 cells. Results: Compound 4i (50 µM) showed better antifungal activity against A. clavatus. Compound 4g (50 µM) with 95% inhibition demonstrated good activity against M. tuberculosis H37Rv. Compound 4k showed CC50 (50 µM) against MT-4 (CD4+ Human T-cells containing an integrated HTLV-1 genome) cells by 50%, while 16 µM concentration value EC50 from the HIV-1 induced cytopathogenicity. Molecular docking study suggested that 4k interacted with the target with binding energy by Vina score (-10.3 Kcal/mol) Conclusion: The preliminary in vitro evaluation results revealed that some of the compounds have promising antimicrobial activities as well as antitubercular potency. Among the various substituents on benzylidene, the nitro group was the most beneficial for improving the anti-HIV-1 activity. Docking result suggested that 4k compound could be acting as a non-competitive or weak inhibitor of Reverse Transcriptase (RT).