New Benzylidene‐Triazole Tethered Coumarin Molecular Hybrids: Synthesis, SAR, Molecular Modelling Simulations Targeting Tubulin α/β Dimer and its Antimicrobial Evaluation

Abstract

A series of new 7‐{3‐[3‐(Benzylidene‐amino)‐[1,2,4]triazole‐1‐yl]‐propoxy}‐4‐methyl‐chromen‐2‐one molecular hybrids 7(a–k) were synthesized using molecular hybridization approach. The synthesized new benzylidene‐triazole tethered coumarin molecular hybrids were characterized by spectroscopic studies and elemental analysis. The coumarin molecular hybrids have been explored for their antifungal efficacy in terms of tubulin inhibitors using molecular modelling studies against tubulin alphabeta hetero dimer protein. The results clearly demonstrated strong binding affinity of coumarin molecular hybrids with indole substituted and 2,4‐dihydroxy substituted as antagonists with respective binding scores of −10.5 and −10.7 kcal/mol towards tubulin alphabeta hetero dimer protein which was higher in comparison to standards griseofulvin (−8.2 kcal/mol) and fluconazole (−8.1 kcal/mol). In addition, broth dilution method was used to conduct in‐vitro antifungal studies against three fungal strains namely Candida albicans, Aspergillus niger and Aspergillus fumigatus. The results obtained clearly illustrate the antifungal activity of indole and 2,4‐dihydroxy substituted compounds which are consistent with docking simulations. Out of all the synthesized molecular hybrids, indole and 2,4‐dihydroxy substituted compounds depict outstanding antifungal activity with Minimum Inhibitory Concentration (MIC) value of 31.25 μg/ml and 62.5 μg/ml towards C.albicans and with MIC value of 31.25 for both these molecules towards A.niger in each case which is quite higher than griseofulvin and fluconazole respectively. Present work clearly demonstrates the potential efficacy of synthesized indole and 2,4‐dihydroxy substituted coumarin molecular hybrids to be considered as lead compounds for the development of new agents against resistant strains for the treatment of fungal infection.