Imidazole-thiazole coupled derivatives as novel lanosterol 14-α demethylase inhibitors: ionic liquid mediated synthesis, biological evaluation and molecular docking study

A novel series of imidazole-thiazole coupled derivatives ( 7a – 7q ) were synthesized using Green protocol and identified by different spectroscopic techniques. The synthesized derivatives ( 7a – 7q ) were evaluated for their in vitro antifungal activity against the six fungi strains. The compounds 7j and 7k exhibited the most promising antifungal activity. The compound 7k exhibited extremely high antifungal activity against C. albicans , C. glabrata, F. oxysporum , A. flavus , A. niger , and C. neoformans with MIC 80 values of 0.2, 0.2, 20, 35, 40, and 5 µg/ml respectively. The mode of action of the most promising antifungal compounds 7j and 7k was established by ergosterol extraction and quantitation assay. From the ergosterol extraction and quantitation assay it was found that the compounds 7j and 7k act by inhibition of ergosterol biosynthesis in C. albicans . The molecular docking study revealed the high spontaneous binding ability of the tested compounds to the active site of lanosterol 14α-demethylase, which proves that the tested compounds inhibit the synthesis of lanosterol 14α-demethylase. The synthesized compounds were analyzed for ADMET properties to establish oral drug like behavior and shows satisfactory results. To establish the antifungal selectivity and safety, the most active compounds were further tested for cytotoxicity against human cancer cell lines HeLa and K-562 and were found to be non-cytotoxic in nature. The in vivo acute oral toxicity study was performed for the most active compounds and results indicate that the compounds are non-toxic in nature.