New azole derivatives showing antimicrobial effects and their mechanism of antifungal activity by molecular modeling studies

Abstract

Azole antifungals are potent inhibitors of fungal lanosterol 14α demethylase (CYP51) and have been used for eradication of systemic candidiasis clinically. Herein we report the design, synthesis, and biological evaluation of a series of 1-phenyl/1-(4-chlorophenyl)-2-(1H-imidazol-1-yl)ethanol esters. Many of these derivatives showed fungal growth inhibition at very low concentrations. Minimal inhibition concentration (MIC) value of 15 was 0.125 μg/mL against Candida albicans. Additionally, some of our compounds, such as 19 (MIC: 0.25 μg/mL), were potent against resistant C. glabrata, a fungal strain less susceptible to some first-line antifungal drugs. We confirmed their antifungal efficacy by antibiofilm test and their safety against human monocytes by cytotoxicity assay. To rationalize their mechanism of action, we performed computational analysis utilizing molecular docking and dynamics simulations on the C. albicans and C. glabrata CYP51 (CACYP51 and CGCYP51) homology models we built. Leu130 and T131 emerged as possible key residues for inhibition of CGCYP51 by 19.