Synthesis and antifungal activity of novel 1,2,4-triazolyl coumarins

Coumarins and triazoles are two interesting groups of heterocyclic compounds, both exhibiting a wide range of biological activities. The joining of these two scaffolds into a hybrid compound with the improved activities has already been reported. [1] In this research, 11 new hybrid compounds were synthesized, utilizing a deep eutectic solvent as an environmentally sustainable method of organic synthesis. Compounds were obtained in good yields through a one-step reaction of coumarinyl hydrazides and various substituted isothiocyanates, without the use of catalysts. [2] Since many commercially available fungicides are based on triazole derivatives, antifungal activity of 1, 2, 4-triazolyl coumarins was evaluated in vitro on two pathogenic fungi, Fusarium oxysporum and Fusarium culmorum. The tested compounds moderately inhibited the mycelial growth of F. oxysporum (35.0-57.5%), but were mostly ineffective against F. culmorum. Compound 1b, as the most potent growth inhibitor, was further analyzed computationally. A molecular docking analysis was performed to evaluate the binding mode of compound 1b with sterol 14 α-demethylase, the target enzyme of triazole based fungicides