Design, synthesis and biological evaluation of novel semicarbazone-selenochroman-4-ones hybrids as potent antifungal agents.

A series of novel 2,3-dihydro-4H-1-benzoselenin-4-one (thio)semicarbazone derivatives were designed and synthesized by using molecular hybridization approach. All the target compounds were characterized by HRMS and NMR and evaluated in vitro antifungal activity against five pathogenic strains. In comparison with precursor selenochroman-4-ones, the hybrid molecules in this study showed significant improvement in antifungal activities. Notably, compound B8 showed significant antifungal activity against other strains excluding Aspergillus fumigatus (0.25 μg/mL on Candida albicans, 2 μg/mL on Cryptococcus neoformans, 8 μg/mL on Candida zeylanoides and 2 μg/mL on fluconazole-sensitive strains of Candida albicans). Moreover, compounds B8, B9 and C2 also displayed most potent activities against four fluconazole-resistance strains. Especially the MIC values of the hybrid molecule B8 against fluconazole-resistant strains were in the range of 0.5-2 μg/mL. Therefore, the molecular hybridization approach in this study provided new ideas for the development of antifungal drug.