In vitro antifungal evaluation and structure-activity relationship of diphenyl diselenide and synthetic analogues.

We report on in vitro antifungal activity and the structure-activity relationship of diphenyl diselenide [(PhSe)(2) ] and its synthetic analogues, (p-Cl-C(6) H(4) Se)(2), (m-CF(3)-C(6) H(4)Se)(2) and (p-CH(3)O-C(6) H(4)Se)(2), against 116 strains of pathogenic fungi. (PhSe)(2) showed the highest inhibitory activity against Candida albicans (minimum inhibitory concentration of 4-32 μg ml(-1) ), Candida dubliniensis (2-16 μg ml(-1)), Aspergillus spp. (0.5-64 μg ml(-1)) and Fusarium spp. (2-16 μg ml(-1)). Its minimum fungicidal concentration (MFC) varied among C. albicans (4-64 μg ml(-1)), C. dubliniensis (2-32 μg ml(-1) ) and Fusarium spp. (4-64 μg ml(-1)). Antifungal activity was decreased by the introduction of functional groups to the (PhSe)(2) molecule: (PhSe)(2) >(p-CH(3)O-C(6)H(4) Se)(2) >(m-CF(3)-C(6)H(4)Se)(2) >(p-Cl-C(6) H(4)Se)(2).