Synthesis and in vitro Antifungal Activity of 2-Aryl-5-phenylsulfonyl-1,3,4-thiadiazole Derivatives

The synthesis and antifungal activity of a series of 2-nitroaryl-5-phenylsulfonyl-1,3,4-thiadiazoles (5a-e) are described. The in vitro antifungal activity of the compounds was determined against a variety of fungal strains in comparison to miconazole (CAS 22916-47-8) and fluconazole (CAS 86386-73-4). Two derivatives (5d, 5e) showed high activity against Candida albicans and Candida spp. having MIC values ranging from 0.048-3.12 μg/ml, providing higher potencies than the reference drug fluconazole. Compound 5a also showed high activity against Cryptococcus neoformans (MIC < 0.048 μg/ml). The activity of this compound against Aspergillus niger and Aspergillus fumigatus was moderate (MIC = 1.56-6.25 μg/ml), while fluconazole was inactive. Moreover, the nitroimidazole derivative 5d possessed good activity against most fungal strains in comparison to fluconazole.