Synthesis and in vitro antifungal and cytotoxicity evaluation of thiazolo-4H-1,2,4-triazoles and 1,2,3-thiadiazolo-4H-1,2,4-triazoles

The increasing clinical importance of drug-resistant fungal pathogens has l ent additional urgency to microbiological and antifungal research. Various thiazolo(or 1,2,3-thiadiazolo)thiosemicarbazides (2a-2e), 3-thiono-1,4-dihy drotriazolothiazoles-(or 1,2,3-thiadiazoles) (3a-3e), their related substit uted thio-4H-1,2,4-triazoles (4a-4p) and sulfones (5a-5o) were synthesized. Most of the compounds tested for antifungal activity exhibited significant effects against Cryptococcus neoofrmans and Sacchromyces cerevisiae MIC ra nges of 0.53 to 12.5 mug/mL, whereas their activities were moderate against Candida albicans and weak against Asgergillus fumigatus. Ar 10 ppm concent ration, all compounds showed low toxicity on brine shrimps (higher than 80% survival), except compounds 4c and 2c. At 100 ppm concentration most of th e compounds showed toxicity except compounds 2b, 2e, 3c, 3d, 3e; and 4e, Co mpounds 4b, 4c, and 4h showed in vitro cytotoxicity against Kbalb cell line s and compounds 4e and 4g against 143B cell lines at 0.1 mM concentration.