Design, Synthesis and Anticandidal Evaluation of Indazole and Pyrazole Derivatives

Abstract

Candidiasis, caused by yeasts of the genus Candida, is the second cause of superficial and mucosal infections and the fourth cause of bloodstream infections. Although some antifungal drugs to treat candidiasis are available, resistant strains to current therapies are emerging. Therefore, the search for new candicidal compounds is certainly a priority. In this regard, a series of indazole and pyrazole derivatives were designed in this work, employing bioisosteric replacement, homologation, and molecular simplification as new anticandidal agents. Compounds were synthesized and evaluated against <i>C. albicans</i>, <i>C. glabrata</i>, and <i>C. tropicalis</i> strains. The series of 3-phenyl-1<i>H</i>-indazole moiety (<b>10a-i</b>) demonstrated to have the best broad anticandidal activity. Particularly, compound <b>10g</b>, with <i>N</i>,<i>N</i>-diethylcarboxamide substituent, was the most active against <i>C. albicans</i> and both miconazole susceptible and resistant <i>C. glabrata</i> species. Therefore, the 3-phenyl-1<i>H</i>-indazole scaffold represents an opportunity for the development of new anticandidal agents with a new chemotype.