Synthesis, antimicrobial evaluation and in silico studies of the (E)-3-(aryl)-5-styryl-1,2,4-oxadiazoles

In recent years, investigations in the field of oxadiazoles have been intensified due to their numerous therapeutic uses. Oxadiazoles are a class of compounds that exhibit several biological applications, citing antimicrobial, anti-inflammatory, anti-diabetic, anthelmintic, anti-tumor, among others. Encouraged by the biological potential of oxadiazoles, were carried out synthesis, antimicrobial evaluation and in silica studies of five (E)-3-(aryl)-5-styryl-1,2,4-oxadiazoles. In this way, (Z)-aryl-N'-hydroxybenzimidamides and ethyl (E)-cinnamate were synthesized, which were subjected to an O-acylamidoxime reaction after by dehydration using microwave irradiation to form the oxadiazole nucleus. The compounds were characterized by spectroscopic techniques, while in vitro antimicrobial activity was evaluated against S. aureus, E. faecalis, E. coli, P. aeruginosa, and against the fungus C. utilis using the microplate microdilution method. Thus, (Z)-aryl-N'-hydroxybenzimidamides, ethyl (E)-cinnamate, and (E)-3-(aryl)-5-styryl-1,2,4-oxadiazoles were synthesized with yields ranging from moderate to good. The (E)-3-(aryl)-5-styryl-1,2,4-oxadiazoles exhibited a reduced spectrum of action, which were active against the bacterium P. aeruginosa and for the fungus C. utilis.

Synthesis and antifungal activity of new O-alkylamidoximes

The continuous prospection for molecules that may be useful in the development of new therapeutic agents is a highly relevant issue, mainly because the launch of new drugs on the market does not accompany the emergence of new resistant microorganisms. In this context, this work describes the synthesis of new O-alkylamidoximes and the evaluation of its antifungal activity. The new O-alkylamidoximes were prepared using easy synthetic protocols and tested against three Candida species using the broth microdilution method. The synthesized compounds were obtained in moderate to good yields in high purity and without any observable decomposition. All tested compounds shown moderate antifungal activity against at least one strain of Candida. Despite the moderate activity of the new compounds, this was the first report involving the antifungal activity of O-alkylamidoximes. In view of the low chemotherapy arsenal and the development of fungal strains resistant to traditional antifungal agents, the present study opens new possibilities for the preparation of a new class of more active antifungal agents.