Ésteres derivados do ácido bifenil-4-carboxílico e atividade antifúngica

Abstract

The candidiasis is a superficial or a systemic fungal infection caused by a species of the yeast Candida.The groups with the greatest predisposition for these infections are immunocompromised patients such HIV infected individuals, carriers of chronic diseases as cancer, diabetes and transplanted patients, as well as the elderly and newborns. Some of the species of this genus have already shown resistance to a wide range of antifungal agents, which is increasing the severity of these infections and also the complexity of the treatment of this pathogenesis. In this work a collection of esters derivatives from biphenyl-4-carboxylic acid was prepared, and the activity of these compounds against the pathogenic species of the genus Candida was investigated. Two types of reactions were used to prepare the esters, the Fischer esterification, and the so-called non-Fischer esterification in which alkyl halides are used. The antifungal assays were performed with the broth microdilution method. Thus, the main objective of this work was to draw a structure-activity relation of the obtained compounds. Among the eight esters prepared in the present study, four presented activity against strains of Candida albicans and Candida tropicalis. The bioactive substances showed good to moderate bioactivity. The ethyl 4-biphenyl carboxylate ester obtained MIC ranging from 1024 to 512μg / mL, and the decanoyl 4-Biphenyl carboxylate ester obtained 512μg / mL MIC for all the strains tested and showing the best bioactivities among the evaluated compounds. In addition, all molecules with the presence of both a heroatom or bulky groups closest to the ester function demonstrated bioactivity.