Síntese de bis-iminas aromáticas e avaliação da atividade biológica contra fungos de interesse clínico

Abstract

In this work were synthesized and characterized nineteen imines with 53 at 95% of yield, divided into two series, from the condensation of hydroxybenzaldehydes (ortho, meta and para) with phenylenediamines (ortho, meta and para) and between the aromatic dialdehydes (ortho, meta and para) with aminephenols (ortho, meta and para). Unfortunately,some of these reactions afforded cyclized derivatives of benzoimidazole (5 and 9) and pyrrolidine (14 e 16). Among all the compounds synthesized, five are new in the literature. The synthesis of a third series of bis-imines (amines) also was proposed, but in despiteall efforts and attempts, it was not obtained. In the second part of this work, the synthesized compounds were assayed in vitroagainst nine strains of clinical interest fungi: Candida albicans (ATCC 18804), Candida Krusei (ATCC 20298), Candida parapsilosis (ATCC 20019), Candida tropicalis (ATCC 750), Aspergillus clavatus (clinical isolate), Aspergillus flavus (clinical isolate), Aspergillusfumigatus (ATCC 16913), Aspergillus niger (clinical isolate) e Aspergillus tamari (clinical isolate). The results for the Aspergillus species were better than for Candida species, especially those derived from pyrrolidine showed to be until 16 times more potent than the reference drug (Fluconazole). The best results for the bis-imines not cyclized were for that compounds which have the hydroxyl group in the ortho position, suggesting the importance of the hydroxyl position for biological activity. Furthermore, the second series compounds, hydroxylated bis-imines,showed better results than first series, demonstrating that the position of the imine nitrogen also influences in the biological activity.