Vasorelaxant activity of 7-β-O-glycosides biosynthesized from flavonoids.

In this work we report the vasorelaxant activity of 7-β-O-glycosides obtained with biosynthesis of naringenin-7-β-O-glycoside (3) and quercetin-7-β-O-glycoside (4). These compounds were obtained from naringenin (1) and quercetin (2) glycosylation catalyzed by Beauveria bassiana ATCC 7159. Screening of the best strain as a catalyst for glycosylation was carried out and the reaction conditions established. Cultures were grown in PDSM medium for 7 days at 27 °C. After purification by reverse-phase preparative HPLC, naringenin-7-β-O-glycoside (3) and quercetin-7-β-O-glycoside (4) were identified by (1)H and (13)C NMR. The right position and β-configuration of the glucose was determined through HSQC and HMBC experiments. The vasorelaxation potential of naringenin, quercetin and its glycosylated derivatives was evaluated using isolated aorta in vitro models. Interestingly, results suggest that vasorelaxation properties of naringenin, rutin and its glycosides are due to different pathways.