Dimeric glycosylated flavan-3-ol and antimicrobial evaluation of extracts.

is a tree known as "catuaba", widely distributed in Brazil. Studies carried out with barks suggest that plant has antidepressant, antidiabetic, antimicrobial, antioxidant, antiviral, and preventive against brain damage. The aim of this work was to isolate and characterise compounds from the semipurified fraction of barks, and to conduct microbiological screening against bacteria and fungi. The crude extract (CE) of "catuaba" was produced by turbo extraction with acetone-water, and later, partitioned to yield ethyl-acetate (EAF) and aqueous (AqF) fractions. From AqF the new catechin-3--α-L-rhamnoside-(4α→8)-epicatechin was isolated, identified, and described here for the first time. Regarding antimicrobial activity, the extracts presented impressive results, mainly for Vancomycin Resistant (VRE) with MIC of 156.5 μg/mL. The results suggest that extract of could potentially be used as an adjuvant to treatment and is a promising candidate for the development of new antimicrobial drugs.