Dimeric glycosylated flavan-3-ol and antimicrobial in vitro evaluation of Trichilia catigua extracts

Abstract

Trichilia catigua is a tree known as “catuaba”, widely distributed in Brazil. Studies carried out with T. catigua 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 T. catigua 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-O-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 Enterococcus faecium (VREfm) with MIC of 156.5 μg/mL. The results suggest that extract of T. catigua could potentially be used as an adjuvant to treatment and is a promising candidate for the development of new antimicrobial drugs.

Graphical Abstract

Keywords:

• Catuaba
• antibacterial
• antifungal
• capillary electrophoresis
• proanthocyanidin

Acknowledgements

The authors are grateful to Brazilian agencies Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Financiadora de Estudos e Projetos (FINEP), Complexo de Centrais de Apoio à Pesquisa (COMCAP/UEM), and Laboratory of Electron Microscopy and Microanalysis (UEL/SETI), for their financial support and fellowships awarded to M.R. Ritter, A.L. Sereia, D. Chierrito, and D. C. Medeiros. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Disclosure statement

The authors declare no conflict of interest.