Leaves of Duroia longiflora: Isolation of a Biflavanoid and Histochemical Analysis

Abstract

Duroia longiflora (Rubiaceae) is an Amazonian plant species with no previous chemical study. The aim of this work was to study the chemical composition of D. longiflora leaves and study their histochemistry. In vivo tissues of the leaves were histolocalized. Extracts were made from dried leaves with hexane, methanol, and water and the methanolic extract was fractionated. Fractionation of the dichloromethane phase of the methanolic leaf extract allowed the isolation of a biflavanoid. Via nuclear magnetic resonance (mono and bidimensional), mass spectrometer analysis, and comparison with existing literature, its chemical structure was identified as 2α,3α-epoxy-5,7,3′,4′-tetrahydroxyflavan-(4β→8)-epicatechin. This is the first report describing the histochemical and phytochemical studies of D. longiflora leaves. As far as we know, this is the first report of this substance in any Rubiaceae species.