Two unusual epicatechin and epiafzelechin derivatives from Mascagnia pubiflora, a plant toxic to cattle

Abstract

Dois novos e incomuns derivados de epicatequina e epiafzelequina contendo unidades feniloctanóides glicosiladas e denominados mascagninas A e B foram isolados, juntamente com quercetina-3-O-α-L-ramnopiranosil-(1→6)-β-D-glucopiranosídeo, das partes aéreas de Mascagnia pubiflora(Malpighiaceae), uma planta tóxica para o gado. Suas estruturas foram determinadas pela combinação de espectroscopia de ressonância magnética nuclear (RMN) uni e bidimensionais e dados de espectroscopia de massas (MS).

ABSTRACT - Mascagnins A and B, two novel and unusual epicatechin and epiafzelechin derivatives bearing glucosylated phenyloctanoid units, along with quercetin-3-O-α-L-rhamnopyranosyl-(1→6)-β-Dglucopyranoside were isolated from the aerial parts of Mascagnia pubiflora(Malpighiaceae), a plant toxic to cattle. Their structures were established by a combination of 1D- and 2D-nuclear magnetic resonance spectroscopic techniques and mass spectrometry data.