<i>In vitro</i> study on α-amylase and α-glucosidase inhibitory activities of a new stigmastane-type steroid saponin from the leaves of <i>Vernonia amygdalina</i>

Abstract

Using various chromatographic separations, four compounds, including one new steroid saponin named vernoamyoside E (<b>1</b>), were isolated from the leaves of the Vietnamese medicinal plant <i>Vernonia amygdalina</i> Delile (Asteraceae). Their structures were established by spectroscopic methods such as 1D- and 2D-NMR, HR-ESI-MS, and HPLC analysis. The inhibitory activities against α-glucosidase and α-amylase of the isolated compounds from <i>V. amygdalina</i> were reported for the first time. The results indicated that compound <b>1</b> significantly inhibited both against α-amylase and α-glucosidase activity.