Constituents of Vernonia gratiosa Hance and their α‐glucosidase and xanthine oxidase inhibitory activities

Abstract

AbstractEight compounds, including 11β,13‐dihydrovernolide (1), apigenin (2), kaempferol (3), quercetin 3‐O‐methyl ether (4), quercetin (5), syringaresinol‐β‐ᴅ‐glucoside (6), 3‐hydroxy‐1‐(4‐hydroxy‐3‐methoxyphenyl)‐2‐[4‐(3‐hydroxy‐1‐(E)‐propenyl)‐2,6‐dimethoxyphenoxy]propyl‐β‐ᴅ‐glucopyranoside (7), and 5‐(methoxymethyl)‐1H‐pyrrole‐2‐carbaldehyde (8) were isolated from the aerial part of Vernonia gratiosa. Their chemical structures were identified by NMR experiments along with the comparison of their spectroscopic data with those reported in the literature. In addition, all compounds were evaluated for their inhibitory effects on α‐glucosidase and xanthine oxidase. Among them, only compound 7 showed the significant inhibition of α‐glucosidase with an IC50 value of 47.08 ± 3.98 μg/mL and xanthine oxidase activity with an IC50 value of 26.92 ± 1.04 μg/mL. Compounds 1‐5 were firstly isolated from V. gratiosa, while compounds 6‐8 were reported from the genus for the first time. This is the first study about this species growing in Vietnam.