RESUMEN
Phytochemical investigation of the trunks from Gnetum latifolium led to the isolation of a novel phenolic glucoside, 2E-2,4-di-(3,4-dihydroxyphenyl)but-2-en-1-yl-O-ß-D-glucopyranoside (1), along with five known stilbene derivatives (2-6). Their structures were determined mainly using high-resolution electrospray ionisation mass spectrometry and nuclear magnetic resonance spectroscopic analyses, followed by comparisons of observed spectral data with reported values. The novel compound 1 in G. latifolium was found to be useful as a chemotaxonomic marker. Biological evaluation revealed that compound 6 had remarkable inhibitory effects on nitric oxide production, with a half-maximal inhibitory concentration (IC50) value of 4.85 ± 0.20 µM, which was much higher than that of the positive control dexamethasone (IC50 = 14.20 ± 0.54 µM).
RESUMEN
This research aims to explore the saponins composition of H. nepalensis in four northwest mountainous areas of Vietnam including Ha Giang, Lai Chau, Lao Cai, and Lang Son with the aid of high-resolution mass spectrometry. As a result, 42 saponins are successfully identified in H. nepalensis leaves by UHPLC-Q-TOF-MS/MS analyses, in which two 30-noroleanane and four oleanane triterpene saponins structures have been reported for the first time. Two structures of compound 20 were discovered in four samples. Two structures of compound 8 were found in H. nepalensis from Ha Giang and Lao Cai, while two structures of compound 28 were not observed in Lang Son. Different environmental and climatic circumstances in various places may have an impact on chemical constituents of H. nepalensis. By providing the phytochemicals profile of H. nepalensis leaves, our study supports the orientation for future research on this medicinal plant as well as other Hedera species.