An analysis of the main secondary metabolites of Dendrobium nobile revealed three new sesquiterpenoids

• Published in: Phytochemistry letters Vol. 53; pp. 226 - 230
• Main Authors: Chen, Xingyue, Wu, Bin, Gong, Daoyong, Fu, Dezhao, Qin, Hongting, Li, Biao
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2023
• Subjects: Antioxidant; Biosynthesis; Dendrobium nobile; Secondary metabolites; Sesquiterpenoids; Dendrobium nobile; Secondary metabolites; Biosynthesis; Antioxidant; Sesquiterpenoids
• ISSN: 1874-3900; 1876-7486
• DOI: 10.1016/j.phytol.2022.12.020

Eight secondary metabolites including three new sesquiterpenoids, named dendronobin (1), dendrobilin L (2) and 1,4-trans-12-hydroxycalamenene-12-O-β-D-glucoside (3), together with five known compounds, dendrobine (4), nobiline (5), dihydroxyconiferyl alcohol (6), 5-methoxy-(+)-isolariciresinol (7), lyoniresinol (8) were isolated from the stems of Dendrobium nobile Lindl. Their structures were determined by extensive spectral analysis using HR-ESI-MS and NMR spectra (1H, 13C, 1H-1H COSY, HSQC, HMBC, and NOESY), and the absolute configurations of compounds 1-3 were determined by electronic circular dichroism (ECD) and theoretical calculations. Among these metabolites (1-8), dendronobin L (2) possessed a unique carbon skeleton. A potential biosynthetic pathway from dendronobin L (2) to dendrobine was suggested. Nobiline (5), dihydroxyconiferyl alcohol (6) and 5-methoxy-(+)-isolariciresinol (7) showed weak antioxidant activity. [Display omitted] •Three new sesquiterpenoids were isolated from Dendrobium nobile stem.•Eight secondary metabolites were determined by extensive spectral analysis.•The possible biosynthetic pathway of dendronobin to dendrobine was proposed.