Related Experiment Video
Updated: May 17, 2026

High-resolution Tandem Mass Spectrometry for Studying Chemical Constituents of Gynura bicolor DC
Published on: February 2, 2024
Two new hemiterpene glycosides from the leaves of Ilex rotunda. Thunb
Manh Heun Kim1, Kwan Hee Park, Myeong Hwan Oh
1Department of Pharmacognosy, College of Pharmacy, Chung-Ang University, Seoul, Republic of Korea.
Abstract:
Chromatographic separation of the 80% MeOH extract of the leaves of Ilex rotunda (IR) led to isolation of two new hemiterpene glycosides, tentatively named as rotundarpenoside A (1) and rotundarpenoside B (2), along with five known caffeoyl derivatives (3-7). The chemical structures of these compounds were elucidated using 1D/2D NMR, HR-MS, and the absolute configuration was confirmed by Mosher's method. In order to evaluate their anti-oxidative activities, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and xanthine oxidase superoxide scavenging activities (NBT) were determined.
Related Concept Videos
Thermal and Photochemical Electrocyclic Reactions: Overview
Thermal Electrocyclic Reactions: Stereochemistry
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.