Title
Baeckeins J and K, Two Novel C-Methylated Biflavonoids from the Roots of Baeckea frutescens and Their Cytoprotective Activities
Author
Bei-Xi Jia, Ao Jia, Chao-Jie Li, Hui-Qin Zhao, Feng-Xiao Ren, Hong-Min Liu, Qiang Wang
Year
2016
Journal
Helvetica Chimica Acta
Abstract
Baeckea frutescens is an aromatic shrub used for ornamentals and food flavor spices in the southern part of China. Two novel C-methylated biflavonoids named baeckeins J (1) and K (2) were isolated from the roots of B. frutescens, which possessed the unique carbon skeleton conjugated of a flavonol and one isoflavanonol molecule via the linkages of C(2)-C(8*) and C(3)-O-C(7*). The structures of compounds 1 and 2 were elucidated by analysis of 1D- and 2D-NMR and HR-ESI-MS spectral data, and the absolute stereochemistry for chiral carbons C(2) and C(3) were assigned by CD spectrometry combined with quantum chemical calculations. In the bioassay, baeckeins J and K exhibited strong cytoprotective effects on H2O2-induced oxidative cell death in PC12 cells
Instrument
J-810
Keywords
Circular dichroism, Absolute configuration, Pharmaceutical