作者:Morio Yoshimura、Hideyuki Ito、Kyoko Miyashita、Tsutomu Hatano、Shoko Taniguchi、Yoshiaki Amakura、Takashi Yoshida
DOI:10.1016/j.phytochem.2008.04.004
日期:2008.12
Two flavonoids and three ellagitannins, squarrosanins A, B, and C, were isolated from the leaves of Melaleuca squarrosa. The flavonoids were characterized structurally as kaempferol-3-O-(2 ''-O-galloyl)-glucuronide and herbacetin-3-O-glucuronide, while the ellagitannins were characterized as monomeric and dimeric C-glucosidic ellagitannins by application of spectroscopic and chemical methods. The antioxidant effect of the polyphenolic constituents of the M. squarrosa leaves was also examined in vitro, and C-glucosidic tannins including oligomers were shown to be more effective radical scavengers against 1,1diphenyl-2-picrylhydi-azyl (DPPH) than flavonoids and ordinary ellagitannins. (c) 2008 Elsevier Ltd. All rights reserved.