Flavonol glucuronides and C-glucosidic ellagitannins from Melaleuca squarrosa.
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 1,1-diphenyl-2-picrylhydrazyl (DPPH) than flavonoids and ordinary ellagitannins.
Yoshimura
Morio
M
College of Pharmaceutical Sciences, Matsuyama University, Bunkyo-cho, Matsuyama 790-8578, Japan.
Ito
Hideyuki
H
Miyashita
Kyoko
K
Hatano
Tsutomu
T
Taniguchi
Shoko
S
Amakura
Yoshiaki
Y
Yoshida
Takashi
T
D044950:Flavanones / Q000737:chemistry / Q000378:metabolism*; D020719:Glucuronides / Q000737:chemistry / Q000378:metabolism*; D047348:Hydrolyzable Tannins / Q000737:chemistry / Q000378:metabolism*; D031650:Melaleuca / Q000737:chemistry* / Q000378:metabolism; D015394:Molecular Structure
D044950:Flavanones; D020719:Glucuronides; D047348:Hydrolyzable Tannins