title: Flavonol glucuronides and C-glucosidic ellagitannins from Melaleuca squarrosa.
abstract: 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.
authors.affiliation: College of Pharmaceutical Sciences, Matsuyama University, Bunkyo-cho, Matsuyama 790-8578, Japan.
authors.forename: Morio
authors.initials: M
authors.lastname: Yoshimura
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Ito
authors.forename: Kyoko
authors.initials: K
authors.lastname: Miyashita
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Hatano
authors.forename: Shoko
authors.initials: S
authors.lastname: Taniguchi
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Amakura
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshida
mesh_terms: 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
chemical_list: D044950:Flavanones; D020719:Glucuronides; D047348:Hydrolyzable Tannins