title: Antioxidant constituents in the dayflower (Commelina communis L.) and their alpha-glucosidase-inhibitory activity.
abstract: The dayflower, Commelina communis L., contains 1-deoxynojirimycin (DNJ) and (2R,3R,4R,5R)2,5-bis(hydroxymethyl)-3,4-dihydroxypyrrolidine (DMDP), potent alpha-glucosidase inhibitors. The extracts and powder of this herb are important food materials for prophylaxis against type 2 diabetes. Eleven flavonoid glycosides as antioxidants, isoquercitrin, isorhamnetin-3-O-rutinoside, isorhamnetin-3-O-beta-D-glucoside, glucoluteolin, chrysoriol-7-O-beta-D-glucoside, orientin, vitexin, isoorientin, isovitexin, swertisin, and flavocommelin, were identified from the aerial parts of C. communis. Their antioxidant activities were measured using in vitro assays employing the 1,1-diphenyl-2-picrylhydrazyl radical- and superoxide radical-scavenging assays. The results showed that glucoluteolin, orientin, isoorientin, and isoquercitrin are the predominant antioxidants in this herb. Moreover, isoquercitrin, isorhamnetine-3-O-rutinoside, vitexin, and swertisin inhibited the activity of alpha-glucosidase from rat intestine.
authors.affiliation: Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka, 569-1094, Japan. shibano@gly.oups.ac.jp
authors.forename: Makio
authors.initials: M
authors.lastname: Shibano
authors.forename: Koji
authors.initials: K
authors.lastname: Kakutani
authors.forename: Masahiko
authors.initials: M
authors.lastname: Taniguchi
authors.forename: Masahide
authors.initials: M
authors.lastname: Yasuda
authors.forename: Kimiye
authors.initials: K
authors.lastname: Baba
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology; D034822:Commelina / Q000737:chemistry*; D003924:Diabetes Mellitus, Type 2 / Q000517:prevention & control; D005419:Flavonoids / Q000302:isolation & purification / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000302:isolation & purification / Q000494:pharmacology; D065089:Glycoside Hydrolase Inhibitors; D006027:Glycosides / Q000302:isolation & purification / Q000494:pharmacology; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000201:enzymology; D035261:Plant Components, Aerial; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D013481:Superoxides / Q000378:metabolism
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D016166:Free Radical Scavengers; D065089:Glycoside Hydrolase Inhibitors; D006027:Glycosides; D010936:Plant Extracts; D013481:Superoxides