title: Kaempferol glycosides with antioxidant activity from Brassica juncea.
abstract: From the leaves of Brassica juncea, three kaempferol glycosides, kaempferol-3-O-(2-O-sinapoyl)-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside-7-O-beta-D-glucopyranoside (1), kaempferol-3-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside-7-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside (2), and kaempferol-3-O-(2-O-sinapoyl)-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside-7-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside (3) were isolated and the structures elucidated on the basis of spectral and chemical evidences. Antioxidant activities were determined by measuring the scavenging activities on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and peroxynitrite (ONOO(-)). Compounds 1 and 3 showed good antioxidant activities with respective IC(50) values of 28.61 and 36.93 microM toward DPPH; respective IC(50) values of 9.79 and 11.40 microM toward ONOO(-). However, compound 2 showed no DPPH scavenging activity and weak ONOO(-) scavenging activity with an IC(50) value of 32.00 microM.
authors.affiliation: Division of Food Science and Biotechnology, Pukyong National University, Busan, Korea.
authors.forename: Hyun Ah
authors.initials: HA
authors.lastname: Jung
authors.forename: Ju Jung
authors.initials: JJ
authors.lastname: Woo
authors.forename: Mee Jung
authors.initials: MJ
authors.lastname: Jung
authors.forename: Geum-Sook
authors.initials: GS
authors.lastname: Hwang
authors.forename: Jae Sue
authors.initials: JS
authors.lastname: Choi
mesh_terms: D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000737:chemistry; D005609:Free Radicals / Q000737:chemistry; D006027:Glycosides / Q000302:isolation & purification / Q000494:pharmacology*; D044949:Kaempferols / Q000302:isolation & purification / Q000494:pharmacology*; D015394:Molecular Structure; D009149:Mustard Plant / Q000737:chemistry*; D030421:Peroxynitrous Acid / Q000737:chemistry; D010851:Picrates / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D005609:Free Radicals; D006027:Glycosides; D044949:Kaempferols; D010851:Picrates; D030421:Peroxynitrous Acid; C006552:kaempferol; C004931:1,1-diphenyl-2-picrylhydrazyl