title: Antioxidative activity of carbazoles from Murraya koenigii leaves.
abstract: The antioxidative properties of the leaves extracts of Murraya koenigii using different solvents were evaluated based on the oil stability index (OSI) together with their radical scavenging ability against 1-1-diphenyl-2-picrylhydrazyl (DPPH). The methylene chloride (CH(2)Cl(2)) extract and the ethyl acetate (EtOAc) soluble fraction of the 70% acetone extract significantly prolonged the OSI values comparable to those of alpha-tocopherol and BHT. Five carbazole alkaloids were isolated from the CH(2)Cl(2) extract and their structures were identified to be euchrestine B (1), bismurrayafoline E (2), mahanine (3), mahanimbicine (4), and mahanimbine (5) based on (1)H and (13)C NMR and mass (MS) spectral data. The OSI value of carbazoles at 110 degrees C decreased in the order 1 and 3 > alpha-tocopherol > BHT > 2 > 4, 5 and control. It is assumed that compounds 1 and 3 contributed to the high OSI value of the CH(2)Cl(2) extract of M. koenigii. The DPPH radical scavenging activity for these carbazoles was in the order ascorbic acid > 2 > 1, 3 and alpha-tocopherol > BHT > 4 and 5.
authors.affiliation: Department of Home Economics, Kenmei Women's Junior College, Honmachi, Himeji, Hyogo 670-0012, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tachibana
authors.forename: H
authors.initials: H
authors.lastname: Kikuzaki
authors.forename: N H
authors.initials: NH
authors.lastname: Lajis
authors.forename: N
authors.initials: N
authors.lastname: Nakatani
mesh_terms: D000975:Antioxidants / Q000302:isolation & purification*; D002227:Carbazoles / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D018515:Plant Leaves / Q000737:chemistry; D027821:Rutaceae / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D013057:Spectrum Analysis
chemical_list: D000975:Antioxidants; D002227:Carbazoles; D016166:Free Radical Scavengers