title: Antioxidants and a new dihydroisocoumarins from Polygala hongkongensis Hemsl.
abstract: A new dihydroisocoumarins, 6-methoxy-8-hydroxy-3-(4-hydroxyphenyl)isochroman-1-one, named as hongkongenin (1), and seven known flavonoids were isolated from the methanol extract whole plant of Polygala hongkongensis Hemsl. Their structures were established on the basis of UV, IR, NMR, and MS spectral data. It is the first report of the occurrence of isocoumarins in Polygala, and the known compounds 2-8 were isolated from this plant for the first time. Flavonoids showed potent antioxidant activities in vitro against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, hydroxyl radicals, and reductive activity to Fe3+.
authors.affiliation: Shenyang Pharmaceutical University, Shenyang 110016, China.
authors.forename: Jian-Feng
authors.initials: JF
authors.lastname: Wu
authors.forename: Si-Bao
authors.initials: SB
authors.lastname: Chen
authors.forename: Jing-Chun
authors.initials: JC
authors.lastname: Gao
authors.forename: Hao-Liang
authors.initials: HL
authors.lastname: Song
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Wu
authors.forename: Shi-Lin
authors.initials: SL
authors.lastname: Chen
authors.forename: Peng-Fei
authors.initials: PF
authors.lastname: Tu
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification*; D001713:Biphenyl Compounds / Q000737:chemistry; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification; D016166:Free Radical Scavengers / Q000737:chemistry / Q000302:isolation & purification; D006834:Hydrazines / Q000737:chemistry; D017665:Hydroxyl Radical / Q000737:chemistry; D020128:Inhibitory Concentration 50; D007501:Iron / Q000737:chemistry; D049934:Isocoumarins / Q000737:chemistry / Q000302:isolation & purification*; D019906:Nuclear Magnetic Resonance, Biomolecular; D009904:Optical Rotation; D010851:Picrates; D035261:Plant Components, Aerial / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry; D031801:Polygala / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D005419:Flavonoids; D016166:Free Radical Scavengers; D006834:Hydrazines; D049934:Isocoumarins; D010851:Picrates; D017665:Hydroxyl Radical; C004931:1,1-diphenyl-2-picrylhydrazyl; D007501:Iron