title: DPPH free radical scavenger components from the fruits of Alpinia rafflesiana Wall. ex. Bak. (Zingiberaceae).
abstract: The methanol extract of the dried ripe fruits of Alpinia rafflesiana was investigated for its DPPH free radical scavenger constituents. 2',3',4',6'-Tetrahydroxychalcone (7), which has never been isolated from natural sources was found to be most active as a DPPH free radical scavenger with the IC50 value of 55 microM. Other known compounds isolated from this species include 5,6-dehydrokawain (1), flavokawin B (2). 1,7-diphenyl-5-hydroxy-6-hepten-3-one (3), (-)-pinocembrin (4), cardamonin (5) and (-)-pinostrobin (6). The DPPH free radical scavenger compounds were detected using TLC autographic analysis. The percentage inhibition of DPPH free radical scavenging activity was measured on isolates (5-7) using colorimetric analysis.
authors.affiliation: Laboratory of Natural Products, Institute of Bioscience, University Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
authors.forename: Habsah
authors.initials: H
authors.lastname: Mohamad
authors.forename: Faridah
authors.initials: F
authors.lastname: Abas
authors.forename: Dharma
authors.initials: D
authors.lastname: Permana
authors.forename: Nordin H
authors.initials: NH
authors.lastname: Lajis
authors.forename: Abdul Manaf
authors.initials: AM
authors.lastname: Ali
authors.forename: Mohd Aspollah
authors.initials: MA
authors.lastname: Sukari
authors.forename: Taufiq Y Y
authors.initials: TY
authors.lastname: Hin
authors.forename: Hiroe
authors.initials: H
authors.lastname: Kikuzaki
authors.forename: Nobuji
authors.initials: N
authors.lastname: Nakatani
mesh_terms: D032429:Alpinia / Q000737:chemistry*; D001713:Biphenyl Compounds / Q000302:isolation & purification / Q000494:pharmacology*; D047188:Chalcones / Q000737:chemistry / Q000302:isolation & purification; D016166:Free Radical Scavengers / Q000302:isolation & purification / Q000494:pharmacology*; D006834:Hydrazines / Q000302:isolation & purification / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D008296:Malaysia; D008958:Models, Molecular; D015394:Molecular Structure; D010851:Picrates; D012639:Seeds / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D001713:Biphenyl Compounds; D047188:Chalcones; D016166:Free Radical Scavengers; D006834:Hydrazines; D010851:Picrates; C004931:1,1-diphenyl-2-picrylhydrazyl