title: Bangangxanthone A and B, two xanthones from the stem bark of Garcinia polyantha Oliv.
abstract: Two xanthones, bangangxanthone A (1) [1,5,8-trihydroxy-6'-methyl-6'-(4-methylpent-3-enyl)- pyrano[2',3':3,4]xanthone] and B (2) [1,4,8-trihydroxy-2-prenylxanthone], along with two known xanthones, 1,5-dihydroxyxanthone, 2-hydroxy-1,7-dimethoxyxanthone and the pentacyclic triterpenoids, friedelin, oleanolic acid and lupeol were isolated from the chloroform extract of the stem bark of Garcinia polyantha. The structures of these compounds were assigned by spectroscopic analysis. Compounds 1-4 showed antioxidant DPPH radical scavenging activities.
authors.affiliation: Department of Organic Chemistry, Faculty of Sciences, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon. alainmeli@yahoo.com
authors.forename: A Meli
authors.initials: AM
authors.lastname: Lannang
authors.forename: J
authors.initials: J
authors.lastname: Komguem
authors.forename: F Ngounou
authors.initials: FN
authors.lastname: Ngninzeko
authors.forename: J Gustave
authors.initials: JG
authors.lastname: Tangmouo
authors.forename: D
authors.initials: D
authors.lastname: Lontsi
authors.forename: Asma
authors.initials: A
authors.lastname: Ajaz
authors.forename: M Iqbal
authors.initials: MI
authors.lastname: Choudhary
authors.forename: Rosa
authors.initials: R
authors.lastname: Ranjit
authors.forename: Krishna P
authors.initials: KP
authors.lastname: Devkota
authors.forename: B Luc
authors.initials: BL
authors.lastname: Sondengam
mesh_terms: D001713:Biphenyl Compounds / Q000737:chemistry; D016166:Free Radical Scavengers / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D029760:Garcinia / Q000737:chemistry*; D006834:Hydrazines / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010851:Picrates; D024301:Plant Bark / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D044004:Xanthones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D006834:Hydrazines; D010851:Picrates; D044004:Xanthones; C506415:bangangxanthone A; C506416:bangangxanthone B; C004931:1,1-diphenyl-2-picrylhydrazyl