title: Prenylated anthronoid antioxidants from the stem bark of Harungana madagascariensis.
abstract: Two new prenylated anthronoids, harunmadagascarins A and B, were isolated from the stem bark of Harungana madagascariensis along with six known compounds including two anthronoids: harunganol B and harungin anthrone, one benzophenone: methyl 3-formyl-2,4-dihydroxy-6-methyl benzoate and three pentacyclic triterpenes: friedelin, lupeol and betulinic acid. Harunmadagascarins A and B were characterized as 8,9-dihydroxy-4,4-bis-(3,3-dimethylallyl)-6-methyl-2,3-(2,2-dimethylpyrano)anthrone and 8,9-dihydroxy-4,4,5-tris-(3,3-dimethylallyl)-6-methyl-2,3-(2,2-dimethylpyrano)anthrone, respectively. The structures of these secondary metabolites were determined by spectroscopic means and comparison with the published data. Methyl 3-formyl-2,4-dihydroxy-6-methyl benzoate was isolated for the first time from a plant. Harunmadagascarins A and B, harunganol B and harungin anthrone exhibited significant antioxidant activity.
authors.affiliation: Department of Chemistry, Higher Teachers' Training College, University of Yaounde 1, BP 47, Yaounde, Cameroon.
authors.forename: Simeon F
authors.initials: SF
authors.lastname: Kouam
authors.forename: Bonaventure T
authors.initials: BT
authors.lastname: Ngadjui
authors.forename: Karsten
authors.initials: K
authors.lastname: Krohn
authors.forename: Pascal
authors.initials: P
authors.lastname: Wafo
authors.forename: Asma
authors.initials: A
authors.lastname: Ajaz
authors.forename: M Iqbal
authors.initials: MI
authors.lastname: Choudhary
mesh_terms: D000873:Anthracenes / Q000737:chemistry*; D000975:Antioxidants / Q000737:chemistry*; D028084:Clusiaceae / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000737:chemistry; D015394:Molecular Structure; D024301:Plant Bark / Q000737:chemistry*; D018547:Plant Stems / Q000737:chemistry
chemical_list: D000873:Anthracenes; D000975:Antioxidants; D016166:Free Radical Scavengers