Prenylated anthronoid antioxidants from the stem bark of Harungana madagascariensis

• Published in: Phytochemistry (Oxford) Vol. 66; no. 10; pp. 1174 - 1179
• Main Authors: Kouam, Simeon F., Ngadjui, Bonaventure T., Krohn, Karsten, Wafo, Pascal, Ajaz, Asma, Choudhary, M. Iqbal
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01-05-2005; Elsevier
• Subjects: Anthracenes - chemistry; anthronoids; Antioxidant; antioxidants; Antioxidants - chemistry; benzophenone; Biological and medical sciences; Chemical constitution; chemical structure; Clusiaceae - chemistry; Free Radical Scavengers - chemistry; Fundamental and applied biological sciences. Psychology; Harungana madagascariensis; harunganol; harungin anthrone; harunmadagascarin; Harunmadagascarins A and B; Hypericaceae; Insecta; Invertebrates; Molecular Structure; Pathology; phytochemicals; Plant Bark - chemistry; plant extracts; Plant physiology and development; Plant Stems - chemistry; Prenylated anthronoids; spectral analysis; stereochemistry; triterpenoids; Cameroon; Hypericaceae; Harungana madagascariensis; Antioxidant; Prenylated anthronoids; Harunmadagascarins A and B; Benzophenone derivatives; Molecular structure; Metabolite; Bark; Triterpene; Isolation; Stem
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2005.03.022

Two new prenylated anthronoids, harunmadagascarins A and B, were isolated from the stem bark of
Harungana madagascariensis.
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.