title: Two new xanthones from the stems of Garcinia cowa.
abstract: Two new xanthones, 1,5,6-trihydroxy-3-methoxy-4-(3-hydroxyl-3-methylbutyl)xanthone (1) and 1,5-dihydroxy-3-methoxy-6',6'-dimethyl-2H-pyrano(2',3':6,7)-4-(3-methylbut-2-enyl)xanthone (2), have been isolated together with six known xanthones: 1,3,5-trihydroxy-6',6'-dimethyl-2H-pyrano(2',3':6,7)xanthone (3), dulxanthone A (4), 1,5,6-trihydroxy-3,7-dimethoxyxanthone (5), 1,7-dihydroxyxanthone (6), 1,3,5-trihydroxy-6-methoxyxanthone (7), 1,3,6,7-tetrahydroxyxanthone (8), from the stems of Garcinia cowa (Guttiferae).
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Shen
authors.forename: Jun-Shan
authors.initials: JS
authors.lastname: Yang
mesh_terms: D029760:Garcinia / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008968:Molecular Conformation; D010936:Plant Extracts / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D012997:Solvents; D021241:Spectrometry, Mass, Electrospray Ionization; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D014970:Xanthines / Q000737:chemistry* / Q000302:isolation & purification; D044004:Xanthones / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: C508618:1,5,6-trihydroxy-3-methoxy-4-(3-hydroxyl-3-methylbutyl)xanthone; C508619:1,5-dihydroxy-3-methoxy-6',6'-dimethyl-2H-pyrano(2',3':6,7)-4-(3-methylbut-2-enyl)xanthone; D010936:Plant Extracts; D012997:Solvents; D014970:Xanthines; D044004:Xanthones