title: Isolation and characterization of rosmarinic acid oligomers in Celastrus hindsii Benth leaves and their antioxidative activity.
abstract: Antioxidative compounds were isolated from the 50% methanol extract of dried leaves of Celastrus hindsii. Eight phenolic compounds (1-8) were finally obtained by reversed-phase high-performance liquid chromatography, and their structures were elucidated by nuclear magnetic resonance spectrometry and mass spectrometry analyses. They were the five known compounds, rutin (1), kaempferol 3-rutinoside (2), rosmarinic acid (3), lithospermic acid (4), and lithospermic acid B (6), and three novel oligomers of rosmarinic acid, a dimer (5) and two trimers (7 and 8). The major components in the extract were rosmarinic acid (3) and lithospermic acid B (6). These phenolic compounds were shown to have antioxidative activities against the autoxidation of methyl linoleate in bulk phase and the radical-initiated peroxidation of soybean phosphatidylcholine in liposomes. In the liposomal peroxidation, the number of phenolic hydroxyl group in each molecule was correlated with the effectiveness of antioxidative activity.
authors.affiliation: Department of Applied Life Science, Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu City, Gifu 501-1193, Japan.
authors.forename: Tram Ngoc
authors.initials: TN
authors.lastname: Ly
authors.forename: Makoto
authors.initials: M
authors.lastname: Shimoyamada
authors.forename: Ryo
authors.initials: R
authors.lastname: Yamauchi
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D031247:Celastrus / Q000737:chemistry*; D002934:Cinnamates / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D053630:Depsides; D018515:Plant Leaves / Q000737:chemistry*; D000097123:Rosmarinic Acid
chemical_list: D000975:Antioxidants; D002934:Cinnamates; D053630:Depsides; D000097123:Rosmarinic Acid