title: Absolute stereostructures of new arborinane-type triterpenoids and inhibitors of nitric oxide production from Rubia yunnanensis.
abstract: The aqueous acetone extract from the roots of a Chinese herbal medicine, Rubia yunnanensis, showed a potent inhibitory effect on nitric oxide production in lipopolysaccharide-activated macrophages. Five new arborinane-type triterpenes, rubianols-a (1), -b (2), -c (3), -d (4), and -e (5), and a new arborinane-type triterpene glycoside, rubianoside I (6), were isolated from the herbal crude extract together with 10 known compounds. The absolute stereostructures of 1-6 were determined on the basis of chemical and physicochemical evidence, including the application of the modified Mosher's method. The effects of the isolated constituents on nitric oxide production in lipopolysaccharide-activated macrophages were examined, and several triterpenes were found to show inhibitory activity.
authors.affiliation: Kyoto Pharmaceutical University, Misasagi, Yamashina-ku, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Morikawa
authors.forename: Jing
authors.initials: J
authors.lastname: Tao
authors.forename: Shin
authors.initials: S
authors.lastname: Ando
authors.forename: Hisashi
authors.initials: H
authors.lastname: Matsuda
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yoshikawa
mesh_terms: D000465:Algorithms; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D020128:Inhibitory Concentration 50; D008070:Lipopolysaccharides / Q000494:pharmacology; D017737:Macrophages, Peritoneal / Q000187:drug effects; D015394:Molecular Structure; D009569:Nitric Oxide / Q000037:antagonists & inhibitors*; D018517:Plant Roots / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D019666:Rubiaceae / Q000737:chemistry*; D013237:Stereoisomerism; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D004365:Drugs, Chinese Herbal; D008070:Lipopolysaccharides; D014315:Triterpenes; D009569:Nitric Oxide