title: Glycosides and xanthine oxidase inhibitors from Conyza bonariensis.
abstract: Fractionation of the xanthine oxidase inhibitory methanol extract of Conyza bonariensis afforded three glycosides, in addition to nine known compounds including amyrin, beta-sitostero1 daucosterol, syringic acid 3-hydroxy-5-methoxybenzoic acid, eugenol 4-O-glucopyranoside, and luteolin, apigenin and takakin 8-O-glucuronide. The structures of the glycosides were established by a combination of spectroscopic methods (IR, MS, 1H and 13C NMR, DEPT, COSY, HMQC and HMBC) as 4-hydroxypyridin-3-carboxylic acid 4-O-glucopyranoside, 8-hydroxy-6,7-dihydrolinalool 8-O-glucopyranoside and bonaroside [viz. 1,3,4,12-tetrahydroxy-2-(9-hexadecenoylamino)octadecane 1-O-glucopyranoside]. The in vitro enzyme assay showed that syringic acid and takakin 8-O-glucuronide displayed weak inhibitory activity against xanthine oxidase with IC50 values of 500+/-41 microM and 170+/-12 microM, respectively.
authors.affiliation: Institute of Functional Biomolecule, State Key Laboratory of Pharmaceutical Biotechnology, School of Life Science, Nanjing University, Nanjing 210093, People's Republic of China.
authors.forename: L D
authors.initials: LD
authors.lastname: Kong
authors.forename: Z
authors.initials: Z
authors.lastname: Abliz
authors.forename: C X
authors.initials: CX
authors.lastname: Zhou
authors.forename: L J
authors.initials: LJ
authors.lastname: Li
authors.forename: C H
authors.initials: CH
authors.lastname: Cheng
authors.forename: R X
authors.initials: RX
authors.lastname: Tan
mesh_terms: D019659:Asteraceae / Q000737:chemistry*; D002236:Carbohydrate Conformation; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification*; D005960:Glucosides / Q000737:chemistry / Q000302:isolation & purification*; D013057:Spectrum Analysis; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors*
chemical_list: D004791:Enzyme Inhibitors; D005960:Glucosides; D014969:Xanthine Oxidase