title: Oxanthrone C-glycosides and epoxynaphthoquinol from the roots of Rumex japonicus.
abstract: Five oxanthrone C-glycosides, namely rumejaposide A-E, and an epoxynaphthoquinol, together with eight known compounds, 2,6-dihydroxy benzoic acid, 4-hydroxy benzoic acid, epicatechin, 4-hydroxy-3-methoxy benzoic acid, 2,6-dimethoxy-4-hydroxyl benzoic acid, rutin, emodin and 2-acetyl-1,8-dihydroxy-3-methyl-6-methoxynaphthalene, were isolated from the roots of Rumex japonicus. The structures of the oxanthrone C-glycosides were elucidated by application of spectroscopic methods as (10R)10-C-beta-glucopyranosyl-1,8,10-trihydroxy-2-carboxyl-3-methyl-9(10H)-anthracenone, (10S)10-C-beta-glucopyranosyl-1,8,10-trihydroxy-2-carboxyl-3-methyl-9(10H)-anthracenone, (10R)10-C-beta-glucopyranosyl-1,6,8,10-tetrahydroxy-2-carboxyl-3-methyl-9(10H)-anthracenone, (10R)10-C-beta-glucopyranosyl-1,6,8,10-tetrahydroxy-3-hydroxymethyl-9(10H)-anthracenone, and (10R)10-C-beta-glucopyranosyl-1,6,8,10-tetrahydroxy-3-methyl-9(10H)-anthracenone. Absolute configurations for each compound were deduced by analyses of CD spectra and comparison with those known similar compounds. The structure of epoxynaphthoquinol was elucidated by spectroscopic methods as 3-acetyl-2-methyl-1,4,5-trihydroxy-2,3-epoxynaphthoquinol, and its relative configuration was determined by a 2D-ROESY experiment.
authors.affiliation: State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Science, 555 Zuchongzhi Road, Zhangjiang Hi-Tech Park, Shanghai 201203, PR China.
authors.forename: Lili
authors.initials: L
authors.lastname: Jiang
authors.forename: Shuwei
authors.initials: S
authors.lastname: Zhang
authors.forename: Lijiang
authors.initials: L
authors.lastname: Xuan
mesh_terms: D004852:Epoxy Compounds / Q000737:chemistry / Q000302:isolation & purification*; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification*; D008958:Models, Molecular; D009284:Naphthols / Q000737:chemistry / Q000302:isolation & purification*; D018517:Plant Roots / Q000737:chemistry*; D031804:Rumex / Q000737:chemistry*; D013057:Spectrum Analysis / Q000379:methods
chemical_list: C525202:3-acetyl-2-methyl-1,4,5-trihydroxy-2,3-epoxynaphthoquinol; D004852:Epoxy Compounds; D006027:Glycosides; D009284:Naphthols