title: Racemization of 6-methoxydihydrosanguinarine in methanol investigated by enantioselective dynamic HPLC.
abstract: A biologically active benzophenanthridine alkaloid, 6-methoxydihydrosanguinarine (MS), was isolated from Hylomecon plants. Although enantiomers of MS can be separated by chiral HPLC, its isomers rapidly form a racemic mixture in methanol. The rate constants for the racemization of MS enantiomers were 9.20x10(-4)s(-1) and 9.95x10(-4)s(-1) for (+)-MS and (-)-MS, respectively, as determined by dynamic HPLC and chiral chromatography. This unusually rapid racemization may originate from the formation of a stable iminium ion intermediate, sanguinarine. Therefore, the variety of biological activities exhibited by MS may be attributable to a combination of (+)-MS, (-)-MS, and sanguinarine.
authors.affiliation: College of Pharmacy, Chungnam National University, Yooseong-Ku, Daejeon 305-764, Republic of Korea.
authors.forename: Enqi
authors.initials: E
authors.lastname: Wu
authors.forename: Sang-Hun
authors.initials: SH
authors.lastname: Jung
authors.forename: Jianbo
authors.initials: J
authors.lastname: Chen
authors.forename: Young Ho
authors.initials: YH
authors.lastname: Kim
authors.forename: Kyung Lae
authors.initials: KL
authors.lastname: Park
authors.forename: Wonjae
authors.initials: W
authors.lastname: Lee
authors.forename: Jong Seong
authors.initials: JS
authors.lastname: Kang
mesh_terms: D053119:Benzophenanthridines / Q000032:analysis / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D007546:Isoquinolines / Q000032:analysis / Q000737:chemistry*; D000432:Methanol / Q000737:chemistry; D028101:Papaveraceae / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: C438021:6-methoxydihydrosanguinarine; D053119:Benzophenanthridines; D007546:Isoquinolines; D010936:Plant Extracts; D012997:Solvents; C005705:sanguinarine; D000432:Methanol