Racemization of 6-methoxydihydrosanguinarine in methanol investigated by enantioselective dynamic HPLC.
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.
Wu
Enqi
E
College of Pharmacy, Chungnam National University, Yooseong-Ku, Daejeon 305-764, Republic of Korea.
Jung
Sang-Hun
SH
Chen
Jianbo
J
Kim
Young Ho
YH
Park
Kyung Lae
KL
Lee
Wonjae
W
Kang
Jong Seong
JS
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
C438021:6-methoxydihydrosanguinarine; D053119:Benzophenanthridines; D007546:Isoquinolines; D010936:Plant Extracts; D012997:Solvents; C005705:sanguinarine; D000432:Methanol