title: Application of 1H-NMR spectroscopy to validation of berberine alkaloid reagents and to chemical evaluation of Coptidis Rhizoma.
abstract: Berberine, palmatine, and coptisine are major pharmacologically active protoberberine alkaloids in Coptidis Rhizoma, and have been used as indices for chemical evaluation of the crude drug. (1)H-NMR spectroscopy was applied to determination of purities of commercial reagents of protoberberine alkaloids. The purities of the alkaloids were calculated from the ratios of the intensities of the H-13 singlet signal at about δ 8.7 ppm of target protoberberine alkaloids to integration of a hexamethyldisilane (HMD) signal at 0 ppm. The concentration of HMD was corrected with SI traceability using potassium hydrogen phthalate of certified reference material (CRM) grade. The purity of the reagent estimated by the (1)H-NMR was, in general, lower than that claimed by the manufacturer, leading to over-estimation of the alkaloid contents of Coptidis Rhizoma when determined by HPLC. The present quantitative (1)H-NMR method was also applicable to direct determination of protoberberine alkaloid contents in Coptidis Rhizoma.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Hasada
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Yoshida
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamazaki
authors.forename: Naoki
authors.initials: N
authors.lastname: Sugimoto
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Nishimura
authors.forename: Akito
authors.initials: A
authors.lastname: Nagatsu
authors.forename: Hajime
authors.initials: H
authors.lastname: Mizukami
mesh_terms: D001599:Berberine / Q000031:analogs & derivatives / Q000737:chemistry; D001600:Berberine Alkaloids / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D039323:Coptis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry
chemical_list: D001600:Berberine Alkaloids; D010936:Plant Extracts; C034384:coptisine; D001599:Berberine; C005413:palmatine