title: Simultaneous determination of the content of isoquinoline alkaloids in Dicranostigma leptopodum (Maxim) Fedde and the effective fractionation of the alkaloids by high-performance liquid chromatography with diode array detection.
abstract: A simple and efficient method was developed for the simultaneous determination of eight isoquinoline alkaloids in methanol extracts of Dicranostigma leptopodum (Maxim) Fedde and the effective fractionation of the alkaloids of D. leptopodum by high-performance liquid chromatography with diode array detection. The chromatographic conditions were optimized on a SinoChrom ODS-BP column to obtain a good separation of the four types of alkaloid analytes, including two aporphines (isocorydine, corydine), two protopines (protopine and allocryptopine), a morphine (sinoacutine), and three quaternary protoberberine alkaloids (berberrubine, 5-hydroxycoptisine, and berberine). The separation of these alkaloids was significantly affected by the composition of the mobile phase, and particularly by its pH value. Acetonitrile (A) and 0.2% phosphoric acid solution adjusted to pH 6.32 with triethylamine (B) were selected as the mobile phase with a gradient elution. With this method, a new quaternary protoberberine alkaloid was isolated and the two structural isomers (isocorydine and corydine) were baseline separated. The appropriate harvest period for D. leptopodum was also recommended based on our analysis. The method for the effective fraction of the alkaloids of D. leptopodum was optimized under this method with regard to the varying significant pharmacological activities of the alkaloids.
authors.affiliation: Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, PR China; Institute of Medicinal Chemistry, School of Pharmacy, Lanzhou University, Lanzhou, PR China.
authors.forename: Yali
authors.initials: Y
authors.lastname: Chen
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.forename: Jianjun
authors.initials: J
authors.lastname: Liu
authors.forename: Qian
authors.initials: Q
authors.lastname: Yan
authors.forename: Mei
authors.initials: M
authors.lastname: Zhong
authors.forename: Junxi
authors.initials: J
authors.lastname: Liu
authors.forename: Duolong
authors.initials: D
authors.lastname: Di
authors.forename: Jinxia
authors.initials: J
authors.lastname: Liu
mesh_terms: D000470:Alkaloids / Q000032:analysis* / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D004365:Drugs, Chinese Herbal / Q000032:analysis* / Q000302:isolation & purification*; D007546:Isoquinolines / Q000032:analysis* / Q000302:isolation & purification*; D028101:Papaveraceae / Q000737:chemistry*
chemical_list: D000470:Alkaloids; D004365:Drugs, Chinese Herbal; D007546:Isoquinolines; C039109:isoquinoline
keywords: Dicranostigma leptopodum (Maxim) Fedde; High-performance liquid chromatography; Isocorydine; Isoquinoline alkaloids