title: Preparative enrichment and separation of astragalosides from Radix Astragali extracts using macroporous resins.
abstract: The enrichment and separation of astragalosides I-IV (AGs I-IV) were studied on eight macroporous resins in the present study. SA-3 resin offered the best adsorption and desorption capacities for AGs I-IV than other resins. The models of adsorption kinetics were investigated in order to elucidate the mechanism of adsorption. The pseudo-second-order model was the better choice than the pseudo-first-order model to describe the adsorption behavior of AGs I-IV onto SA-3 resin. The equilibrium experimental data were well fitted to Langmuir and Freundlich isotherms. SA-3 resin adsorption chromatography tests were carried out to optimize the separation process of AGs I-IV from Radix Astragali extracts. With the optimum parameters for adsorption and desorption, the contents of AGs I-IV were 8.78-, 11.60-, 10.52- and 11.28-fold increased with the recovery yields being 65.88, 90.92, 84.25 and 94.17%, respectively. The preparative enrichment and separation of AGs I-IV from Radix Astragali extracts can be easily and effectively achieved by SA-3 resin adsorption chromatography. The developed methodology can also be referenced for the separation of other active constituents from herbal materials and manufacture of Radix Astragali products.
authors.affiliation: Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin, P. R. China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Kong
authors.forename: Ming-Ming
authors.initials: MM
authors.lastname: Yan
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Cai-Yun
authors.initials: CY
authors.lastname: Chen
authors.forename: Bao-Shan
authors.initials: BS
authors.lastname: Zhao
authors.forename: Yuan-Gang
authors.initials: YG
authors.lastname: Zu
authors.forename: Yu-Jie
authors.initials: YJ
authors.lastname: Fu
authors.forename: Meng
authors.initials: M
authors.lastname: Luo
authors.forename: Michael
authors.initials: M
authors.lastname: Wink
mesh_terms: D000327:Adsorption; D027883:Astragalus Plant / Q000737:chemistry*; D002845:Chromatography; D010936:Plant Extracts / Q000737:chemistry*; D016062:Porosity; D012117:Resins, Synthetic / Q000737:chemistry*; D012503:Saponins / Q000302:isolation & purification*; D014315:Triterpenes / Q000302:isolation & purification*
chemical_list: D010936:Plant Extracts; D012117:Resins, Synthetic; D012503:Saponins; D014315:Triterpenes; C052064:astragaloside A