title: On-line comprehensive two-dimensional normal-phase liquid chromatography × reversed-phase liquid chromatography for preparative isolation of Peucedanum praeruptorum.
abstract: A new on-line comprehensive preparative two-dimensional normal-phase liquid chromatography × reversed-phase liquid chromatography (2D NPLC × RPLC) system was developed for the separation of complicated natural products. It was based on the use of a silica gel packed medium-pressure column as the first dimension and an ODS preparative HPLC column as the second dimension. The two dimensions were connected with normal-phase (NP) and reversed-phase (RP) enrichment units, involving a newly developed airflow assisted adsorption (AAA) technique. The instrument operation and the performance of this NPLC × RPLC separation method were illustrated by gram-scale isolation of ethanol extract from the roots of Peucedanum praeruptorum. In total, 19 compounds with high purity were obtained via automated multi-step preparative separation in a short period of time using this system, and their structures were comprehensively characterized by ESI-MS, (1)H NMR, and (13)C NMR. Including two new compounds, five isomers in two groups with identical HPLC and TLC retention values were also obtained and identified by 1D NMR and 2D NMR. This is the first report of an NPLC × RPLC system successfully applied in an on-line preparative process. This system not only solved the interfacing problem of mobile-phase immiscibility caused by NP and RP separation, it also exhibited apparent advantages in separation efficiency and sample treatment capacity compared with conventional methods.
authors.affiliation: School of Pharmaceutical Sciences and the Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, South Xiang-An Road, Xiamen, Fujian 361102, China.
authors.forename: Xin-Yuan
authors.initials: XY
authors.lastname: Wang
authors.affiliation: School of Pharmaceutical Sciences and the Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, South Xiang-An Road, Xiamen, Fujian 361102, China.
authors.forename: Jia-Fu
authors.initials: JF
authors.lastname: Li
authors.affiliation: School of Pharmaceutical Sciences and the Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, South Xiang-An Road, Xiamen, Fujian 361102, China.
authors.forename: Ya-Mei
authors.initials: YM
authors.lastname: Jian
authors.affiliation: School of Pharmaceutical Sciences and the Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, South Xiang-An Road, Xiamen, Fujian 361102, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wu
authors.affiliation: School of Pharmaceutical Sciences and the Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, South Xiang-An Road, Xiamen, Fujian 361102, China.
authors.forename: Mei-Juan
authors.initials: MJ
authors.lastname: Fang
authors.affiliation: School of Pharmaceutical Sciences and the Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, South Xiang-An Road, Xiamen, Fujian 361102, China. Electronic address: qyk@xmu.edu.cn.
authors.forename: Ying-Kun
authors.initials: YK
authors.lastname: Qiu
mesh_terms: D019661:Apiaceae / Q000737:chemistry*; D001688:Biological Products / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid; D056148:Chromatography, Reverse-Phase; D007536:Isomerism; D059625:Liquid-Liquid Extraction / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy
chemical_list: D001688:Biological Products
keywords: Airflow assisted adsorption technique; Coumarins; Peucedanum praeruptorum; Two dimensional normal-phase liquid chromatography×reversed-phase liquid chromatography