Preparative separation and purification of alkylamides from Zanthoxylum bungeanum Maxim by high-speed counter-current chromatography

摘要

High-speed counter-current chromatography (HSCCC) was successfully applied to preparative isolation and purification of alkylamides, the tingling-taste components, from pericarp extract of Zanthoxylum bungeanum Maxim (Dahongpao). With the lower phase of n-hexane-ethyl acetate-methanol-water (7:3:5:5, v/v) eluted at a flow rate of 1.5mL×min -1, and the revolution speed at 850rpm, 0.19g of alkylamides in purity of 98.0% by the relative peak area of HPLC was obtained from 1.0g of extract in one run within 2hr. On the basis of MS, IR, and 1H NMR analysis, the product of alkylamides was confirmed to be composed of hydroxy-α-sanshool, hydroxy-β-sanshool, and hydroxy-ε-sanshool. Furthermore, using the HSCCC product as external standard, alkylamide in the extract was determined to be in total of 21.41%, among which hydroxy-α-sanshool, hydroxy-β-sanshool, and hydroxy-ε-sanshool were in 15.69%, 4.76%, and 0.96%, respectively.