Preparative separation and enrichment of syringopicroside from Folium syringae leaves with macroporous resins

Syringopicroside is the major constituent in Folium syringae leaves with known pharmacological activities. In this study, a simple method for preparative separation of syringopicroside from F. syringae leaves with macroporous resins was developed. Adsorption characteristics of syringopicroside on six types of macroporous resins, including ADS-8, ADS-17, D141, NKA-9, HPD450, and HPD600, have been compared, among which D141 resin showed the best adsorption and desorption capacities for syringopicroside. Adsorption isotherms were used to D141 resin at different temperatures and fitted well to Langmuir and Freundlich equations. Dynamic adsorption and desorption tests were performed on D141 resin-packed column to optimize the separation process of syringopicroside. After one run with D141 resin, the content of syringopicroside was increased 24-fold from 2.32% to 55.74% with a recovery yield of 92.16%. The chromatographic process optimized in this work avoids toxic organic solvent and, thus, is a promising basis for large-scale preparation of syringopicroside.