An Efficient Method for the Preparative Isolation and Purification of Flavonoids from Leaves of Crataegus pinnatifida by HSCCC and Pre-HPLC.

In this work, flavonoid fraction from the leaves of was separated into its seven main constituents using a combination of HSCCC coupled with pre-HPLC. In the first step, the total flavonoid extract was subjected to HSCCC with a two-solvent system of chloroform/methanol/water/-butanol (4:3:2:1.5, ), yielding four pure compounds, namely (-)-epicatechin (), quercetin-3--(2,6-di-α-l-rhamnopyranosyl)-β-d-galactopyranoside (), 4''--glucosylvitexin () and 2''--rhamnosylvitexin () as well as a mixture of three further flavonoids. An extrusion mode was used to rapidly separate quercetin-3--(2,6-di-α-l-rhamnopyranosyl)-β-d-galactopyranoside with a big -value. In the second step, the mixture that resulted from HSCCC was separated by pre-HPLC, resulting in three pure compounds including: vitexin (), hyperoside () and isoquercitrin (). The purities of the isolated compounds were established to be over 98%, as determined by HPLC. The structures of these seven flavonoids were elucidated by ESI-MS and NMR spectroscopic analyses.