Direct extraction of specific pharmacophoric flavonoids from gingko leaves using a molecularly imprinted polymer for quercetin

A new straightforward approach to extract active components from Chinese traditional herb was reported by using a molecularly imprinted polymer (MIP) as the sorbent material. The MIP was prepared using quercetin, a typical active compound of the flavonoid family in gingko leaves as the template. Acrylamide was used as the functional monomer and two polar solvent tetrahydrofuran was used as the porogen. Afterwards, the polymer was evaluated by chromatographic analysis. It exhibited high selectivity for quercetin and good affinity to its structural analogues. Specific binding amount of quercetin on the MIP in the solvent methanol was 12 mug/g polymer by the cartridge test. The MIP cartridge could directly trap a specific class of compounds including quercetin and kaempferol from the hydrolyzate of gingko leaves. The result demonstrated the possibility of direct extraction of certain pharmacophoric constituents from herb by MIP technology. The compounds extracted were confirmed by time-of-flight mass spectrometry. (C) 2001 Published by Elsevier Science B.V.