Synthesis of gelatin-PVA adsorbent and its application in the separation of ginkgo flavonol glycosides and terpene lactones

Spherical adsorbents derived from the glutaraldehyde cross-linked hybrid of gelatin and polyvinyl alcohol (PVA) were synthesized, and their adsorption selectivity for ginkgo flavonol glycosides and terpene lactones was also i nvestigated in detail. An adsorbent with an appropriate gelatin content can selectively adsorb flavonol glycosides with a high adsorption capacity bas ed mainly on hydrogen bond interactions, while showing only a fairly low ad sorption capacity for terpene lactones. A much higher adsorption affinity o f flavonol glycosides than that of terpene was calculated from the adsorpti on isotherms. Thus, a simple preparative separation procedure for ginkgo fl avonol glycosides and terpene lactones from a ginkgo leaf was established, An enriched extract containing flavonol glycosides of up to 60% and terpene lactones as low as 0.2% and an extract with a terpene lactones content up to 30% was prepared by this method, respectively. (C) 2001 Elsevier Science B.V. All rights reserved.