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 investigated in detail. An adsorbent with an appropriate gelatin content can selectively adsorb flavonol glycosides with a high adsorption capacity based mainly on hydrogen bond interactions, while showing only a fairly low adsorption capacity for terpene lactones. A much higher adsorption affinity of flavonol glycosides than that of terpene was calculated from the adsorption isotherms. Thus, a simple preparative separation procedure for ginkgo flavonol 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.