Abstract
Extracts of the dried leaves of Ginkgo biloba [Family Ginkgoaceae] are used therapeutically. The extracts utilized in clinical trials (EGb761 and LI1370) are standardized in a multi-step procedure designed to concentrate the desired active principles from the plant. These extracts contain approximately 24% flavone glycosides (primarily composed of quercetin, kaempferol, and isorhamnetin) and 6% terpene lactones (2.8-3.4% ginkgolides A, B, and C, and 2.6-3.2% bilobalide). Other constituents include proanthocyanidins, glucose, rhamnose, organic acids (hydroxykynurenine, kynurenic, protocatechuic, vanillic, shikimic), D-glucaric acid and ginkgolic acid, and related alkylphenols (at most 5 ppm ginkgolic acids).