Specification: Assay (Specification 1, By HPLC) 10% 20% 30% 40% Genistin:Daidzin=1.3:1 Genistein+Daidzein 2% (Specification 2, By HPLC) 40% Genistin:Daidzin=3:1 Genistein+Daidzein 2% Name of the plant: Ginkgo Biloba L. Part of the plant used: Leaves Description: Trees to 30 m. Crown somewhat ovoid to obovoid, tending to be asymmetric, primary branches ascending at ca. 45 from trunk. Long shoots faintly striate; spurs thick, knoblike or to 3 cm, gray, covered with bud-scale scars. Buds brown, globose, scales imbricate, margins scarious. Leaves fan-shaped, glabrous except for tuft of hairs in axils, blades 2-9.5 2-12 cm, mostly 1.5 times wider than long, apices cleft to truncate; venation dichotomous, appearing parallel; leaf scars semicircular; petioles channeled on adaxial surface, 2.5-8.5 cm. Seeds obovoid to ellipsoid, yellow to orange, 2.3-2.7 1.9-2.3 cm, mostly 1.1-1.2 times longer than broad, glaucous, rugose, with apical scar, maturing in single season, usually 1 per peduncle, occasionally polyembryonic, outer coat foul-smelling; peduncles orange, glaucous, ridged, 3-9.5 cm, collar broadly elliptic, 7.2-8.6 mm broad. 2n = 24" Traditional Usage: The medical benefits of ginkgo biloba extract (GBE) rely on the proper balance of two groups of active components: the ginkgo flavone glycosides and the terpene lactones. Chemical definition: Ginkgo flavones glycosides and terpene lactones Specification: Assay (Ginkgo flavones glycosides, By HPLC) 24% (Total terpene lactones, By HPLC) 6% Appearance: Light brown fine powder withcharacteristic odor