This crude drug is the seed without testa of  Ginkgobiloba L. (family: Ginkgoaceae).

This species is a perennial deciduous tree with two types of branches, the long ones and the short ones. The stem bark is light grayish brown and longitudinally shallowly cracked when young and becomes darker in colour and longitudinally deeply cracked when old. The leaves are scattered and arranged spirally along a long branch, and grow in clusters of 3-8 on a short branch; the blade is fan-shaped, pale green, hairless, with numerous small biforked veins arranged side by side,     the upper margin being 5-8cm wide, shallowly sinuate and sometimes lobed or partite at the center. The flowers are unisexual cones, dioecious or rarely monoecious, occurring from axils of scalelike leaves at top of short branches; the male one is spikelike, drooping; the female one possesses a long stalk which is usually biforked at the tip, each fork bearing on the top a discal base, from which an ovule arises; only one of the two ovules of a female cone develops into a seed. The seed is drupaceous, elliptical to subsphaeroidal; the outer layer of seed coat is fleshy, powdery, turning light yellow or orange yellow when ripe; the middle layer of seed coat is bony, white, 2-3-ridged; the inner layer of seed coat is membranaceous; the endosperm is large.

After picked, the seeds are piled up on the ground or soaked in water in a vat so that the succulent testa gets rotten; or the succulent seed coat is removed by rubbing on a wood block, and the rest of the seed with a hard cover is cleaned and dried in the sun. Sometimes, the seeds with a hard cover are cooked in boiling water for a short time or steamed until vapour is produced, and then dried.

The seed without the outer layer of seed coat is ovoid or elliptical, 1.5-3cm long, 1-2.2cm wide, with a smooth bony skin (the middle layer of seed coat) which has a yellowish white or light brownish yellow surface. It is ridged marginally (one ridge or occasionally 3) and shows a tiny rounded bump at the base. The inner layer of seed coat is membranaceous, reddish brown or pale yellowish brown. The kernel is flat-spheroidal, light yellowish green, with a fleshy and mealy endosperm which is gapped in the middle; the embryo is very tiny. This crude drug is smellless and tastes slightly sweet and bitter.

The seeds contains 4-O-methylpyridoxine (ginkgotoxin), 6-(8-pentadecen)-2,4-dihydroxybenzoic acid, 6-tridecyl-2,4-dihydroxybenzoic acid, anacaridc acid;elements: K, P, Mg, Ca, Zn, Cu; protein, fat, carbohydrate, sugar^[1].

The leave contains flavonoid: keampferol, luteolin, myricetin, quercetin, isorhamnetin, syringetin, kaempferol-3-rhamnoglucoside, kaempferol-3-(6′′′-p-coumaroylglucosyl-β-1,4-rhamnoside), kaempfer-ol-3-O(2′′-O-β-D-glucopyranosyl)-α-L-rhamnopyranoside, kaempferol-3-O-[2′′′-O-6′′-O[p-(7′′′′-O-β-D-glucopyranosyl)coumaroyl]-β-D-glucopyranosyl]-α-L-rhamnopyranoside, kaempferol-3-O-(2′′-O-α-L-rhamnopyranosyl-6′′-O-α-D-glucopyranoside), 3′-O-methylmyricetin, quercetin-3-O-(2′′-O-β-D-glucopyranosyl)-α-L-rhamnopyranoside, quercetin-3-O-[2′′-O-6′′′-O-[p-(7′′′′-O-β-D-glucopyranosyl)coumaroyl]β-D-glucopyranosyl]-α-L-rhamnopyranoside, quercetin-3-O-[2′′-O-(6′′′-O-p-coumaroyl)-β-D-glucopyranosyl]-α-L-rhamnopyanosyl-7-O-β- D-glucopyranoside, quercetin-3-O-(2′′-O-α-L-rhamnopyranosyl-6′′-O-α-D-rhamnopyranosyl-β-D-glucopyranoside), quercetin-3-O-α-(6′′′-p-cumaroyl-glucosyl-β-1，4-rhamnoside), quercetin-3-O-rutinoside, isorhamnetin-3-O-rutinoside, syringetin-3-rutinoside^[2], rutin, kaempferol-3-O-β-D-rutinoside, kaempferol-3-O-β-D-glucoside, quercetin-3-O-β-D-glucoside, isorhamnetin-3-O-β-D-rutinoside, quercetin-3-O-β-D-glucosyl (1-2)-α-L-rhamnoside, kaempferol-3-O-β-D-glucosyl(1-2)-α-L-rhamnoside, isorhamnetin-3-O-β-D-glucosyl(1-2)-α-L-rhamnoside^[3];

Biflavonoids: amentoflavone, bilobetin, ginkgetin, isoginkgetin, sciadopitysin, 5′-methoxybilobetin^[2];

catechins: catechin, epicatechin, gallocatechin, epigallocatechin^[2];

terpenes: ginkgolide A, ginkgolide B, ginkgolide C, ginkgolide J, ginkgolide M, bilobalide A^[2];

alkaloid: 6-hydroxykynurenic acid^[2];

acid and ester: ginkgolic acid, hydroginkgolicacid, hydroginkgolinic acid, anacardic acid, shikimic acid, quinic acid, ascorbic acid, 6-hydroxy-2-tetradecylbenzoic acid, linolenic acid, 6-pentadecenyl salicylic acid, 6-heptadecenylsalicylic acid^[2];

amino acid: threonine, valine, methionine, leucine, isoleucine, phenylalanine, lysine^[2];

trace element: kalium, manganese, phosphorus, strontium, calcium, iron, magnesium, zinc, aluminum, barium^[2];

water-soluble polysaccharides: neutral polysaccharide GF₁, acidic polysaccharides GF₂, acidic polysaccharides GF₃^[2];

volatile oil: 3-hexen-l-ol, p-cymene, linalooloxide, α-ionone, β-ionone, thymol^[2];

other: ginnol, 1-octacosanol, 1-hexacosanol, sequoyitol, α-hexenal, ginnone, bilobanone, ginkgol, pinite, β-sitosterol, polyprenol, (Z,Z)-1，5-dihydroxyphenyl-1,4-pentadiene, α-sesamin^[2], 6-tridecyl-salicylicacid, 6-(8′Z-pentadecenyl)-salicylicacid, 6-(8′Z,11′Z-heptadecadienyl)-salicylicacid, 6-(10′Z-heptadecenyl)-salicylicacid^[4].

1. The water extract of Ginkgo Blloba L Episperm can decrease the dogs arterial pressure and their left ventricle pressure,reduce the output of the aorta and increase the output of the coronary. The extract can also dilate rabbits blood vesse1s, improve the mice bearing hypoxia ability^[1-3].

2. The  water extract of Ginkgo Blloba L Episperm could inhibit humoral and cellular immunity, reduce the release of histamine^[4-6].

1.Acne: ( 1) baiguo(Ginkgo Seed) and bingpian(ornel), adding saline, ethanol, wiped on face, 3~4 times a day, 7 days for a course, avoiding all drugs and cosmetics. Results showed that 44 cases were cured, 9 cases improved, the curative rate was 83%, the total efficiency was 100%. 15 cases were cured after 1 course, 23 cases were cured after 2 courses, 6 cases were cured after 3 courses, without any discomfort, dryness of the skin desquamation and adverse reaction in the treatment periods ^[1]. (2) Baiguo(Ginkgo Seed) cream for external use, 2~3 times a day,the Control group treated with simply appling the cream base, 2~3 times a day. The two groups were treated for 15 days as 1 course. After 2 courses, the total effectiveness of two groups was 84.61% and 36.67% respectively. there was significant difference ( P<0.05 ) ^[2].

2.Hemoptysis: 90 cases were treated with Baiguo(Ginkgo Seed) 15～30g, mahuang(ephedra)30g, xingren (almond)10g, gancao(radix glycyrrhizae) 6g. Decocted with water, 1 agent daily, 2 times daily. It had good effect ^[3].