Ginkgo Seed is the dried ripe seed of Ginkgo biloba L. (Fam. Ginkgoaceae). The drug is collected in autumn when the seed is ripe, removed from the fleshy testa, washed clean, steamed or boiled briefly, and dried by baking gently.
Description Somewhat ellipsoidal, one end relatively acute and the other end obtuse, 1.5-2.5 cm long, 1-2 cm wide, about 1 cm thick. Externally yellowish-white or pale brownish-yellow, smooth, with 2-3 ribs. Mesotesta (shell) bony and hard. Endotesta membranous. Kernel broadly ovoid or ellipsoidal, one end pale brown and the other end golden-yellow; transverse section yellow, gelatinized in the outer part, and pale yellow or pale green in the inner part, starchy, with a fissure in the centre. Odourless; taste, sweet, slightly bitter.
Identification To 10 g of the powder add 40 ml of methanol, heat and reflux for 1 hour, filter, evaporate the filtrate to dryness, add 15 ml of water to dissolve the residue, filter with a few cotton, the filtrates pass through a pre-prepared polyamide small column (80-100 mesh, 3 g, 10-15 mm in inner diameter), elude with 70 ml of water, shake and extract the eludes with ethyl acetate for 2 times, each of 40 ml, combine the ethyl acetate solutions, evaporate to dryness, dissolve the residue with 1 ml of methanol and use as the test solution. Prepare a solution of bilobalide A, C CRS containing 0.5 mg respectively per ml as the reference solution. Carry out the method for thin layer chromatography (Appendix VI B), using silica gel G previously prepared with 4% solution of sodium acetate, containing sodium carboxymethylcellulose, as the coating substance and a mixture of toluene-ethyl acetate-acetone-methanol (10:5:5:0.6) as the mobile phase. Apply separately to the plate 10 ml each of the two solutions. After developing and removal of the plate, dry it in air, spray with acetic anhydride, heat at 140-160oC for 30 minutes to the spots distinct, examine under ultraviolet light (365 nm). The fluorescent spot in the chromatogram obtained with the test solution corresponds in position and colour to the spot in the chromatogram obtained with the reference solution.
Processing Nux Ginkgo Remove foreign matter and shell from Semen Ginkgo. Break into pieces before use.
Nux Ginkgo (stir-baked) Stir-bake the clean Nux Ginkgo as described under the method for simple stir-baking (Appendix II D) to scented. Break into pieces before use.
Action To arrest persistent cough and asthma, and to reduce leukorrhea and urinatiom.
Indications Persistent cough and asthma with profuse expectoration; morbid leukorrhea with whitish discharge; enuresis, frequent urination.
Usage and dosage 4.5-9 g.
Precaution Raw Semen Ginkgo is toxic.
Storage Preserve in a ventilated and dry place.