Extraction of leaves of ginkgo biloba (Ginkgo biloba L.)

Ginkgo biloba (Ginkgo biloba L.) is characterized by a complex chemical composition. Leaves of this plant species, among the others, contain ginkgoflavon glycosides, proanthocianidines, terpenes (of non-flavonoid origin), essential oils, tannins, etc. Of the sub­stances that have a greater pharmacological importance, this plant contains flavonoids and ginkgolides. Extracts of ginkgo biloba leaves represent the source of hope for the persons of middle and older age exhibiting signs of reduced brain circulation (senility, forgetting vertigo, headache, ear buzzing, and depression). In the frame of this work an investigation was carried out of the extraction in the system: ginkgo biloba leaves - 60% ethanol. The objective was to find a correlation between the extraction kinetic and grinding degree of the material. For a quantitative characterization of fast extraction the coefficient of fast extraction b was adopted. An approximate calculation of the internal diffusion coefficient was carried out. The obtained results indicate that with increase in the grinding degree of the material, the value of the internal diffusion coefficient decreases, whereby the coefficient of fast extraction shows an increase. .