Supercritical fluid extraction of ginkgo flavonoids
Supercritical fluid extraction (SFE) is known as "super solvent". This technology uses the characteristics of supercritical fluid to change the solubility of Ginkgolides by controlling the temperature and pressure of the working system on the basis of rational selection of entrainers, so as to achieve the crystallization separation of ginkgolides.
With the development of pharmacological and toxicological studies on the bioactive components of Ginkgo biloba leaves, their medicinal functions have been gradually explored. Ginkgo flavonoids have the functions of dilating coronary vessels, spasmolysis, eliminating free radicals in vivo, and can be used to treat coronary heart disease, and have the effects of analgesia and anti-aging. Ginkgolides and ginkgolides are peculiar components of Ginkgo biloba and are the preferred natural drugs for treating cardiovascular and cerebrovascular diseases and nervous system diseases. Ginkgolide is a very effective platelet activating factor antagonist, which has a significant effect on preventing and treating atherosclerosis, hypertension, cerebral ischemia, etc. Baiguolide has a unique effect on the treatment of neurological diseases such as Alzheimer's disease and encephalopathy. In addition, white fruit phenol and Ginkgo phenol, which represent the harmful components of Ginkgo biloba, have anti-cancer effects in addition to pesticides.
Because the content of total lactones in standard extracts of Ginkgo biloba leaves is relatively low, and the molecular structure of impurities is similar to that of medicinal ingredients, and the polarity difference is small, the extraction and separation process of effective ingredients is rather complicated. Supercritical carbon dioxide extraction is a new separation method. It has many advantages, such as high extraction efficiency, no residual toxicity of solvents, natural active ingredients and thermosensitive ingredients are not easy to be decomposed and destroyed, the natural characteristics of extracts can be maintained to the greatest extent, and selective separation can be achieved.