Supercritical CO2 Extraction of Ginkgo Flavonoids
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 analgesic and anti-aging effects. Ginkgolides and albinolides are unique components of Ginkgo biloba and are the preferred natural drugs for treating cardiovascular and cerebrovascular diseases and nervous system diseases. Ginkgolides are very effective platelet activating factor antagonists, which have significant effects on preventing and treating atherosclerosis, hypertension, cerebral ischemia, etc. Baiguolide has unique effects on treating neurological diseases such as Alzheimer's disease and encephalopathy. In addition, the 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 easily decomposed and destroyed, it can maintain the natural characteristics of extracts to the maximum, and it can achieve selective separation. Supercritical fluids are called "super solvents". This technology utilizes the characteristics of supercritical fluids, and on the basis of reasonable selection of entrainers, changes the solubility of solutes by controlling the temperature and pressure of the working system to achieve the crystallization separation of total ginkgolides.