35 results about "Ginkgolides" patented technology

The invention discloses a method for synthesizing ginkgolide B through converting a ginkgolide mixture by using stereum hirsutum thalli as a catalyst, belonging to the field of biotechnologies. The method comprises the following steps: carrying out amplification culture on stereum hirsutum strains, taking thalli which are obtained through a test tube slant, a liquid shake flask, seed culture and thallus separation as the catalyst, converting ginkgolide into ginkgolide B, and enabling a conversion solution to be subjected to centrifugation, ethyl acetate extraction and anhydrous alcohol crystallization, so as to separate ginkgolide B from fermentation liquor. By using the method, the purity of obtained ginkgolide B is not lower than 99%, and the ginkgolide conversion ratio is higher than 90%.

The invention provides a high-purity and low-cost purification method for separating ginkgolide A and ginkgolide B (GA and GB) from ginkgo extract powder on the basis of the activation characters of the ginkgolide A and ginkgolide B. The method includes the following steps: (1) alkaline-dissolving and heating the ginkgo extract powder and regulating the pH to 7-9, so that the GA and the GB are ring-opened and deformed to form activated GA and GB; (2) adding hydrochloric acid to the alkaline solution containing the activated GA and GB to regulate the pH to 2.0-2.5, and cooling and separating the alkaline solution to obtain a solution and insoluble impurities; (3) adding NaOH to the solution to regulate the pH to about 4-6, so that the activated GA and GB are combined with the impurities to form a GA combined substance and a GB combined substance, thus forming a coarse grain precipitate; and (4) hot-melting the coarse grain with ethanol to decompose the GA and GB, and re-crystallizing the GA and GB to obtain a finish product. The finish product is 22.95% in content of the GA and is 76.15% in content of the GB, total ginkgolic acid being not detected. Due to the high purity, the product can be used as a raw material for high-quality chemical drugs and health-caring products.

Process for removing pesticides from Ginkgo biloba extracts, which involves submitting an extract obtained by conventional methods to the following steps:a. Liquid-liquid extraction of the extract to obtain a medium polarity fraction containing ginkgo terpenes and pesticides not removable with hexane, and a high polarity fraction containing ginkgo flavone glycosides;b. crystallisation from the medium polarity fraction obtained at step a) to give an intermediate with a ginkgolide content of not less than 50%;c. crystallisation from the residual solution obtained at step b) to give an intermediate with a bilobalide content of not less than 50%;d. mixing of the high polarity fraction obtained at step a) with the ginkgo terpene intermediate and the bilobalide intermediate obtained at steps b) and c).