Study On Chiefly Active Components Of Natural Ginkgo Biloba L.

Ginkgo biloba L. called "living fossil" of gymnosperm, is a special floristics of our country .Since 19th century,Ginkgo leaves have been studied a lot all over the world. It has been found the flavonol glycosides and terpene trilactones are considered the two pharmacologically most important groups present. Ginkgo biloba is an ancient Chinese phytomedi -cine used to treat various ailments including circulatory and demential disorders. The positive effects of Ginkgo extracts are thought to result from the synergistic action of two distinct groups of compounds, the flavonoids and triterpene lactones . The flavonoids are responsible for the free radical scavenging effects of Ginkgo , while the ginkgolides are potent anti-platelet factor (PAF) antagonists .Chinese herb medicine is the precious natural resources of China. China possesses over three-quarters of Ginkgo resources of the world, but falls behind the developed countries in researching and developing the uses of Ginkgo leaves.so we need to research it further. In comparison with advantages and disadvantages of existing methods and actual experimental conditions, ethanol refluxing extraction,ultrasonic wave extraction and microwave extraction were detailled researched. By studying the effect of different factors such as temperatures, time, phase ratios and extracting times, The optimum extracted conditions of flavones from Ginkgo biloba leaves was determined by single factor and orthogonal experiments, the results showed that the ultrasonic method was superior to ethanol refluxing extraction and microwave extraction.Refered to related literature and analyses of other natural products by LC-MS, 20 flavonoids and 5 terpene lactones were identified through optimizing the systems of UPLC and MS by uptodate UPLC-MS" in 7 minutes All flavonoids and terpene lactones were analyzed by UPLC-MS" in a single run. The UV absorption chromatogram, total ion current chromatogram of the sample and first and second ESI-MS spectrum of the corresponding chromatographic peaks were obtained.Through the MS/MS study on the each peak, all structures of 20 flavonoids and 5 terpene lactones from Ginkgo biloba were characterized.The method is rapid, efficient, simple and accurate.