Synthetic Investigation Toward Astragalus Saponins And The Flavonoid 4’-o-glycosides

1.Synthetic Investigation Toward Astragalus SaponinsAstragali Radix(Huangqi),the root of Astraglus membranaceus,has long been used as one of the most important tonic herbs in traditional Chinese medicine.Studies on its pharmacological and clincal application demonstrated that Astragali Radix has many biological functions.But the content of it is very low which restricts its further research.However,no synthetic investigation toward these biologically important compounds has been reported up to now.Herein We had Successfully first synthesized four types of astragalosides,the cycloastragenol 25-O;3-O;3,6-O-bis;and 3,25-O-bisglycoside,through a series of protection and Au(I)-catalyzed Yu glycosylation.2.The Flavonoid 4’-O-glycosidesFlavonoid glycosides are an important class of biologically active compounds which were founded in many natural products.Flavonoids have many Pharmacological activities,such as antihypertensive,hypolipidemic,anti-aging,improve the body’s immune activity and so on,at the same time their side effects are little.However,studies have shown that 4’-O glycosidic linkages are particularly difficult to construct due to the low activity of 4’-OH.we wanted to explore the glycosylation of the 4′-hydroxyl group of flavonoids which will solve the problem on the synthesis flavonoids 4’-O glycosides.