Innovation of extraction and isolation technique of shikimic acid from Ginkgo biloba leaves utilizing an ionic liquid

Shikimic acid is an important biosynthetic intermediate in plants, and is the starting material in the commercial synthesis of oseltamivir phosphate (Tamiflu^®). Here, we report the efficient extraction and isolation technique of shikimic acid from the leaves of Ginkgo biloba, which is cultivated worldwide. Through the utilization of an ionic liquid 1-butyl-3-methylimidazolium chloride ([bmim]Cl), which dissolves cellulose, the procedure gave twice the amount of or more of shikimic acid than the normal method. The proposed technique is likely to be applicable to other plant leaves, allowing for isolation of greater quantities of other natural products as well as unknown natural compounds.