Extraction Technology of Flavonoids from Ginkgo biloba L. Shells

[Objective] To study the extraction technology of flavonoids from Ginkgo biloba L. shells. [Method] With ethanol solution as the extraction solvent, flavonoids were extracted from G. biloba shells. Effects of ethanol concentration, solid-liquid ratio, extraction time and extraction temperature on the extraction rate of flavonoids were studied by single factor test. The optimal conditions of traditional ethanol extraction and microwave-assisted extraction were researched by orthogonal test. [Result] The optimal condition of traditional ethanol extraction was as follows: 60℃ extraction temperature, 75% ethanol concentration, 1∶45 solid-liquid ratio (W/V, g/ml), and 2h extraction time. Under this condition, the extraction rate of flavonoids reached 0.503 4%. The optimal condition of microwave-assisted extraction was as follows: 60℃ microwave temperature, 45% ethanol concentration, 1:30 solid-liquid ratio, and 480s microwave time. Under this condition, the extraction rate of flavonoids reached 0.815%. [Conclusion] Microwave-assisted extraction was rapid, simple and high-efficient. As a new extraction technology, microwave-assisted extraction was superior to traditional ethanol extraction in certain extent.