Methods :The flavonids were extracted by ethanol as the solvent from Ipomoea batatas Lam leaves with ultrasonic wave and ethanol extraction.

• 方法:采用超声波乙醇浸提法从红薯叶中提取黄酮类物质,对所提取的黄酮类物质进行验证,并用紫外分光光度法测定含量。