Extraction and Content Determination of Flavonoids in Sonchus oleraceus L.

[Objective] To study the extraction methods of flavonoids from Sonchus oleraceus L. and the variations of their contents with growth months and parts. [Method] The contents of flavonoids in S.oleraceus grown at different months and their distributions at different parts of S. oleraceus were detailed studied in this article. The extraction process of total flavonoids from S. oleraceus leaves was optimized through orthogonal design method. [Result] It was discerned from the experiment that the extraction solvent concentration> solid-liquid ratio>extraction time. The optimized extraction condition was that the solid-liquid ratio was 1∶20 （g/ml）, extraction solvent was 75% alcohol and extraction time was 2 h. The flavonoids contents in different parts were flower>leaf>stem>root. Flavonoids in S. oleraceus L collected in April were higher than that of other months. [Conclusion] The result is valuable for further development and utilization of S. oleraceus resources.