Studies on the Optimum Extraction Technology of Total Flavonoids from Lespedeza virgata(Thunb.) DC.by Orthogonal Test

[Objective] To optimize the extraction technology of total flavonoids from traditional Chinese medicine Lespedeza virgata(Thunb.) DC.[Method] The extraction technology of total flavonoids from L.virgata was optimized by means of single factor test and orthogonal test.The content of total flavonoids was determined by UV spectrophotometer.[Result] The optimum conditions of extraction were established as follows:40% ethanol,material-solvent ratio 1:8(g/ml) and extracting time 1 h.Under these conditions,the content of total flavonoids was as high as 3.62%.[Conclusion] This extraction technology was low-cost and efficient.