Determination of total flavonoids on 5 species of Oxytropis

In this study, the total flavonoids of Oxytropis kansuensis, O. ochrocephala, O. glabra, O.glocialis and O. deflixa were determined through qualitative analysis of colour reaction and quantitative analysis of ultraviolet spectrophotometry, with rutin as control. The results showed that flavonoids existed in 5 crazyweed herbs. A maximum absorption peak appeared at wave length 274 nm and completely overlaped for both testing and control sample. In addition, there was a significant difference of total flavonoids among different species of crazyweed herbs, the total flavonoids content was from 9.7 mg/g to 33.85 mg/g, the order of total flavonoids from high to low is as followed: O. kansuensis, O. glabra, O. deflixa, O. ochrocephala and O.glocialis. Extracted with petroleum ether made the result of determination more accurate.