Determination of the content of flavonoids in the fresh pods of Cassia obtusifolia L.by spectrometry

Objective To explore medical feasibility of the fresh pods of Cassia obtusifolia L.,enrich medical resource of Cassia obtusifolia L.and to establish a way for determining flavonoids content in the fresh pods of Cassia obtusifolia L.by spectrometry.Method Flavonoids in the Cassia obtusifolia L.and Semen Cassiae were extracted with methanol.The content of total flavonoids was determined by spectrometry,using rutin as standard substance and developing colour reaction with 5%NaNO2-10%Al(NO3)3-4%NaOH.The detecting wavelength was set at 200 nm～700 nm.Results Under optimum conditions the intensity of visible spectrum showed a linear relationship with the concentration of rutin over the range of 8.0～48.0 μg.ml-1 with a regression equation of A=0.0948C+0.0008(r=0.9994).The contents of total flavonoidas in Semen Cassiae and the fresh pods of Cassia obtusifolia L.were respectively 0.39%(n=3),and 0.31%(n=3),the average recovery rate and the average RSD of recovery were 93.8%(n=6),1.6% and 94.2%(n=6),2.2% respectively.Conclusion The total flavonoids contents in Semen Cassiae and the fresh pods of Cassia obtusifolia L.have no significant difference.