Object To study the effects of different solvent, storage
temperature, decoction time, and when extracted in
combination
with other compatible drugs on the UV absorption spectra of cassia seed extract Methods Extracts of cassia seed obtained under different conditions of extraction were scanned by UV at 190～400 nm with a UV Vis spectrophotometer Results Aqueous and alcoholic aqueous extracts showed an absorption peak at 278 nm, while an ethanolic extract was devoid of such peak, and its absorbance at 237～400 nm was 0 The absorbance of an aqueous extract of cassia seed stored at ambient
temperature was lower than that stored at refrigerator temperature, but increased with the time of decoction The UV spectrum showed no change when cassia seed was extracted in
combination with Chrysanthemum morifolium Ramat , Prunella vulgaris L or Uncaria rhychophylla (Miq ) Jacks , but the former decreased, while the latter two increased the absorbance The UV spectrum showed additional peaks at 207, 278, and 311 nm when cassia seed was extracted in combination with Scutellaria baicalensis Georgi Conclusion If the hypotensive activity of aqueous, alcoholic aqueous, and ethanolic extracts of cassia seed was due to a similar constiuent, its absorbance at 237～400 nm must be 0 Aqueous extract of cassia seed should be stored at a low refrigerator temperature Considering the dissolution rate with heat energy expenditure, the time for decoction should not exceed 1 h C morifolium showed an inhibitory effect on the dissolution, while both P vulgaris and U rhynchophylla showed solubilizing activities S baicalensis not only effected the dissolution of chemical constituent in cassia seed, but also showed a profound influence on the chemical composition of the extract