Abstract: In order to determine the content of chrysophanol and aurantio obtusin in different tissues of Cassia tora,the seed,root,stem,flower,leaf,pod,cotyledons,hypocotyl,callus and adventitious root were collected,the chrysophanol and aurantio obtusin were extracted using reflux extraction.The content of chrysophanol and aurantio obtusin was determined using HPLC method with Hypersil ODS2 column (4.6 mm×200 mm,5 μm).The analysis condition was as follows:flow rate of 1 mL/min,detection wavelength at 284 nm,temperature at 30 ℃,acetonitrile and 0.1% phosphoric acid in water as mobile phase.The results showed that,the distribution of chrysophanol and aurantio obtusin in C.tora was tissue-specific.The seed,hypocotyl,cotyledon,adventitious roots and callus contained aurantio obtusin and chrysophanol.The root contained chrysophanol merely and the other tissues did not contain either chrysophanol or aurantio obtusin.The total anthraquinone content was cotyledon> adventitious root> callus> hypocotyl> root> flower.During the mature process of seed,the content of chrysophanol showed wave-like increasing tendency with a peak value appeared in the end of November and the content of aurantio obtusin showed bell-shape curve with a peak value appeared in the beginning of November.As the content of chrysophanol and aurantio obtusin in the different maturity of different peak,it is recommended to harvest in late November of the cassia seed to obtain chrysophanol,harvest in early November of the cassia seed to get more aurantio obtusin.The total anthraquinone,chrysophanol and aurantio obtusin were the highest in the mature cassia seed,indicating that the medicinal value of the part was the highest,hence it was scientific to choose the seed.In our country,Cassia has always been the seed medicine,but the collection of seed due to seasonal restrictions,can only be collected once a year,and the number is limited.Plant tissue culture of callus,adventitious root are not subject to seasonal restrictions,and easy to collect large amount,it is recommended to carry out large-scale tissue culture as a new anthraquinone source.The trend of accumulation of chrysophanol and aurantio obtusin in different tissues of Cassia was reported in this study.It provided information for the further study on the expression and regulation of related genes in the synthesis process of chrysophanol and aurantio obtusin.

Key words: HPLC, chrysophanol, aurantio obtusin, tissue distribution