Quantification of two biologically active anthraquinones emodin and chrysophanol in Cassia tora seed extracts

Cassia tora L. is a weed herb and is distributed throughout tropical and subtropical regions of world. Its’ medicinal properties have been described in Indian System of Medicines. Methanolic extracts of seeds from 29 accessions of C. tora were processed using ultrasonication method at room temperature. Emodin and chrysophanol contents in extract were analysed using a reversed phase high performance liquid chromatography - photo diode array detection method. Wide variation in seed extract yield (6.13-19.93%), content of emodin (0.0058 ± 0.002- 0.1002 ± 0.0008 %) and chrysophanol (0.0015 ± 0.0001- 0.182 ± 0.0027 %) of C. tora was recorded. Total phenolics content also showed wide variability in the range of 0.1869 - 0.9375 % in seeds. High emodin content was recorded in C. tora accessions, DCT-4, DCT-14, DCT-10 and DCT-5. Similarly, high chrysophanol content was recorded in accessions DCT-2, DCT-19, DCT-21 and DCT-1. These identified accessions of C. tora can be used for further genetic improvement. RP-HPLC-PDA method developed in the study would also be useful to explore further genetic variability in emodin and chrysophanol contents in C. tora germplasms.