Abstract: A method for extraction and purification of isostrictiniin from Nymphaea Candida was developed.The extraction process was optimized by orthogonal design and single factor experiment with the yield of isostrictiniin as evaluation indexes.The optimal extraction process was as follows: N.Candida powder was extracted by 50 times of 50% ethanol with reflux for two times in 1.5 h,and the yield of isostrictiniin reached 0.95%±0.001%.The extract from N.Candida was dissolved in hot water,and made into 0.354 mg/mL isostrictiniin solution.This solution was loaded on the H1020 macroporous resin column with the sample flow rate of 2 BV/h,and then column was washed by 10 BV of water for removing impurities,10 BV of 50% ethanol with 2 BV/h flow rate for purifying,to obtain isostrictiniin with more than purity of 10.0% and transferring rate of 90%.The verification experiments showed that the process was stable and feasible.The result can provide reference base for development of N.Candida and isostrictiniin.

Key words: Nymphaea Candida, isostrictiniin, extraction, macroporousresin, purification