Studies On The Extraction And Separation Technology Of Emodin And Resveratrol From Polygonum Cuspidatum

Polygonum cuspidatum is the root and rootstock of Polygonum cuspidatum Sieb.et Zucc belonged to Polygonaaceae. Resveratrol is a kind of small molecular weight and having biologic active phytoalexin produced by plants when they react against the stimulus of enviroment. The resveratrol content in Polygonum cuspidatum is the highest among all studied plant species. It has not been reported that two or more effective component are comperehensively extrated and separated from Polygonum cuspidatum. Adopting Polygonum cuspidatum as the research materials, we studied the method of comprehensive extraction and separation of resveratrol and emodin from Polygonum cuspidatum, and offered valuable reference data for the corporation.The procedures to analyze resveratrol and emodin with UV, TLC and HPLC methods were set up. The HPLC analysis method can be used for detemining final product because of its highest preciseness. The TLC and UV analysis methods can be used for analyzing half-finished product in producting process because of its convenience and quickness.The content of resveratrol and emodin in Polygonum cuspidatum of diffent picking period is determined, and is the highest in August and September which achieve 0.162% and 0.648%. August and September is reasonable picking period of Polygonum cuspidatum.Based on the results of single factor experiments and orthogonal experiments, the best extracting procedures is extracting them with 10 times amount of 75% ethanol at 60℃for 2 hours and repeating the process three times. This method is better than heat return extraction of water, and near to ultrasonic extraction. Experiments of comprehensive extraction and separation of resveratrol and emodin from Polygonum cuspidatum were enlarged. After concentrating, extracting, hydrolyzing, decolorizing and crystalling, resveratrol and emodin can be effectively extracted and separated from Polygonum cuspidatum. The extracting ratio of resveratrol (98.04%) is 64.76%. The extracting ratio of emodin (98.11%) is 32.08%.