Extraction and Purification of Flavonoids from Radix Puerariae

Pengyue Li, Yang Lu*, Shouying Du*, Jie Bai, Huimin Liu, Qingli Guo and Yiwang Guo

School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100102, China

*For correspondence: Email: pengyuelee@126.com, dushouying@263.net, landocean@163.com; Tel: 010-84738615, 010-84738615

Received: 30 July 2013                                              Revised accepted: 9 November 2013 

Tropical Journal of Pharmaceutical Research, December 2013; 12(6): 919-927

Purpose: To develop an efficient method for the purification of flavonoids from Radix puerariae

Methods: Optimal extraction technology was obtained using orthogonal test. Through adsorption and desorption tests, 8 resins with different polarity, diameter, and surface area were studied. Finally, a novel macroporous resin, HPD200A, was applied in the work. Desorption tests were performed in a glass column packed with HPD200A resin, and several parameters of purification were studied. The content of puerarin and flavonoids in the samples were tested by a HPLC and a UV-Vis Spectrophotometer, respectively.

Results: Optimum extraction technology was confirmed as follows: extraction time is 1.5 h; ratio of solvent to material 12; and repetition of extraction 3 times. Optimum purification technology was confirmed as follows: decoction is concentrated into 1.05 ~ 1.10 g/ml; 95 % ethanol is added to remove the impurities and the volume ratio is 1.5 : 1; the concentration of loading sample is 0.25 g/ml (based on the weight of the crude drug), the volume of loading sample is 2 BV (bed volume). The mobile phases of desorption are water (2BV) and 30 % ethanol (4BV) in succession. The contents of puerarin and flavonoids in the extract were improved greatly after the purification procedure, by up to 32 and 75 %, respectively.  

Conclusion: This efficient method has potential for purification and preparation of flavonoids in the future.