Studies On Chemical Quality Evalution And The Antioxidant Activity Of Flos Puerariae

Flos Puerariae,the flowers of Pueraria lobata(Willd.)Ohwi and P.thomsonii Benth,is an important herbal medicine used to ameliorate ethanol intoxication in Chinese Traditional Medicine.In this dissertation,systematic chemical quality evaluation of Flos Puerariae botanicaUy from different species and collected from different habitat were studied using isoflavones as marker compounds.Furthermore,the antioxidant activities of isoflavone compounds as well as the extracts of Flos Puerariae were also investigated.The following studies were carried out.1.By means of solvent extraction,re-crystallization,and the chromatographic methods of macroporous resin column,polyamide column and sephadex LH-20 column,preparatve methods,physico-chemical identification and spectral elucidation of five reference substances, including kakkalide,irisolidone,biochanin A,tectoridin and tectorigenin,were established. These studies provided material basis for the chemical quality evaluation of Flos Puerariae.2.A rapid and clear TLC analysis of the flowers of P.lobata and P.thomsonii was developed using kakkalide,tectorodin and tectorigenin as marker compounds for the frist time..3.A HPLC method for simultaneous determination of kakkalide,irisolidone,biochanin A,tectorigenin-7-O-xylosylglucoside,tectoridin and tectorigenin in Flos Puerariae was developed.This method is simple,accurate and practical for quantitative analysis of Flos Puerariae.There were significant differences in the contents and main components of isoflavones between the flowers of P.lobata and P.thomsonii.Comparative studies on the contents of kakkalide,irisolidone,biochanin A and tectorigenin-7-O-xylosylglucoside during different flowering period and in different parts of the flower of P.lobata were carried out. Moreover,the stability of the four isoflavone compounds in flower of P.lobata with different storage temperature and time were investigated as well.The results indicated that isoflavone components mainly distributed in the bud and flower,and the content of kakkalide in unfully bloomed flower were the highest.However,kakkalide and tectorigenin-7-O-xylosylglucoside were easily enzymolysised in fresh raw materials.4.HPLC chromatographic fingerprints analysis of isoflavone compounds of Flos Puerariae were studied for the frist time.The established 18 common peaks were identified by means of co-HPLC and PDA-UV spectrum with reference substances.Using hierarchical cluster analysis and similarity analysis,7 tested herbal samples were divided into two kinds,the flower of P.lobata and the flower of P.thomsonii,which was consistent with the results from morphologic identification.5.The effects of isoflavone compounds and the extracts of Flos Puerariae on lipid peroxidation in rat liver homogenate were investigated by determining the content of malondialdyhyde(MDA).The results showed that both isoflavone compounds and the extracts of Flos Puerariae exhibited the activities of anti-lipid peroxidation.