Research On Entrichment, Separation And Bioactiviy Of Flavonoids From Gynura Divaricata (L.)DC

G. divaricata (L.) DC (Compositae) belongs to Gynura Cass., is called "Bai Bei San Qi", which has been planted widely from Taiwan to southern part and southwest of China. It is one of the most famous traditional Chinese medicinal herbs, and usually used to cure bronchitis, pulmonary tuberculosis, kink cough rheumatism, diabetes and so on. In Fujian area, the leaf of G. divaricata is a commonly tea for reducing blood glucose. It could significantly decrease the blood glucose of diabetic patient. This thesis preliminarily researched the antioxidant activity, constituents analysis, flavonoids enrichment of G. divaricata extracts, and the interaction between flavonoids compound and bovine serum albumin (BSA) was further studied, which would offer scientific proof for the depth development and clinical application of G. divaricata.In the first chapter, a review was presented to introduce the plant origin, chemical constituent, advances in pharmacological activity research, extraction and content evaluation method of flavonoids about G. divaricata.In the second chapter, the antioxidant activity of different fractions from G. divaricata crude extract was tested by several model analysis including the scavenging activity of DPPH radicals, reducing power, chelating ability and total antioxidant activity, the pertinences between antioxidant activity and flavonoids content was further studied. The results showed:there were obvious differences among the different fractions from G. divaricata crude extract on their antioxidant activity. Ethyl acetate (EF) extraction had the highest content of flavonoids and showed the strongest antioxidant activity, contrasting with the other extractions (n-butanol, chloroform and water extraction). While, all of them showed worse chelating ability. Which indicated the antioxidant activity of extractions mainly depend on the total flavonoids, especially its content and structure. And EF extraction' scavenging radicals activity equaled BHT, could used as nature antioxidants or curing disease caused by radicals.In the third chapter, five kinds of macroporous resins were screened to enrich the total flavonoids from Gynura divaricata crude extract. By static and dynamic experiment, the better macroporous resins and its optimized process parameters on enrichment of flavonoids from Gynura divaricata were screened out. That was HPD-100 showed the best adsorption capacity and desorption rate, and after treatment with it under the optimal conditions, the flavonoids content was increased more than 6-fold, with a recovery yield of 85%. Adsorption pH and concentration, adsorption and desorption rate, eluent were the main factors of effecting flavonoids enrichment by macroporous resins from Gynura divaricata.In the forth chapter, HPLC-ESI-MS method was firstly applied to analyze and identify the flavonol glycosides from Gynura divaricata. Combining UV,1HNMR, 13CNMR and references,10 compounds were determined to be kaempferol-3-0-robinobioside-7-O-β-d-glucopyranoside(1),kaempferol-3,7-di-O-β-D-glucoside(2),kaempferol-3-O-rutinoside-7-O-β-D-glucoside(3),p-coumaroylquinic acid(4),quercetin-3-O-rutinoside(5),quercetin-3-O-β-D-glucoside(6),Kaempferol-3-O-robinobioside(7),kaempferol-3-O-mrutinoside(8),kaempferol-3-O-β-D-galacoside(9),k aempferol-3-O-β-D-glucoside(10). Among them, compound 1,3 was identified for the first time from Gynura divaricata.In the fifth chapter, by fluorescentspectrometry, the interaction of kaempferol-3, 7-di-O-β-D-glucoside (KG) and kaempferol-3-O-rutinoside-7-O-β-D-glucoside (KR) with bovine serum albumin (BSA) under physiological condition was researched; furthermore, the effect of some irons on the combination of KG and KR with BSA was also investigated. The results demonstrated that both of them could bind with BSA spontaneously, and quench the intrinsic fluorescence of BSA in a static quenching process. Synchronous fluorescence method showed the conformation of BSA was not influenced by their binding reaction. The bonding of KG and KR to BSA involved hydrogen bonds and Van der Waals forces mainly. Moreover, the combination of KG and KR with BSA could effected by some irons existed in body.