Study On Molecular Modification And Physiological Activity Of The Anthocyanin From Gynura Bicolor

Gynura bicolor is a nutrient-rich,high-grade vegetable that also has multiple health functions.In this thesis,the species and structure of the anthocyanins contained in the leaves were studied and the anthocyanins molecular were modified to enhance the stability of the natural pigments under natural conditions.Meanwhile,the anticancer activity of the anthocyanins in the Gynura bicolor was studied.In this paper,the acidic water was used to extract the crude anthocyanidins from Gynura bicolor,and then purified by macroporous resin HZ-802 and Sephadex LH-20,the purified product was identified by ultraviolet spectrum and infrared spectrum and liquid chromatography-mass spectrometry;in this paper,succinic anhydride esterification and sodium alginate embedding were used to treat the anthocyanins,and various esterification conditions and embedding conditions were optimized.The esterification results were identified by infrared and ultraviolet spectroscopy.Finally,the best esterification conditions and embedding conditions were determined;This experiment detected the effect of anthocyanins on hepatoma cells by MTT assay,microscopy,flow cytometry and DNA electrophoresis,and analyzed the changes of cytokines in the process of apoptosis;At last,the inhibitory effect on ABTS and DPPH free radicals was detected.The experimental results presumed that the anthocyanins of the Gynura bicolor may contain Petunidin-3-polyxylosidase,Petunidin-3-arabia glucoside,Malvidin-3-polyxylosidase,Malvidin-3-arabia glucoside,Peonidin-3-sebodiodiglycoside,Peonidin-3,5-dioxyriboside,Peonidin-3,7-dioxyriboside.Stability experimental results showed that the best succinic anhydride esterification conditions were measured as below:ester donor-to-pigment ratio was 9:1,liquid-solid ratio was 30:1,esterification time was 1.5h,while esterification temperature was 55?.The best embedding conditions were as below:sodium alginate:gelatin was 1:1,wall material concentration was 4%,core material:wall material was 1:1,and CaCl2 concentration was 2%.Study on the anticancer activity in vitro showed that the anthocyanins from Gynura bicolor can significantly decrease the cell viability,cell became shrink,round and other phenomena,and were easy to be stained by Annexin V-FITC and PI dyes.In apoptosis experiments,the ratio of apoptotic and necrotic cells was 29.7%when co-cultured with 200?g/mL pigment for 48h,which was significantly higher than that of the control group 3.6%,indicating that the anthocyanins of the Gynura bicolor can induce the apoptosis of hepatoma cells.Meanwhile,the results of RT-PCR showed that the anthocyanins can activate the expression of NF-?B p65 in cells,but there was no trapezoidal ladder pattern in DNA electrophoresis.The antioxidant test results showed that the scavenging capacity of pigments on the ABTS free radicals was dose-dependently increased(P<0.05),and the ability of anthocyanins to scavenge DPPH free radicals was better than that of ABTS free radicals(P<0.01).Conclusions:The anthocyanins of Gynura bicolor is composed of a variety of pigment monomers with glycosides.The stability of esterification provides a certain theoretical basis for the storage of natural pigments.At the same time,the pigment of Gynura bicolor has certain inhibition effect on the growth of hepatoma cells and the scavenging effect on free radicals in vitro,which is the basis for the development and identification of plant anthocyanins for the development of functional foods and drugs.