Study On Enzymatic Biosynthesis Of Novel Bavachin Glucosides And Antitumor Activity

Objective:1.The novel structure of the bavachin was obtained by modifying the enzymatic glycosylation reaction in vitro by using the bavachin as the base.2.The solubility,stability and antitumor activity of the bavachin were improved by glycosylation modification,and the pH stability and temperature stability were investigated to achieve the repeatability of the experiment under the same conditions.3.The best reaction conditions of enzymatic glycosylation reaction in vitro were determined by single factor experiment.Methods:1.In order to get their enzymatic glycosylation products,modify the structure of the substrate(bavachin)by using UDP-glycosyltransferase.2.By liquid chromatography tandem mass spectrometry(LC-MS),nuclear magnetic resonance(NMR)analysis and identify their structures and collect the amount of the product.3.By high performance liquid chromatography(HPLC)analysis the water solubility,temperature stability and pH stability of their enzymatic glycosylation products.The best reaction conditions of enzymatic glycosylation reaction in vitro were explored by using the amount of compound 1,compound 2 and compound 3 in the process of glycosylation reaction.4.MTT assays were used to detect the antiproliferative effect of the compounds on four human cancer cell lines.Results:1.We obtained three glucosides of bavachin for the first time by enzymatic synthesisusing a UDP-glycosyltransferase,and its water solubility and bioactivity were better than that of bavachin.2.Under the same conditions compound 1,compound 2,compound 3 each water solubility is higher than the water solubility of the bavachin,some increase several times some increase dozens of times times.In the same condition,compound 1,compound 2 and compound 3 have higher stability when pH value is 8.8;compound 1,compound 2 and compound 3 have high stability when the temperature is 70°c under the same condition.3.According to the factors such as the concentration of the glucose-transferase,the pH of the buffer fluid and the incubation time,the best reaction condition is that the concentration of the 3mmol/l,pH is 8.8 and the incubation time is 3h,the reaction occurs completely and the product reaches the maximum amount.4.Based on the spectroscopic data,the glucosides were identified as bavachin-4?-O-?-D-glucopyranoside(1),bavachin-7-O-?-D-glucopyranoside(2),bavachin-4?,7-di-O-?-D-glucopyranoside(3)5.Compound 1,compound 2,compound 3 exhibited weak anti-proliferative activities against the 4 human cancer cell lines.However bavachin showed moderate antiproliferative activities against the 4 human cancer cell lines.Conclusions:1.The sugar-based transferase(Yjic)has a good substrate selectivity to the complement of bavachin.Bavachin might have therapeutic potential for type 2diabetes,promote osteoblasts proliferation,treat inflammatory diseases.However,the low water solubility and poor absorption after oral administration limit its further clinic use.2.The best reaction conditions of enzymatic glycosylation in vitro were related to the concentration of glucose radical,incubation time and the ph of buffer fluid.3.Compared with the substrate of bavachin,the product of compound 1,compound 2and compound 3 can improve the water-soluble and stability.4.Compared with the substrate of bavachin,the product of compound 1,compound 2and compound 3 exhibited weak antiproliferative activities against the 4 human cancer cell lines.