| Licorice is a common herb with abundant resources in China.It can be used as food or medicine.Several studies have shown that there are many active ingredients in licorice,but there are few studies on the activity of lowering blood glucose.Currently,most of the hypoglycemic drugs used in clinical practice are synthesized by chemistry or biosynthesis.Although the effect of hypoglycemic drugs is obvious,they also bring many side effects.Therefore,in recent years,the extraction of active ingredients from natural products for the prevention and treatment of diabetes related research has become a major trend.In this paper,the enzymatic extraction,purification and hypoglycemic activity of glycyrrhizin from aksu licorice in xinjiang were studied.Firstly,the basic elements of liquorice are measured in the reference to the National standard and the literature method,the results showed that:The water content of liquorice was 5.32 ± 0.03%,The content of ash was 2.76 ± 0.02%.The content of protein was 8.15± 0.02%.The crude fiber content was 9.29± 0.04%.The fat content was 1.88±0.01%.The total flavonoids content was 8.79±0.07%.The content of total saponins was 7.89±0.04%.The content of total suger was 22.41±0.06%.Single factor and orthogonal experiment were carried out on the extraction of glycyrrhizic acid by using cellulase and pectinase,and the extraction conditions were optimized.The results showed that:Enzyme solution temperature of 40℃,enzyme solution pH is 4.5,the adding quantity of 5 mL,extraction temperature is 80℃,and solid-liquid ratio 1:15,ethanol concentration was 60%,the best extraction,extraction rate was 92.4%,1.87 times higher than the average extraction method.The glycyrrhizic acid was isolated and purified by organic reagent extraction,ultrafiltration and dialysis,and silica gel column chromatography.The purity of GA1,GA2 and GA3 was 46.77%,64.37%and 93.53%by HPLC.Large-scale instruments such as infrared spectroscopy and nuclear magnetic resonance were used to analyze the molecular structure of GA3.Taking PNPG as the substrate and acarbose as the positive control,the inhibitory activity of the components GA1,GA2 and GA3 obtained by three different purification methods on alpha-glucosidase was studied.The inhibition rate was 24.71%,27.75%and 29.54%,respectively.The results showed that the inhibition effect of glycyrrhizin was more obvious with the improvement of the purification degree of glycyrrhizin,of which GA3 was the most obvious.STZ induced hyperglycemia and hyperlipidemia which was used to study the hypoglycemic effect in mice.The physiological and biochemical indexes of mice were tested after 35 d of intragastric administration with different doses of GA3.The results showed that glycyrrhizin could decrease the blood sugar of diabetic miceThe serum level of TG,TC,LDL-C,HDL-C and insulin levels of the high-dose glycyrrhizin group were 1.17±0.36%,3.13 ±0.5%,0.43±0.23%,4.46±1.14%,31.31±3.08%.respectively,which were similar to that of the blank control group.The results showed that the lipid metabolic disorder of diabetic mice could be effectively improved and the damaged islets could be repaired. |
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