The Activities Research Of Myrica Rubra Crude Peptides And Anthocyanins

Chinese bayberry (Myrica rubra Sieb.et Zucc) is one of myricaceae perennial subtropical fruits. There are a lot of research about Myrica rubra polyphenols, flavonoids and anthocyanins' function, while the report of Myrica rubra protein is scarce. Therefore, the study of Myrica rubra peptide's activity would contribute to a more comprehensive understanding of the function of Myrica rubra. The paper studied the optimal extraction method by alkali-solution and acid-isolation for Myrica rubra protein firstly, and the enzymatic hydrolysis by pepsin and trypsin successively.6different molecular weight peptides were obtained by using ultrafiltration. After that, the optimal Myrica rubra peptide was picked up by investigating their antioxidant activity, hypoglycemic activity, hypotensive activity and bacteriostatic activity. Furthermore, the stability of antioxidant and hypoglycemic activity of optimal Myrica rubra peptide were studied. In addition, the optimal angiotensin converting enzyme(ACE) inhibition small peptides with its molecular weight were obtained by purificating the optimal Myrica rubra peptide. Meanwhile, the paper also studied the optimal extraction method for Myrica rubra anthocyanins and its bacteriostatic activity. The main conclusions are as follows:The optimal alkali soluble extraction conditions of Myrica rubra protein: material to liquid(w/v)1:6.1, pH10.44, at46.7?for3.5h, then sinking the Myrica rubra protein by HCl at pH2, and the protein content of the Myrica rubra protein is28.8g/100g. After that it was enzymatic hydrolyzed by pepsin and trypsin successively, and6peptides were obtained with different molecular weights by using ultrafiltration.The result of antioxidant activity, hypoglycemic activity, hypotensive activity and bacteriostatic activity of6different molecular weight peptides indicates that all of them had no bacteriostatic activity, and the MW<5000Da peptide is the optimal Myrica rubra peptide. Meanwhile,6different molecular weight peptides were compared with Vc, acarbose and captopril for antioxidant activity, hypoglycemic activity and hypotensive activity, respectively, and the result are as follows:The antioxidant activity:MW<5000Da peptide's total antioxidant capacity is11.14U/mL(Vc is24.4U/mL); O2-'inhibition capacity is58.73U/L(Vc is the criterion group), DPPH radical scavenging capacity is28.61%(Vc is35.06%), hypoglycemic (?-glucosidase inhibition) activity is40.93%(acarbose is58.03%), hypotensive (ACE inhibition) activity is46.56%(captopril is84.88%). 3The optimal Myrica rubra peptides were disposed by different temperature, pH, saccharides, antiseptics and metal ions firstly,and then study the stability of antioxidant and hypoglycemic activity as the active retention is indicator.The result is:?As for the stability of antioxidant activity:In the condition of25?-100?, pH?7, benzoic, NaCl, Mg2+and K+had no significant effects on antioxidant activity; but saccharides could increase the antioxidant activity significantly in the order of glucose>lactose>sucrose.Meanwhile in the condition of pH>7, Zn2+and Cu2+, the antioxidant activity was decreased.?As for the stability of hypoglycemic activity:In the condition of25?-100?, pH?7, lactose, benzoic and K+had no significant effects on hypoglycemic activity; but pH>7, NaCl and Mg2+could increase the hypoglycemic activity significantly. Meanwhile in the condition of Zn2+and Cu2+, the hypoglycemic activity was decreased. However, because of the glucose, lactose and sucrose can be the products of a-glucosidase inhibition capacity measurement system, three saccharides promote reaction system has a backward reaction, therefore, saccharides can't intuitive the influence of hypoglycemic activity.4Their are two products obtained from the optimal Myrica rubra peptides purificated by sephadex G-25, and study their antioxidant activity, hypoglycemic activity and hypotensive activity found that:product1has a better hypotensive activity, product2have no hypotensive activity, what's more, product2have a better antioxidant activity and hypoglycemic activity;Their are three products obtained from the product1and product2purificated by sephadex G-10, respectively. And the product2-2has the best antioxidant activity and hypoglycemic activity in three products of product2, the product1-2has the best hypotensive activity in three products of product1and its molecular weight ranged from153Da to1558Da.5The optimal extraction conditions of Myrica rubra anthocyanins:material to liquid(w/v)1:8, ultrasounded time15min, extraction time74.13min, concentration of HCl in alcohol0.5%, extraction temprature43.81?, concentration of alcohol in HCl79.12%.And Myrica rubra anthocyanins has a significant bacteriostatic activity for Escherichia coli and Salmonella typhimurium.