The Study Of Preparing Antihypertensive Peptides Of Coix Seed By Biological Transformation

In this paper peptides of coix seed have been studied obtained by the method of biological transformation. We conclude that coix seed peptide plays a role in the anti-hypertensive process in vitro, and hope it can be a reference for further study of antihypertensive drugs. Also enzymatic method and fermentation have been compared, the result showed that the activity of peptides obtained by fermentation have a stronger anti-hypertensive activity in vitro.Enzymatic method and fermentation have been studied separately preparing for coix seed peptide .one hand, Water extraction conditions and hydrolysis conditions were optimized in this trial. The results show that the best conditions for pH, temperature and solid-liquid ratio is 10,70℃and 1:15. At this point he peptide content much is much higher than it in hydrolysis. The absorption of enzymolysis products of DA201-C macroporous resin was better than others. The best conditions for pH, sample injection rate and concentration of alcohol are 5.5, 1BV/h and 75% in purification process of the resin. The molecular weight after purification was determined using High Performance Liquid Chromatography. The molecular weight of 99.3% of purified product was between 278.6 and 943.32. Dextran gel Sephadex G-15 was used for the separation for purification products. Three peaks can be obtained when deionized water as the buffer, of which Peak B has the highest ACE inhibition rate which was 80.1%.On the other hand, fermentation conditions was optimized in this trial.The results showed that peptide content fermented with Aspergillus oryzae and Monascus were 6.14mg/ml,2.58mg/ml and 2.93mg/ml respectively. So Aspergillus niger was determined to be the best one for mixed fermentation. The best conditions for fermentation time, coix seed concentration, PH and inoculum were 90h,9%,5 and 11%. Yellow rice wine yeast, alcohol yeast and beer yeast were determined for mixed fermentation, and yellow rice wine yeast was the best one. Then the products were purified with the resin. The molecular weight after purification was determined using High Performance Liquid Chromatography. The molecular weight of 98.4% of purified products was between 267.91 and 930.35. Sephadex G-15 was used for the separation for purified products. Five peaks can be obtained when deionized water as the buffer, of which Peak B has the highest ACE inhibition rate which was 83.2%.