Process for the preparation of angiotensis converting enzyme (ACE) inhibitors and its use

Abstract

A process for preparing Angiotensin Converting Enzyme (ACE) inhibitors from glycinin of soy flour and its use as ACE inhibitors.

1 . A process for the preparation of Angiotensin Converting Enzyme (ACE) inhibitory peptides from glycinin of defatted soy flour, said process comprising the steps of: 
 (a) isolating glycinin from defatted soy flour;    (b) dispersing 10-25% solution glycinin in a buffer;    (c) hydrolyzing the mixture with proteolytic enzyme (2-4% w/v);    (d) incubating the mixture at 37-50° C. for a period of 16-18 hours;    (e) arresting the reaction by adding trichloroacetic acid (TCA-100%);    (f) centrifuging the mixture at 15-20,000 rpm for 30-40 minutes, at a temperature of about 4-8° C.;    (g) obtaining a mixture of protein hydrolysates containing polypeptides; and    (h) separating and purifying the active peptide fractions designated as 2, 3 & 4 having ACE inhibitory activity.    
     
     
         2 . The process of  claim 1 , glycinin is an isolated protein fraction from defatted soy flour.  
     
     
         3 . The process of  claim 1 , wherein the buffer of step (a) is selected from Tris-HCl and sodium phosphate.  
     
     
         4 . The process of  claim 1 , wherein in step (a) the pH is maintained in the range of 6.2-8.2 and a molarity of 0.05-0.1M.  
     
     
         5 . The process of  claim 1 , wherein different proteases are used to prepare the hydrolysate.  
     
     
         6 . The proteases of  claim 5 , wherein the plant protease having specificity of cleaving C-terminal to proline.  
     
     
         7 . The proteases of  claim 5 , wherein the proteolytic enzymes are fungal proteases selected form  Aspergillus niger , bovine trypsin, bovine chymotrypsin or plant protease or a protease from ginger ( Zingiber officinale ) or a combination of the above.  
     
     
         8 . The process of  claim 1 , wherein the step (h) are performed by RP-HPLC on an octadecyl column using a linear gradient of 0.1% TFA and 70% acetonitrile.  
     
     
         9 . The use of polypeptide fractions of  claim 1 , wherein said polypeptide fractions are uses as Angiotensin Converting Enzyme (ACE) inhibitors.  
     
     
         10 . The use of  claim 9 , wherein the ACE inhibitory activity of the fractions 2, 3 & 4 is 66, 81 and 75% respectively.  
     
     
         11 . The use of  claim 9 , wherein the IC  50  value of in vitro ACE inhibition is in the range of 5-39 μg N 2  equivalence.