ANALYSIS OF PROTEIN FRACTION CONTENT AND PEPTIDE ACTIVITY OF COIX LACRYMA-JOBI L. VAR. MA-YUEN STAPF (POACEAE) FROM DIFFERENT REGIONS OF CHINA

Coix lacryma-jobi L. var. maYuen Stapf has been used for the treatment of edema, dysuria, and diarrhea in traditional Chinese medicine for many years. Main components and the protein fractions content, including albumin, globulin, prolamin, and glutelin, of 11 batches of this plant collected from different regions of China were studied. Small molecular peptides were generated by hydrolyzing glutelin with pepsin. Angiotensin converting enzyme (ACE) inhibitory activity of the peptides and triolein, the main active pharmaceutical ingredient, were evaluated by UV-HPLC and ELSD-HPLC, respectively. In the protein fractions, glutelin content ranged from 35.48% to 40.81% with significant differences among batches. Diversity in ACE inhibitory activity was also detected. HCA results showed that samples Y1 from Liaoning Muren, Y5 from Yunnan Qujing, and Y6 from Yunnan Lancang manifested great antihypertensive potential. The data generated from this study revealed the characteristic diversity of Coix collected from different locations, which will facilitate the utilization of antihypertensive peptides from glutelin.