Purification and identification of an ACE inhibitory peptide from the peptic hydrolysate of Acetes chinensis and its antihypertensive effects in spontaneously hypertensive rats

Summary Acetes chinensis is a marine shrimp found in the coastal waters of China. The shrimp was hydrolysed by pepsin to prepare hydrolysates with angiotensin I‐converting enzyme (ACE) inhibitory activity. The hydrolysate with the highest ACE inhibitory activity resulted from a 3–5 h incubation at 45 °C and pH 2.5 with pepsin. Gel filtration and RP‐HPLC were used to separate ACE inhibitory peptides from the hydrolysate. The gel filtration fraction of the hydrolysate with a molecular weight range from 1320 Da to 311 Da exerted the highest ACE inhibition activity. This fraction was separated by RP‐HPLC into fifteen fractions, of which fraction F9 showed 92.7% of the ACE inhibition activity. Its peptide sequence was determined to be Leu–His–Pro. It showed a potent antihypertensive activity in spontaneously hypertensive rats. The results suggested that this peptide may be a potent ACE inhibitor which might be developed into a healthy food to lower blood pressure.