Tyr-Pro-Lys, an angiotensin I-converting enzyme inhibitory peptide derived from broccoli (Brassica oleracea Italica)

Abstract

To investigate the naturally Occurring angiotensin I-converting enzyme (ACE) inhibitor, broccoli (Brassica oleracea Italica) extracts were used for its isolation and identification. After treatment with 50% acetone for membrane breakdown, ethyl acetate, n-butanol. and water were used for the preparation of broccoli extracts. The water-soluble extract from broccoli had 76.9% ACE inhibitory activity. while those of other organic solvent extracts showed lower ACE inhibitory activities. An ACE inhibitory peptide was isolated using column chromatographic methods including: Amberlite XAD-4, Sephadex LH-20, and high performance liquid chromatography. The purified ACE inhibitory peptide wits identified to be a tripeptide, Tyr-Pro-Lys, having an IC50 value of 10.5 mu g protein/ml.