Separation and identification of angiotensin I-converting enzyme inhibitory peptides from peptic digest of Hizikia fusiformis protein

Abstract

A peptidic fraction (SP-I) having inhibitory activity against angiotensin I-converting enzyme (ACE) was separated from the peptic digest of protein prepared from the brown alga Hizikia fusiformis by ion-exchange chromatographies and gel filtration. Oral administration of SP-I into spontaneously hypotensive rats at 200mg/kg resulted in a marked hypotensive effect. Further separation of SP-I by ODS HPLC afforded three active peptides, Gly-Lys-Tyr (IC50; 3.92μM), Ser-Val-Tyr (8.12μM), and Ser-Lys-Thr-Tyr (11.07μM).