NEW PEPTIDE, ITS SALT AND HYPOTENSIVE AGENT CONTAINING THE SAME AS ACTIVE INGREDIENT

摘要

PURPOSE:To obtain a new peptide, having an amino acid sequence of Tyr-Val- Pro-Phe-Pro-Pro-Phe and further hypotensive, opioid antagonistic and arterial relaxing activities, etc., and useful as a hypotensive agent, etc. CONSTITUTION:A human milk whole casein is fractionated by gel filtration and a fraction eluted in a void volume is collected to provide a solution containing kappa-casein, etc., and lactoferrin. The resultant fraction is then regulated to pH2 with HCl. Pepsin is subsequently added and reacted at 37 deg.C for 5hr. The pH is then regulated to 7.5 with 1 N NaOH and carboxypeptidase A is subsequently added to carry out reaction at 37 deg.C for 5hr. The obtained hydrolyzate is boiled for 10min and centrifuged to remove insoluble substances. The obtained supernatant is developed with an acetonitrile gradient containing 0.1% trifluoroacetic acid according to high-performance liquid chromatography using a column treated with octadecylsilane to afford the objective new peptide (salt) expressed by the formula Tyr-Val-Pro-Phe-Pro-Pro-Phe.