| 摘要 |
<p>N-acyltetrapeptides of formula R-Val-X-Ala-X (I) (where R=acyl with straight, branched or cyclic chain as main carbon chain, e.g. acetyl, parmitoyl, lactoyl, isobutylyl, isovalely, benzoyl, phenoxyacetyl, 2-phenoxypropyonyl, malonyl, oxalyl, beat-hydroxypropyonyl 4-amino-3-hydroxy-6-methyheptanic acid, and X=) and, their salts and esters are new. They are useful as proteolytic enzyme inhibitors and antiulcer agents. The N-acyltet peptide, having LD0 of >4000 mg/kg I.P. (acyl =acetyl and isovaleryl) and a water solubility of above 10,000 and above 5,000 mcg/ml (acyl as above), shows high inhibitory activity for acidic proteolytic enzymes, e.g. ID90 for pepsin of 0.024 and 0.021 mcg/ml (acyl= as above), thus being useful as anti ulcer agents, other pharmaceuticals and laboratory chemicals. (I) without acyl are produced from R-val-val-X-Ala-X using microorganisms as in J49028849. These intermediates are acylated to produce (I).</p> |
