| 摘要 |
<p>(A) Novel pancreoxymin-cholecystokinin (P-C) active peptides (I) consists of the C-terminal section of P-C 25-33 in which (a) aminoacid 25 carries a strongly basic gp., (b) 28 has hydrophilic character of the hydroxyamino acid type and (c) 31 has strongly hydrophobic character of the type shown by amino acids with an aliphatic side chain. Pref. (I) are nonapeptides with Thr, Ser or hydroxy-Pro as unit 28 and Nle, Leu, nor-Val, or alpha-aminobutyric acid as unit 31; esp. they have formula H-X-Asp-Tyr(SO3H)-Y-Gly-Trp-Z -Asp-Phe-NH2 (X = Arg, homo-Arg, nor-Arg, N epsilon, N epsilon-dialkyl-lysine, or N delta, N delta-dialkyl ornithine; Y = Thr, Ser or hydroxy-Pro; Z = nor-Leu, nor-Val or alpha-aminobutyric acid). (B) Also new are tyrosine-O-sulphate barium salt (II) and its N-acyl derivs. (I) are more active than pancreozymin and can be used to control function of the gall bladder and enzyme secretion by the pancreas. They are more stable than the natural hormone (having methionine at positions 28 and 31) and are easier to prepare. (II) is an intermediate for (I), and other proteins and peptides, and allows Tyr(SO3H) to be introduced during standard synthetic steps without the need for a subsequent sulphonation.</p> |
