New octapeptide compounds and their therapeutic use

摘要

Octapeptide compound (I) and their salts are new. Octapeptide compounds of formula (R-AA1-cyclo(AA2-Tyr3-D-Trp4-AA5-Val6-Cys7)-Thr8-NH 2) (I) and their salts are new. AA1 : amino acid group of formula (-NH-CH(CH 2-R1)-C(=O)-) (II); R1 : naphthyl group optionally substituted with one or more alkyl groups; R : H, alkyl or acetyl; AA2 : amino acid group of formula (-NH-CH((CH 2) n2-SH)-C(=O)-) (III); n2 : 1-2; AA5 : amino acid group of formula (-NH-CH((CH 2) n5-NR5R5a)-C(=O)-) (IV); R5, R5a : H, alkyl or acetyl; and n5 : 1-6. Provided that: if AA2 represents an cysteine amino acid radical, then AA1 is not a naphthylalanine amino acid radical and AA5 represents a lysine amino acid radical, or AA1 represents naphthylalanine amino acid radical and AA5 does not represent a lysine amino acid radical, or AA1 is not a naphthylalanine radical and AA5 is not represent a lysine radical; if AA2 is not a cysteine radical, then AA1 represents a naphthylalanine amino acid radical and AA5 is a lysine amino acid radical; and all amino acids can be D or L configuration. ACTIVITY : Endocrine-Gen.; Cytostatic; Ophthalmological; Dermatological. MECHANISM OF ACTION : Somatostatin receptor binder. The affinity of (I) for somatostatin (SRIF) receptors was tested by measuring the inhibition of the binding of [ 1> 2> 5>I-Tyr11] SRIF-14 in CHO-K1 cells. The result showed that (H-D-2-naphthyl (Nal)-cyclo(Cys-Tyr-Asp-Trp-Lys(acetyl)-Val-Cys)-Thr-NH 2) exhibited an affinity of = 5 mu M.