Dynorphin analogs specific for kappa opioid receptors

Claim 1

A cyclic or linear dynorphin having structure I, II or III shown below, ##STR31## H-XXX.sup.1 -Gly.sup.2 -Gly.sup.3 -WWW.sup.4 -YYY.sup.5 -Arg.sup.6 -Arg.sup.7 -ZZZ.sup.8 -Arg.sup.9 -BBB.sup.10 -AAA.sup.11 -E (III) wherein in structure I, XXX 1 is a D or L-aromatic amino acid or a halogen, nitro, cyano or C 1-6 alkyl ring-substituted aromatic amino acid, YYY 5 is D-Cys, L-Cys, D-homoCys, L-homoCys, D-Pen or L-Pen; WWW 4 is a Dnitro, or L-aromatic or aliphatic amino acid or a halogen, cyano, hydroxy, or C 1-6 alkyl ring substituted aromatic amino acid; ZZZ 8 is L-Ile, L-Val, L-Nle, L-Leu or D-Ala, BBB 10 is L-Pro, D-Pro, L-Sar or D-Sar and AAA 11 is D-Cys, L-Cys, D-homoCys, L-homoCys D-Pen or L-Pen, wherein the thiol groups of amino acids YYY 5 and AAA 11 are bonded together so as to form a disulfide ring; in structure II, XXX 1 is as defined above, YYY 5 is D-Leu, L-Leu, D-Met or L-Met; WWW 4 is a D-- or L-aromatic or aliphatic amino acid or a halogen, nitro, cyano, hydroxy, or C 1-6 alkyl ring substituted aromatic amino acid; ZZZ 8 is D-Cys, L-Cys, D-homoCys or L-homoCys, BBB 10 is as defined above, AAA 11 is a basic amino acid and CCC13 is D-Cys, L-Cys, D-homoCys, L-homoCys, D-Pen or L-Pen, wherein the thiol groups of amino acids ZZZ 8 and CCC 13 are bonded together so as to form a disulfide ring; in structure III, XXX 1 , WWW 4 , ZZZ 8 , and BBB 10 are as defined for structure I, YYY 5 is a D- or L-aliphatic or aromatic amino acid, and AAA 11 is a basic amino acid; and wherein E is a carboxylic acid or a peptidase-stable carboxylic acid derivative.