Polypeptides, processes for their production, pharmaceutical compositions comprising said polypeptides and their use

A polypeptide of formula (I) ##STR39## wherein A is C.sub.1-12 alkyl, C.sub.7-10 phenylalkyl or a group of formula RCO--, whereby

• (i) R is hydrogen, C.sub.1-11 alkyl, phenyl or
• C.sub.7-10 phenylalkyl, or
• (ii) RCO-- is
• (a) an L- or D-phenylalanine residue optionally ring-substituted by halogen, NO.sub.2, NH.sub.2, OH, C.sub.1-3 alkyl and/or C.sub.1-3 alkoxy
• (b) --Asn-- or the residue of a natural .alpha.-amino acid having a hydrocarbyl side chain other than defined under (a) above or of a corresponding D-amino acid, or
• (c) a dipeptide residue in which the individual amino acid residues are the same or different and are selected from those defined under (a) and/or (b) above, the .alpha.-amino group of amino acid residues (a) and (b) and the N-terminal amino group of dipeptide residues (c) being optionally mono- or di-C.sub.1-12 alkylated,
• A' is hydrogen or, when A is C.sub.1-12 alkyl or C.sub.7-10 phenylalkyl, also C.sub.1-12 alkyl or C.sub.7-10 phenylalkyl,
• B is --Phe-- optionally ring-substituted by halogen, NO.sub.2, NH.sub.2, OH, C.sub.1-3 alkyl and/or C.sub.1-3 alkoxy,
• C is --(L)-- or --(D)--Trp-- optionally .alpha.-N-methylated and optionally benzene-ring-substituted by halogen, NO.sub.2, NH.sub.2, OH, C.sub.1-3 alkyl and/or C.sub.1-3 alkoxy,
• D is --Lys-- optionally .alpha.-N-methylated and optionally .epsilon.-N-C.sub.1-3 alkylated,
• E is --Thr-- or --Ala-- each in (D)- or (L)- form and each being optionally .alpha.-N-methylated,
• F is a group of formula ##STR40## wherein R.sub.1 is hydrogen or C.sub.1-3 alkyl,
• R.sub.2 is hydrogen or the residue of a physiologically acceptable, physiologically hydrolysable ester,
• R.sub.3 is hydrogen, C.sub.1-3 alkyl, phenyl, benzyl or C.sub.9-10 phenylalkyl,
• R.sub.4 is hydrogen, C.sub.1-3 alkyl or, when R.sub.3 is hydrogen or methyl, also a group of formula --CH(R.sub.5)--X wherein
• R.sub.5 is hydrogen, --(CH.sub.2).sub.2 --OH, --(CH.sub.2).sub.3 --OH, --CH.sub.2 --OH, --CH(CH.sub.3)--OH, isobutyl or benzyl and
• X is a group of formula ##STR41## wherein R.sub.1 and R.sub.2 have the meanings given above,
• R.sub.6 is hydrogen or C.sub.1-3 alkyl and
• R.sub.7 is hydrogen, C.sub.1-3 alkyl, phenyl or C.sub.7-10 phenylalkyl, the group --CH(R.sub.5)--X having the D- or L-configuration, and
• Y.sub.1 and Y.sub.2 are each hydrogen or together represent a direct bond,
• whereby the residues in the 1- and 6-position each independently have the L- or D-configuration,
• with the proviso (i) that D- and/or L-cysteine residues are present at the 1- and 6-positions only, and (ii) that when R.sub.5 is benzyl, X is a group of formula ##STR42## or a group of formula --COOR.sub.1, wherein R.sub.1 is C.sub.1-3 alkyl, or a pharmaceutically acceptable acid addition salt or complex thereof.