Polypeptides.

摘要

The invention relates to a polypeptide of formula I:- R<1>-A<1>-A<2>-A<3>-A<3>-A<4>-A<5>-A<6>-A<7>-A<8>-A<9>-Q wherein each of the generic terms is disclosed in full in the specification and includes:- R<1> is (2-6C)alkanoyl or (1-4C)alkoxycarbonyl; A<1> is a direct link to A<2>, or is Gly or Arg; A<2> is a direct link to A<3>, or is Gly or Pro; A<3> is a direct link to A<4>, or is Lys or Lys(Z); A<4> is His or D-His; A<5> is Trp or MeTrp; A<6> is Ala or MeAla; A<7> is Val or MeVal; A<8> is Gly or Sar; A<9> is His or MeHis; and Q is a group of the formula -A<1><0>.R<2> in which A<1><0> is Leu or D-Leu and R<2> is hydroxy, amino, (1-3C)alkylamino or (1-3C)alkoxy; or Q is (1-6C)alkoxy or (1-10C)alkylamino; provided that when R<1> is acetyl and -A<4>-A<5>-A<6>-A<7>-A<8>-A<9>-Q is -His-Trp-Ala-Val-Gly-His-Leu-NH2 then -A<1>-A<2>-A<3>- is not a direct link to His. The compounds possess antagonist properties against bombesin-like peptides and are of value in the treatment of malignant disease in warm-blooded animals.