Polypeptides. Part X. Variations of the tryptophyl position in the C-terminal tetrapeptide amide sequence of the gastrins

Abstract

The synthesis is described of analogues of L-tryptophyl-L-methionyl-L-aspartyl-L-phenylalanine amide (the C-terminal sequence of the gastrins), and its N-benzyloxycarbonyl or N-t-butoxycarbonyl derivatives, wherein the tryptophyl residue has undergone replacement by glycyl, histidyl, lysyl, phenylalanyl, tyrosyl, 4-, 5- or 6-methyltryptophyl, N^α-methyltryptophyl, or 2- or 5-hydroxytryptophyl residues, or has been modified in various other ways.