Linear, peptidase-resistant beta(2)/beta(3)-di- and alpha/beta(3)-tetrapeptide derivatives with nanomolar affinities to a human somatostatin receptor - Preliminary communication

Abstract

N-Acyl-β /β -dipeptide-amide somatostatin analogs, 5-8, with β -HTrp-β -HLys ('natural' sequence) and β -HLys-β -HTrp (retro-sequence) have been synthesized (in solution). Depending on their relative configurations and on the nature of the terminal N-acyl and terminal C-amino group, the linear β-dipeptide derivatives have affinities for the human receptor hsst 4, ranging from 250 to > 10000 nanomolar (Fig. 3). Also, N-Actetrapeptide amides 9 and 10, which contain one α- and three β-amino acid residues (N-β-α-β-β-C), have been prepared (solid-phase synthesis), with the natural (Phe, Trp, Lys, Thr) and the retro-sequence (Thr, Lys, Trp, Phe) of side chains and with two different configur..