Assignment of the 1H 500 MHz n.m.r. spectra of a synthetic eight‐membered ring analogue of somatostatin in aqueous solution

Abstract

A somatostatin octapeptide analogue has been synthesized and its conformational properties have been studied by high field n.m.r. in water. All the proton signals of the individual amino acids have been assigned except for the aromatic protons, by use of 2D homonuclear correlation spectroscopy. Neither temperature effects on the amide protons nor the values of the coupling constants provided any significant arguments for predominant conformations. As in the case of somatostatin itself, analogues with this ring size remain very flexible.