Synthesis and 1 H‐nmr studies of α‐deuterated analogues of des ‐Trp 1 , Nle 12 ‐human minigastrin

Three analogues of the tridecapeptide amide H‐Leu‐(Glu) 5 ‐Ala‐Tyr‐Gly‐Nle‐Asp‐Phe‐NH 2 were synthetized with α‐deuterated glutamate residues in specific positions in order to assign unambiguously the 1 H nmr spectrum of the parent peptide in water and in water‐trifluoroethanol mixtures. The synthetic route is described and the assignment illustrated. A previous, tentative assignment based solely on indirect evidence [Mammi, S., Mammi, N. J. & Peggioa, E. (1988) Biochemistry 27 , 1374–1379] was partially modified.