The synthesis of motilin, II: Preparation of the complete sequences of [13-norleucine] motilin and [13-leucine] motilin (author's transl)

Syntheses of two analogs of the intestinal hormone motilin containing in position 13 norleucine and leucine, respectively, are described. For this purpose a suitably protected octapeptide-derivative, corresponding to the sequence 1-8, was prepared and condensed with the tetradecapeptides 9-22 of 13-norleucine]-motilin and 13-leucine] motilin (described in the preceding paper) to give to overall protectdd docosapeptides Boc-Phe-Val-Pro-IIe-Phe-Thr-(But)-Tyr(But)-Gly-Glu(OBut)-Leu-Gln-Arg-(HBr)-Nle-Glu(OBut)-Glu(OBut)-Lys(Boc)-Glu-(OBut)-Arg(HBr)-Asn-Lys(Boc)-Gly-Gln-OBut and its 13-leucine analog.