[Basic peptides in bee venom, II. Synthesis of two pentapeptides from the sequence of the mast-cell-degrading peptide (author's transl)].

The synthesis of two protected pentapeptides is described. The peptides are fragments of the sequence of a mast-cell degranulating peptide from bee venom. The fragments Boc-Lys(Z)-Ile-Cys(SiPr)-Gly-Lys(Z)(I) and Boc-Pro-His(Trt)-Ile-Cys(Trt)-Arg(Tos) (II) were synthesized conventionally. The deprotection of the alpha-amino group by HCl/acetic acid of Boc-Ile-Cys(SiPr)-Gly-Lys(Z) was accompanied by a disulfide exchange at the cysteine residue. After the hydrolysis of fragment II with 6N HCl, allo-isoleucine could be detected by gas chromatography and amino-acid analysis.