SYNTHESIS OF ALPHA-AMINOPHOSPHONIC OCTAPEPTIDE, PHE-GLY-SER-LEU-ALA(P)-PHL-LEU-PRO, AN ANALOG WITH PARTIAL SEQUENCE OF ERB B-2 GENE-PRODUCT

A chemical synthesis was performed of an octapeptide with a phosphonic ester linkage, which corresponds to a variation of the partial sequen ce of a gene product of erb B-2. The phosphonic ester linkage was succ essfully prepared through a coupling reaction of magnesium salt of the hydroxypeptide with phosphonochloridate, without damage of the peptid e bond. The free aminophosphonic peptide as the final product gave a s ingle peak on the ODS column, and a reasonable ratio of the component amino acids. The reaction series exploited here might be useful as a g eneral procedure for preparation of the phosphonic peptide.