It is of great importance to study the catalytic antibody that catalyzes the hydrolysis of peptide bond. The synthesis of a new kind of antigen(10) containing phosphorus was reported in this paper, which was designed and synthesized according to hippuryl phenylalanine, a substrate of carboxypeptidase A(CPA). To mimic the structure of the substrate, the free C-terminal carboxylic group was remained. However, it was not easy to synthesize the phosphonamide peptide hapten(7) directly, so compound 5 was synthesized firstly, after the catalytic hydrogenolysis it was coupled with p-nitrobenzoyl chloride to get compound(7). The synthesis of antigen and further preparation of antibody will be a good foundation for the activity study of the antibody.
