New synthetic route for RGD tripeptide

A new route was employed to synthesize RGD. First, Gly-Asp dipeptide was synthesized by a novel chemical method in two steps, including chloroacetylation of L-aspartic acid and ammonolysis of chloroacetyl L-aspartic acid. Second, Nalpha-Z- L-Arginine was reacted with Gly-Asp to synthesize RGD by the N-carboxyanhydride method. Less protected amino acids were used in this synthesis. This method possessed advantages of low cost, simplicity, and rapidity with a reasonable yield of 62% calculated from arginine. In addition, compared with the above method, a conventional solid phase method was also used to synthesize RGD, the yield was 75% calculated from the first amino acid anchored to resin.