Synthesis of Cell Adhesive Motif RGD Tripeptide by a Novel Chemical Method and Its Purification1

The cell adhesive motif RGD tripeptide was synthesized by using a novel chemical method. First, Gly-Asp(GD) was synthesized in two steps including the chloroacetylation of free L-aspartic acid and the ammonolysis of the chloro-acetylated L-aspartic acid. The yield of chloroacetylated L-aspartic acid was 83. 0%. For the ammonolysis of chloro-acetylated L-aspartic acid, the yield of the ammonolyzed product was 92. 3%. Second, the coupling between Arg and Gly-Asp was carried out by using the NCA method. The maximum yield of RGD was about 50% at 0 °C and pH = 9. 5. The prepared RGD tripeptide was confirmed by using amino acid component analysis and mass spectrographic analysis.