Synthesis, characterization and biological activities of thymopentin ethyl ester.

The ethyl ester derivative of thymopentin was synthesized and characterized. The biological activities of thymopentin were evaluated by mouse spleen lymphocyte proliferation test and superoxide dismutase activity assay. Compared with thymopentin, the synthesized ethyl ester showed more potent immunoregulation activity in the MTT assay and anti-oxidation activity in the immune-suppressed rat model induced by hydrocortisone. The half life of the ester derivate in rat plasma determined by HPLC was slightly longer than that of thymopentin. The ester derivate gained advantages in activity and stability compared to thymopentin.