Chemical Synthetic Research On Peptide Segments Ligation, Peptide Derivatives And Conjugate Of Modifer-peptide Derivative

This thesis consists of three projects that belong to the field of peptide chemical synthesis.In the first project, a new method has been established to synthesizing peptide with long sequence. Two unprotected peptide fragments has been synthesized by Fmoc solid phase peptide synthesis (SPPS), then the fragment that contains C-terminal hydrizide is transfered to a peptide active ester using transfer active ester condensation (TAEC) technology, which is conjugated with another unprotected peptide fragment following the mechanism that in native chemical ligation (NCL) method under the liquid synthesis conditions, and produces the target long sequence peptide product by formation of a natural peptide bond at the designed position. The method established in this project will become a useful tool in the field of the chemical synthesis of long sequence peptide.The second project focuses on the research and exploring conditions to establish efficient methods for the synthesis of the thymopentin (TP5) derivatives. In this project, various amino acid derivatives are synthesized and used as the building blocks for the synthesis of the TP5 derivatives; a series of peptide segments including dipeptide, tripeptide, tetrapeptide and pentapeptide derivatives are synthsized as well. The total 30 synthetic compounds and the established methods will provide benefits for the further synthesises of TP5 as well as its derivatives.The third project is on the synthesis of special conjugate of TP5 derivative, which is produced by formation of a natural peptide bond at the designed position selectively between a functional precision structure modifer (FPSM) and a tetrapeptide derivative. The FPSM-TP5 derivative conjugate synthesized in this project is a compound with single structure and molecular weight, and a potential immunomodulator with better anti-enzymolysis ability than TP5.