The Study of Protection of Amino Acid and Peptide Bond Synthesis
|Keywords||Amino acid Protection Peptide bond Organic synthesis|
Amino acids are the necessary substances for all the life, which exist in nature, and also the basic substances to form the protein in vivo. Two or more amino acids form peptide chains through dehydration condensation, namely the original protein fragments, and then form proteins by one or more peptide chains in a particular way. With the continuous deepening of biological science,people have a further understanding for the role of amino acids, peptides and proteins in vivo. But peptides are a class of compounds, whose molecular structure is between amino acids and proteins, and they are formed by many sorts of amino acids according to a certain order through peptide bonds. The synthesis of peptide has important theoretical significance and applied values, and become a focal point for scientific research.Peptide can be synthesized from the condensation of amino acids. However, amino acids themselves have many active groups, which leads to many side reactions, then they must be temporarily closed by using protecting groups before peptide synthesis, so as to the reaction can be proceed smoothly. Therefore, the protection of amino acids become the most fundamental problem to be solved while synthesizing peptide. The protection of amino acids includes the contents as folloes:amino protection, carboxyl protection and Side chain protection of active groups(guanidine, sulfhydryl, hydroxyl, imidazole, indole, etc). Both amino and active groups of side chain need to be protected in the reaction of peptide synthesis, and then take off protective groups. Otherwise, the amino acids may connect wrongly and cause many side reactions. Currently, there are about hundreds of protective groups used to protect the common functional groups, and the various protection groups of amino acids developed rapidly and are widely used, so choosing a suitable protecting group is the key to successfully synthesize the target compounds.The present thesis focuses on a series of reactions as starting material of 4-piperidine formic acid. In addition, the major work are protection conditions of glycine, lysine etc. We have synthesized different kinds of protected amino acids, optimized the synthesis condition, reduced the synthesis costs to make it easier for industrial production and determined their structures by elemental analysis, NMR spectra and other methods.