Application Of ³¹P NMR In The Chiral Selectivity Of The N-phosphoryl Amino Acids

Phosphorus is an essential element of life, which participates in almost all the life process directly or indirectly. For example, Phosphorous is a fundamental element in forming phosphodiester bond of the nucleosides of DNA and RNA. It is also present in ATP, which contains three phosphorus atoms or the tripolyphosphate and works as energy currency in substance and energy metabolism, the translation and expression of genetic information. The catalytic reactions of most enzymes depend on their phosphorylation and dephosphorylation reaction. Since phosphorous plays an important role throughout life process, it has been considered as the regulation center for life activities.Amino acid is the basic unit of the protein, such as kinase, on which the phosphorylation regulates the protein structure and function. Therefore, N-phosphoamino acids could be used as models in the study of reactions of the phosphoryl group in the life process.First of all, a series of model N-phosphpoamino acids were synthesized. And their ester exchange reaction on the phosphorous center was studied by ³¹P NMR, HPLC, ESI-MS and ESI-MS/MS. It was found that the ester exchange reaction of phosphorous is a molecular autocatalytic reaction. In addition, the side chains of amino acids play very important role for the chiral selection of amino acids.Secondly, in the perspective of phosphorous chemistry, peptides were synthesized with the amino protection by phospohoryl group and phosphorous condensation reagents. By ³¹P NMR, it was found that the racemization of amino acids was minimized. And it seams that L-amino acid has different reaction acticity from the D-amino acids. From this point of view, some amino acids were selected for the study of chiral selectivity in the formation of peptides.