Diversity Of Inorganic Phosphorus Reagent-assisted Amino Acid Reaction

Peptide formation is one of the most important reactions in prebiotic evolution. Moreover, Phosphor plays an important role in prebiotic evolution and in process of the life. Therefore, it is very important for comprehending the process of biochemistry and the origin of life to study the diversity in the process of peptide formation from amino acids assisted by inorganic phosphorus reagents.Self-assembly peptide formation directed by inorganic phosphorus reagents from amino acids has been investigated in detail. Amino acids could assemble into oligo-peptides, furthermore, as the reaction time was prolonged, the length of the peptides was increased. It was found that amino acids, mediated by phosphorous reagents, not only can assemble into oligo-peptides, but also can produce cyclic peptides and amino acid hydridophorane. This result reveals the complexity and diversity in the process of peptide formation from amino acids assisted by inorganic phosphorus reagent.In this thesis, the reaction of amino acids assembling into cyclic peptides and amino acid hydridophorane directed by inorganic phosphorus reagents was studied by NMR, ESI-MS, HPLC and X-ray techniques. Moreover, the mass spectrometry characteristics of the related compounds were investigated in detail for the structural elucidation. The results of the thesis are illustrated as follows:Starting fromα-amino acids and phosphorus trichloride, seven amino acid hydridophoranes were synthesized using triethylamine as antacids. The method has the higher yields and simpler reactive conditions for the synthesis of amino acid hydridophorane. Since the products of amino acid hydridophorane are normaly a diastereoisomer, the method of separation for a pure isomer were explored by HPLC and recrystallization. Furthermore, the configurations of amino acid hydridophoranes were investigated by HPLC. One of the absolute structure of valine hydridophorane was determined by the help of X-ray diffraction analysis. The MS/MS fragmentation characterizations of amino acid hydridophoranes were investigated in detail and their fragmentation pathways were summarized.Seven cyclic dipeptides were synthesized from the reaction ofα-amino acids and phosphorus trichloride. Compare with the previous method of the synthesis of cyclic dipeptide, the method doesn't need the protection of active group and has only one step. It is helpful for us to explore a new method for the synthesis of cyclic dipeptide. Furthermore, the MS/MS fragmentation characterizations of cyclic dipeptides were investigated in detail and their fragmentation pathways were summarized.