| Centering on the amino acids chemistry, this thesis is on the research of the seperation, purification, synthesis and resolution of amio acids and their chiral derivatives; it has also discussed about their applications in the chiral synthesis.In Chapter Two, the author focused on the study of reactive solvent extraction of amino acids. Having exploited different kinds of extract reagents and various extraction conditions, this part mainly researched on the various effects of extraction and stripping from different amino acid solutions.First, taking DNNSA, D2EHPA, NA as the extractants of the reactions, the author has experimented on the extraction balance of the EtOAc sole solution , under the conditions of using the same amino acid, of room temperature, of different acidity and alkalinity. The tested amino acids included arginine, glycine and Aspartic acid . It has been found out that DNNSA can bring as high an extraction degree as more than 40% for the alkaline and neutral amino acids, but less than 20% for the acidic amino acids; it has also been found out that the extraction rate was closely related with the pH value, which showed a satisfying separating property. Meanwhile, P204 promised a higher extraction degree for the alkaline or neutral amino acids, and it had a better contraction than extraction effect with acidity, whereas NA was good at neither separation nor contraction for amino acids.The following experiments were about the extraction of sole amino acid from the acidic W/O emulsion. Using the soaped DNNSA, D2EHPA and NA as the surface active agent and extract agent respecrtively, together with sulfrate kerosene,water, the amino acid emulsion extraction system was made up. According to the data obtained from those experiments, which were conducted under the room temperature, the author concluded that the separation effect was satisfying; on the other hand, emulsion-disperse agent was needed, due to the much use of the surface active agents. It was noticed that the effects of separation and contraction were not as good as those of the better emulsion.Next came the experiments on the DNNSA emulsion's separation balance of amino acids mixture. It showed that in case of separating, the DNNSA emulsion provided an appropriate separation.The experiments on the separation of amino acids mixture were based on the preceding ones. First, the author made a mixture of Gly, Ala, Lys, Asp and His; then let P204 acetic ether react in the mixture, of which the .pH value was varied; consequently basic amino acids, acidic amino acids, together with histidine, were obtained. Having separated the neutral amino acids mixture through the help of DNNSA emulsion, 96% amino acids was recovered.Chapter Three is devoted to the study of separation of amino acids from the leftovers of hides. First, hydrolyzed the raw materials with acids. Next, added catalytic agent to the finely shattered raw materials, which had been treated instantaneously under high temperature; using the acids rationally, the high-contented amino acid hydrolytic powder was obtained. As for the purification of amino acids from the amino acids hydrolyzed powder, after extracting the mixture of proline and hydroproline, which was feasible due to the different dissolving conditions, the author seperated the mixture by using D001 macroporous resins. Following was the separation of leucine from arginine; the left amino acid mixture was to be separated and purified under the help of combined reactions.The neutral amino acids extract was obtained when to separate the soaped P204 emulsion, of which the pH value was 2 . 7. Having separated the amino acids mixture of the aqueous phase through the combined reactions, with the pH values 2-2 . 5, 3-3.5, 4-4.5, 5-5.5 respectively, the author got the neutral amino acids, the acidic amino acids and tryptophan , by using the DNNSA-EtOAc systems.Finally 15 kinds of amino acids were available. The yields were between 49%-87 ?46%.Chapter Four is on the synthesis and resolution of phenylalanine.
|
PDF Full Text Request