The Glycosyl Modification Of L-amino Acids And Small Peptides

The saccharides, amino acids and peptides have attracted the scientists' attention because they take part in many actions in life and have obvious physiological activation. Therefore, the amino acids and peptides modified by the glycose, such as glycopepetides, also a lot of important physiological and pharmic functions, such as recognition of cell's signals, adjusting growth, communication of cell's signals, adjusting immunity and so on. The synthesis of the glycopeptides has been the focus of synthetists' interests, and a lot of work has done about this. However, the other amino acids and peptides modified by glycose but for glycopeptieds were scarcely synthesized. Because of this, in the paper we have introduced the glycosyl part into amino acids and dipeptides and a series of glycosyl amino acids and glycosyl dipeptides were synthesized.The mainly works in the paper:1. A series of amino acid derivatives modified by glycose have been prepared by the reaction of glycosyl isothiocycanates with carbobenzoxy-L -amino acid hydrazides which were synthesized from L-amino acids through amino-protection, esterification and hydrazinolysis.2. A series of dipeptide derivatives modified by glycose have been prepared by the reaction of glycosyl isothiocycanates with carbobenzoxy-dipeptide hydrazides which were synthesized from carbobenzoxy dipeptide esters obtained by the liquid-phrase synthesis method through hydrazinolysis.The innovations of the thesis are based on the follows:1. A series of new compounds have been obtained by building up one molecular with the glycosyl part, thiourea part and i-amino acid or dipeptide part at the same time.2. The reaction condition in which glycosyl parts were introduced into amino acid and dipeptide derivatives with glycosyl isothiocyanates as the key intermediate was studied.The structures of all the compounds were confirmed by elemental analysis, IR, ~1H NMR and MS spectral data. The mass spectrums of some representative compounds were explained in detail.