细胞粘附位点RGD前体二肽的化学合成与酯化

Chemical Synthesis and Esterification of a Precursor Dipeptide of RGD as a Site for Cell Adhesion

用一种新颖的化学法合成了细胞粘附位点RGD前体二肽GD（Gly-Asp）．并利用ROH-HCl法进一步完成了GD二肽乙酯化和甲酯化．考察了GD二肽对乙醇／甲醇的摩尔比、反应温度和反应时间对酯化收率的影响，使GD二肽酯化的条件得到了优化，GD二肽对乙醇／甲醇的摩尔比为1：40，反应温度30℃，反应时间1～2．5h，最大收率为80％～85％，利用质谱分析法确证了两种GD二肽酯为Gly-Asp-（OEt）2和Gly-Asp-（OMe）2．

A precursor dipeptide of RGD as a site for cell adhesion, GD（ Gly-Asp）, was synthesized by a novel chemical method in two steps including chloroacetylation of L-aspartic acid and ammonolysis of chloroacetylated L-aspartic acid. GD dipeptide ethyl ester and methyl ester were synthesized by ROH-HCl method. The condition of the esterification was optimized by examining the effects of some key factors, such as the molar ratio of GD to ethanol/methanol, reaction temperature and reaction time, on the yields of GD esters. The optimal esterification condition for the two GD esters was established being the molar ratio of GD dipeptide to ethanol/methanol（1：40） , 30℃, for 1-2.5 h, under which the maximum yield of 80%-85% was obtained. The two GD esters were confirmed as Gly-Asp-（OEt） 2 and Gly-Asp-（OMe） 2 by mass spectrographic analysis.