Oligosaccharides related to tumor-associate antigens. Part 3. Synthesis of the propyl glycosides of the trisaccharide ?-D-Galp-(1?3)-?-D-GalpNAc-(1?3)-?-D-Galp and of the Tetrasaccharide ?-L-Fucp-(1?2)-?-D-Galp-(1?3)-?-D-GalpNAc-(1?3)-?-D-Galp, components of a tumor antigen recognized by the antibody MBr1
作者:Luigi Lay、Luigi Panza、Giovanni Russo、Diego Colombo、Fiamma Ronchetti、Elena Adobati、Silvana Canevari
DOI:10.1002/hlca.19950780302
日期:1995.5.10
The synthesis of the trisaccharide β-D-Galp-(13)-β-D-GalpNAc-(13)-α-D-Galp-1-OPr (2) and of the tetrasaccharide α-L-Fucp-(12)-β-D-GalpNAc-(13)-β-D-Galp-1-OPr (3), starting from the disaccharidic dihydrooxazole donor 5, is described. Glycosylation of 5 with 6 in the presence of Me3SiOTf gave the trisaccharide 7 which was deprotected with standard methods to give, via8, compound 2 (Scheme 1). Alternatively
三糖β-d-Gal的合成p - (13)-β-d-Gal的p NAc-(13)-α-d-Gal的p -1-OPR(2)和四糖α-L-岩藻糖的p - (12)-β-d-Gal的p NAc-(13)-β-d-Gal的p -1-OPR(3)中,从二糖供体二氢恶唑开始5,进行说明。在Me 3 SiOTf存在下将5与6进行糖基化反应,制得三糖7,将其用标准方法脱保护,通过8生成化合物2(流程1)。备选地,将8保护为4',6'- O-亚苄基衍生物9,随后用10进行糖基化并通过标准脱保护得到四糖3(方案2)。生物测试表明,三糖2不能抑制单克隆抗体MBR1到靶肿瘤细胞MCF7的结合,而四糖3抑制在结合CA。7倍程度相对于先前测试的三糖α-L-岩藻糖p - (12)-β-d-Gal的p - (13)-β-d-Gal的pNAc-1-OPr。这些结果表明,与化合物1的单元D相对应的半乳糖在定义MBr1识别的表