Synthesis of mono- and di-α-l-fucosylated 2-acetamido-2-deoxy-N-glycyl-β-d-glucopyranosylamines modeling N-glycoprotein carbohydrate-peptide bond region based on 2-acetamido-N-(N-tert-butyloxycarbonylglycyl)-2-deoxy-β-d-glucopyranosylamine
作者:L. M. Likhosherstov、O. S. Novikova、N. N. Malysheva、V. E. Piskarev
DOI:10.1007/s11172-015-1030-3
日期:2015.6
A synthesis of glycyl-spacered N-β-glycosides of diand trisaccharides such as α-l-Fucp-(1→3)-β-d-GlcNAcp-NHCOCH2NH2 (1), α-l-Fucp-(1→6)-[α-asl}-Fucp-(1→3)]-β-d-GlcNAcp-NHCOCH2NH2 (2), α-l-Fucp-(1→6)-β-d-GlcNAcp-NHCOCH2NH2 (sn3}), which model the carbohydrate-peptide bond region of fucosylated N-glycoproteins of animals and plants, was accomplished. The synthesis was carried out by the fucosylation of unprotected N-glycoside β-}scd-GlcNAcp-NHCOCH2NHBoc (Boc is the tert-butyloxycarbonyl) (4), 4,6-O-benzylidene derivative of compound 4, and protected disaccharide 1 (α-l-FucpBn3-(1→3)-β-d-GlcNAcp-NHCOCH2NHBoc (Bn is the benzyl)) with ethyl 2,3,4-tri-O-benzyl-1-thio-β-l-fucoside (in the presence of CuBr2 and an excess of Et4NBr). A possibility of the selective ?-fucosylation of N-glycoside 4 at the primary hydroxy group in the presence of secondary hydroxy groups (in 34% yield) was demonstrated. Amino spacered N-glycosides 1–3 were obtained after the removal of protecting groups.
合成了二糖和三糖的甘氨酸间隔N-β-糖苷,例如 α-l-古洛糖-(1→3)-β-d-氨基葡萄糖苷-NHCOCH2NH2 (1)、α-l-古洛糖-(1→6)-[α-asl}-古洛糖-(1→3)]-β-d-氨基葡萄糖苷-NHCOCH2NH2 (2)、α-l-古洛糖-(1→6)-β-d-氨基葡萄糖苷-NHCOCH2NH2 (sn3}),这些化合物模拟了动物和植物中马糖基化N-糖蛋白的碳水化合物-肽键区域。合成是通过对未保护的N-糖苷β-}scd-氨基葡萄糖苷-NHCOCH2NHBoc(Boc为叔丁氧羰基)(4)、化合物4的4,6-O-苄亚胺衍生物以及保护的二糖1(α-l-古洛糖Bn3-(1→3)-β-d-氨基葡萄糖苷-NHCOCH2NHBoc (Bn为苄基))与乙基2,3,4-三-O-苄基-1-硫-β-l-古洛糖苷(在CuBr2和过量Et4NBr的存在下)进行的。实验表明,在存在次级羟基的情况下,选择性地对N-糖苷4的一级羟基进行?-古洛糖基化是可能的(得率为34%)。通过去除保护基团获得了氨基间隔的N-糖苷1-3。