van Seeventer P B, Kamerling J P, Vliegenthart J F
Bijvoet Center, Department of Bio-Organic Chemistry, Utrecht University, The Netherlands.
Carbohydr Res. 1997 Apr 21;299(3):181-95. doi: 10.1016/s0008-6215(97)00013-x.
To contribute to the possibility of studying in greater detail the biological significance of Sda-containing glycans as occur in Tamm-Horsfall glycoprotein, the following three spacer-linked tetrasaccharides have been synthesized: the Sda determinant alpha-Neu p5Ac-(2-->3)-[beta- D-GalpNAc-(1-->4)]-beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1-->O)(CH2)5NH 2 (1), the Gal-analogue alpha-Neup5Ac-(2-->3)-[beta-D-Galp-(1-->4)]-beta-D-Galp-(1-->4) -beta-D-GlcpNAc-(1-->O)(CH2)5NH2 (2), and the GlcNAc-analogue alpha-Neup5Ac-(2-->3)-[beta-D-GlcpNAc-(1-->4)]- beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1-->O)(CH2)5NH2 (3). The general trisaccharide acceptor 5-azidopentyl (methyl 5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy- D-glycero-alpha-D-galactonon-2-ulopyranosylonate)-(2-->3)-(2 ,6-di-O-benzyl- beta-D-galactopyranosyl)-(1-->4)-3,6-di-O- benzyl-2-deoxy-2-phthalimido-beta-D-glucopyranoside was prepared, using methyl (phenyl 5- acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-2-thio-D-glycero-D-galacto- non- 2-ulopyranosid)- onate as the sialyl donor. For the syntheses of 1, 2, and 3 the glycosyl donors 3,4,6-tri-O- acetyl-2-deoxy-2-phthalimido-alpha-D-galactopyranosyl bromide, 2,3,4,6-tetra-O-acetyl-alpha-D- galactopyranosyl bromide, and 3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido -beta-D-glucopyranosyl trichloroacetimidate, respectively, proved to be the most suitable.
为更详细地研究存在于Tamm-Horsfall糖蛋白中的含Sda聚糖的生物学意义提供可能，已合成了以下三种间隔连接的四糖：Sda决定簇α-Neup5Ac-(2→3)-[β-D-GalpNAc-(1→4)]-β-D-Galp-(1→4)-β-D-GlcpNAc-(1→O)(CH2)5NH2 (1)、半乳糖类似物α-Neup5Ac-(2→3)-[β-D-Galp-(1→4)]-β-D-Galp-(1→4)-β-D-GlcpNAc-(1→O)(CH2)5NH2 (2)和N-乙酰葡糖胺类似物α-Neup5Ac-(2→3)-[β-D-GlcpNAc-(1→4)]-β-D-Galp-(1→4)-β-D-GlcpNAc-(1→O)(CH2)5NH2 (3)。使用甲基(苯基5-乙酰氨基-4,7,8,9-四-O-乙酰基-3,5-二脱氧-D-甘油-α-D-半乳糖壬-2-酮吡喃糖醛酸酯)作为唾液酸供体，制备了通用的三糖受体5-叠氮戊基(甲基5-乙酰氨基-4,7,8,9-四-O-乙酰基-3,5-二脱氧-D-甘油-α-D-半乳糖壬-2-酮吡喃糖醛酸酯)-(2→3)-(2,6-二-O-苄基-β-D-吡喃半乳糖基)-(1→4)-3,6-二-O-苄基-2-脱氧-2-邻苯二甲酰亚氨基-β-D-吡喃葡萄糖苷。对于化合物1、2和3的合成，已证明糖基供体3,4,6-三-O-乙酰基-2-脱氧-2-邻苯二甲酰亚氨基-α-D-吡喃半乳糖基溴、2,3,4,6-四-O-乙酰基-α-D-吡喃半乳糖基溴和3,4,6-三-O-乙酰基-2-脱氧-2-邻苯二甲酰亚氨基-β-D-吡喃葡萄糖基三氯乙酰亚胺分别是最合适的。
