Synthesis and Conformational Analysis of (α-D-Galactosyl)phenylmethane and α-,β-Difluoromethane Analogues: Interactions with the Plant Lectin Viscumin
Synthesis and Conformational Analysis of (α-D-Galactosyl)phenylmethane and α-,β-Difluoromethane Analogues: Interactions with the Plant Lectin Viscumin
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DOI：
10.1002/chem.200801394
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发表时间：
2009-01-01
影响因子：
4.3
通讯作者：
Vogel, Pierre
中科院分区：
文献类型：
--
作者：
Kolympadi, Maria;Fontanella, Marco;Vogel, Pierre
α-D-半乳糖基）苯基甲烷 (1)。已经制备了（α-和β-D-半乳糖基）-（二氟）苯基甲烷（2和3），并通过结合力场计算和核磁共振波谱研究描述了它们在溶液中的构象。半乳糖苷 I 采用 C-4(1) 椅式构象和外型异头取向。天然α-半乳糖苷的情况也是如此。其二氟亚甲基衍生物2的X射线晶体结构同样显示C-4(1)椅构象。令人惊讶的是，化合物 2 在溶液中时在 C-1(4) 椅式和 S-1(3) 斜船构象之间表现出不同的平衡，并且在假糖苷键周围表现出显着的灵活性。 β-立体异构体 3 采用主要的 C-4(1) 椅式构象。有趣的是，C-半乳糖苷 1、2 和 3 与粘胶素 (VAA)（一种半乳糖苷特异性凝集素）结合，这一点已通过 NMR 实验和对接计算得到证实。
alpha-D-Galactosyl)phenylmethane (1). (alpha- and beta-D-galactosyl)-(difluoro)phenylmethane (2 and 3) have been prepared and their conformations in solution were described by using a combination of force-field calculations and NMR spectroscopic studies. Galactoside I adopts a C-4(1) chair conformation and an exo anomeric orientation. as is the case for natural alpha-galactosides. The X-ray crystal structure of its difluoromethylene derivative 2 similarly shows a C-4(1) chair conformation. Surprisingly, compound 2 exhibits a different equilibrium between C-1(4) chair and S-1(3) skew boat conformations and significant flexibility around the pseudoglycosidic linkage when in solution. The beta-stereoisomer 3 adopts a major C-4(1) chair conformation. Interestingly, C-galactosides 1, 2, and 3 bind to viscurnin (VAA), a galactoside-specific lectin, which is confirmed by NMR experiments and docking calculations.