Mossine V V, Barnes C L, Glinsky G V, Feather M S
Department of Biochemistry, University of Missouri, Columbia 65211, USA.
Carbohydr Res. 1996 Apr 18;284(1):11-24. doi: 10.1016/0008-6215(95)00406-8.
Heyns compounds, 2-carboxymethylamino-2-deoxy-D-glucose (1), -mannose (2), and -galactose (3), were prepared by N-carboxymethylation of the corresponding hexosamines and 1 was also prepared via the reaction of D-fructose with glycine. Both 1 and 3 crystallize from aqueous solutions as zwitterions in the alpha-pyranose form and in the 4C1 conformation. Crystalline 1 is nearly isostructural to N-acetylglucosamine, forming stacks of molecules with infinite chains of homodromic hydrogen bonds along the stacks. For both 1 and 3, all hydroxyl, ammonium, and carboxyl groups are involved in intermolecular hydrogen-bonding, and an intramolecular hydrogen bond in 3 is formed via interaction of the ammonium and carboxyl groups. 1H and 13C NMR spectra (D2O solutions) indicate that all of the compounds are conformationally unstable, and that the major form present in D2O solution at 25 degrees C is the 4C1 alpha-pyranose form, with the 4C1 beta-pyranose form present in lesser amounts. In addition, for solutions of 2 and 3, considerable amounts of alpha- and beta-furanose forms are present and exist in conformations favorable for a cis-relationship between the carboxymethylammonium and anomeric hydroxyl groups.
海因斯化合物，即2-羧甲基氨基-2-脱氧-D-葡萄糖（1）、-甘露糖（2）和-半乳糖（3），是通过相应己糖胺的N-羧甲基化制备的，1也可通过D-果糖与甘氨酸反应制备。1和3在水溶液中均以两性离子形式结晶，呈α-吡喃糖形式且为4C1构象。结晶态的1与N-乙酰葡糖胺几乎同构，形成分子堆叠，沿堆叠方向有由同向氢键构成的无限长链。对于1和3，所有羟基、铵基和羧基都参与分子间氢键形成，3中通过铵基和羧基的相互作用形成分子内氢键。1H和13C NMR光谱（D2O溶液）表明所有化合物构象不稳定，25℃下D2O溶液中主要存在形式为4C1 α-吡喃糖形式，4C1 β-吡喃糖形式含量较少。此外，对于2和3的溶液，存在相当数量的α-和β-呋喃糖形式，且其构象有利于羧甲基铵基和异头羟基之间的顺式关系。
