水合棉子糖晶体结构中的氢键。

The hydrogen bonding in the crystal structure of raffinose pentahydrate.

作者信息

Jeffrey G A, Huang D B

机构信息

Department of Crystallography, University of Pittsburgh, Pennsylvania 15260.

出版信息

Carbohydr Res. 1990 Oct 10;206(2):173-82. doi: 10.1016/0008-6215(90)80058-b.

DOI:10.1016/0008-6215(90)80058-b

PMID:2073630

Abstract

The crystal structure of raffinose pentahydrate, O-alpha-D-galactopyranosyl-(1----6)-O-alpha-D-glucopyranosyl-(1----2)- beta-D- fructofuranose pentahydrate, C18H32O16.5H2O, has been redetermined using low-temperature, 119 K, CuK alpha X-ray data. All hydrogen atoms were unambiguously located on difference syntheses. The final R-factor is 0.036 for 2423 observed structure amplitudes. The hydrogen bonding is composed of infinite chains, which are linked through the water molecules to form a three-dimensional network containing a chain of five linked water molecules. Three of the infinite chains extend in the directions of the crystallographic axis of the space group P2(1)2(1)2(1). Four of the water molecules accept two hydrogen bonds and one accepts one. All the hydroxyls and the ring and glycosidic oxygen atoms are involved in the hydrogen bonding. With one exception, the ring and glycosidic oxygens are hydrogen-bonded by means of the minor components of unsymmetrical three-center bonds.

摘要

水合棉子糖，即O-α-D-吡喃半乳糖基-(1→6)-O-α-D-吡喃葡萄糖基-(1→2)-β-D-呋喃果糖五水合物，化学式为C18H32O16·5H2O，其晶体结构已利用低温（119K）的CuKα X射线数据重新测定。所有氢原子均在差值合成图上清晰定位。对于2423个观测到的结构振幅，最终的R因子为0.036。氢键由无限长链组成，这些链通过水分子相连，形成一个包含由五个相连水分子构成的链的三维网络。其中三条无限长链沿空间群P2(1)2(1)2(1)的晶轴方向延伸。四个水分子接受两个氢键，一个水分子接受一个氢键。所有羟基以及环和糖苷氧原子均参与氢键形成。除了一个例外，环和糖苷氧通过不对称三中心键的次要成分形成氢键。