5-溴-2',3'-二脱氧尿苷的结构与构象
Structure and conformation of 5-bromo-2',3'-dideoxyuridine.
作者信息
Kim H, Parthasarathy R
机构信息
Department of Biophysics, Roswell Park Memorial Institute, Buffalo, NY 14263.
出版信息
Acta Crystallogr C. 1991 Sep 15;47 ( Pt 9):1892-5. doi: 10.1107/s0108270191000859.
C9H11BrN2O4, Mr = 291.11, monoclinic, P2(1), a = 11.307 (1), b = 5.954 (1), c = 15.829 (2) A, beta = 93.25 (1) degree, V = 1063.90 A3, Z = 4, Dx = 1.82 g cm-3, lambda(Cu K alpha) = 1.54184 A, mu = 53.58 cm-1, F(000) = 584, T = 295 K, R = 0.034 for 1927 observed reflections [I greater than 3 sigma(I)]. The crystal structure contains two independent molecules forming a dimer linked by a pair of N3--H...O2 hydrogen bonds; the crystal structure is stabilized by four additional hydrogen bonds. Two of these are internal C6--H6...O5' hydrogen bonds, one in molecule A and another in molecule B. These two molecules exhibit two different conformations; their sugar ring puckers are 2'-endo-3'-exo for molecule A and 3'-endo-2'-exo for molecule B. The Cl'--N1 distance, the chi CN torsion angle and the glycosidic conformation are 1.464 (8) A, -130.0 degrees and -anticlinal for molecule A and 1.506 (8) A, -168.9 degrees and -antiperiplanar for molecule B, respectively.
C9H11BrN2O4，Mr = 291.11，单斜晶系，P2(1)，a = 11.307(1)，b = 5.954(1)，c = 15.829(2) Å，β = 93.25(1)°，V = 1063.90 Å3，Z = 4，Dx = 1.82 g cm-3，λ(Cu Kα) = 1.54184 Å，μ = 53.58 cm-1，F(000) = 584，T = 295 K，对于1927个观测反射[I大于3σ(I)]，R = 0.034。晶体结构包含两个独立分子，通过一对N3--H...O2氢键形成二聚体；晶体结构通过另外四个氢键得以稳定。其中两个是分子内C6--H6...O5'氢键，一个在分子A中，另一个在分子B中。这两个分子呈现出两种不同的构象；它们的糖环褶皱对于分子A是2'-内-3'-外，对于分子B是3'-内-2'-外。分子A的Cl'--N1距离、χ CN扭转角和糖苷构象分别为1.464(8) Å、-130.0°和反斜式，分子B的分别为1.506(8) Å、-168.9°和反叠式。
Zotero 插件