.alpha.-Cyclodextrin-catalyzed regioselective phosphorus-oxygen(2') cleavages of 2',3'-cyclic monophosphates of ribonucleosides
.alpha.-Cyclodextrin-catalyzed regioselective phosphorus-oxygen(2') cleavages of 2',3'-cyclic monophosphates of ribonucleosides
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DOI：
10.1021/ja00190a045
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发表时间：
1989-04
影响因子：
15
通讯作者：
M. Komiyama
中科院分区：
文献类型：
--
作者：
M. Komiyama
以环糊精（a-CyD）为催化剂，在pH 11.08,20 C条件下，胞苷（la）、尿苷（lb）、腺苷（Ic）和鸟苷（Id）的2′，3′-环单磷酸基在P-0（2′）区域选择性裂解为相应的3′-单磷酸基（lia - d）。随着cyd浓度的增加，Ia-d的选择性逐渐增加，在0.05 M-CyD浓度下，Ia-d的选择性分别达到98、94、76和67%。然而，在缺乏- cyd的情况下，P-0（3’）键会同时发生明显的断裂，因此对伊利亚- d的选择性仅为47、50、54和52%。在cyd -la复合物中，la的P-0（2’）裂解速率是自由la的14倍，而复合物中P-0（3’）裂解速率几乎为零，ß-and- cyd没有区域选择性催化作用。* H NMR表明，cyd -la和lb配合物是由氢键形成的，I 's位于cyd空腔的仲羟基侧。在cyd的催化下，核糖核苷酸二聚体CpC、CpU、CpA和CpG选择性地裂解为Ilia。
Regioselective P-0 (2') cleavages of 2', 3'-cyclic monophosphates of cytidine (la), uridine (lb), adenosine (Ic), and guanosine (Id) to the corresponding 3'-monophosphates (Ilia—d) are achieved at pH 11.08, 20 C by-cyclodextrin (a-CyD) as catalyst. The selectivities asymptotically increase with increasing concentration of-CyD, attaining 98, 94, 76, and 67% for the cleavages of Ia-d, respectively, at the concentration of 0.05 M-CyD. In the absence of-CyD, however, significant concurrent cleavages of the P-0 (3') bonds take place and the selectivities for Ilia—d are only 47, 50, 54, and 52%. The rate of the P-0 (2') cleavage of la in the-CyD-la complex is 14 times as large as that of free la, and the rate of the P-0 (3') cleavage in the complex is virtually zero, ß-and-CyDs show no regioselective catalyses.* H NMR spectroscopy indicates that the-CyD-la and-lb complexes are formed by hydrogen bondings and I’s are located on the secondary hydroxyl side of the cavity of-CyD. The selective cleavages of ribonucleotide dimers CpC, CpU, CpA, and CpG to Ilia are also successfully carried out by-CyD as catalyst.