CONFORMATION OF BETA-PSEUDOURIDINE ABOUT GLYCOSIDIC BOND AS STUDIED BY H-1 HOMONUCLEAR OVERHAUSER MEASUREMENTS AND MOLECULAR-ORBITAL CALCULATIONS
CONFORMATION OF BETA-PSEUDOURIDINE ABOUT GLYCOSIDIC BOND AS STUDIED BY H-1 HOMONUCLEAR OVERHAUSER MEASUREMENTS AND MOLECULAR-ORBITAL CALCULATIONS
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DOI：
10.1139/v74-059
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发表时间：
1974-01-01
期刊：
影响因子：
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通讯作者：
SMITH, ICP
中科院分区：
文献类型：
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作者：
NANDA, RK;TEWARI, R;SMITH, ICP
通过内核Overhauser效应和CNDO分子轨道计算研究了β-假尿苷糖苷键的构象。人们发现同构象和反构象都处于快速平衡状态，每种构象的数量大致相等。在 7.1 至 11.6 范围内，同反构象的比例不会随 pD 发生显着变化。 CNDO 计算表明，同步构象通过形成氢键 C4=O … O-H5' 来稳定，但 nmr.数据表明，如果存在这样的键，其概率在 pD7.1 和 11.6 时是相同的。对 n.O.e. 的主要贡献可能通过最稳定的构象以外的构象发生。
The conformation of β-pseudouridine about the glycosidic bond has been studied by both the internal nuclear Overhauser effect and CNDO molecular orbital calculations. Bothsynandanticonformations are found to exist in rapid equilibrium, with roughly equal populations of each. The proportion ofsyntoanticonformations does not change significantly with pDover the range 7.1 to 11.6. The CNDO calculations suggest that thesynconformation is stabilized by formation of a hydrogen bond, C4=O … O—H5′, but the n.m.r. data indicate that if such a bond exists its probability is the same at pD7.1 and 11.6. Major contributions to n.O.e. may occur through conformations other than those which are most stable.