关键词: 胞嘧啶核苷, 水溶液, 分子结构, 计算机应用, 核磁共振谱法, 镧系元素, 质子磁共振谱法, 耦合常数, 探针, 腺嘌呤

Lanthanide ions were used as NMR probes to study the conformation distributions of 5'-CMP, 5'-AMP, and 5'-IMP in acidic aqueous solns. The experimental data of pseudo-contact shift together with the data of spin-lattice relaxation rate as well as spin-coupling constants of 1H spectra were processed by computer. The results show that in aqueous solns. the conformations of the nucleotides exist in equilibrium as a group of conformers. In comparison with crystalline state, the dihedral angles around single bonds and the puckering forms of ribose ring have changed to some extent. However, the base groups are still in anti-forms.

Key words: CYTIDINE, AQUEOUS SOLUTION, MOLECULAR STRUCTURE, COMPUTER APPLICATIONS, NMR SPECTROMETRY, LANTHANON, PROTON MAGNETIC RESONANCE SPECTROMETRY, COUPLING CONSTANT, PROBES, ADENINE