Study of Creatinine and its 5-Alkoxy Analogs: Structure and Conformational Studies in the Solid and Solution States by X-Ray Crystallography, NMR, UV and Mass Spectrometry
作者:Aruna V. Arakali、J. McCloskeyt、R. Parthasarathy、J. L. Alderfer、G. B. Chheda∗∗、T. Srikrishnan
DOI:10.1080/07328319708002567
日期:1997.12
Creatinine (2-amino-1,5-dihydro-1-methyl-4-imidazolone) is a natural by-product of cellular metabolism related to muscular mass. It is excreted in human urine and is necessary for normal kidney function. Urinary secretion of creatinine serves as a bench mark for several clinical measurements. Recently, in our laboratories, during the course of an investigation of the urine of cancer patients for tumor markers, we found some new metabolites of creatinine. These were identified as 5-methoxy and 5-ethoxy creatinine by UV, NMR and Mass spectrometry and their tautomeric structures confirmed by crystal structural investigations of the metabolites. The x-ray crystallographic analysis confirmed the structures of the compound and showed that it exists in the 2-amino form. The spectral characteristics of these new compounds and the generality of the reaction are discussed in this paper. Creatinine, when allowed to react with methanol, ethanol and propanol respectively, in the presence of charcoal and air gave the 5-methoxy, 5-ethoxy and 5-propoxy creatinine derivatives respectively, suggesting a generality of a reaction. The reaction of creatinine with alcohols in the presence of charcoal and air takes place through a free radical reaction mechanism.
1H and 13C NMR spectra and solution structures of novel derivatives of 5-substituted creatinines
作者:Hanna Krawczyk、Agnieszka Pietras、Anna Kraska
DOI:10.1016/j.saa.2006.02.035
日期:2007.1
annular tautomerism of the investigated compounds. One can predict that 5-substituted creatinines, just like creatinine, appear in solution in the form of 2-amino-1,5-dihydro-1-methyl-4-imidazolone. Correlations between experimental and calculated substituent-induced chemicalshifts for two tautomeric forms of 5-substituted creatinines indicate that the mechanism of the substituent influence in both tautomers
1H NMR, 13C NMR and computational studies of novel derivatives of substituted creatinines
作者:Hanna Krawczyk、Agnieszka Pietras
DOI:10.1016/j.molstruc.2007.09.020
日期:2008.6
anhydride were investigated using 1 H, 13 C NMR and DFT calculations. The alpha-cleavage of the C O group with release of hydrogen was observed in MS-ESI spectra during the analysis of the novel compounds. During our experiments, unlike in reference data, we observed an intramolecular hydrogen bond in deuterated chloroform and gas phase of substituted creatinines.
摘要 使用 1 H、 13 C NMR 和 DFT 计算研究了 5-取代肌酐的五种产物与乙酸酐或与 ( S )-(+)-2-甲基丁酸酐的分子内相互作用的结构和能量特征。在分析新化合物的过程中,在 MS-ESI 光谱中观察到 CO 基团的 α 裂解和氢的释放。在我们的实验中,与参考数据不同,我们在氘代氯仿和取代肌酐的气相中观察到分子内氢键。