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

Creatinine (2-amino-1,5-dihydro-1-methyl-4-imidazolone) is a natural b y-product of cellular metabolism related to muscular mass. It is excre ted in human urine and is necessary for normal kidney function. Urinar y secretion of creatinine serves as a bench mark for several clinical measurements. Recently, in our laboratories, during the course of an i nvestigation of the urine of cancer patients for tumor markers, we fou nd some new metabolites of creatinine. These were identified as 5-meth oxy 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 fo rm. The spectral characteristics of these new compounds and the genera lity of the reaction are discussed in this paper. Creatinine, when all owed to react with methanol, ethanol and propanol respectively, in the presence of charcoal and air gave the 5-methoxy, 5-ethoxy and 5-propo xy creatinine derivatives respectively, suggesting a generality of a r eaction. The reaction of creatinine with alcohols in the presence of c harcoal and air takes place through a free radical reaction mechanism.