Preliminary Study on J-Resolved NMR Method Usability for Toxic Kidney's Injury Assessment.

BACKGROUND: Nowadays, the Nuclear Magnetic Resonance (NMR) techniques are tested for metabolomic urine profile in order to detect early damage of kidney. OBJECTIVES: The purpose of this investigation was the initial assessment of two-dimensional J-resolved NMR urine spectra analysis usability for early kidney injuries detection. The amino acids (AA) and acids profile change after the exposure to nephrotoxic agent (the cisplatin infusion) was examined. MATERIAL AND METHODS: The material was the urine of patients with non-small-cell lung cancer, treated with cisplatin in Pulmonology and Lung Cancers Clinic in Wroclaw. The urine of healthy volunteers was also examined. The identification of metabolites in urine was based on two-dimensional JRES signals in spectra, described in Human Metabolites Database (HMD). The molar concentration of metabolites was calculated from the volume under the signals. The analysis was focused on amino acids and organic acids (lactid acid and pyruvic acid) profiles. RESULTS: Any specific amino acids were identified after cisplatin infusion in comparison to the state before infusion. However, the differences in concentration were observed over 2-fold increase in valine, isoleucine and leucine, over 3-fold in alanine. Also, the concentration of pyruvic and lactic acids increased significantly (p≤0.05, p≤0.01). CONCLUSIONS: There were no specific amino acids identified in response to the infusion of cisplatin; however, some changes in the concentrations of amino acids and other small molecules were found. The analysis of two-dimensional JRES spectra showed an increase of alanine, leucine, isoleucine and valine concentration after the application of cisplatin. It seems that it is worth developing the JRES method based on special computer program.

Theoretical study of spin-spin coupling across the hydrogen (O-H...N) bond in adenosine derivatives.

The study of spin-spin coupling constants across hydrogen bond provides useful information about configuration of complexes. The interesting case of such interactions was observed as a coupling across an intramolecular hydrogen bond in 8-bromo-2',3'-O-isopropylideneadenosine between the -CH2OH (at 5'' proton) group and the nitrogen atom of adenine. In this paper we report theoretical investigations on the 4hJNH coupling across the H''-C-O-H...N hydrogen bond in adenosine derivatives in various solvent models.