13C-Formylation for Improved NMR Profiling of Amino Metabolites in Biofluids

摘要

The increased interest in metabolite profiling is driving the need for improved analytical techniques with greater performance for a variety of important applications. Despite their limited sensitivity NMR methods are attractive because of their simplicity, reproducibility, quantitative nature, and wide applicability. The use of chemoselective isotopic tags has the potential to advance the application of NMR for analyzing metabolites in complex biofluids by allowing detection of metabolites down to the low μM level with high resolution and specificity. Here, we report a new ¹³C-tagging method using ¹³C-formic acid that delivers high sensitivity, good quantitation and excellent resolution for ¹H-¹³C 2D NMR profiling of amino metabolites. High reproducibility (CV = 2%) was observed for metabolites in urine with concentrations down to 10 μM. As amino compounds comprise an important class of metabolites and small molecules of biological roles, this new method therefore should be amenable to a variety of applications.