NMR/MS Translator
for the Enhanced Simultaneous Analysis
of Metabolomics Mixtures by NMR Spectroscopy and Mass Spectrometry:
Application to Human Urine
posted on 2015-06-05, 00:00authored byKerem Bingol, Rafael Brüschweiler
A novel
metabolite identification strategy is presented for the
combined NMR/MS analysis of complex metabolite mixtures. The approach
first identifies metabolite candidates from 1D or 2D NMR spectra by
NMR database query, which is followed by the determination of the
masses (m/z) of their possible ions,
adducts, fragments, and characteristic isotope distributions. The
expected m/z ratios are then compared
with the MS1 spectrum for the direct assignment of those
signals of the mass spectrum that contain information about the same
metabolites as the NMR spectra. In this way, the mass spectrum can
be assigned with very high confidence, and it provides at the same
time validation of the NMR-derived metabolites. The method was first
demonstrated on a model mixture, and it was then applied to human
urine collected from a pool of healthy individuals. A number of metabolites
could be detected that had not been reported previously, further extending
the list of known urine metabolites. The new analysis approach, which
is termed NMR/MS Translator, is fully automated and takes only a few
seconds on a computer workstation. NMR/MS Translator synergistically
uses the power of NMR and MS, enhancing the accuracy and efficiency
of the identification of those metabolites compiled in databases.