Ratio Analysis of NMR/MS

The complexity of biological mixtures invariably poses a major challenge for reliable compound identification using data from nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). Generally, peaks from the interfering compounds either overlap or lead to additional peaks in the spectra, which make interpretation and assignment difficult or less reliable.

Focused on overcoming this challenge, new methods have been developed, in our laboratory, which isolate peaks for the same compound from the complex NMR or MS spectra, based on the ratios of peak areas/intensities, and help establish the identity of unknown compounds. Thus, the method Ratio Analysis of Nuclear Magnetic Resonance Spectroscopy (RANSY) was first developed for the analysis of NMR spectra [1] and, more recently, the method Ratio Analysis of Mass Spectrometry (RAMSY) was shown to be useful for unraveling complex mass spectra and obtaining reliable compound identification [2]. Notably, the performance of this approach is shown to be typically better than the results from correlation methods. Considering that biological matrices are highly complex and a vast majority of peaks detected, specifically by MS, are yet unidentified, ratio analysis approach should add complementary value and, when combined with currently used algorithms, should benefit unknown metabolite identification in metabolomics or other fields.

A free RANSY/RAMSY software package with easy to use instructions and data template are provided here for the analysis of your NMR or MS data.

1. RANSY/RAMSY website calculator (coming soon)

2. RANSY/RAMSY Matlab script

3. RANSY/RAMSY Excel template

[1] Wei, S., Zhang, J., Liu, L., Ye, T., Nagana Gowda, G.A., Tayyari, F., Raftery, D.: Ratio Analysis NMR Spectroscopy (RANSY) for Selective Metabolite Identification in Complex Samples. Anal. Chem. 83:7616-7623, 2011.

[2] Gu, H., Nagana Gowda, G.A., Carnevale Neto, F., Opp, M.R., Raftery, D.: RAMSY: Ratio Analysis of Mass Spectrometry to Improve Compound Identification. Anal. Chem. 85: 10771-10779, 2013.

[3] Paudel, L., Nagana Gowda, G.A., Raftery, D.: Extractive Ratio Analysis NMR Spectroscopy for Metabolite Identification in Complex Biological Mixtures. Anal. Chem. 91:7373-7378, 2019.