Metabolite Fraction Libraries for Quantitative NMR Metabolomics

Area of Science:

• Metabolomics
• Nuclear Magnetic Resonance (NMR) Spectroscopy
• Analytical Chemistry

Background:

• One-dimensional proton (1D ¹H) NMR is common in metabolomics but faces challenges due to significant spectral overlap.
• Accurate quantification and structural elucidation of metabolites in complex biological mixtures remain difficult.

Purpose of the Study:

• To develop a novel NMR-based approach for comprehensive metabolite quantification and structural identification.
• To overcome spectral overlap limitations in 1D ¹H NMR metabolomics.

Main Methods:

• Utilized chromatographically separated fractions from a pooled sample to create a metabolite fraction library (mFL).
• Developed an algorithm to extract correlated peaks from mFL, forming a metabolite basis set (mBS).
• Applied mBS fitting to NMR profiling data for quantification.

Main Results:

• Accurately quantified 50 out of 53 metabolites in 10 test mixtures.
• Identified one impurity and one oxidation product.
• Quantification covered 91-96% of total spectral intensity.
• In Neurospora crassa, identified 45 high-confidence and 45 medium-confidence metabolites, covering 94% of spectral intensity.

Conclusions:

• The mFL and mBS approach significantly enhances metabolite quantification and identification in complex mixtures.
• This method improves upon traditional 1D ¹H NMR by addressing spectral overlap.
• The approach is effective for analyzing fungal metabolomes and potentially other biological systems.