Enhancing detection of low‑abundance metabolites in proton NMR through band‑selective suppression and presaturation

Metabolomics provides powerful means to analyze metabolite profiles in biological samples, enabling insights into biochemical changes under genetic, environmental, or pathological conditions. Nuclear Magnetic Resonance (NMR) spectroscopy is central to metabolomics, but its utility is often constrained by the strong and overlapping resonances of abundant components, such as sugars in plant‑ and food‑derived materials, which obscure signals of lower‑abundance metabolites. Here, we introduce a modified NMR acquisition method that increases sensitivity and specificity by selectively suppressing dominant signals, while enhancing weaker metabolite signals across the spectrum. The method integrates water presaturation with excitation sculpting (ES), yielding a robust 1D presat‑¹H‑ES pulse sequence. Validation on a range of sugar-rich samples demonstrated 2-fourfold signal enhancement for low‑abundance metabolites compared with conventional ¹H‑ES. Multivariate analyses show the method improves reproducibility and discrimination, enabling detection and comparison of low‑abundance metabolites not accessible with conventional approaches'. Beyond sugar‑rich systems, the method is broadly applicable to other spectral regions where dominant metabolite classes obscure lower‑concentration compounds, including primary metabolites and structurally diverse natural products. Overall, the 1D presat‑¹H‑ES significantly enhances resolution and sensitivity of NMR‑based metabolomics, shortens analysis time, and supports more precise profiling for both fundamental studies and translational applications in metabolomics and natural‑products discovery.