Profiling of carbohydrate mixtures at unprecedented resolution using high-precision 1H-13C chemical shift measurements and a reference library

Abstract

Complex mixtures of carbohydrates pose distinct challenges in routine and high-throughput analysis, so that only a few carbohydrate components are routinely resolved and identified in biofluids, extracts, foods and other complex mixtures. Here, we conduct precise measurements of ¹H and ¹³C anomeric chemical shifts to construct a reference library of specific carbohydrate signals with high-resolution two-dimensional ¹H-¹³C NMR spectra. High-resolution multidimensional NMR spectra largely abolish resolution problems in carbohydrate analysis with state-of-the-art instrumentation. Accurate measurements of anomeric ¹H-¹³C chemical shifts at parts per billion precisions permit robust carbohydrate identification using a very limited number of instrument-independent reference values.