Lindoside, newly identified glycoside in linden honey using NMR spectroscopy

NMR is a powerful tool for the analysis of complex mixtures, such as honey, as it can identify relevant molecules without the need for isolation. NMR profiling of Slovenian honey revealed a linden-specific signal in the aliphatic region of the ¹H NMR spectra that could not be attributed to any previously identified compound, prompting further structural characterization of a glycoside. The 2D NMR spectra showed that the aglycone part consists of a (2-hydroxyisopropyl)phenyl ring bound to a disaccharide moiety via ester bond. The disaccharide residue was determined to be β-gentiobiose based on diffusion-ordered spectroscopy and selective excitation NMR experiments. This study also establishes an NMR-based workflow for identifying glycosides in complex mixtures such as food. The identification of novel glycosides contributes to our understanding of the molecular composition of linden honey, to authentication of linden honey and provides a solid foundation for further studies of its potential biological functions.