Chemical dereplication of wine stilbenoids using high performance liquid chromatography-nuclear magnetic resonance spectroscopy.

Abstract Wine is a major dietary source of numerous potentially health promoting stilbenoidsthat have been the subject of many qualitative and quantitative studies. However, our initial HPLC–MS analyses of crude wine samples demonstrated the presence of compounds with molecular weights matching characteristic stilbenoiddimers, trimers, and tetramers that were unaccounted for in the literature. Due to the likelihood that these are known compounds, a chemical dereplication method is highly desirable. We developed such a method using LC-DAD–MS monitored fractionation steps, using adsorption and centrifugal partition chromatography(CPC), to obtain fractions rich in stilbenoidsfor analysis in stopped-flowLC–NMR. 1 H NMR spectra and MS data were cross-referenced with our laboratory database and the literature for identification. This method yielded highly useful structural information, allowing the characterization of previously unidentified stilbenoidsin wine, ampelopsinC, isohopeaphenol, quadrangularin A, and E - ω - viniferin. These results demonstrate the usefulness of stop-flowLC–NMR in conjunction with LC–MS guided fractionation for the dereplication of compounds of interest in general, and specifically for expanding the current knowledge of wine chemistry.