Metabolomic Mining of the Botanical Dietary Supplement Wild Yam (Dioscorea villosa L.)

Abstract

A metabolomic mining methodology targeting new secondary metabolites from plants was developed on the basis of qHNMR and chromatographic profiles. Guided by NMR-derived information about partial-structures, two new classes of secondary metabolites, diarylheptanoids and lipidated steroid saponins, were isolated and identified from wild yam (Dioscorea villosa L. Dioscoreaceae) using a combination of HR-ESI-MS, GC-MS, 1D and 2D NMR, 1 H iterative Full Spin Analysis (HiFSA), and Mosher's ester analysis. These discoveries exhibit the advantage of metabolomic mining methodology in exploring the chemical diversity of previously investigated botanicals and emphasizes the usefulness of 1H NMR data analysis in the initial stages of any phytochemical study. The two new classes of phytoconstituents and particularly the lipidated steroid saponins from wild yam may serve to inspire further biological studies, which take into account their lipophilic character and significantly altered physiochemical characteristics as compared with their polar congeners.