A multi-platform based metabolic comparison of dill (Anethum graveolens) and fennel (Foeniculum vulgare) using NMR and UPLC–QTOF/MS

Fennel and dill are well-known aromatic plants and are widely used commercially. They have also been recognized as a medicinal herb with numerous pharmacological activities. Thus, the interest in dill and fennel has been growing, and their industrial use is becoming more important. In this study, seeds of fennel and dill were extracted and analyzed using nuclear magnetic resonance (NMR) spectroscopy and ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC–QTOF/MS)-based metabolomics. Through 1D and 2D NMR analysis, a total of 34 primary metabolites were identified, and using UPLC–QTOF/MS, different chromatograms of dill and fennel were obtained in less than 20 min. In the multivariate statistical analysis of data obtained from NMR and MS, it was confirmed that seeds of dill and fennel discriminated clearly. Sugars and organic acids were identified as the primary metabolites contributing to significant differentiation of fennel and dill. Also, flavonoids, which were identified as secondary metabolites, significantly differentiated dill and fennel.