Advantages of a Multi-Platform Workflow Integrating Biphasic Extraction, Chromatography, and NMR for Characterization of Metabolites in Extracts of Malakabi Ajwa Date Seeds
Mufeed M. Basti, Shanelle Flowers, Anika R. Barnes, Leonard L. Williams, Daniel A. Todd, Kiran Subedi, Amira A. AyadBackground/Objectives: Date seeds contain a wide range of biologically active constituents and have been associated with multiple health benefits. Our study aimed to evaluate the utility of biphasic aqueous methanol/chloroform extraction for separating diverse metabolites from powdered Malakabi Ajwa date seeds and to identify the most effective chromatographic and spectroscopic techniques for their comprehensive profiling and structural characterization. Methods: Biphasic extraction generated organic, aqueous, and insoluble phases. Proper chromatography-mass spectrometry and spectroscopy analytical tools were then utilized to profile the metabolites in the aqueous and organic phases. Results and Conclusions: In the organic phase, fatty acids and their methyl esters were identified using GC-MS and confirmed by 1H NMR, while the absence of an O–H band in the FT-IR spectrum, together with 1H NMR data, supported the natural esterification of these fatty acids. In the aqueous phase, UV-Vis spectroscopy and LC-MS revealed anthocyanin pigments, and LC-MS additionally detected four amino acids. HPLC was used to quantify and validate the sugar composition, and 1H 1D and 2D NMR spectra enabled the assignment of α- and β-glucopyranose, β-fructopyranose, and sucrose signals. 31P NMR indicated that orthophosphate monoesters were the predominant phosphorus-containing compounds in both organic and aqueous phases. Overall, our findings show how an integrated chromatographic and spectroscopic workflow provides a robust strategy for comprehensive metabolite profiling of natural products such as Malakabi Ajwa date seeds.