Metabolic characterization of Prunus cerasus L. and Prunus mahaleb L. fruits

The human health benefits of fruits and vegetables are ascribed to their phytochemical content, such as carotenoids and polyphenolics. In the search for antioxidative chemicals from native fruits of the Puglia region of Italy, Prunus cerasus L., an acidic cherry widely used for culinary purposes, and Prunus mahaleb L., a tree species commonly used as rootstock in cherry crop, were studied. The P. mahaleb fruits have a high content of organic acids, fructose and vitamin C, but are not consumed fresh because of a bitter and sour taste. In this work we obtained the 1H NMR spectra of the two species and from the comparison of these spectra, we found that P. mahaleb fruits have an higher concentration of phenolic compounds, such as flavonoids, and organic acids, in comparison to P. cerasus fruits. The same results were obtained when we focused on anthocyanins. In this study we identified the signals of anthocyanin protons in 1H NMR spectra of a mixture of compounds in aqueous extracts of both P. cerasus and P. mahaleb fruits but the latter species showed a higher concentration and a larger number of these compounds. This metabolomic analysis gave us the data to scientifically revalue traditionally-used plants like P. mahaleb and to identify the potential as source of biofunctional compounds to be used in food and/or pharmaceutical industry. Moreover, in this study, NMR spectroscopy coupled with multivariate data analysis was applied to Prunus metabolomics in order to investigate the botanical origins of Prunus cerasus and to identify the compounds responsible for differentiation of these two species of Prunus (cerasus and mahaleb) and of two cultivars of Prunus cerasus ('Montmorency' and 'Marasca di Zara').