Abstract :

A paucity of local information concerning the chemical profiles and biological activities of extracts obtained from less-studied P. granatum peel of Jordanian origin was considered in this study for the first time. Fractionation of the crude ethanol extracts was performed because of their higher phenolic and flavonoid contents compared to the water and acetone extracts. The chemical compositions of the respective samples, that is, extracts/fractions were identified by LC–MS/MS, and the elemental content of the raw materials was also analysed using atomic absorption spectrometry. Antioxidant activities of extracts andfractions were evaluated against DPPH and ABTS radical scavenging assays, and the antibacterial activities were investigated by disc diffusion method and MIC (Minimum Inhibitory Concentration). The LC– MS/MS results correlated strongly with the total phenolic and flavonoid contents, where ethanol displayed higher efficacy for extracting bioactive ingredients. Overall, a total of 19 phenolics were detected in the ethanolic peel extract of P. granatum. All of the analysed extracts showed strong antioxidant activities. Fractionation of ethanolic extracts resulted in fractions with almost similar chemical LC–MS/MSprofiles, but the relative proportion of constituents was different. All fractions showed lower intensities of antioxidant capacities than crude extracts, highlighting the superiority of some components, either individually or combined, as well as their relative proportion on the biological activity of each fraction. The results of the present study emphasise the need to further explore the effect of putative interactions among plant bioactive ingredients and focus on possible interactions with drugs along with foods.