Chemometric multivariate analyses of phenolics and biological activities for characterization and discrimination of Tunisian Ephedra alata

Recently, the tendency towards application of natural products and botanical extracts as safer antioxidant and antimicrobial agents has been increased. Herein, ethyl acetate, ethanolic and aqueous extracts of Ephedra alata from seven natural Tunisian geographic locations were phytochemically assessed and evaluated regarding bioactive, antioxidant and antibacterial properties. Significant differences (p < 0.05) in the phytochemical content, antioxidant and anti-food-borne bacterial activities were detected among the E. alata populations. For each extraction solvent, linear regression analysis showed that environmental factors: altitude, average annual precipitation (AAP), average annual temperature (AAT) and relative air humidity (RH), are affecting variability in phytochemical contents In fact, altitude and AAP acted positively on total flavonoid contents (TFC) and the increasing of AAT was directly related to all phenolic contents (TPC, TFC and total anthocyanins content (TAC)). The evaluation of experimental data for all extracts was performed by applying chemometric approach: hierarchical cluster analysis (HCA) and principal component analysis (PCA). It was found that the seven population’s E. alata could be classified geographically into four distinct groups. Equally, relationships linking all data through Pearson coefficient correlation were also reported. The findings of this study will help medicinal plant growers and pharmaceuticals to identify suitable habitats and extraction solvent for the effective harnessing of E. alata phytochemicals.