Statistical evaluation of main extraction parameters in twenty plant extracts for obtaining their optimum total phenolic content and its relation to antioxidant and antibacterial activities

Abstract

The main extraction parameters were statistically evaluated for 20 medicinal plants to obtain the optimum conditions for maximum extraction of total phenolic content (TPC) in each plant. Among various extraction parameters, pH, temperature, and concentration at different levels were studied. The results were analyzed using the analysis of variance to achieve the optimum conditions of phenolic extraction for all plants. Also, investigation of the optimum antioxidant (AnOX) activities using DPPH (2,2-diphenyl-1-picrylhydrazyl) method and antibacterial potential against common pathogenic bacteria of Staphylococcus aureus, Escherichia coli, Pseudomonas spp., and Candida spp. through disk diffusion method for the extract of all plants under the optimum total phenolic concentration of each plant extract confirmed a direct relation among bioactivity and TPC.