*4.1. Chemicals and Reagents*

Analytical reagent-grade chemicals and bi-distilled water were used throughout this experiment. Methanol used was of HPLC-grade, ≥99.9%, CHROMASOLV™ (Honeywell Riedel-de Haën™); KNO3, acetone (Multisolvent® HPLC grade), NaOH, and H2SO<sup>4</sup> were purchased from Merck KGaA, Darmstadt, Germany. Methyl viologen, oxalic acid anhydrous 99%, salicylic acid acs 99%, sodium carbonate (Na2CO3), glucose solution, anthrone 97%, L-ascorbic acid, Folin–Ciocâlteu reagent, DPPH• radical reagent, Trolox, and gallic acid were purchased from Merck KGaA, Darmstadt, Germany. Standard solutions were prepared with bi-distilled water.
