Isolation, characterization, quantification and antioxidant activity of compounds from Myrica esculenta

In the present study, 85% aqueous ethanol extract of Myrica esculenta stem bark (MESB) showed the isolation of six bioactive compounds including myricanone (1), myricanol-5-O-β-D-glucopyranoside (2), myricetin (3), myricolol (4), β-sitosterol (5), and β-sitosterol-D-glucoside (6). The HPLC approach revealed 3 as a key bioactive compound, with a 69% abundance in the crude ethanol (CE) extract. Furthermore, the CE was assessed for antioxidant activity using DPPH and hydroxyl radical tests, while purified compounds were examined for total antioxidant capacity using cyclic voltammetry and verified using the density functional theory (DFT) method. Amongst them, compound 2 had a significantly higher total antioxidant capacity (43.03%) than ascorbic acid (3.0%) in a cyclic voltammetry assay. Furthermore, the DFT investigation supported the overall antioxidant capacity of 2. Thus, our study is the first to highlight the total antioxidant capacity of isolated molecules from MESB and validate it using a DFT study.