Effect of solvent on antioxidant activity of Zanthoxylum oxyphyllum Edgew and its DFT study
Background: Free radicals can easily damage DNA, proteins, lipids within the tissue. Anti-oxidants from natural sources can diminish the actions of free radicals with no to very few adverse effects. The current study deals with the chemical composition and antioxidant activity from leaves of Zanthoxylum oxyphyllum Edgew. Methods: The antioxidant activities for DPPH, FRAP, ABTS radicals, phosphomolybdate assay, reducing power, and chelating power assay were evaluated in ethanol (ET), methanol (ME), chloroform (CH), ethyl acetate (EA), and petroleum ether (PE) extracts of the leaves. The Density Functional Theory (DFT) study was carried out on major phytochemicals to evaluate the most responsible bioactive molecule responsible for antioxidant activity. Results: It was observed that the ME extract showed the most potent scavenging activities in DPPH, FRAP, ABTS radicals, phosphomolybdate assay, reducing power, and chelating power assay. The phenolic acids and flavonoids like quercetin, gallic acid, sinapic acid, etc were identified. The DFT study was done for major phytochemicals of ME extract to evaluate the most responsible bioactive molecule for antioxidant activity. The Gallic acid has the lowest bond dissociation energy (BDE) 314.9 kcal/mol in gas, 309.2 kcal/mol in methanol respectively along with the highest value of radical stabilization energy (RSE) 29.5 kcal/mol. Conclusion: It revealed that gallic acid is the most responsible antioxidant among the other compounds and ME is the best solvent system for extraction followed by CH.