In vitro Evaluation of Antioxidant Potential of Isolated Compounds and Various Extracts of Peel of Punica granatum L.

Background: Punica granatum L. (Lythraceae) peel has been proven to exhibit widespread pharmacological application against multitude of diseases due to the presence of bioactive principles. Objective: The objective is to isolate the bioactive compounds from the pericarp of P. granatum and to evaluate the antioxidant activity of various extracts. Materials and Methods: Dried peel of P. granatum was extracted with aqueous acetone and chromatographed on Diaion HP-20. Enriched fractions were rechromatographed on Sephadex LH-20 and purified on preparative high-performance liquid chromatography to identify individual compounds. The dried peel was extracted with different solvents to evaluate the antioxidant activity of the extracts. Results: On the chemical investigation, three compounds were isolated and characterized as punicalagin, 2,3-(S)-hexahydroxydiphenoyl-D-glucose, and punicalin, using various spectroscopic techniques. Conclusion: Results indicate that the isolated compounds have possessed antioxidant activity, and aqueous, methanol, and aqueous acetone extract showed significant scavenging of 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) radicals.