HPLC Analysis and DPPH Assay of Some Bioactive Compounds in Pomegranate Peel Extracts

Abstract

Pomegranate (Punica granatum L.) and their derivative parts contain various phytochemical compounds. The pomegranate peels had the highest antioxidant activity as compared to other parts of pomegranate fruit. HPLC-UV technique was used to identify and quantify the individual ascorbic acid and bioactive compounds (i.e. gallic acid, procatachouic acid, quercetin, and kaempferol) in solvents extract of peels of pomegranate cultivated in Yemen, while scavenging assay of DPPH of dried and undried peel extracts were used to measure antioxidant capacity expression as EC₅₀ value. The resulted findings by HPLC analysis showed that the amount of ascorbic acid was higher than the phenolic acids (gallic acid and protocatechuic acid), and flavonoids (quercetin and kaempferol) in all extracts and the highest amount of ascorbic acid was found in aqueous extract followed by methanolic whereas the last one was in ethanol solvent. While the phenolic acids were higher than the flavonoids in all extracts, the amount of protocatechuic acid in aqueous extract was higher than the amount of other polyphenols, and the quercetin amount was the lowest one. To compare the anti-oxidative activity of dried and undried peel extract by acetone and water, the EC₅₀ value of dried and undried peel acetonic extracts were 1.2±0.35 and 5±1.8 µg/ml, respectively, which were higher than aqueous extracts of dried and undried peel (8.1±0.66 and 7.9 ±0.08 µg/ml) respectively.