Identification of bioactive phytochemical from two Punica species using GC-MS and estimation of antioxidant activity of seed extracts.

Punica species are medicinally important plants belonging to the family Lythraceae. The pomegranate is widely reported to exhibit antiviral, antioxidant, anticancer, anti-proliferative activities. In the present study the ethanolic extract of the peel seeds of two species of Punica (Punica granatum and Punica protopunica) were subjected to GC-MS analysis. Twenty-one and 14 compounds were identified in P. granatum and P. protopunica peel seeds, respectively. The main chemical constituents in P. granatum-peel seeds were propanoic acid, benzenedicarboxylic acid, methoxypropionic acid and methyl amine. The corresponding constituents of P. protopunica peel seeds were benzenedicarboxylic acid, benzoic acid and propanoic acid. Moreover, the antioxidant effects of the aqueous ethanolic extracts were estimated in vitro. The two tested extracts contained significantly different phenolic and total flavonoid contents in P. granatum than in P. protopunica. Different in vitro methods of antioxidant activity determination produced varying results. In malondialdehyde (MDA), hydrogen peroxide (H₂O₂) scavenging and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays, the two peel seed extracts exhibited very high antioxidant activities, with higher activity observed for the P. granatum extract.