Abstract

PHYTOCHEMICAL COMPOSITION, TANNIN CONTENT, DPPH ASSAY AND ANTIBACTERIAL ACTIVITY OF PEEL EXTRACTS OF PUNICA GRANATUM. L

B. Janarthanam and E. Sumathi*

Abstract

The present study aims at investigating the phytochemical composition, tannin content, DPPH assay and antibacterial activity of peel extracts of Punica granatum. Phytochemical screening of various extracts such as aqueous, ethanol, chloroform, acetone and petroleum ether of peel extracts, revealed the presence of tannins, saponins, phenols, flavonoids, cardiac glycosides, terpenoids, alkaloids and steroids. The peel extracts were evaluated for tannins content with tannic acid as standard. The optimum yield of tannins was found in ethanol peel extract (87.3mg TAE/ g) of Punica granatum. Five different solvent extracts of Punica granatum peel were evaluated for antioxidant activities by DPPH (1, 1 – diphenyl -2- picryl-hydrazyl) radical scavenging activity using Butylated Hydroxy Toluene (BHT) as standard. Among five different solvents used, maximum antioxidant activity was found in ethanol peel extract (94.5 %) followed by others. Different concentrations of ethanolic peel extracts were tested for the anti-bacterial activity against Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis and Escherichia coli using the agar disc diffusion technique. The ethanolic extracts from dry powdered peel of Punica granatum had superior level of antimicrobial activity. The powerful antibacterial effect is attributed to the greater amount of tannins compound in the ethanolic peel extracts of Punica granatum.

Keywords: Punica granatum, Phytochemical analysis, DPPH, Antibacterial activity, Tannins.