Comparative Study on Phytochemical and Antimicrobial Activity of Different Solvent Extracts of Pinattu

Abstract

Palmyrah (Borassus flabellifer) fruit is mostly used as fresh fruit, because of its perishable nature it is traditionally preserved as dried fruit pulp as pinattu and constituents of crude extracts of pinattu were evaluated. Samples were collected from three different branches of Palmyrah Development Board and extracted with different solvents as aqueous, methanol, ethyl acetate and petroleum ether and concentrated extracts were used for the study. Alkaloids and tannins were not detectable in all the extracts while aqueous and methanol extracts gave positive results for carbohydrates, proteins, phytosterols, saponins, flavonoids, phenols and amino acids and fats and fixed oils. Spectroscopic determination of total phenolic, flavonoids and saponin content were significantly (p<0.05) different among the solvents and the highest amount was identified, in aqueous extract (19.92±0.5)mg/g, methanol extract (0.18±0.0)mg/g and methanol extract (509.88±4.18)mg/g respectively. Based on their diameter of the zone of inhibition least MIC of aqueous extract for Staphylococcus (1.4±0.1cm), E.coli (1.2±0.0cm), Pseudomonas (1±0.0cm) and methanol extract for E.coli (1.4±0.1cm) and Pseudomonas (1.1±0.00cm) was 0.5mg/ml. The Salmonella and Bacillus was showed 0.75mg/ml for aqueous extract while 0.25 and 1.0mg/ml for methanolic extract respectively. Klebsiella was showed 0.25mg/ml for both aqueous extract (1.1±0.0cm) and methanol extract (1.35±0.0cm). Highest inhibition zone was observed for 1 mg/ml of aqueous extract (2.15±0.2cm) in Protease when compared with positive control (1.9±0.1cm).This finding shows that crude aqueous and methanol extract of pinattu contains high amount of phytochemicals, exhibit significant antibacterial activity with relatively lower MIC (≤ 1mg/ml) when compared with ethyl acetate and petroleum extracts. Keywords: