Abstract

PRELIMINARY PHYTOCHEMICAL ANALYSIS AND ANTIBACTERIAL ACTIVITY OF LEAF EXTRACT OF PSIDIUM GUAJAVA AGAINST BACTERIAL PATHOGEN

Deshpande S. N.*

Abstract

Psidium guajava L. commonly known as guava is used for the medicinal purposes. Every part of the plant like leaves, bark, fruit and roots is used to treat various diseases. In the present study, Preliminary phytochemical analysis of methanol, ethanol, ethyl acetate, petroleum ether, chloroform and water leaf extract prepared by cold extraction method of Psidium guajava L. was carried out by chemical tests and antibacterial activity was determined by agar well diffusion method against Staph. aureus, Salmonella typhimurium, Salmonella enteritidis, Salmonella paratyphi B, Proteus vulgaris, Pseudomonas aeruginosa, Klebsiella pneumonia, Escherichia coli. Alkaloids, carbohydrates, tannins, phytosterols and cardiac glycosides were present in all extracts. However, flavonoids, antraquinine, saponins, aminoacids were absent in all extracts. All the extracts inhibited the growth of bacterial pathogens under investigation. Ethyl acetate extract showed highest antibacterial activity against Salmonella typhimurium and Escherichia coli followed by aqueous and chloroform against Escherichia coli and Salmonella paratyphi B respectively. The inhibition zone of gentamycin [reference control] was 32 mm.

Keywords: Psidium guajava, cold extraction, agar well diffusion, gentamycin, alkaloids, saponins.