Asian Journal of Microbiology, Biotechnology & Environmental Sciences Paper

COMPARISON OF ANTIBACTERIAL ACTIVITIES OF SOME NATURAL AND SYNTHETIC COMPOUNDS

RATHISH NAIR, ANJANA SHAH, SHIPRA BALUJA AND SUMITRA CHANDA

Abstract

This study describes the antibacterial activity of two natural and eight synthetic compounds. The two natural compounds were the leaves of Punica granatum and Maytenus emargmata . The eight synthetic compounds were Schiff bases derived from sulfonamide, 4-amino antipyrene and raceacetophenone. Both natural and synthetic compounds were screened for antibacterial activity against few clinical isolates (isolated from Urine, Blood, Tracheal secretion and Pus). The Schiff bases produced were 1) 4[2-aza-2- (2-chlorophenyl) vinyl] benzene sulfonamide [AD1] (2) 4[2-aza-2- (2-hydroxyphenyl) vinyl] benzene sulfonamide [AD21 (3) [1-aza-4-phenylbuta-1, 3-dienyl] benzene sulfonamide [AD3] (4) 4-[1-aza-2- (2-chlorophenyl) vinyl] 2, 3- diinethyl- 1-pheny1-3-pyrazolin-5-one [AS1] (5) 441-aza2- (2- hydroxyphenyl) vinyl]- 2, 3-dimethy1-1-phenyl-3- pyrazolin.-5-one [AS2] (6) 441-aza-4-phenylbuta1, 3-dienyl] 2,3-dimethy1-1-phenyl-3-pyrazolin-5-one [A.S3] (7) 4[2-aza-1 -methyl-2- (2-nitro_p henyl) viny1]-6-ethylbenzene1l3_3-diol [ADS1] (8) 4[2-aza-2- (5-ehty1-2, 4-dihydroxyphenyl) prop-1-enyll benzene sulfonamide [ADS2]. Extracts of these compounds (both natural and synthetic) were tried on 5 pathogenic [E. coli, Pseudomonas aeruginosa„Droteus znilgaris, Klebstella pneuinonias and Staphylococcus aureusl strains. The antibacterial activity was evaluated by the Agar Ditch method, Both natural and synthetic compounds were extracted in DMF (polar) and 1,4 Dioxan (non polar). Among the medicinal plants studied, P.granatum showed strong activity against K.pneumoniae, S.aureus and P.aeruginosa but showed moderate activity against E.coli and P.vulgaris while lvf.emarginata showed strong activity against K.pneumoniae, S.aureus and E.coli but showed moderate activity against P.aeruginosa. and P.vulgaris. Amongst the two natural compounds P. granatum was better than M. emarginata; while amongst the synthetic compounds, sulfonamide moiety with Cinnamaldehyde side chain (ADS) proved to be the best. The non-polar solvent 1,4 Dioxan proved to be the best. It appears that some of these natural and synthetic compounds with particular structure cold be used as a lead molecule in drug designing to combat the diseases caused by these bacteria.