A preliminary study on the antimicrobial activities and gas chromatography-mass spectrometry (GC-MS) analysis of the ethyl acetate extract of Dennettia tripetala G. Baker seeds

Abstract

The study investigated the antimicrobial properties and the chemical composition of ethyl acetate extract of Dennettia tripetala (pepper fruit) seeds. Crude extract obtained by maceration of pulverized seeds in ethyl acetate was evaluated for antimicrobial activity against Escherichia coli, Staphylococcus aureus, Klebsiella aerogenes, Pseudomonas aeruginosa, Bacillus subtilis, Candida albicans and Aspergillus niger using standard agar-well diffusion method. GC-MS method was used to determine the chemical constituents of the extract. The extract was oily, yellowish-brown with a yield of 1.66 % and had activity against most of the test microorganisms, with inhibition zone diameters ranging between 10 to 25 mm. About 41 chemical constituents were present in the extract with formic acid methyl esters and fatty acids accounting for 57.23 and 18.49 % respectively. Ethyl acetate extract of Dennettia tripetala seeds possessed antimicrobial activity against bacteria but not fungi. The observed activity may be due to the presence of formic and fatty acid esters in the seed. The study further established a scientific proof for the traditional use of Dennettia tripetala seed extracts in treating microbial infections.