Study of bioactivities of lipid content of fresh Lagenaria siceraria seeds pulp and identification of its chemical constituents

The aim of the present work was to analyse antimicrobial activities of the lipid content of seeds pulp of the fresh fruit of Lagenaria siceraria and identification of its chemical constituents by gas chromatography-mass spectrometry (GC-MS). Methanolic extract of the seeds pulp exhibited moderate to good efficacy against Achromobacter xylosoxidans, Pseudomonas aeruginosa, Bacillus megaterium and Escherichia coli having zone of inhibition (ZOI) 21.5, 20.0, 17.5 and 15.0 mm, respectively, at concentration 100 mg/ml. It showed better potency than antibiotic amoxylin against Enterobacter aerogenes, P. aeruginosa and Bacillus megaterium. The hexane fraction, that contained most of the lipid content, exhibited highest lethality against all the test microorganisms with ZOI 16.0 to 30.0 mm. It displayed highly significant efficacy against B. megaterium and Salmonella typhi with ZOI 30.0 and 22.5 mm, respectively. Minimum inhibitory concentration (MIC) of hexane fraction against B. megaterium and A. xylosoxidans was 0.40 mg/ml, while for others it ranged from 0.80 to 2.80 mg/ml. Palmitic acid exhibited significant potency against Staphylococcus aureus (ZOI, 20.0 mm, at concentration of 40 mg/ml), and moderately good efficacy against Stenotrophomonas maltophilia, Salmonella typhi and Enterobacter cloacae. Most compounds identified in the seeds pulp through GC-MS analysis were fatty acids or their esters. The compounds present in considerable concentration included azelaic acid (31.0%), (Z,Z)-9,12-octadecadienoic acid methyl ester (27.75%), and palmitic acid methyl ester (13.0%). Major component of ethyl acetate fraction was 4-hydroxybenzenemethanol (19.28%), while chloroform fraction contained 4-methoxymethylphenol (6.42%) and pentanoic acid 2-hydroxy-4-methyl-methyl ester (6.75%) as major constituents. The lipid content of seeds pulp of Lagenaria siceraria fruit contains components which are capable to inhibit bacterial growth, and the ones with strong anti-oxidative potential.