Spectral analysis and anti-bacterial activity of methanolic fruit extract of <i>Citrullus colocynthis</i> using gas chromatography-mass spectrometry

Abstract

Phytochemicals are chemical compounds often referred to as secondary metabolites. Thirty three bioactive phytochemical compounds were identified in the methanolic extract of Citrullus colocynthis. The identification of phytochemical compounds is based on the peak area, retention time molecular weight and molecular formula. Gas chromatography-mass spectrometry (GC-MS) analysis of C. colocynthis revealed the existence of the methyl 6-oxoheptanoate, hexanoic acid, 2-isopropyl-2-methyl- 5-oxo-, methyl ester, dodecanoic acid, 3-hydroxy, benzofuran,2,3-dihydro, 1,1-Cyclopropanedimethanol, 2-methyl-α-phenyl, 1,1-cyclopropanedimethanol, 2-methyl-α-phenyl, 12,15-octadecadiynoic acid, methyl ester, (5ß)pregnane-3,20ß-diol, 14α,18α-[4-methyl-3-oxo-(1-oxa-4-azabutan, 3-(N,Ndimethyllaurylammonio) propanesulfonate, 2H-1-benzopyran-3,4-diol,2-(3,4-dimethoxyphenyl)- 3,4dihydro-6-met, 11,13-dihydroxy-tetradec-5-ynoic acid, methyl ester, Cyclopenta[1,3]cyclopropa[1,2]cycloheptan-3(3aH)-one,1,2,3b,6,7, 4-(2,4,4-trimethyl-cyclohexa-1,5- dienyl)-but-3-en-2-one, 1-tetradecanamine,N,N-dimethyl, α-D-glucopyranoside, O-α-D-glucopyranosyl- (1,fwdarw.3)-ß-D-fructo, acetamide, N-methyl-N-[4-(3-hydroxypyrrolidinyl)-2-butynyl]-, 9- octadecenamide,(z)-, butyrophenone,2´,3,4´,6´-tetramethyl-, ethyl 5,8,11,14,-eicosatetraenoate, 9,12,15- octadecatrienoic acid, 2,3,-dihydroxypropyl ester, (Z,Z,Z)-, 1H-cyclopropa[3,4]benz[1,2-e]ezulene - 5,7b,9,9a 476.241018tetrol,1a,1b,4,4a, 9,12,15-octadecatrienoic acid, 9,10-Secocholesta -5,7,10(19)- triene-3,24,25,-triol,(3ß,5Z,7E)-, 9,12,15-Octadecatrienoic acid,2,3-dihydroxypropyl ester, (Z,Z,Z)-, triazido-(1,2,3,4,5-pentamethylcyclopenta-2,4-dienyl)-german, ethyl iso-allocholate, α-N-Normethadol, Octadecanoic acid, 2-hydroxy-1-(hydroxymethyl)ethyl ester, phthalic acid , decyl oct-3-yl ester, 1,2- Benzenedicarboxylic acid , bis(8-methylnonyl)ester, phthalic acid, di(6-ethyl-3-octyl)ester, y-tocopherol, 1,4-ethanonaphthalene -6,9(4H)-dione,1,4a,5,8a-tetrahydro-4,5,7,10 and vitamin E. Methanolic extract of bioactive compounds of C. colocynthis was assayed for in vitro antibacterial activity against Proteus mirabilis, Escherichia coli, Pseudomonas aerogenosa, P. mirabilis, Staphylococcus aureus and Klebsiella pneumonia by using the diffusion method in agar. The zone of inhibition was compared with different standard antibiotics. The diameters of inhibition zones ranged from 4.91±0.260 to 1.03±0.200 mm for all treatments.

Key words: Gas chromatography-mass spectrometry, phytochemicals, Citrullus colocynthis.