Phytochemical investigation of saponifiable matter & volatile oils and antibacterial activity of Moluccella laevis L., family Lamiaceae (Labiatae)

Abstract The current study was aimed to evaluate some parts of Moluccella laevis viz., phytochemical and antibacterial. Regarding to GC/MS of the saponifiable matters of petroleum ether fraction of total ethanolic extract of the aerial parts (TEE), the main recognized unsaturated fatty acids were methyl linolenate (25.58%) and methyl linoleate (15.87%). Whereas, the major saturated fatty acids were, palmitic (25.4%) followed by stearic acid (10.48). A comparative analysis of the volatile constituents of M. laevis flowers and leaves was performed by Head Space GC/MS. The volatile mixtures of both plant parts displayed comparable amounts of hydrocarbons and oxygenated compounds, with a noticeable greater contribution of the latter in the leaves.Besides, a-pinene (40.84%), chrysanthenyl acetate (17.89%) and isobornyl acetate (10.64%), were identified as the major volatile components in the flowers. While, isobornyl acetate (35.09%) was characterized as the major constituent followed by, 2-methyl-4-butanolide (22.12%), 1-heptene oxide (7.47%) and benzoic acid, methyl ester (4.05%) of the volatile oil composition of the leaves. Moreover, this study included the antibacterial activity of TEE and its different fractions against Gram positive and negative bacteria. TEE exhibited MIC values of 326 476, and 541 µg/mL against E. coli, K. pneumonia and P. aeruginosa, respectively, while the aqueous fraction showed MICs of 410, 633, 748 and 10713 µg/mL against P. aeruginosa, K. pneumonia, E. coli and S. aureus, respectively. Finally, the EtOAc fraction displayed MICs 449, 541 and 1085 µg/mL against K. pneumonia, E. coli and P. aeruginosa, respectively.