Phytochemical Investigation And Antibacterial Activities Of The Seeds Extracts And Oils Of Lepidium Sativum

Abstract

Since long time, the study of organic chemistry contribute to the development of science and better social life by discovering new and useful compounds from nature, especially from plant origin. Objective of the present study was to carry out the phytochemical investigation and antibacterial activities of the seeds extracts and oils of L. sativum obtained from the local area Kersu Kebele, Goma Wereda, Jimma zone.The study was conducted by extraction of the seeds with organic solvents such as n-hexane, dichloromethane, ethyl acetate and methanol. Based on the TLC analysis,the methanol extract was subjected to column chromatography and two compounds coded as LSM-9 and LSM-11were isolated and characterized using 13 C- NMR, 1HNMR, IR and UV-VIs spectroscopic data. In addition, the study performed on extraction of essential oil of the seed through hydrodistillation and investigation of phytochemical constituents of each solvent extract. The n-hexane extract (oil) and the essential oil of the seed extract were analyzed with GC-MS and 11 components were obtained from each types of oil.7,10,13hexadecatrienoic acid(64.42%) and Indol(63.78%) were the major components of n-hexane extracted and essential oil of the seeds respectively. Moreover both oils were held unsaturated fatty acid, saturated fatty acid and aromatic derivative compounds.The preliminary phytochemical test revealed the presence of phytoconstituents such as alkaloids, flavonoids, glycosides, phenols, saponins, anthraqunnes, and tannins. Antibacterial activities of the methanol crude extract, LSM-9 and the essential oil were implemented by disc diffusion method against one Gram positive bacterium Stphylococus aureus and three Gram negative bacteria: E.coli, Proteus mirabilis and Klibsiella pneumoniae. The inhibition zones of the samples were compared with standard drug ceftriaxone. The essential oil showed antibacterial activities on all the tested bacteria and LSM-9 inhibit the tested Gram negative bacteria. While the methanol crude extract did not show inhibition activities against the tested bacteria.