Essential Oil Chemical Characterization and Antibacterial Activities of Lepidium sativum Seed

Lepidium sativum plants are available abundantly in all part of Ethiopia and traditionally used for the treatment of various ailments. The work done on essential oil chemical characterization and biological activity of this plant are still insufficient reports in Ethiopia. Therefore the aim of the present study was to carry out essential oil chemical characterization 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 n-hexane, dichloromethane, ethyl acetate and methanol. 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, 13-hexadecatrienoic 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 alkaloids, flavonoids, glycosides, phenols, saponins, anthraqunnes, and tannins. Antibacterial activities of 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.

Suitability of a lignin-derived mono-phenol mimic to replace phenol in phenol-formaldehyde resin for use in wood treatment

The goal of this study was to assess the suitability of a single mono-aromatic for substitution of petroleum-based phenol for phenol-formaldehyde (PF) resin synthesis and the usage of a new resin for wood treatment. After proper thermal decomposition of wood-based lignin, pyrolysis oil can be obtained. Due to the heterogeneity of the lignin macromolecule, oil contains large variety of organic-based compounds, mainly mono-aromatics, which are proposed to be used for replacement of phenol during PF resin synthesis. Therefore, for this purpose, nine of the most abundant mono-aromatic compounds in bio-oil were selected: ortho-, meta-, para-cresol, guaiacol, catechol, 4-methylcatechol, resorcinol, syringol, 4-ethylphenol and resol-type resin from each mono-aromatic were synthesized. Relevant features of the resin such as pH, viscosity, average molecular weight and curing behavior of resins using differential scanning calorimetry (DSC) were analyzed. Scots pine (Pinus sylvestris L.) sapwood samples were used to evaluate the suitability of resin for wood treatment in terms of dimensional stability and were compared with the PF resin-treated wood. From all tested resins, those made of guaiacol or ortho-, or meta-, or para-cresol and/or 4-ethylphenol proved to be suitable for wood treatment, whereas resins made of catechol or 4-methylguaiacol and syringol did not. Suitability of mono-aromatics for synthesis of resol-type resin depends on chemical structure, where the reactivity of the mono-aromatic (derivative of hydroxybenzene) is defined by the type, location and number of substituents.

Synthesis, Characterization and Epoxidation ofcis-Enriched New Polycarbonates Catalyzed by Efficient Organotin Compound

Presence of active functional groups on polymer chain is a suitable aspect of polymer structure which allows performing next favourite reactions on polymer molecule. In this research a novel aromatic derivative ofcis-but-2-endiol was synthesized as monomer. The synthesized monomer was polymerized using diphenyl carbonate and 1,4-butandiol as second and third monomer along with organotin catalyst. Polymerization reaction performed by using melt-phase transesterification process to produce a new terpolymer of polycarbonate. During the reaction the double bonds are preserved on polymer chain and epoxidized bym-chloroperbenzoic acid (MCBPA) in good yield to demonstrate the reactivity and possibility of performing further reactions on double bonds of polymer.