Segni Ladjel

Chemical composition and antibacterial activity of the essential oils from Launaea resedifolia L

Background Several species of the genus Launaea are used in folk medicine such as in bitter stomachic, skin diseases, and reported to have antitumor, insecticide, and cytotoxic activities. The antimicrobial activities of coumarin constituents and the neuropharmacological properties have been investigated as well. In this study, the chemical composition of essential oils from Launaea resedifolia L. has been identified using the ordinary GC-MS technique to reveal the presence of 19 compounds dominated by dioctyl phthalate. Moreover, the antibacterial activity of the crude oil has been carried out using disk diffusion method against seven bacteria strains. Results Nineteen compounds of essential oil of L. resedifolia L. were identified, representing 86.68% of the total oil. The compounds were identified by spectral comparison to be mainly esters, alcohols, ketones, and terpenes. The principal constituents are dioctyl phthalate (39.84%), Decanoic acid, decyl ester (12.09%), 11-Octadecenal (11.24%), and Eucalyptol (07.31%), while others were present in relatively small amounts. As far as antibacterial essays are concerned, it was found that the oils are active against most of the tested bacterial strains. Conclusion A major constituent in visible parts was Dioctyl phthalate (39.84%) and the yield of essential oils was 0.9%. These extracts reveal in vitro antibacterial activity on the studied bacterial, confirmed by the inhibition zone diameter ranging from 11 to 37 mm and a MIC value between 0.09 and 0.69 depending on the microorganism being tested.

The Valorization of the Green Alga Spirogyra’s Biomass in the Region of Ouargla-Algeria into Renewable Biofuel

The research focus on renewable energy has become a necessity due to the ecological and environmental effects, and biofuels are one of the most effective substrate for existing fossil fuels. Indeed, the algae are presented as a potential source of biofuel with their several important advantages; they have a great deal of attention as a renewable alternative source of biomass for bioethanol production. One of the algae which has the potential to be developed as a raw material for bioethanol is Spirogyra alga. It has been demonstrated that Spirogyra species can accumulate high levels of polysaccharides and starch in their complex cell walls, which allows using it as a source of bioethanol production.

Biodiesel Production by Transesterification of Recycled Vegetable Oils

Biofuels constitute an effective alternative to existing fossil fuels, for they offer the prospect of ecological sustainability with their various advantages. Biodiesel has become one of the most important biofuels on a worldwide level; and it is synthesized by oil transesterification.

Effet du séchage sur le rendement des huiles essentielles de la plante Teucrium polium ssp. aurasianum Labiatae

In the context of the exploitation of medicinal plants Algerian renowned for their therapeutic virtues, we are interested in the study of the plant Teucrium polium ssp. aurasianum Labiatae. The present work is devoted to the study of the effect of the drying of aerial parts on the yield of extraction, we have proceeded to the extraction of the essential oils of the plant by the technique for hydrodistillation. The plant is put to dry in the laboratory at ambient temperature for 8 day periods. The optimum yield is obtained at the 2 th day of drying which gives an extraction efficiency of 0.585 %