The present study focuses on the determination of oil contents of thirteen different jatropha seed collections from Ethiopia. The oil was extracted with a Soxhlet extractor using n-hexane which was selected out of four different solvents: diethyl ether, ethanol, n-heptane, and n-hexane. Cotton and thimble were used as filter for the extractions. Some properties of the oil of Chali seed collection and a sample of mixed oils (a mixture of equal volume of oils from thirteen different seed collections) were determined. The energy contents of selected de-oiled jatropha seed residues were also estimated. In the extraction with cotton and thimble, the largest percentage of oil yield was obtained from Dana seed (48.29%) and Chali seed (45.79) collections, respectively. The acid value (1.32 mg KOH/g) and percentage of free fatty acids (%FFA) (0.66%) of Chali seed oil were lower than the acid value (2.12 mg KOH/g) and %FFA (1.06%) of the mixed oil, and thus, the former oil is more suitable for alkaline-catalyzed biodiesel production. The iodine values of both Chali seed oil (116.02 g/100 g) and mixed oil (109.24 g/100 g) did not exceed the maximum standard for biodiesel according to the European EN 14214 specification, and the oils could be used for biodiesel production. The gross calorific values of de-oiled jatropha seed residues after oil extraction were found to range from 18.57 to 24.03 MJ/kg, and with the average value of 19.64 MJ/kg. Thus, the de-oiled seed residues can be used as the source of heat.

No abstract

Background: Stereospermum kunthianum plant is known by local name Botoro, in Ethiopia and widely used by traditional medical practitioners for the treatment of venereal diseases, dysentery and to treat toothache in different regions of the country. Objective: The study was designed to evaluate in vitro antibacterial activity of the crude stem bark extracts of S.kunthianum based on the result obtained from phytochemical exploration test. Methods: The plant part was collected from Wayu Tuka district, and air dried. The powdered plant material was subjected to gradient extraction with solvent system using maceration technique and the constituent matter was concentrated, separated and collected for further investigation. Preliminary phytochemical screening test was made using the dried extract. Results: Qualitative phytochemical exploration results showed that, the presence of alkaloid, flavonoids, terpenoids, saponins, Phenolics and tannins. The crude extract of the respected solvent containing relatively many phytochemicals was subjected to in vitro antibacterial evaluation using disc diffusion method against clinically isolated bacterial strains. In this study a promising results were recorded at higher concentration (500 ppm) of methanol extract against gram positive bacteria S. progens and S. aurous with zone of inhibition of 23± 1.46 and 21 ± 0.71, respectively and against gram negative strain, E.coli with zone of inhibition of 20 ± 1.63 showing close comparable antibacterial result with the antibiotics used as standard. Conclusion: in vitro antibacterial result of this study depicts that, antibacterial effect of methanol stem bark extracts of S.kunthianum was positively associated due to the presence tannins and phenolic phytochemicals.