4 research outputs found
Chemical constitutents and cytotoxicity of some Tanzanian wild mushrooms
The sterol ergosterol and ergosta-4,22-diene-3β,7α-diol, together with 4-hydroxybenzaldehyde were isolated from the mushroom species Polyporus molluscensis, Cantharellus isabelinus, C. symoensii and a Podaxis species. Their structures were established on the basis of spectroscopic data. The ethanol extracts of mushroom samples of Agaricus sp. and Termitomyces letestui also showed cytotoxicity against the brine shrimp larvae. Tanzania Journal of Science Vol. 31 (2) 2005: pp. 1-
Synthesis of some cis-4,4-dimethyl-2-isopropenylcyclopentane derivatives as potential intermediates towards the protoilludane skeleton
The three gem-dimethyl-substituted cyclopentane derivatives 1-(2-propionyl)-4,4-dimethyl-2-isopropenylcyclopentane, 2-isopropenyl-4,4-dimethylcyclopentanecarboxyaldehyde and 1-hydroxy- methyl-2-isopropenyl-4,4-dimethylcyclopentane have been synthesized employing a thermally induced ene reaction as a key step. Each of the three compounds has been obtained predominantly as the cis isomer. The successful synthesis of these compounds affords opportunities for their further ellaboration towards sesquiterpenes of the protoilludane skeleton.
Tanz. J. Sci. Vol.29(2) 2003: 89-9
Antibacterial activities of constituents from Isolona cauliflora and Cleistochlamys kirkii
Antibacterial activities of caulindole D, a mixture of caulindole E and F, pinocembrin and an oxyheptanoid (cleistenolide), obtained from stem barks of Isolona cauliflora and Cleistochlamys kirkii, on Staphylococcus aureus and Pseudomonas phaseolicola were determined. An in vitro assay test by paper disc method showed that the caulindole D, E and F from Isolona cauliflora produced no inhibition zone on both bacteria pathogens at 100-200 ppm while cleistochlamic acid from C. kirkii showed weak to moderate inhibition zone at 100-200 ppm. At concentration above 200 ppm, the bacteria pathogens were inhibited by all the compounds isolated from the plant extracts. Furthermore, there was an influence of bioassay method on the sensitivity of extracts on both test bacteria.
Tanz. J. Sci. Vol.29(2) 2003: 19-2