Now showing items 1-10 of 222
Propargylation of Alkyl Halides: (E)-6,10-dimethyl-5,9-undecadien-1-yne and (E)-7,11-dimethyl-6,10-dodecadien-2-yn-1-ol
El siguiente documento es parte de un experimento científico que se titula “Propargylation of Alkyl Halides: (E)-6,10-dimethyl-5,9-undecadien-1-yne and (E)-7,11-dimethyl-6,10-dodecadien-2-yn-1-ol”. El mismo fue realizado ...
Effect on cell growth, viability and migration of geraniol and geraniol-containing essential oil from Lippia alba (Verbenaceae) on gastric carcinoma cells
Natural products used to treat cancer, or as leads for the development of preventive and co-adjuvant treatment strategies, are still a current approach. We studied the effect of essential oils from the medicinal plant ...
Síntesis de la feromona sexual de la polilla de la papa, Scrobipalpopsis Solanivora
Se sintetizó el acetato (E) -3- dodecenilo, atrayente sexual de la polilla de la papa (Scrobipalpopsis solanivora), utilizando dos procedimientos: una ruta acetilénica y mediante la condensación de Knoevenagel.
Fate of buturon-14C in soil during seven seasons of exposure under outdoor conditions
Buturon (ring 14C) was applied to wheat and soil in two successive years (3 kg/ha each year) at outdoor conditions. Residual radioactive substances in the upper soil layer (0-10-cm depth) were measured 1.5, 2.5, 3.5, 6.0, ...
Polyphenolic HRMS Characterization, Contents and Antioxidant Activity of Curcuma longa rhizomes from Costa Rica
Curcuma longa constitutes an important source of secondary metabolites that have been associated with multiple health benefits. For instance, curcumin, demethoxycurcumin and bisdemethoxy-curcumin, have been found to perform ...
Seco-manool and other constituents from fleischmannia microstemon
The aerial parts of Fleischmannia microstemon afforded in addition to sesamin and two clerodanes, ent-manoyl oxide and two derivatives of the latter, one a 6β-acetoxy derivative and the other a seco-labdane. From F. pratensis ...
Room temperature gas-solid reaction of titanium on glass surfaces forming a very low resistivity layer
Titanium films were deposited on quartz, glass, polyamide and PET substrates in a high vacuum system at room temperature and their electrical resistance monitored in vacuo as a function of thickness. These measurements ...
Grids III: Hydrogen Bridges in Introductory Chemistry
Cuadrículas III: Puentes de Hidrógeno en Química General
Based on IUPAC recommendations for the definition of the hydrogen bond, a series of grids is presented to provide instructors of introductory chemistry courses with visual examples of H-bridged systems. The grids ...
Naphthalenones and Isocoumarins from a Costa Rican Fungus Xylariaceae sp. CR1546C
A new naphthalenone, (R)-4,6,8-trihydroxy-3,4-dihydro-1(2H)-naphthalenone and a new isocoumarin, 6,8-dihydroxy-(3R)-(2-oxopropyl)-3,4-dihydroisocoumarin, together with eight related known compounds were isolated from the ...
A facile method for the preparation of bishomopropargylic alcohols from acyl chlorides
Controlled dilithiation of propargyl bromide with two equivalents of n-butyllithium, in the presence of TMEDA, produces the operational equivalent of the dianion 1,3-dilithiopropyne. The latter reacts efficiently with ...