RESUMEN
Introducción: Vernonanthura patens (Kunth) H. Rob. es una especie que crece silvestre en el Ecuador, para la cual existen escasos antecedentes de estudios químicos y biológicos, y en ninguno de estos se aborda el estudio de fracciones lipídicas. Objetivos: estudiar las fracciones de compuestos lipídicos presentes en las hojas, tallos y flores de la especie. Métodos: la planta se recolectó en estado adulto, en época de floración, los órganos vegetales fueron secados en estufa por separado, se molinaron hasta tamaño de partícula 2 mm y se extrajeron por maceración con etanol. Los extractos etanólicos concentrados se separaron por columna cromatográfica, las fracciones lipídicas separadas con hexano fueron saponificadas y analizadas por el sistema acoplado de cromatografía gaseosa-espectrometría de masas. Resultados: se identificaron los ácidos grasos y compuestos insaponificables presentes en los órganos estudiados, encontrándose algunas diferencias de composición entre estos. Conclusiones: se identificaron 29 ácidos grasos y 8 compuestos insaponificables presentes en los órganos vegetales estudiados.
Introduction: Vernonanthura patens (Kunth) H. Rob. is a species that grows wild in Ecuador. Few chemical and biological studies have been conducted on this species, and none of them deal with lipid fractions. Objectives: study the fractions of lipid compounds present in the leaves, stems and flowers of the species. Methods: the plant was collected in its adult stage, during the flowering season. Plant organs were oven dried separately, ground to 2 mm particle size, and extracted by maceration with ethanol. The concentrated ethanolic extracts were separated by column chromatography. Lipid fractions were separated with hexane, and then saponified and analyzed by coupled gas chromatography mass spectrometry. Results: identification of the fatty acids and unsaponifiable compounds present in the organs studied revealed some differences in their composition. Conclusions: 29 fatty acids and 8 unsaponifiable compounds were identified in the plant organs studied.
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There is a severe fluoride problem in Nawa tehsil of Nagaur district. Villagers are suffering from dental fluorosis and skeletal fluorosis. So an extensive geochemical study of 27 villages of eastern, south-eastern and southern zone of Nawa tehsil was done. Total 46 ground water samples were collected and analyzed for various physicochemical parameters as well as fluoride content. The ground water samples collected in clean polyethylene plastic containers were analyzed for pH, electrical conductivity, total dissolved salts, calcium, magnesium, total hardness, chloride and alkalinity. The fluoride concentration in the three different zones ranged from 0.64 to 14.62 mg l-1 where 13.04% samples were found within permissible limit while 86.96% had fluoride beyond permissible limit (> 1.5 mg l-1). It was found that among the three different zones south-eastern zone was under serious fluoride contamination where fluoride concentration ranged between 1.10 to 14.62 mg l-1. In the eastern zone fluoride concentration was recorded from 1.52 to 5.13 mg l-1 whereas in the southern zone it was found between 0.64 to 3.63 mg l-1.
RESUMEN
Surface-enhanced Raman spectra of membrane protein, located in native mem brane, bacteriorhodopsin, adsorbed by silver electrodes and hydrosols have been obtained for the first time. The distance between the retinal Schiff's base and the external side of purple membrane of Halobacteriim halobiim was shown to be 6–9 A. The possible distribition of the point charges aroind protonated retinal Schiff's base has been proposed on the basis of the resonance Raman data and quantim chemical CNDO/S-CI calculations. Such a model contains tyrosine residue located near the retinal Schiff's base and connected with COO– groip via hydrogen bond COO– group acts as a protonated Schiff’s base counterion. The distance between oxygen atoms of COO– group and retinal Schiff's base plane is 2·5-3·0A. The hydrogen bond (O-H. . .O–) length between oxygen atom of OHgroup and oxygen atom of COO_ group has been chosen 2·7±0·1Å Tyrosine hydroxyl group is located at 2·8-3·5 A from retinal Schiff's base plane· It was shown that in contrast to generally accepted Honig and Nakanishi model the spectral properties of Brh570, K610, L550 and Μ4Ϊ2 forms of bacteriorhodopsin photocycle as well as observed tyrosine deprotonation and COO– group protonation during M412 formation can be explained reasonably well by the suggested charge distribution· Furthermore, such a model of bacteriorhodopsin active site microenvironment allows to explain catalyzing of photoinduced protonated retinal Schiff's base deprotonation observed in our preliminary experiments.