نتایج جستجو برای: barbituric acid
تعداد نتایج: 747479 فیلتر نتایج به سال:
Efficient Knoevenagel condensation of barbituric acid with different aromatic aldehydes on basic alumina was performed in a conventional microwave over in the absence of solvent.
Several nitrogen-containing dietary supplements were fed to chicks to study their effects on growth and tissue nitrogen products. An antibiotic mixture was added to the diet to determine its effect on the metabolism of nitrogenous compounds. In the first experiment, 2.0% protein equivalent was added as diammonium citrate (DAC) or isolated soy protein (ISP) to a balanced practical diet. DAC lowe...
Three novel colorimetric methods of detecting urinary nicotine metabolites called the barbituric acid, diethylthiobarbituric acid (DETB), and DETB extraction methods were evaluated for use as a simple, cheap, objective test of smoking. Urine samples were collected from 103 male smokers and 78 male non-smokers working at two London factories. The smokers recorded the number of cigarettes smoked ...
RNA is a product of chemical and biological evolution and the identification of its heterocyclic ancestors is essential for understanding the molecular origins of life. Among a diverse array of selection pressures thought to have shaped the composition of the nucleobases on prebiotic Earth, protection against intense ultraviolet radiation must have been essential. In this contribution, a detail...
Novel near-infrared pyrimidine-fused pH fluorescent probes were prepared by an unusual barbiturate-mediated debenzoindolation and subsequent heteroannulation. A plausible mechanistic pathway is proposed, and the final structures were further elucidated by 2D-NMR. All new compounds are highly fluorescent in the near-infrared region and possess excellent spectral sensitivities to environmental pH...
The asymmetric unit of the title compound,, C(4)H(4)N(2)O(5)·0.5C(4)H(8)O(2), contains one molecule of 5,5-dihydroxybarbituric acid with a nearly planar barbiturate ring and half a molecule of 1,4-dioxane. The geometry of the centrosymmetric dioxane molecule is close to an ideal chair conformation. The crystal structure exhibits a complex three-dimensional hydrogen-bonded network. Barbiturate m...
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