نتایج جستجو برای: barbituric acid

تعداد نتایج: 747479  

Aboulghasem Hashemi Ali Khalafi Nezhad

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.

2012
Howard Massey Frederick

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...

Journal: :Thorax 1985
H Peach G A Ellard P J Jenner R W Morris

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 ...

Journal: :Physical chemistry chemical physics : PCCP 2016
M M Brister M Pollum C E Crespo-Hernández

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...

Journal: :Organic letters 2009
Hyeran Lee Mikhail Y Berezin Kevin Guo Jeff Kao Samuel Achilefu

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...

2010
Thomas Gelbrich Denise Rossi Ulrich J. Griesser

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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