We have found that the anaerobic protozoan parasite Giardia lamblia is incapable of de novo pyrimidine metabolism, as shown by its inability to incorporate orotate, bicarbonate, and aspartate into the pyrimidine nucleotide pool. Results from high performance liquid chromatography of pyrimidine and pyrimidine nucleoside pulse-labeled nucleotide pools and enzyme assays suggest that the parasite s...

In the title compound, C(6)H(10)N(3) (+)·C(7)H(3)N(2)O(6) (-)·2H(2)O, the amino-pyrimidine mol-ecule is protonated at one of the pyrimidine N atoms. The carboxyl-ate group of the 3,5-dinitro-benzoate anion inter-acts with the protonated pyrimidine N atom and the 2-amino group through a pair of N-H⋯O hydrogen bonds, forming an R(2) (2)(8) motif. Two inversion-related pyrimidine rings are linked ...

In the biogenesis of riboflavin by the yeast, Eremothecium ashbyii, carbon atoms constituting the pyrimidine ring of adenine were incorporated into the 6,7-dimethylisoalloxazine ring of riboflavin with much greater efficiency than was the 8 position of the purine ring (1). It remained to determine whether the carbon atoms which constitute the pyrimidine ring of the purine are incorporated direc...

Understanding prebiotic nucleotide synthesis is a long standing challenge thought to be essential to elucidating the origins of life on Earth. Recently, remarkable progress has been made, but to date all proposed syntheses account separately for the pyrimidine and purine ribonucleotides; no divergent synthesis from common precursors has been proposed. Moreover, the prebiotic syntheses of pyrimi...

In this article we present a model for molecularly imprinted polymers, which considers both complexation processes in the pre-polymerization mixture and adsorption in the imprinted structures within a single consistent framework. As a case study we investigate MAA/EGDMA polymers imprinted with pyrazine and pyrimidine. A polymer imprinted with pyrazine shows substantial selectivity towards pyraz...

Coumarin derivatives containing pyrazolo[1,5-a]pyrimidine, tetrazolo[1,5-a]pyrimidine, imidazo[1,2-a]pyrimidine, pyrazolo[3,4-d]pyrimidine, 1,3,4-thiadiazoles and thiazoles were synthesized from 6-bromo-3-(3-(dimethylamino)acryloyl)-2H-chromen-2-one, methyl 2-(1-(6-bromo-2-oxo-2H-chromen-3-yl)ethylidene)hydrazine carbodithioate, 2-(1-(6-bromo-2-oxo-2H-chromen-3-yl)ethylidene) hydrazine carbothi...

In the crystal structure of the title polymeric complex, [Ca(C(5)H(3)N(2)O(2))(2)](n), the Ca(II) cation has site symmetry m2 and is N,O-chelated by four pyrimidine-2-carboxyl-ate anions in a square-anti-prismatic geometry. The planar pyrimidine-2-carboxyl-ate anion is located on a crystallographic special position, three C atoms have site symmetry 2mm, while the carboxyl O atom, the pyrimidine...

The stabilization of the pyrimidine anion by the addition of water molecules is studied experimentally using photoelectron spectroscopy of mass-selected hydrated pyrimidine clusters and computationally using quantum-mechanical electronic structure theory. Although the pyrimidine molecular anion is not observed experimentally, the addition of a single water molecule is sufficient to impart a pos...

Gold(I) Thiolates, (Benzylthiolato)gold(I) Complexes, Gold(I) Mercaptocarboxylates, Polynu­ clear Gold(I) Complexes In a search for air-stable and water-soluble mercapto compounds of gold with a high gold content, benzylthiol, a-mercapto-acetic acid, /3-mercapto-propionic acid, and thiosalicylic acid were converted into aurated sulfonium salts by treatment with reagents of the type [(R^PjAufiO*...

Background: Brucellosis is one of the important zoonotic diseases with variety of symptoms and signs. Using of cost effective, easy and safe diagnostic methods in screening of brucellosis is an important priority. Several studies have been carried out to recognize appropriate diagnostic methods and each have reported different results. Aim: The aim of this study was to investigate the sensitivi...