michael addition of pyrimidine and purine nucleobases to substituted as well as unsubstituted α,β-unsaturated esters efficiently proceeds in the presence of catalytic amount of zinc oxide in ionic liquid 1-butyl-3-methylimidazolium bromide (zno/[bmim]br) under microwave irradiation to afford carboacyclic nucleosides, as biologically important compounds, in good to excellent yields and in short ...

A metal-mediated base pair that discriminates between the canonical pyrimidine nucleobases S1 A metal-mediated base pair that discriminates between the canonical pyrimidine nucleobases

in the present study, we investigate the potentiometric behavior of cu2+ carbon paste electrodes based on two mercapto compounds 2-ethylmino-5-mercapto-1,3,4-thiadiazole (eamt) and 2-acetylamino-5-mercapto-1,3,4-thiadiazole (aamt) self-assembled on gold nano-paricle (gnp) as ionophore. then, the results obtained from the modified electrodes are compared. the self-assembled ionophores exhibit a ...

Platinum nanoparticles (PtNPs), with diameters of 3-10 nm, were synthesized by water phase reduction, using 3-mercapto-1-propanesulfonate (3MPS) as a hydrophilic capping agent. PtNPs were deposited by a dipcoating technique on titania nanofibers (TiO2NFs), obtained by electrospinning. The investigated properties of the Pt-TiO2 hybrid at room temperature show that this material combines the prop...

The mechanism of inhibition of gastric peroxidase (GPO) activity by mercaptomethylimidazole (MMI), an inducer of gastric acid secretion, has been investigated. Incubation of purified GPO with MMI in the presence of H2O2 results in irreversible inactivation of the enzyme. No significant inactivation occurs in the absence of H2O2 or MMI, suggesting the involvement of peroxidase-catalysed oxidized...

We report the synthesis of three gold(i) complexes [Au(H(2)-mmta)(2)]Cl·(3)H(2)O (1), Na(3)[Au(mmta)(2)]·6H(2)O (2) and Na(3)[Au(mmta)(2)]·10.5H(2)O (3) (H(2)-mmta = 2-mercapto-4-methyl-5-thiazoleacetic acid) in which the Au(i) centre is incorporated either in cationic or anionic units of the [Au(SR)(2)](+/-) type depending on the protonation state of the ligand. All structures were characteriz...

Abstract Background Cancer is a global health challenge, it impacts the quality of life and its treatment associated with several side effects. Resistance cancer cells to existing drugs has led search for novel anticancer agents. Pyrimidine, privileged scaffold, part living organisms plays vital role in various biological procedures as well pathogenesis. Due resemblance structure nucleotide bas...

Transcription of the carAB operon encoding the unique carbamoylphosphate synthase of Escherichia coli reflects the dual function of carbamoylphosphate in the biosynthesis of arginine and pyrimidine nucleotides. The tandem pair of promoters is regulated by various mechanisms depending on the needs of both pathways and the maintenance of a pyrimidine/purine nucleotide balance. Here we focus on th...

The title compound, C(15)H(13)ClN(6), contains two pyrimidine rings and one benzene ring, where the dihedral angle between the planes through the pyrimidine rings is 81.57 (10)°, and those between the pyrimidine rings and the benzene ring are 84.02 (8) and 89.46 (7)°, indicating that the three rings are almost perpendicular. In the crystal, inter-molecular N-H⋯N hydrogen bonds link the mol-ecul...

African trypanosomes are capable of both pyrimidine biosynthesis and salvage of preformed pyrimidines from the host. However, uptake of pyrimidines in bloodstream form trypanosomes has not been investigated, making it difficult to judge the relative importance of salvage and synthesis or to design a pyrimidine-based chemotherapy. Detailed characterization of pyrimidine transport activities in b...