a new efficient method for the synthesis of carboacyclic nucleosides as biologically interesting compounds via aza-conjugate addition of pyrimidine nucleobases to a,β-unsaturated esters in the presence of catalytic amount of lioh.h2o (1.2-4.8 mol%) under microwave irradiation is described. this method affords the title compounds in good to excellent yields and in short reaction times.

The Treponema denticola ATCC 35405 genome annotation contains most of the genes for de novo pyrimidine biosynthesis. To initiate characterization of pyrimidine synthesis in Treponema, we focused on TDE2110 (the putative pyrF, encoding orotidine-50-monophosphate decarboxlyase). Unlike the parent strain, an isogenic pyrF mutant was resistant to 5-fluoroorotic acid. In complex medium, growth of th...

In the crystal structure of the title compound, [Mn(NCSe)(2)(C(4)H(4)N(2))(2)(H(2)O)(2)], the manganese(II) cation is coordinated by two N-bonded pyrimidine ligands, two N-bonded seleno-cyanate anions and two O-bonded water mol-ecules in a distorted octa-hedral coordination mode. The asymmetric unit consists of one manganese(II) cation, located on a centre of inversion, as well as one seleno-cy...

Nucleoside : purine (pyrimidine) deoxyribosyltransferase activity (EC 2.4.2.6.) has been demonstrated in bacteria by a number of investigators (l-5). Similar activity in mammalian tissues was reported by deVerdier and Potter (6). With the mammalian enzyme, however, the substrate specificity of the transfer reaction appeared to be restricted to pyrimidine bases and their deoxyribonucleosides. Tr...

Total electron-scattering cross sections of pyrimidine, the basic component for the nucleic bases cytosine and thymine, were measured for electron energies from 5 eV to 1 keV using the linear transmission method. The measured results were compared to semiempirical data obtained by means of the additivity rule and to experimental data for benzene since it has a similar ring structure and the sam...

Unstimulated human T lymphocytes are exquisitely sensitive to UVB irradiation. This hypersensitivity appears to relate to low deoxyribonucleotide pool sizes. They have also been reported to be defective in global excision of cyclobutane pyrimidine dimers, but such experiments may have been carried out at supralethal doses, where unrepaired excision breaks persist indefinitely. We use a T4 endon...

Direct glycosylation of the sodium salt of 4,6-dichloro- or 4,6-dibromo-2-methylthiopyrrolo[2,3-d]pyrimidine with 2,3,5-tri-O-benzoyl-D-ribofuranosyl bromide gave good yield of the corresponding N7-glycosylated pyrrolo [2,3-d]pyrimidine. The intermediate 4-amino-6-chloro-2-methylthio-7-beta-D-ribofuranosylpyrrolo[2,3-d] pyrimidine provided a new synthetic route to tubercidin, via 6-chlorotuberc...

The epidermal growth factor receptor (EGFR) sensitivity to tyrosine kinase inhibitors gefitinib and erlotinib-activated mutants is common in non-small cell lung cancer. An in-silico screening study of quinazolines pyridopyrimidines against the wild-type (WT) mutation EGFR was conducted, employing several computational approaches such as covalent docking molecular dynamics simulation followed by...

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 ...

Pyrimidine is a heterocyclic aromatic organic compound similar to benzene and pyridine, containing two nitrogen atoms at positions 1 3 of the six-member ring. Three nucleobases found in nucleic acids, cytosine (C), thymine (T), uracil (U), are pyrimidine derivatives. A has many properties common with as number ring increases pi electrons become less energetic electrophilic substitution gets mor...