Treatment of the protected and unprotected nucleosides with 1,3-dibromo-5,5- dimethylhydantoin in aprotic solvents such as CH(2)Cl(2), CH(3)CN, or DMF effected smooth bromination of uridine and cytidine derivatives at C-5 of pyrimidine rings as well as adenosine and guanosine derivatives at C-8 of purine rings. Addition of Lewis acids such as trimethylsilyl trifluoromethanesulfonate enhanced ef...

A series of seventeen β-hydroxyphosphonate ribonucleoside analogues containing 4-substituted-1,2,3-triazoles was synthesized and fully characterized. Such compounds were designed as potential inhibitors of the cytosolic 5'-nucleotidase II (cN-II), an enzyme involved in the regulation of purine nucleotide pools. NMR and molecular modelling studies showed that a few derivatives adopted similar st...

The syntheses of novel hydrazono acyclic nucleosides similar to miconazole scaffolds are described. In this series of acyclic nucleosides, pyrimidine as well as purine and other azole derivatives replaced the imidazole function in miconazole and the ether group was replaced with a hydrazone moiety using phenylhydrazine. To interpret the dominant formation of (E)-hydrazone derivatives rather tha...

BACKGROUND Our previous studies in a group of arylpiperazine derivatives of 1,3-dimethyl-3,7-dihydro-purine-2,6-diones, aimed at chemical diversification of the purine-2,6-dione by introduction of hydrophobic substituent in a 7- or 8- position or elongation of the linker length between arylpiperazine and purine core, allowed a selection of potent 5-HT1A, 5-HT2A and 5-HT7 receptor ligands displa...

Trimethoprim is a specific inhibitor of dihydrofolate reductase. When added to amino acid supplemented cultures of Escherichia coli, protein, ribonucleic acid (RNA), and deoxyribonucleic acid synthesis are rapidly inhibited. It is shown that thymidylate and purine synthesis must continuously occur if the inhibition is to be maintained. These results are interpreted as demonstrating that in vivo...

The transcriptomes of vancomycin intermediate-resistance Staphylococcus aureus (VISA) clinical isolates HIP5827 and Mu50 (MIC = 8 micro g/ml) were compared to those of highly vancomycin-resistant S. aureus (VRSA; MIC = 32 micro g/ml) passage derivatives by microarray. There were 35 genes with increased transcription and 16 genes with decreased transcription in common between the two VRSAs compa...