Niels Svenstrup

Biological Characterization of Novel Inhibitors of the Gram-Positive DNA Polymerase IIIC Enzyme

ABSTRACT Novel N-3-alkylated 6-anilinouracils have been identified as potent and selective inhibitors of bacterial DNA polymerase IIIC, the enzyme essential for the replication of chromosomal DNA in gram-positive bacteria. A nonradioactive assay measuring the enzymatic activity of the DNA polymerase IIIC in gram-positive bacteria has been assembled. The 6-anilinouracils described inhibited the polymerase IIIC enzyme at concentrations in the nanomolar range in this assay and displayed good in vitro activity (according to their MICs) against staphylococci, streptococci, and enterococci. The MICs of the most potent derivatives were about 4 μg/ml for this panel of bacteria. The 50% effective dose of the best compound (6-[(3-ethyl-4-methylphenyl)amino]-3-{[1-(isoxazol-5-ylcarbonyl)piperidin-4-yl]methyl}uracil) was 10 mg/kg of body weight after intravenous application in a staphylococcal sepsis model in mice, from which in vivo pharmacokinetic data were also acquired.

Improved synthesis of antibacterial 3-substituted 6-anilinouracils.

3-Substituted 6-anilinouracils, presently the most promising class of inhibitors of the bacterial DNA polymerase in Gram-positive bacteria, have been prepared by a general and straightforward three-step procedure starting from a readily available 1-benzyloxymethyl-protected derivative of 6-chlorouracil.

Diversity-oriented synthesis of substituted pyrazolo〔4,3-d〕〔1,2,3〕triazin-4-ones

An efficient synthesis of 3,7-disubstituted 3,5-dihydro-4H-pyrazolo-[4,3-d][1,2,3]triazin-4-ones (2), especially suited for late-stage decoration, is described. Diverse 3-benzyl analogs were obtained by amidation-cyclization in one pot and various pyrazolotriazinone-7-bromides were employed in Suzuki and Sonogashira cross-coupling reactions.