Sandra Kay Sigmund

Bicyclic pyrazolidinones, a new class of antibacterial agent based on the β-lactam model

Abstract Several bicyclic pyrazolidinones were synthesized as γ-lactam analogs of the β-lactam antibiotics. Two of these compounds exhibited in vitro antibacterial activity, and thus constitute a new class of antibacterial agents.

Synthesis and structure-activity relationships of benzophenones as inhibitors of cathepsin D

Abstract Non peptide inhibitors of cathepsin D, an aspartyl protease that has been implicated in many disease states including Alzheimers disease, were prepared and evaluated. The most potent inhibitor of cathepsin D in this series was found to be (Z)-5-[[4-(4-benzoyl-3-hydroxy-2-propylphenoxy) methylphenyl]methylene]-2-thioxo-4-thiazolidinone ( 3f , IC 50 = 210 nM).

Bicyclic pyrazolidinones, steric and electronic effects on antibacterial activity

Abstract Bicyclic pyrazolidinones were synthesized as γ-lactam analogs of the β-lactam antibiotics. Several of these compounds exhibited broad spectrum in vitro antibacterial activity.

1,3-Dipolar cycloaddition reactions of pyrazolidinium ylides with vinyl sulfones. A regioselective synthesis of bicyclic pyrazolidinone antibacterial agents

Abstract The 1, 3-dipolar cycloaddition reaction of pyrazolidinium ylide 1 with substituted vinyl sulfones 5 was studied. Elimination of benzenesulfinic acid from the resulting cycloadducts gave rise to bicyclic pyrazolidinones 3 . The (E)-olefin isomers were found to undergo cycloaddition in a highly regioselective fashion. These pyrazolidinones 3 represent the nuclei of an exciting new class of potent antibacterial agents that mimic β-lactams.