Scott B. Seibel

Cyclic homopentapeptides. 1. Analogs of tuberactinomycins and capreomycin with activity against vancomycin-resistant enterococci and Pasteurella

Abstract A 6a-(3′,4′-dichlorophenylamino) analog of viomycin was uncovered by a high-throughput screen against the animal health pathogen Pasteurella haemolytica, and has served as a novel lead structure for our infectious disease programs. We report herein the synthesis and activity of analogs of tuberactinomycins and capreomycin that are active against Pasteurella spp., methicillin-resistant Staphylococcus aureus, and vancomycin-resistant enterococci. This paper describes the synthesis and activity of some C-6a-substituted analogs of tuberactinomycins and capreomycin, which are active against Pasteurella spp., methicillin-resistant Staphylococcus aureus, and vancomycin-resistant enterococci.

Comparative structure–activity relationship studies of 1-(5-methylsulfonylpyrid-2-yl)-5-alkyl and (hetero)aryl triazoles and pyrazoles in canine COX inhibition

Structure-activity relationship (SAR) studies of novel 5-alkyl and 5-aryl/heteroaryl substituted 1,2,4-triazoles are described. The in vitro activity is compared to the pyrazole class of compounds with analogous side chains to delineate the contribution of the triazole ring nitrogen in binding to the active site. Both series are quite potent and selective in the canine whole blood (CWB) COX-2 assay, suggesting the increased binding contribution of the hydrophobic side chains.

Cyclic homopentapeptides 2. Synthetic modifications of viomycin

Abstract This paper describes synthetic modifications of the C-19 position of tuberactinomycin B (viomycin) and related analogs. The in vitro antibacterial activity of selected analogs against Pasteurella multocida, Escherichia coli and methicillin-resistant Staphylococcus aureus is also discussed. Although C-19 arylation and thiolation did not improve antibacterial activity, C-19 benzyl carbamates, benzyl- and phenyl ureas were found to be more potent than the parent antibiotic.