Discovery and initial development of a novel class of antibacterials: inhibitors of Staphylococcus aureus transcription/translation.

The novel bacterial transcription/translation (TT) inhibitor 1 was identified through a combination of high throughput screening and exploratory medicinal chemistry. Initial optimization of the anthranilic acid moiety and sulfonamide amine diversity was accomplished via 1- and two-dimensional solution phase libraries, resulting in an improvement in the MIC of the lead from 64 to 8mug/mL (compound 4l). Subsequent modification of the central aromatic ring and further refinement of the sulfonamide amines required the development of a solid phase route on Wang resin. The resulting libraries generated a number of potent antibacterials with MICs of 1mug/mL (e.g., 10b, 12, and 13). During the course of this work, it became apparent that the antibacterial activity of the series is not fully correlated with TT inhibition, suggesting that at least one additional mechanism of action is operative.

Design, synthesis, structure-activity relationship, and in vivo activity of azabicyclic aryl amides as alpha7 nicotinic acetylcholine receptor agonists.

A novel set of azabicyclic aryl amides have been identified as potent and selective agonists of the alpha7 nAChR. A two-pronged approach was taken to improve the potential hERG liability of previously disclosed alpha7 nAChR agonist, PNU-282,987, while maintaining the compound's other desirable pharmacological properties. The first approach involved further exploration of the aryl carboxylic acid fragment of PNU-282,987, while the second approach focused on modification of the azabicyclic amine portion of PNU-282,987. The best compounds from each series are characterized by rapid brain penetration, good oral bioavailability in rat, and demonstrate in vivo efficacy in a rat P50 auditory sensory gating assay. At least one analog from each series (1h, 1o, 2a, 9a, and 18a) shows an improved hERG safety profile over PNU-282,987.