Novel tricyclics (e.g., GSK945237) as potent inhibitors of bacterial type IIA topoisomerases.

During the course of our research on the lead optimisation of the NBTI (Novel Bacterial Type II Topoisomerase Inhibitors) class of antibacterials, we discovered a series of tricyclic compounds that showed good Gram-positive and Gram-negative potency. Herein we will discuss the various subunits that were investigated in this series and report advanced studies on compound 1 (GSK945237) which demonstrates good PK and in vivo efficacy properties.

Novel hydroxyl tricyclics (e.g., GSK966587) as potent inhibitors of bacterial type IIA topoisomerases.

During the course of our research to find novel mode of action antibacterials, we discovered a series of hydroxyl tricyclic compounds that showed good potency against Gram-positive and Gram-negative pathogens. These compounds inhibit bacterial type IIA topoisomerases. Herein we will discuss structure-activity relationships in this series and report advanced studies on compound 1 (GSK966587) which demonstrates good PK and in vivo efficacy properties.

Novel amino-piperidines as potent antibacterials targeting bacterial type IIA topoisomerases.

We have identified a series of amino-piperidine antibacterials with a good broad spectrum potency. We report the investigation of various subunits in this series and advanced studies on compound 8. Compound 8 possesses good pharmacokinetics, broad spectrum antibacterial activity and demonstrates oral efficacy in a rat lung infection model.

Novel cyclohexyl-amides as potent antibacterials targeting bacterial type IIA topoisomerases.

As part of our wider efforts to exploit novel mode of action antibacterials, we have discovered a series of cyclohexyl-amide compounds that has good Gram positive and Gram negative potency. The mechanism of action is via inhibition of bacterial topoisomerases II and IV. We have investigated various subunits in this series and report advanced studies on compound 7 which demonstrates good PK and in vivo efficacy properties.

Characterization of peptidyl boronic acid inhibitors of mammalian 20 S and 26 S proteasomes and their inhibition of proteasomes in cultured cells.

Proteasomes are large multisubunit proteinases which have several distinct catalytic sites. In this study a series of di- and tri-peptidyl boronic acids have been tested on the chymotrypsin-like activity of purified mammalian 20 S and 26 S proteasomes assayed with succinyl-Leu-Leu-Val-Tyr-amidomethylcoumarin (suc-Leu-Leu-Val-Tyr-AMC) as substrate. The inhibition of 20 S proteasomes is competitive but only slowly reversible.