The increasing prevalence of drug-resistant bacterial infections is driving the discovery and development not only of new antibiotics, but also of inhibitors of virulence factors that are crucial for in vivo pathogenicity. One such virulence factor is the type III secretion system (T3SS), which plays a critical role in the establishment and dissemination of Pseudomonas aeruginosa infections. We have recently described the discovery and characterization of a series of inhibitors of P. aeruginosa T3SS based on a phenoxyacetamide scaffold. To better characterize the factors involved in potent T3SS inhibition, we have conducted a systematic exploration of this structure, revealing several highly responsive structure-activity relationships indicative of interaction with a specific target. Most of the structural features contributing to potency were additive, and combination of those features produced optimized inhibitors with IC50 values <1 µM.

[reaction: see text] The asymmetric synthesis of the methylated tryptophan portion of hemiasterlin peptides is described. The key reactions are a SnCl4-mediated ring opening of epoxynitriles or epoxysulfones by N-methylindole followed by an asymmetric Strecker reaction. A second approach involving opening of glycidic esters by indoles is also described.

There is an unmet medical need for the development of non-addicting pain therapeutics with enhanced efficacy and tolerability. The current study examined the effects of AQU-118, an orally active inhibitor of metalloproteinase-2 (MMP-2) and MMP-9, in the spinal nerve ligation (SNL) rat model of neuropathic pain. Mechanical allodynia and the levels of various biomarkers were examined within the dorsal root ganglion (DRG) before and after oral dosing with AQU-118. The rats that received the SNL surgery exhibited significant mechanical allodynia as compared to sham controls. Animals received either vehicle, positive control (gabapentin), or AQU-118. After SNL surgery, the dorsal root ganglion (DRG) of those rats dosed with vehicle had elevated messenger RNA (mRNA) expression levels for MMP-2, IL1-β & IL-6 and elevated protein levels for caspase-3 while exhibiting decreased protein levels for myelin basic protein (MBP) & active IL-β as compared to sham controls. Rats orally dosed with AQU-118 exhibited significantly reduced mechanical allodynia and decreased levels of caspase-3 in the DRG as compared to vehicle controls. Results demonstrate that oral dosing with the dual active, MMP-2/-9 inhibitor, AQU-118, attenuated mechanical allodynia while at the same time significantly reduced the levels of caspase-3 in the DRG.

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