Inhibitors of the Elastase LasB for the treatment of Pseudomonas aeruginosa lung infections

Abstract

Infections caused by the Gram-negative pathogen Pseudomonas aeruginosa are emerging worldwide as a major threat to human health. Conventional antibiotic monotherapy suffers from rapid resistance development, underlining urgent need for novel treatment concepts. Here, we report on a non-traditional approach to combat P. aeruginosa-derived infections by targeting its main virulence factor, the elastase LasB. We discovered a new chemical class of phosphonates with an outstanding in vitro ADMET and PK profile, auspicious activity both in vitro and in vivo. We established the mode of action through a co-crystal structure of our lead compound with LasB and in several in vitro and ex vivo models. The proof of concept of a combination of our pathoblocker with levofloxacin in a murine neutropenic lung infection model and the reduction of LasB protein levels in blood as a proof of target engagement demonstrate the great potential for use as an adjunctive treatment of lung infections in humans.

Targeting Plasmodium falciparum IspD in the Methyl-D-Erythritol Phosphate Pathway: Urea-Based Compounds with Nanomolar Potency on target with low micromolar whole-cell activity

“…Ultimately, we chose 4-methyl-1-oxo-1-(p-tolylamino)pentane-2-sulfonic acid as our internal standard, as its elution time was in the range of that of CDP-ME and showed consisted results. 15 To demonstrate the potential of our new assay, we determined the Michaelis constant (Km) of both substrates and obtained similar results as previously published (Table 4). 10,12,16 To our knowledge, this is the only reported IspD assay that is not dependent on auxiliary enzymes.…”

“…HPLC purity: 99%. (15). According to GP-2, naphtalen-2-amine (0.1 g, 0.70 mmol), to afford after washing with MeOH (5x, 5mL), 15 as an off-white solid (0.02 g, 8% yield).…”

“…To another 96-well plate, 190 µL of ice cold 3:1:1 ACN, isopropanol, water mixture was added containing 100 nM 4-methyl-1-oxo-1-(p-tolylamino)pentane-2-sulfonic acid, adenylyl-imidodiphosphate and adenosine-5'-[(α,β)methyleno]triphosphate as internal standard. 15 Thereafter, 10 µL of each of the supernatants from the assay plate were added to the plate containing the mixture with our internal standard. The plate was centrifuged again at 4000 rpm at 4 °C for 5 min, after which, 50 µL of the supernatant was transferred to an LC-MS plate and closed with a silicon cover.…”