1029431-47-7Relevant academic research and scientific papers
Tetrafluorophenoxymethyl ketone cruzain inhibitors with improved pharmacokinetic properties as therapeutic leads for Chagas' disease
Neitz, R. Jeffrey,Bryant, Clifford,Chen, Steven,Gut, Jiri,Hugo Caselli, Estefania,Ponce, Servando,Chowdhury, Somenath,Xu, Haichao,Arkin, Michelle R.,Ellman, Jonathan A.,Renslo, Adam R.
, p. 4834 - 4837 (2015)
Inhibition of the cysteine protease cruzain from Trypanosoma cruzi has been studied pre-clinically as a new chemotherapeutic approach to treat Chagas' disease. Efficacious effects of vinylsulfone-based cruzain inhibitors in animal models support this therapeutic hypothesis. More recently, substrate-activity screening was used to identify nonpeptidic tetrafluorophenoxymethyl ketone inhibitors of cruzain that showed promising efficacy in animal models. Herein we report efforts to further optimize the in vitro potency and in vivo pharmacokinetic properties of this new class of cruzain inhibitors. Through modifications of the P1, P2 and/or P3 positions, new analogs have been identified with reduced lipophilicity, enhanced potency, and improved oral exposure and bioavailability.
Nonpeptidic tetrafluorophenoxymethyl ketone cruzain inhibitors as promising new leads for chagas disease chemotherapy
Brak, Katrien,Kerr, Iain D.,Barrett, Kimberly T.,Fuchi, Nobuhiro,Debnath, Moumita,Ang, Kenny,Engel, Juan C.,McKerrow, James H.,Doyle, Patricia S.,Brinen, Linda S.,Ellman, Jonathan A.
scheme or table, p. 1763 - 1773 (2010/08/20)
A century after discovering that the Trypanosoma cruzi parasite is the etiological agent of Chagas disease, treatment is still plagued by limited efficacy, toxicity, and the emergence of drug resistance. The development of inhibitors of the major T. cruzi cysteine protease, cruzain, has been demonstrated to be a promising drug discovery avenue for this neglected disease. Here we establish that a nonpeptidic tetrafluorophenoxymethyl ketone cruzain inhibitor substantially ameliorates symptoms of acute Chagas disease in a mouse model with no apparent, toxicity. A high-resolution crystal structure confirmed the mode of inhibition and revealed key binding interactions of this novel inhibitor class. Subsequent structure-guided optimization then resulted in inhibitor analogues with improvements in potency despite minimal or no additions in molecular weight. Evaluation of the analogues in cell culture showed enhanced activity. These results suggest that nonpeptidic tetrafluorophenoxymethyl, ketone cruzain inhibitors have the potential to fulfill the urgent need for improved Chagas disease chemotherapy.
NONPEPTIDIC INHIBITORS OF CRUZAIN
-
Page/Page column 59-60; 68; 28; 31, (2009/07/17)
Cruzain is the major cysteine protease of T. cruzi, which is the causative agent of Chagas' disease and is a promising target for the development of new chemotherapy. With the goal of developing potent nonpeptidic inhibitors of cruzain, the Substrate Activity Screening (SAS) method was used to screen a library of protease substrates initially designed to target the homologous human protease cathepsin S. Structure-based design was next used to further improve substrate cleavage efficiency by introducing additional binding interactions in the S3 pocket of cruzain. The optimized substrates were then converted to inhibitors by the introduction of cysteine protease mechanism-based pharmacophores. Inhibitor (38) was determined to be reversible even though it incorporated the vinyl sulfone pharmacophore that is well documented to give irreversible cruzain inhibition for peptidic inhibitors. The previously unexplored β-chloro vinyl sulfone pharmacophore provided mechanistic insight that led to the development of potent irreversible acyl- and aryl- oxymethyl ketone cruzain inhibitors. For these inhibitors, potency did not solely depend on leaving group pTa, with 2,3,5,6-tetrafluorophenoxy methyl ketone (54) identified as one of the most potent inhibitors with a second order inactivation constant of 147,000 s-1M-1. This inhibitor completely eradicated the T. cruzi parasite from mammalian cell cultures and consequently has the potential to lead to new chemo therapeutics for Chagas' disease.
Identification of a new class of nonpeptidic inhibitors of cruzain
Brak, Katrien,Doyle, Patricia S.,McKerrow, James H.,Ellman, Jonathan A.
, p. 6404 - 6410 (2008/12/22)
Cruzain is the major cysteine protease of Trypanosoma cruzi, which is the causative agent of Chagas disease and is a promising target for the development of new chemotherapy. With the goal of developing potent nonpeptidic inhibitors of cruzain, the substrate activity screening (SAS) method was used to screen a library of protease substrates initially designed to target the homologous human protease cathepsin S. Structure-based design was next used to further improve substrate cleavage efficiency by introducing additional binding interactions in the S3 pocket of cruzain. The optimized substrates were then converted to inhibitors by the introduction of cysteine protease mechanism-based pharmacophores. Inhibitor 38 was determined to be reversible even though it incorporated the vinyl sulfone pharmacophore that is well documented to give irreversible cruzain inhibition for peptidic inhibitors. The previously unexplored β-chloro vinyl sulfone pharmacophore provided mechanistic insight that led to the development of potent irreversible acyl- and aryl-oxymethyl ketone cruzain inhibitors. For these inhibitors, potency did not solely depend on leaving group pKa, with 2,3,5,6- tetrafluorophenoxymethyl ketone 54 identified as one of the most potent inhibitors with a second-order inactivation constant of 147,000 s-1 M-1. This inhibitor completely eradicated the T. cruzi parasite from mammalian cell cultures and consequently has the potential to lead to new chemotherapeutics for Chagas disease.
