ABSTRACT
We describe here our attempts to optimise the human fatty acid amide hydrolase (FAAH) inhibition and physicochemical properties of our previously reported tetrasubstituted azetidine urea FAAH inhibitor, VER-156084. We describe the SAR of a series of analogues and conclude with the demonstration of in vivo dose-dependant FAAH inhibition in an anandamide-loading study in rats.
Subject(s)
Amidohydrolases/antagonists & inhibitors , Azetidines/pharmacology , Enzyme Inhibitors/pharmacology , Urea/pharmacology , Amidohydrolases/metabolism , Animals , Azetidines/chemical synthesis , Azetidines/chemistry , Cytochrome P-450 Enzyme Inhibitors , Cytochrome P-450 Enzyme System/metabolism , Dose-Response Relationship, Drug , ERG1 Potassium Channel , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Ether-A-Go-Go Potassium Channels/antagonists & inhibitors , Humans , Models, Molecular , Molecular Structure , Rats , Stereoisomerism , Structure-Activity Relationship , Urea/chemical synthesis , Urea/chemistryABSTRACT
Inhibitors of the Hsp90 molecular chaperone are showing considerable promise as potential molecular therapeutic agents for the treatment of cancer. Here we describe novel 2-aminothieno[2,3-d]pyrimidine ATP competitive Hsp90 inhibitors, which were designed by combining structural elements of distinct low affinity hits generated from fragment-based and in silico screening exercises in concert with structural information from X-ray protein crystallography. Examples from this series have high affinity (IC50 = 50-100 nM) for Hsp90 as measured in a fluorescence polarization (FP) competitive binding assay and are active in human cancer cell lines where they inhibit cell proliferation and exhibit a characteristic profile of depletion of oncogenic proteins and concomitant elevation of Hsp72. Several examples (34a, 34d and 34i) caused tumor growth regression at well tolerated doses when administered orally in a human BT474 human breast cancer xenograft model.
Subject(s)
Antineoplastic Agents/chemical synthesis , HSP90 Heat-Shock Proteins/antagonists & inhibitors , Pyrimidines/chemical synthesis , Administration, Oral , Animals , Antineoplastic Agents/pharmacology , Binding, Competitive , Crystallography, X-Ray , Female , Fluorescence Polarization , Humans , Male , Mice , Mice, Inbred BALB C , Pyrimidines/pharmacology , Xenograft Model Antitumor AssaysABSTRACT
We report the discovery of a novel, chiral azetidine urea inhibitor of Fatty Acid Amide Hydrolase (FAAH,) and describe the surprising species selectivity of VER-156084 versus rat and human FAAH and also hCB1.
Subject(s)
Amidohydrolases/antagonists & inhibitors , Amidohydrolases/chemistry , Azetidines/chemistry , Azetidines/chemical synthesis , Enzyme Inhibitors/chemical synthesis , Piperidines/chemical synthesis , Urea/chemistry , Animals , Azetidines/pharmacology , Catalysis , Chemistry, Pharmaceutical/methods , Drug Design , Enzyme Inhibitors/pharmacology , Humans , Mice , Mice, Knockout , Models, Chemical , Piperidines/pharmacology , Rats , Receptor, Cannabinoid, CB1/chemistry , StereoisomerismABSTRACT
A flexible, practical, and stereoselective synthesis of enantiomerically pure trans-5-oxohexahydropyrrolo[3,2-b]pyrroles (pyrrolidine-trans-lactams) is described. The key reaction involves addition of Z-ketene acetal 24 to the acyliminium ion derived from 48. This reaction is mediated by BF3·OEt2 and introduces the 6S and 6aS stereocenters stereoselectively. The acyliminium precursor was prepared in four different ways: from racemic 2,4-diaminobutyric acid 8, from (R)-asparagine, from (R)-methionine, and via a crystallization-induced dynamic resolution of a salt of the racemic amine 56. (R)-Methionine is the preferred starting material for the preparation of enantiomerically pure material. The best conditions for addition of the ketene acetal to the acyliminium ion derived from 48 were determined by systematically screening a range of ketene acetals and Lewis acids. The best ketene acetal was Z-(1-ethoxy-3-methylbut-1-enyloxyl)triisopropylsilane 24. In this series, the bulk of the silyl group of the Z-ketene acetal can be correlated with increased 6S isopropyl product. Use of the E-ketene acetal does not lead to a significant change in stereoselectivity for the 6R isopropyl product. In contrast, variation of the Lewis acid has a considerable effect on the product stereochemistry. While BF3·OEt2 gives predominantly 6S,6aS product, AlCl3 and TiCl4 give predominantly mixtures of the 6R,6aS and 6S,6aS products and TMSOTf gives 6aR material with predominantly one unknown isopropyl isomer (trans-lactam numberings used). The synthesis can conveniently be carried out on a large scale to produce multigram quantities of the trans-lactam 28, which is a key precursor of pharmacologically active molecules such as 1, a selective and orally active human neutrophil elastase inhibitor. The overall chemical yield of 1 is 1.3%, corresponding to an average of >70% yield for each of the 14 steps, and the synthesis contains only one chromatographic purification.
