Didier Jean-Claude Berthelot

Analogues of morphanthridine and the tear gas dibenz[b,f][1,4]oxazepine (CR) as extremely potent activators of the human transient receptor potential ankyrin 1 (TRPA1) channel.

The TRPA1 channel can be considered as a key biological sensor to irritant chemicals. In this paper, the discovery of 11H-dibenz[b,e]azepines (morphanthridines) and dibenz[b,f][1,4]oxazepines is described as extremely potent agonists of the TRPA1 receptor. This has led to the discovery that most of the known tear gases are potent TRPA1 activators. The synthesis and biological activity of a number of substituted morphanthridines and dibenz[b,f][1,4]oxazepines have given insight into the SAR around this class of TRPA1 agonists, with EC(50) values ranging from 1 μM to 0.1 nM. Compounds 6 and 32 can be considered as the most potent TRPA1 agonists known to date, with 6 now being used successfully as a screening tool in the discovery of TRPA1 antagonists. The use of ligands such as 6 and 32 as pharmacological tools may contribute to the basic knowledge of the TRPA1 channel and advance the development of TRPA1 antagonists as potential treatment for conditions involving TRPA1 activation, including asthma and pain.

Design and Synthesis of a Novel Series of Bicyclic Heterocycles As Potent γ-Secretase Modulators

The design and the synthesis of several chemical subclasses of imidazole containing γ-secretase modulators (GSMs) is described. Conformational restriction of pyridone 4 into bicyclic pyridone isosteres has led to compounds with high in vitro and in vivo potency. This has resulted in the identification of benzimidazole 44a as a GSM with low nanomolar potency in vitro. In mouse, rat, and dog, this compound displayed the typical γ-secretase modulatory profile by lowering Aβ42 and Aβ40 levels combined with an especially pronounced increase in Aβ38 and Aβ37 levels while leaving the total levels of amyloid peptides unchanged.

Tricyclic 3,4-dihydropyrimidine-2-thione derivatives as potent TRPA1 antagonists.

The transient receptor potential A1 (TRPA1) channel has been implicated in a number of inflammatory and nociceptive processes, and antagonists of the TRPA1 receptor could offer a potential treatment for conditions such as inflammatory or neuropathic pain, airway disorders, and itch. In a high throughput screen aimed at the identification of TRPA1 antagonists, 4-phenyl-2-thioxo-1,2,3,4-tetrahydro-indeno[1,2-d]pyrimidin-5-one (1) was identified as a potent TRPA1 receptor antagonist. A series of analogous tricyclic 3,4-dihydropyrimidine-2-thiones has been prepared via the multi-component Biginelli reaction and subsequent derivatization. This has led to TRPA1 antagonists with potencies around 10nM for both rat and human derived TRPA1 receptors. The activity was shown to reside exclusively in the 4R-enantiomers.

Ruthenium‐Catalyzed α‐(Hetero)Arylation of Saturated Cyclic Amines: Reaction Scope and Mechanism

Transition-metal-catalyzed sp(3) C-H activation has emerged as a powerful approach to functionalize saturated cyclic amines. Our group recently disclosed a direct catalytic arylation reaction of piperidines at the α position to the nitrogen atom. 1-(Pyridin-2-yl)piperidine could be smoothly α-arylated if treated with an arylboronic ester in the presence of a catalytic amount of [Ru3(CO)12] and one equivalent of 3-ethyl-3-pentanol. A systematic study on the substrate and reagent scope of this transformation is disclosed in this paper. The effect of substitution on both the piperidine ring and the arylboronic ester has been investigated. Smaller (pyrrolidine) and larger (azepane) saturated ring systems, as well as benzoannulated derivatives, were found to be compatible substrates with the α-arylation protocol. The successful use of a variety of heteroarylboronic esters as coupling partners further proved the power of this direct functionalization method. Mechanistic studies have allowed for a better understanding of the catalytic cycle of this remarkable transformation featuring an unprecedented direct transmetalation on a Ru(II)-H species.

Design and synthesis of bicyclic heterocycles as potent γ-secretase modulators.

The evolution of amide 3 into conformationally restricted bicyclic triazolo-piperidine 14-S as a γ-secretase modulator is described. This is a potential disease modifying anti-Alzheimers drug which demonstrated high in vitro and in vivo potency against Aβ42 peptide, reduced lipophilicity and enhanced brain free fraction compared to the previous series.

Anilinotriazoles as potent gamma secretase modulators.

The design and synthesis of a novel series of potent gamma secretase modulators is described. Exploration of various spacer groups between the triazole ring and the aromatic appendix in 2 has led to anilinotriazole 28, which combined high in vitro and in vivo potency with an acceptable drug-like profile.

Iron-Catalyzed Synthesis of Sulfur-Containing Heterocycles

An iron-catalyzed synthesis of sulfur- and sulfone-containing heterocycles is reported. The method is based on the cyclization of readily available substrates and proceeded with high efficiency and diastereoselectivity. A variety of sulfur-containing heterocycles bearing moieties suitable for subsequent functionalization are prepared. Illustrative examples of such postcyclization modifications are also presented.

Iron-Catalyzed Synthesis of C2 Aryl- and N-Heteroaryl-Substituted Tetrahydropyrans

An iron-catalyzed cyclization of hydroxy allylic derivatives into tetrahydropyrans possessing an N-heteroaryl at C2 is disclosed. The reaction proceeds with good yield and in high diastereoselectivity in favor of the more stable isomer. The diastereoselectivity results from an iron-induced reopening of the tetrahydropyrans, allowing a thermodynamic equilibration. The method allows access to a variety of 2,6-disubstituted as well as 2,4,6-trisubstituted tetrahydropyrans that could be considered as attractive scaffolds for the pharmaceutical industry.

Abstract 3229: Managing stress: Discovery of inhibitors of the atypical kinase eEF2K and the class III PI3K, VPS34

Adaptation to nutrient deprivation in the tumour microenvironment was recently shown to be dependent on the appropriate regulation of protein elongation rate through activation of the atypical kinase, eukaryotic elongation factor 2 kinase (eEF2K) (Leprivier et al., 2013, Cell 153(5):1064-79). We have solved the crystal structure of the kinase domain of eEF2K, and used structure-based design as well as screening approaches to optimize a chemical series into single-digit nM inhibitors of eEF2K, with remarkable selectivity across the protein kinome (only 5-10 kinases out of 400 tested are inhibited to more than 50% at 1 μM). These compounds inhibit the phosphorylation of eEF2 in nutrient-starved or metabolically stressed cells, and increase protein elongation rates through stabilization of the ribosomal elongation complex under stress. Evotec9s Cellular Target Profiling of these compounds in cell lysates, revealed that a subset of the eEF2K inhibitors also bind with low nM affinity to the class III phosphatidylinositol-3-kinase, VPS34, but not to class I or II PI3Ks, and pull down the entire beclin-UVRAG-VPS34 complex. Proteomic and biochemical screening of the compound set enabled deconvolution of potent EF2K versus VPS34 inhibitors. Inhibition of VPS34 results in abrogation of autophagic flux, as indicated by rapid and massive accumulation of p62, and impairs survival in specific subsets of tumor cell lines, consistent with a pro-survival role for autophagy in those models (Cheng et al., 2013, Pharmacol Rev 65(4):1162-97). Interestingly, a whole-genome pooled shRNA screen in a KRAS/PI3KCA mutant colorectal cancer cell line revealed that reduction of beclin levels significantly increased sensitivity to VPS34 inhibition. In contrast, inhibition of eEF2K does not appear to be anti-proliferative across a wide panel of cancer cell lines under standard cell culture conditions. Our work has provided the first potent inhibitors to unravel the functional relevance of eEF2K and VPS34 in adaptation to cellular stress, and to examine the utility of inhibiting these kinases in nutrient-deprived and/or autophagy-addicted tumours. Citation Format: Matthias Versele, Claire Moore, Christopher G. Proud, Cindy Rockx, Inez Van de Weyer, Kurt Van Baelen, Stephanie Blencke, Sebastian K. Wanndinger, Gaston Diels, Didier Berthelot, Marcel Viellevoye, Bruno Schoentjes, Berthold Wroblowski, Lieven Meerpoel, William N. Hait. Managing stress: Discovery of inhibitors of the atypical kinase eEF2K and the class III PI3K, VPS34. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3229. doi:10.1158/1538-7445.AM2014-3229