Stéphane De Lombaert

Non-peptidic inhibitors of neutral endopeptidase 24.11 1. Discovery and optimization of potency

Abstract Although based on a single α-amino acid residue, N -phosphonomethyl-(S)-(4-phenyl)phenylalanine ( 2 ) was discovered to produce strong inhibition of the zinc metalloprotease, neutral endopeptidase (NEP 24.11). Structural optimization of this new lead culminated with the design of the phosphonic acid tetrazole 17 (CGS 26303), a non-peptidic and extremely potent NEP inhibitor.

Structure-Based Optimization of Arylamides as Inhibitors of Soluble Epoxide Hydrolase

Inhibition of soluble epoxide hydrolase (sEH) is hypothesized to lead to an increase in circulating levels of epoxyeicosatrienoic acids, resulting in the potentiation of their in vivo pharmacological properties. As part of an effort to identify inhibitors of sEH with high and sustained plasma exposure, we recently performed a high throughput screen of our compound collection. The screen identified N-(3,3-diphenyl-propyl)-nicotinamide as a potent inhibitor of sEH. Further profiling of this lead revealed short metabolic half-lives in microsomes and rapid clearance in the rat. Consistent with these observations, the determination of the in vitro metabolic profile of N-(3,3-diphenyl-propyl)-nicotinamide in rat liver microsomes revealed extensive oxidative metabolism and a propensity for metabolite switching. Lead optimization, guided by the analysis of the solid-state costructure of N-(3,3-diphenyl-propyl)-nicotinamide bound to human sEH, led to the identification of a class of potent and selective inhibitors. An inhibitor from this class displayed an attractive in vitro metabolic profile and high and sustained plasma exposure in the rat after oral administration.

Potent non-peptidic dual inhibitors of endothelin-converting enzyme and neutral endopeptidase 24.11 ☆

Abstract Structural modifications of CGS 26303, a non-peptidic α-aminophosphonate dual ECE/NEP inhibitor lead, were performed to maximize inhibition of recombinant human ECE-1, while maintaining strong NEP inhibition. Specifically, substitution of the α-aminophosphonate moiety with aryl ethyl side-chains led to the discovery of a new class of potent, non-peptidic, dual inhibitors, such as CGS 31447, which blocked ECE-1 and NEP activities with IC50s of 17 and 5 nM, respectively.

Practical syntheses of a novel tricyclic dipeptide mimetic based on a [6H]-azepino indoline nucleus: Application to angiotensin-converting enzyme inhibition

Two stereocontrolled synthetic approaches towards 5-(S)-amino-1,2,4,5,6,7-hexahydro-azepino [3,2,1-hi] indole-4-one-2- (S)-carboxylic acid 1, based on intramolecular Friedel-Crafts acylations, are reported. This conformationally restricted tricyclic dipeptidomimetic has been applied to the design of a potent and orally active inhibitor of angiotensin-converting enzyme (ACE).

3-Aryl pyrazolo[4,3-d]pyrimidine derivatives: nonpeptide CRF-1 antagonists

The synthesis of a series of 3-aryl pyrazolo[4,3-d]pyrimidines as potential corticotropin-releasing factor (CRF-1) antagonists is described. The effects of substitution on the aromatic ring, the amino group and the pyrazolo ring on CRF-1 receptor binding were investigated.

Synthesis, SAR, and series evolution of novel oxadiazole-containing 5-lipoxygenase activating protein inhibitors: discovery of 2-[4-(3-{(r)-1-[4-(2-amino-pyrimidin-5-yl)-phenyl]-1-cyclopropyl-ethyl}-[1,2,4]oxadiazol-5-yl)-pyrazol-1-yl]-N,N-dimethyl-acetamide (BI 665915).

The synthesis, structure-activity relationship (SAR), and evolution of a novel series of oxadiazole-containing 5-lipoxygenase-activating protein (FLAP) inhibitors are described. The use of structure-guided drug design techniques provided compounds that demonstrated excellent FLAP binding potency (IC50 < 10 nM) and potent inhibition of LTB4 synthesis in human whole blood (IC50 < 100 nM). Optimization of binding and functional potencies, as well as physicochemical properties resulted in the identification of compound 69 (BI 665915) that demonstrated an excellent cross-species drug metabolism and pharmacokinetics (DMPK) profile and was predicted to have low human clearance. In addition, 69 was predicted to have a low risk for potential drug-drug interactions due to its cytochrome P450 3A4 profile. In a murine ex vivo whole blood study, 69 demonstrated a linear dose-exposure relationship and a dose-dependent inhibition of LTB4 production.

Discovery of novel 6,6-heterocycles as transient receptor potential vanilloid (TRPV1) antagonists.

The transient receptor potential cation channel, subfamily V, member 1 (TRPV1) is a nonselective cation channel that can be activated by a wide range of noxious stimuli, including capsaicin, acid, and heat. Blockade of TRPV1 activation by selective antagonists is under investigation in an attempt to identify novel agents for pain treatment. The design and synthesis of a series of novel TRPV1 antagonists with a variety of different 6,6-heterocyclic cores is described, and an extensive evaluation of the pharmacological and pharmacokinetic properties of a number of these compounds is reported. For example, the 1,8-naphthyridine 52 was characterized as an orally bioavailable and brain penetrant TRPV1 antagonist. In vivo, 52 fully reversed carrageenan-induced thermal hyperalgesia (CITH) in rats and dose-dependently potently reduced complete Freunds adjuvant (CFA) induced chronic inflammatory pain after oral administration.

The design, synthesis and structure–activity relationships of 1-aryl-4-aminoalkylisoquinolines: A novel series of CRF-1 receptor antagonists

The design, synthesis and structure-activity relationships of a novel series of CRF-1 receptor antagonist, the 1-aryl-4-alkylaminoisoquinolines, is described. The effects of substitution on the aromatic ring, the amino group and the isoquinoline core on CRF-1 receptor binding were investigated.

2-Aryl-3,6-dialkyl-5-dialkylaminopyrimidin-4-ones as novel crf-1 receptor antagonists

The discovery, synthesis and structure-activity studies of a novel series of 2-arylpyrimidin-4-ones as CRF-1 receptor antagonists is described. These compounds are structurally simple and display appropriate physical properties for CNS agents

Design and synthesis of a potent and selective endothelin-converting enzyme inhibitor, CGS 35066.

CGS 26303 has previously been shown to inhibit human endothelin converting enzyme-1 (ECE-1) with an IC50 of 410 nM and to be efficacious in several animal disease models. However, it is a more potent inhibitor of neutral endopeptidase 24.11 (NEP) with an IC50 of 1 nM. The aim of this study was to optimize CGS 26303 for greater potency and selectivity towards ECE-1 inhibition. The in vivo activity of the compounds was assessed by inhibition of the big endothelin-1 (ET-1)-induced pressor response in anesthetized rats at 90 min after treatment with a dose of 10 mg/kg, i.v. Under these conditions, CGS 26303 inhibited the pressor response to big ET-1 by 50%. Replacement of the biphenyl and tetrazol groups in CGS 26303 with a dibenzofuran and carboxylic acid, respectively, yielded CGS 35066, a potent ECE-1 inhibitor having an IC50 of 22 nM. In contrast, these substitutions markedly weakened the NEP inhibitory activity of the compound to an IC50 of 2.3 microM. CGS 35066 also exhibited a potent and sustained ECE-1 inhibitory activity in vivo, blocking the pressor response to big ET-1 by 84%. Its orally active prodrug, CGS 35339, was obtained by introducing two phenyl groups at the phosphonic acid substituent in CGS 35066. Therefore, CGS 35066 and CGS 35339 represent novel compounds for assessing the pathogenic role of ET-1 overproduction in various disease states.