Design and Synthesis of the First Generation of Novel Potent, Selective, and in Vivo Active (Benzothiazol-2-yl)acetonitrile Inhibitors of the c-Jun N-Terminal Kinase (original) (raw)

Synthesis and SAR of novel isoxazoles as potent c-jun N-terminal kinase (JNK) inhibitors

Bioorganic & Medicinal Chemistry Letters, 2014

The design and synthesis of isoxazole 3 is described, a potent JNK inhibitor with two fold selectivity over p38. Optimization of this scaffold led to compounds 27 and 28 which showed greatly improved selectivity over p38 by maintaining the JNK3 potency of compound 3. Extensive SAR studies will be described as well as preliminary in vivo data of the two lead compounds.

Identification and Characterization of a Novel Class of c-Jun N-terminal Kinase Inhibitors

Molecular Pharmacology, 2012

In efforts to identify novel small molecules with anti-inflammatory properties, we discovered a unique series of tetracyclic indenoquinoxaline derivatives that inhibited lipopolysaccharide (LPS)-induced NF-κB/AP-1 activation. Compound IQ-1 (11H-indeno[1,2b]quinoxalin-11-one oxime) was found to be a potent, non-cytotoxic inhibitor of proinflammatory cytokine [interleukin (IL)-1α, IL-1β, IL-6, IL-10, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and granulocyte-macrophage colony-stimulating factor (GM-CSF)] and nitric oxide production by human and murine monocyte/macrophages. Three additional potent inhibitors of cytokine production were identified through further screening of IQ-1 analogs. The sodium salt of IQ-1 inhibited LPS-induced TNF-α and IL-6 production in MonoMac-6 cells with IC 50 values of 0.25 and 0.61 μ M, respectively. Screening of 131 protein kinases revealed that derivative IQ-3 (11H-indeno[1,2-b]quinoxalin-11-one-O-(2-furoyl)oxime) was a specific inhibitor of the c-Jun N-terminal kinase (JNK) family, with preference for JNK3. This compound, as well as IQ-1 and three additional oxime indenoquinoxalines, were found to be high-affinity JNK inhibitors with nanomolar binding affinity and ability to inhibit c-Jun phosphorylation. Furthermore, docking studies showed that hydrogen bonding interactions of the active indenoquinoxalines with Asn152, Gln155, and Met149 of JNK3 played an important role in enzyme binding activity. Finally, we showed that the sodium salt of IQ-1 had favorable pharmacokinetics and inhibited the ovalbumin-induced CD4 + T-cell immune response in a murine delayed-type hypersensitivity (DTH) model in vivo. We conclude that compounds with an indenoquinoxaline nucleus can serve as specific small-molecule modulators for mechanistic studies of JNKs, as well as a potential leads for the development of anti-inflammatory drugs.

Novel c-Jun N-Terminal Kinase (JNK) Inhibitors with an 11H-Indeno[1,2-b]quinoxalin-11-one Scaffold

Molecules

c-Jun N-terminal kinase (JNK) plays a central role in stress signaling pathways implicated in important pathological processes, including rheumatoid arthritis and ischemia-reperfusion injury. Therefore, inhibition of JNK is of interest for molecular targeted therapy to treat various diseases. We synthesized 13 derivatives of our reported JNK inhibitor 11H-indeno[1,2-b]quinoxalin-11-one oxime and evaluated their binding to the three JNK isoforms and their biological effects. Eight compounds exhibited submicromolar binding affinity for at least one JNK isoform. Most of these compounds also inhibited lipopolysaccharide (LPS)-induced nuclear factor-κB/activating protein 1 (NF-κB/AP-1) activation and interleukin-6 (IL-6) production in human monocytic THP1-Blue cells and human MonoMac-6 cells, respectively. Selected compounds (4f and 4m) also inhibited LPS-induced c-Jun phosphorylation in MonoMac-6 cells, directly confirming JNK inhibition. We conclude that indenoquinoxaline-based oximes ...

Design, synthesis and biological evaluation of novel O-substituted tryptanthrin oxime derivatives as c-Jun N-terminal kinase inhibitors

Frontiers in Pharmacology

The c-Jun N-terminal kinase (JNK) family includes three proteins (JNK1-3) that regulate many physiological processes, including inflammatory responses, morphogenesis, cell proliferation, differentiation, survival, and cell death. Therefore, JNK represents an attractive target for therapeutic intervention. Herein, a panel of novel tryptanthrin oxime analogs were synthesized and evaluated for JNK1-3 binding (Kd) and inhibition of cellular inflammatory responses (IC50). Several compounds exhibited submicromolar JNK binding affinity, with the most potent inhibitor being 6-(acetoxyimino)indolo[2,1-b]quinazolin-12(6H)-one (1j), which demonstrated high JNK1-3 binding affinity (Kd = 340, 490, and 180 nM for JNK1, JNK2, and JNK3, respectively) and inhibited lipopolysaccharide (LPS)-induced nuclear factor-κB/activating protein 1 (NF-κB/AP-1) transcription activity in THP-1Blue cells and interleukin-6 (IL-6) production in MonoMac-6 monocytic cells (IC50 = 0.8 and 1.7 μM, respectively). Compoun...

Novel Tryptanthrin Derivatives with Selectivity as c–Jun N–Terminal Kinase (JNK) 3 Inhibitors

Molecules

The c-Jun N-terminal kinase (JNK) family includes three proteins (JNK1-3) that regulate many physiological processes, including cell proliferation and differentiation, cell survival, and inflammation. Because of emerging data suggesting that JNK3 may play an important role in neurodegenerative diseases, such as Alzheimer’s disease (AD) and Parkinson’s disease, as well as cancer pathogenesis, we sought to identify JNK inhibitors with increased selectivity for JNK3. A panel of 26 novel tryptanthrin-6-oxime analogs was synthesized and evaluated for JNK1-3 binding (Kd) and inhibition of cellular inflammatory responses. Compounds 4d (8-methoxyindolo[2,1-b]quinazolin-6,12-dione oxime) and 4e (8-phenylindolo[2,1-b]quinazolin-6,12-dione oxime) had high selectivity for JNK3 versus JNK1 and JNK2 and inhibited lipopolysaccharide (LPS)-induced nuclear factor-κB/activating protein 1 (NF-κB/AP-1) transcriptional activity in THP-1Blue cells and interleukin-6 (IL-6) production by MonoMac-6 monocyti...

Synthesis, Biological Evaluation, X-ray Structure, and Pharmacokinetics of Aminopyrimidine c-jun-N-terminal Kinase (JNK) Inhibitors

Journal of Medicinal Chemistry, 2010

Given the significant body of data supporting an essential role for c-jun-N-terminal kinase (JNK) in neurodegenerative disorders, we set out to develop highly selective JNK inhibitors, with good cell potency, and good brain penetration properties. The structure activity relationships (SAR) around a series of aminopyrimidines was evaluated utilizing biochemical and cell-based assays to measure JNK inhibition, and brain penetration in mice. Microsomal stability in three species, P450 inhibition, inhibition of generation of reactive oxygen species (ROS), and pharmacokinetics in rats were also measured. Compounds 9g, 9i, 9j, and 9l had greater than 135-fold selectivity over p38, and cellbased IC 50 values < 100 nM. Moreover, compound 9l showed an IC 50 = 0.8 nM for inhibition of ROS and had good pharmacokinetic properties in rat, along with a brain-to-plasma ratio of 0.75. These results suggest that biaryl substituted aminopyrimidines represented by compound 9l may serve as the first small molecule inhibitors to test efficacy of JNK inhibitors in neurodegenerative disorders.

1-Aryl-3,4-dihydroisoquinoline inhibitors of JNK3

Bioorganic & Medicinal Chemistry Letters, 2009

A series of 1-aryl-3,4-dihydroisoquinoline inhibitors of JNK3 are described. Compounds 20 and 24 are the most potent inhibitors (pIC50 7.3 and 6.9, respectively in a radiometric filter binding assay), with 10-and 1000-fold selectivity over JNK2 and JNK1, respectively, and selectivity within the wider mitogen-activated protein kinase (MAPK) family against p38a and ERK2. X-ray crystallography of 16 reveals a highly unusual binding mode where an H-bond acceptor interaction with the hinge region is made by a chloro substituent.

The neuroprotective action of JNK3 inhibitors based on the 6, 7-dihydro-5H-pyrrolo [1, 2-a] imidazole scaffold

Bioorganic & medicinal …, 2005

Imidazole-based structures of p38 inhibitors served as a starting point for the design of JNK3 inhibitors. Construction of a 6,7-dihydro-5H-pyrrolo[1,2-a]imidazole scaffold led to the synthesis of the (S)-enantiomers, which exhibited p38/JNK3 IC 50 ratio of up to 10 and were up to 20 times more potent inhibitors of JNK3 than the relevant (R)-enantiomers. The JNK3 inhibitory potency correlated well with inhibition of c-Jun phosphorylation and neuroprotective properties of the compounds in low K + -induced cell death of rat cerebellar granule neurones.