RESUMO
Fatty acid synthase (E.C. 2.3.1.85; FASN) is a multifunctional enzyme system that catalyzes the formation of fatty acids from acetyl-CoA, malonyl-CoA, and NADPH and plays a central role in lipid biosynthesis. Two classes of FASN exist: FASN I in animals and fungi, and FASN II in plants and prokaryotes. Animal FASN I is a homodimeric protein found in the cytosol of lipogenic tissues such as the liver and brain. Many human carcinomas exhibit elevated levels of FASN I, though the benefit to cancer cells is still unclear. Inhibition of FASN I selectively effects apoptosis in cancer cells, and the role of FASN I in chemotherapy is a growing area of research with the use of natural products and small molecule inhibitors.
Assuntos
Antineoplásicos/farmacologia , Ácido Graxo Sintase Tipo I/antagonistas & inibidores , Inibidores da Síntese de Ácidos Graxos/farmacologia , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Ácido Graxo Sintase Tipo I/metabolismo , Inibidores da Síntese de Ácidos Graxos/química , Humanos , Neoplasias/patologiaRESUMO
Interleukin receptor-associated kinase 4 (IRAK4) is a critical element of the Toll-like/interleukin-1 receptor inflammation signaling pathway. A screening campaign identified a novel diaminopyrimidine hit that exhibits weak IRAK4 inhibitory activity and a ligand efficiency of 0.25. Hit-to-lead activities were conducted through independent SAR studies of each of the four pyrimidine substituents. Optimal activity was observed upon removal of the pyrimidine C-4 chloro substituent. The intact C-6 carboribose is required for IRAK4 inhibition. Numerous heteroaryls were tolerated at the C-5 position, with azabenzothiazoles conferring the best activities. Aminoheteroaryls were preferred at the C-2 position. These studies led to the discovery of inhibitors 35, 36, and 38 that exhibit nanomolar inhibition of IRAK4, improved ligand efficiencies, and modest kinase selectivities.
Assuntos
Descoberta de Drogas , Quinases Associadas a Receptores de Interleucina-1/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/farmacologia , Relação Dose-Resposta a Droga , Humanos , Quinases Associadas a Receptores de Interleucina-1/metabolismo , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Pirimidinas/síntese química , Pirimidinas/química , Relação Estrutura-AtividadeRESUMO
IRAK4 plays a key role in TLR/IL-1 signaling. Previous efforts identified a series of aminopyrimidine IRAK4 inhibitors that possess good potency, but modest kinase selectivity. Exploration of substituents at the C-2 and C-5 positions generated compounds that maintained IRAK4 potency and improved kinase selectivity. Additionally, it was found that the pyrimidine core could be replaced with a pyridine and still retain potency and kinase selectivity. The optimization efforts led to compound 26 which had an IRAK4 IC50 of 0.7 nM, an IC50 of 55 nM on THP-1 cells stimulated with LPS, a TLR4 agonist, and greater than 100-fold selectivity versus 96% of a panel of 306 kinases.
Assuntos
Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Quinases Associadas a Receptores de Interleucina-1/antagonistas & inibidores , Pirimidinas/síntese química , Pirimidinas/farmacologia , Anti-Inflamatórios não Esteroides/síntese química , Anti-Inflamatórios não Esteroides/farmacologia , Linhagem Celular , Ensaios de Triagem em Larga Escala , Humanos , Lipopolissacarídeos/farmacologia , Relação Estrutura-Atividade , Especificidade por Substrato , Receptor 4 Toll-Like/antagonistas & inibidoresRESUMO
Allosteric HIV-1 integrase (IN) inhibitors, or ALLINIs, are a new class of antiviral agents that bind at the dimer interface of the IN, away from the enzymatic catalytic site and block viral replication by triggering an aberrant multimerization of the viral enzyme. To further our understanding of the important binding features of multi-substituted quinoline-based ALLINIs, we have examined the IN multimerization and antiviral properties of substitution patterns at the 6 or 8 position. We found that the binding properties of these ALLINIs are negatively impacted by the presence of bulky substitutions at these positions. In addition, we have observed that the addition of bromine at either the 6 (6-bromo) or 8 (8-bromo) position conferred better antiviral properties. Finally, we found a significant loss of potency with the 6-bromo when tested with the ALLINI-resistant IN A128T mutant virus, while the 8-bromo analog retained full effectiveness.
Assuntos
Inibidores de Integrase de HIV , Integrase de HIV , HIV-1 , Quinolinas , Regulação Alostérica , Antivirais/farmacologia , Integrase de HIV/metabolismo , Inibidores de Integrase de HIV/química , Inibidores de Integrase de HIV/farmacologia , HIV-1/metabolismo , Quinolinas/farmacologia , Replicação ViralRESUMO
3-Aryl-1-phosphinoimidazo[1,5-a]pyridine ligands were synthesized from 2-aminomethylpyridine as the initial substrate via two complementary routes. The first synthetic pathway underwent the coupling of 2-aminomethylpyridine with substituted benzoyl chlorides, followed by cyclization, iodination and palladium-catalyzed cross-coupling phosphination reactions sequence to give our phosphorus ligands. In the second route, 2-aminomethylpyridine was cyclized with aryl aldehydes, followed by the iodination and palladium-catalyzed cross-coupling phosphination reactions to yield our phosphorus ligands. The 3-aryl-1-phosphinoimidazo[1,5-a]pyridine ligands were evaluated in palladium-catalyzed sterically-hindered biaryl and heterobiaryl Suzuki-Miyaura cross-coupling reactions.
RESUMO
The original structure of a high-throughput screening hit obtained from an external vendor was revised based on multiple NMR studies. The active compound was re-synthesized via a novel route and its structure and biological activity as a BRS-3 agonist were unambiguously confirmed. Multi-gram quantities of the hit were prepared for pharmacokinetic and efficacy studies. The synthetic strategy allowed for the preparation of multiple analogs for SAR exploration.
Assuntos
Fármacos Antiobesidade/síntese química , Naftiridinas/síntese química , Pirazóis/síntese química , Receptores da Bombesina/agonistas , Animais , Fármacos Antiobesidade/química , Fármacos Antiobesidade/farmacocinética , Ensaios de Triagem em Larga Escala , Humanos , Naftiridinas/química , Naftiridinas/farmacocinética , Pirazóis/química , Pirazóis/farmacocinética , Ratos , Receptores da Bombesina/metabolismo , Relação Estrutura-AtividadeRESUMO
SAR around non-peptidic potent bombesin receptor subtype-3 (BRS-3) agonist lead 2 is presented. Attempts to replace the carboxylic acid with heterocyclic isosteres to improve oral bioavailability and brain penetration are described.
Assuntos
Fármacos Antiobesidade/síntese química , Imidazóis/química , Receptores da Bombesina/agonistas , Administração Oral , Animais , Fármacos Antiobesidade/química , Fármacos Antiobesidade/uso terapêutico , Encéfalo/metabolismo , Humanos , Imidazóis/síntese química , Imidazóis/uso terapêutico , Camundongos , Obesidade/tratamento farmacológico , Ratos , Receptores da Bombesina/metabolismo , Relação Estrutura-AtividadeRESUMO
This Letter describes a series of potent and selective BRS-3 agonists containing a biarylethylimidazole pharmacophore. Extensive SAR studies were carried out with different aryl substitutions. This work led to the identification of a compound 2-{2-[4-(pyridin-2-yl)phenyl]ethyl}-5-(2,2-dimethylbutyl)-1H-imidazole 9 with excellent binding affinity (IC(50)=18 nM, hBRS-3) and functional agonist activity (EC(50)=47 nM, 99% activation). After oral administration, compound 9 had sufficient exposure in diet induced obese mice to demonstrate efficacy in lowering food intake and body weight via BRS-3 activation.
Assuntos
Imidazóis/química , Imidazóis/uso terapêutico , Obesidade/tratamento farmacológico , Receptores da Bombesina/agonistas , Receptores da Bombesina/metabolismo , Animais , Peso Corporal/efeitos dos fármacos , Ingestão de Alimentos/efeitos dos fármacos , Humanos , Imidazóis/farmacocinética , Camundongos , Ratos , Relação Estrutura-AtividadeRESUMO
We report SAR studies on a novel non-peptidic bombesin receptor subtype-3 (BRS-3) agonist lead series derived from high-throughput screening hit RY-337. This effort led to the discovery of compound 22e with significantly improved potency at both rodent and human BRS-3.
Assuntos
Descoberta de Drogas , Imidazóis/química , Imidazóis/farmacologia , Receptores da Bombesina/agonistas , Animais , Disponibilidade Biológica , Humanos , Imidazóis/farmacocinética , Ratos , Relação Estrutura-AtividadeRESUMO
3-Aryl-2-phosphinoimidazo[1,2-a]pyridine ligands were synthesized from 2-aminopyridine via two complementary routes. The first synthetic route involves the copper-catalyzed iodine-mediated cyclizations of 2-aminopyridine with arylacetylenes followed by palladium-catalyzed cross-coupling reactions with phosphines. The second synthetic route requires the preparation of 2,3-diiodoimidazo[1,2-a]pyridine or 2-iodo-3-bromoimidazo[1,2-a]pyridine from 2-aminopyridine followed by palladium-catalyzed Suzuki/phosphination or a phosphination/Suzuki cross-coupling reactions sequence, respectively. Preliminary model studies on the Suzuki synthesis of sterically-hindered biaryl and Buchwald-Hartwig amination compounds are presented with these ligands.
RESUMO
Phosphodiesterase 10A (PDE10) is a cyclic nucleotide (e.g. cGMP) degrading enzyme highly expressed in the brain striatum where it plays an important role in dopaminergic neurotransmission, but has limited expression and no known physiological function outside the central nervous system. Here we report that PDE10 mRNA and protein levels are strongly elevated in human non-small cell lung cancer cells and lung tumors compared with normal human airway epithelial cells and lung tissue, respectively. Genetic silencing of PDE10 or inhibition by small molecules such as PQ10 was found to selectively inhibit the growth and colony formation of lung tumor cells. PQ10 treatment of lung tumor cells rapidly increased intracellular cGMP levels and activated cGMP-dependent protein kinase (PKG) at concentrations that inhibit lung tumor cell growth. PQ10 also increased the phosphorylation of ß-catenin and reduced its levels, which paralleled the suppression of cyclin D1 and survivin but preceded the activation of PARP and caspase cleavage. PQ10 also suppressed RAS-activated RAF/MAPK signaling within the same concentration range and treatment period as required for cGMP elevation and PKG activation. These results show that PDE10 is overexpressed during lung cancer development and essential for lung tumor cell growth in which inhibitors can selectively induce apoptosis by increasing intracellular cGMP levels and activating PKG to suppress oncogenic ß-catenin and MAPK signaling.
RESUMO
Cantharidin is a natural toxin and an active constituent in a traditional Chinese medicine used to treat tumors. Cantharidin acts as a semi-selective inhibitor of PPP-family ser/thr protein phosphatases. Despite sharing a common catalytic mechanism and marked structural similarity with PP1C, PP2AC and PP5C, human PP4C was found to be insensitive to the inhibitory activity of cantharidin. To explore the molecular basis for this selectivity, we synthesized and tested novel C5/C6-derivatives designed from quantum-based modeling of the interactions revealed in the co-crystal structures of PP5C in complex with cantharidin. Structure-activity relationship studies and analysis of high-resolution (1.25Å) PP5C-inhibitor co-crystal structures reveal close contacts between the inhibitor bridgehead oxygen and both a catalytic metal ion and a non-catalytic phenylalanine residue, the latter of which is substituted by tryptophan in PP4C. Quantum chemistry calculations predicted that steric clashes with the bulkier tryptophan side chain in PP4C would force all cantharidin-based inhibitors into an unfavorable binding mode, disrupting the strong coordination of active site metal ions observed in the PP5C co-crystal structures, thereby rendering PP4C insensitive to the inhibitors. This prediction was confirmed by inhibition studies employing native human PP4C. Mutation of PP5C (F446W) and PP1C (F257W), to mimic the PP4C active site, resulted in markedly suppressed sensitivity to cantharidin. These observations provide insight into the structural basis for the natural selectivity of cantharidin and provide an avenue for PP4C deselection. The novel crystal structures also provide insight into interactions that provide increased selectivity of the C5/C6 modifications for PP5C versus other PPP-family phosphatases.
Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/química , Cantaridina/química , Inibidores Enzimáticos/química , Proteínas Nucleares/química , Fosfoproteínas Fosfatases/química , Proteína Fosfatase 1/química , Sequência de Aminoácidos , Sítios de Ligação , Domínio Catalítico , Clonagem Molecular , Cristalografia por Raios X , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Humanos , Cinética , Simulação de Acoplamento Molecular , Mutagênese Sítio-Dirigida , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fosfoproteínas Fosfatases/antagonistas & inibidores , Fosfoproteínas Fosfatases/genética , Fosfoproteínas Fosfatases/metabolismo , Ligação Proteica , Domínios Proteicos , Proteína Fosfatase 1/antagonistas & inibidores , Proteína Fosfatase 1/genética , Proteína Fosfatase 1/metabolismo , Estrutura Secundária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Relação Estrutura-AtividadeRESUMO
A series of 4-bicyclic heteroaryl 1,2,3,4-tetrahydroisoquinoline inhibitors of the serotonin transporter (SERT), norepinephrine transporter (NET), and dopamine transporter (DAT) was discovered. The synthesis and structure-activity relationship (SAR) of these triple reuptake inhibitors (TRIs) will be discussed. Compound 10i (AMR-2), a very potent inhibitor of SERT, NET, and DAT, showed efficacy in the rat forced-swim and mouse tail suspension models with minimum effective doses of 0.3 and 1 mg/kg (po), respectively. At efficacious doses in these assays, 10i exhibited substantial occupancy levels at the three transporters in both rat and mouse brain. The study of the metabolism of 10i revealed the formation of a significant active metabolite, compound 13.