RESUMO
Voltage-gated sodium channels have been shown to play a critical role in neuropathic pain. A series of low molecular weight biaryl substituted pyrazole carboxamides were identified with good in-vitro potency and in-vivo efficacy. Compound 26, a Nav1.7 blocker has excellent efficacy in the Chung model of neuropathic pain.
Assuntos
Neuralgia/tratamento farmacológico , Pirazóis/química , Pirazóis/uso terapêutico , Bloqueadores dos Canais de Sódio/química , Bloqueadores dos Canais de Sódio/uso terapêutico , Canais de Sódio/metabolismo , Animais , Cães , Haplorrinos , Humanos , Microssomos Hepáticos/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.7 , Pirazóis/farmacocinética , Pirazóis/farmacologia , Ratos , Bloqueadores dos Canais de Sódio/farmacocinética , Bloqueadores dos Canais de Sódio/farmacologia , Relação Estrutura-AtividadeRESUMO
Voltage-gated sodium channels have been shown to play a critical role in neuropathic pain. With a goal to develop potent peripherally active sodium channel blockers, a series of low molecular weight biaryl substituted imidazoles, oxazoles, and thiazole carboxamides were identified with good in vitro and in vivo potency.
Assuntos
Neuralgia/tratamento farmacológico , Oxazóis/uso terapêutico , Bloqueadores dos Canais de Sódio/uso terapêutico , Canais de Sódio/metabolismo , Tiazóis/uso terapêutico , Animais , Cães , Humanos , Imidazóis/química , Imidazóis/metabolismo , Imidazóis/farmacologia , Imidazóis/uso terapêutico , Microssomos Hepáticos/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.7 , Oxazóis/química , Oxazóis/metabolismo , Oxazóis/farmacologia , Ratos , Bloqueadores dos Canais de Sódio/química , Bloqueadores dos Canais de Sódio/metabolismo , Bloqueadores dos Canais de Sódio/farmacologia , Tiazóis/química , Tiazóis/metabolismo , Tiazóis/farmacologiaRESUMO
A series of novel biphenyl pyrazole dicarboxamides were identified as potential sodium channel blockers for treatment of neuropathic pain. Compound 20 had outstanding efficacy in the Chung rat spinal nerve ligation (SNL) model of neuropathic pain.
Assuntos
Compostos de Bifenilo/química , Neuralgia/tratamento farmacológico , Pirazóis/química , Bloqueadores dos Canais de Sódio/química , Canais de Sódio/química , Animais , Compostos de Bifenilo/síntese química , Compostos de Bifenilo/uso terapêutico , Cães , Avaliação Pré-Clínica de Medicamentos , Humanos , Camundongos , Microssomos Hepáticos/metabolismo , Atividade Motora/efeitos dos fármacos , Pirazóis/farmacocinética , Pirazóis/uso terapêutico , Ratos , Bloqueadores dos Canais de Sódio/farmacocinética , Bloqueadores dos Canais de Sódio/uso terapêutico , Canais de Sódio/metabolismoRESUMO
A series of beta-aminoamides bearing triazolopiperazines have been discovered as potent, selective, and orally active dipeptidyl peptidase IV (DPP-4) inhibitors by extensive structure-activity relationship (SAR) studies around the triazolopiperazine moiety. Among these, compound 34b with excellent in vitro potency (IC50 = 4.3 nM) against DPP-4, high selectivity over other enzymes, and good pharmacokinetic profiles exhibited pronounced in vivo efficacy in an oral glucose tolerance test (OGTT) in lean mice. On the basis of these properties, compound 34b has been profiled in detail. Further refinement of the triazolopiperazines resulted in the discovery of a series of extremely potent compounds with subnanomolar activity against DPP-4 (42b- 49b), that is, 4-fluorobenzyl-substituted compound 46b, which is notable for its superior potency (IC50 = 0.18 nM). X-ray crystal structure determination of compounds 34b and 46b in complex with DPP-4 enzyme revealed that (R)-stereochemistry at the 8-position of triazolopiperazines is strongly preferred over (S) with respect to DPP-4 inhibition.
Assuntos
Amidas/síntese química , Inibidores da Dipeptidil Peptidase IV , Piperazinas/síntese química , Pirazinas/síntese química , Triazóis/síntese química , Amidas/farmacocinética , Amidas/farmacologia , Animais , Cristalografia por Raios X , Dipeptidil Peptidase 4/química , Cães , Teste de Tolerância a Glucose , Haplorrinos , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Piperazinas/farmacocinética , Piperazinas/farmacologia , Pirazinas/farmacocinética , Pirazinas/farmacologia , Ratos , Estereoisomerismo , Relação Estrutura-Atividade , Triazóis/farmacocinética , Triazóis/farmacologiaRESUMO
A series of 3-amino-1,5-benzodiazepinones were synthesized and evaluated as potential sodium channel blockers in a functional, membrane potential-based assay. One member of this series displayed subnanomolar, state-dependent sodium channel block, and was orally efficacious in a mouse model of epilepsy.
Assuntos
Anticonvulsivantes/farmacologia , Benzodiazepinonas/farmacologia , Epilepsia/tratamento farmacológico , Canais de Potássio Éter-A-Go-Go/antagonistas & inibidores , Bloqueadores dos Canais de Sódio/farmacologia , Animais , Anticonvulsivantes/síntese química , Anticonvulsivantes/farmacocinética , Benzodiazepinonas/síntese química , Benzodiazepinonas/farmacocinética , Eletrofisiologia , Eletrochoque , Epilepsia/metabolismo , Canais de Potássio Éter-A-Go-Go/metabolismo , Transferência Ressonante de Energia de Fluorescência , Humanos , Camundongos , Estrutura Molecular , Ratos , Bloqueadores dos Canais de Sódio/síntese química , Bloqueadores dos Canais de Sódio/farmacocinéticaRESUMO
A simple and efficient method for the preparation of pyrimidine 2'-O-hydroxyethoxymethylribonucleosides and 2'-O-hydroxypropoxymethylribonucleosides has been developed. These modified nucleosides were incorporated into oligoribonucleotides, which were shown to form stable RNA/RNA duplexes. The effect of 2' -O-modification in the antisense and sense strands of small interference RNA was evaluated in multi-drug resistant NIH 3T3 cells.
Assuntos
Oligorribonucleotídeos/química , Pirimidinas/química , RNA/química , Ribonucleosídeos/síntese química , Ribonucleosídeos/químicaRESUMO
Hexitol nucleic acids (HNAs) are nuclease resistant and provide strong hybridization to RNA. However, there is relatively little information on the biological properties of HNA antisense oligonucleotides. In this study, we compared the antisense effects of a chimeric HNA 'gapmer' oligonucleotide comprising a phosphorothioate central sequence flanked by 5' and 3' HNA sequences to conventional phosphorothioate oligonucleotides and to a 2'-O-methoxyethyl (2'-O-ME) phosphorothioate 'gapmer'. The antisense oligomers each targeted a sequence bracketing the start codon of the message of MDR1, a gene involved in multi-drug resistance in cancer cells. Antisense and control oligonucleotides were delivered to MDR1-expressing cells using transfection with the cationic lipid Lipofectamine 2000. The anti-MDR1 HNA gapmer was substantially more potent than a phosphorothioate oligonucleotide of the same sequence in reducing expression of P-glycoprotein, the MDR1 gene product. HNA and 2'-O-ME gapmers displayed similar potency, but a pure HNA antisense oligonucleotide (lacking the phosphorothioate 'gap') was ineffective, indicating that RNase H activity was likely required. Treatment with anti-MDR1 HNA gapmer resulted in increased cellular accumulation of the drug surrogate Rhodamine 123 that correlated well with the reduced cell surface expression of P-glycoprotein. Thus, HNA gapmers may provide a valuable additional tool for antisense-based investigations and therapeutic approaches.
Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Antineoplásicos/química , Antineoplásicos/farmacologia , Oligonucleotídeos Antissenso/química , Oligonucleotídeos Antissenso/farmacologia , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Animais , Antineoplásicos/metabolismo , Transporte Biológico/efeitos dos fármacos , Western Blotting , Linhagem Celular , Citometria de Fluxo , Corantes Fluorescentes/metabolismo , Regulação da Expressão Gênica , Camundongos , Células NIH 3T3 , Oligonucleotídeos Antissenso/metabolismo , Rodamina 123/metabolismo , Álcoois Açúcares/química , Tionucleotídeos/químicaRESUMO
A novel series of beta-amino amides incorporating fused heterocycles, i.e., triazolopiperazines, were synthesized and evaluated as inhibitors of dipeptidyl peptidase IV (DPP-IV) for the treatment of type 2 diabetes. (2R)-4-Oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine (1) is a potent, orally active DPP-IV inhibitor (IC(50) = 18 nM) with excellent selectivity over other proline-selective peptidases, oral bioavailability in preclinical species, and in vivo efficacy in animal models. MK-0431, the phosphate salt of compound 1, was selected for development as a potential new treatment for type 2 diabetes.
Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Dipeptidil Peptidase 4/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Hipoglicemiantes/farmacologia , Pirazinas/química , Pirazinas/farmacologia , Triazóis/química , Triazóis/farmacologia , Administração Oral , Animais , Sítios de Ligação , Bioquímica/métodos , Glicemia/análise , Cristalografia por Raios X , Dipeptidil Peptidase 4/química , Dipeptidil Peptidase 4/metabolismo , Cães , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos/métodos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacocinética , Glucagon/sangue , Glucagon/efeitos dos fármacos , Peptídeo 1 Semelhante ao Glucagon , Teste de Tolerância a Glucose , Hipoglicemiantes/química , Hipoglicemiantes/farmacocinética , Camundongos , Camundongos Endogâmicos C57BL , Modelos Moleculares , Fragmentos de Peptídeos/sangue , Fragmentos de Peptídeos/efeitos dos fármacos , Conformação Proteica , Precursores de Proteínas/sangue , Precursores de Proteínas/efeitos dos fármacos , Pirazinas/farmacocinética , Ratos , Fosfato de Sitagliptina , Relação Estrutura-Atividade , Triazóis/farmacocinéticaRESUMO
Antisense oligonucleotides were potentially very powerful tools to modulate gene expression. Progress in chemical modification of oligonucleotides to enhance the strength and stability of interaction, without loosing specificity, has made the antisense strategy very attractive for therapeutic manipulation of the gene expression. However, pharmacological applications of oligonucleotides have been hindered by the inability to effectively deliver these compounds to their sites of action within cells. In this study we evaluated a new concept for antisense delivery in cellular systems. We have shown that formation of a duplex between the active oligonucleotide (with a chemically modified backbone) and an easily degradable complementary oligodeoxynucleotide in the presence of Lipofectamine 2000 leads to better intracellular uptake and more significant pharmacological effect of the active oligonucleotide. To evaluate our approach we targeted the MDR1 gene, which coded for P-glycoprotein, a membrane ATPase associated with multi-drug resistance in tumor cells. The 2'-O-methyl gapmer antisense RNA (active component of the duplex) was complementary to a site flanking the AUG of the MDR1 message. Effective inhibition of P-glycoprotein expression was attained with sub-micromolar concentrations of duplexes under serum-replete conditions and was much stronger than with traditional single stranded antisense delivery. The results obtained suggested that double stranded delivery could provide a simple and effective means for enhancing cell uptake of pharmacologically active oligonucleotides.
Assuntos
Sistemas de Liberação de Medicamentos , Oligorribonucleotídeos Antissenso/administração & dosagem , RNA de Cadeia Dupla/administração & dosagem , Células 3T3 , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Animais , Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , TransfecçãoRESUMO
An efficient synthesis of the truncated 3"-aldehyde (3) from nodulisporic acid A (1) under mild conditions is described. Further oxidation of 3 to 3"-carboxylic acid (4) and its subsequent oxidative degradation produced 1"-aldehyde (5). These new derivatives are versatile intermediates for the preparation of new, side chain modified derivatives of nodulisporic acid A. [reaction: see text]
Assuntos
Aldeídos/síntese química , Ácidos Carboxílicos/síntese química , Indóis/química , Inseticidas/química , Indicadores e Reagentes , OxirreduçãoRESUMO
The first synthesis of 1,19-aza-1,19-desoxy-avermectin B(1a) (2) is described. This new macrolactam, prepared efficiently from avermectin B(1a) (1a) in seven steps, was designed to form an intramolecular hydrogen bond between the amide carbonyl and the adjacent C7 tertiary hydroxyl via a six-center hydrogen bonding network. The presence of this intramolecular hydrogen bond is anticipated to confer additional conformational rigidity to the 16-membered macrocycle.
RESUMO
The alleged "madness" of the Anglo-Indian prince known as Dyce Sombre (1808-1851) has been attributed to anti-Asian prejudice, biased observations, and insensitivity to ethno-cultural variations in behavior. However, whereas all these factors may have contributed to misdiagnosis and mistreatment, there is compelling evidence pointing to an "organic" explanation for Dyce Sombre's aberrant behavior. We posit that the interaction of drug toxicity and possible central nervous system infection were primarily responsible for Dyce Sombre's clinical symptoms. The case provides an important lesson for modern-day psychiatrists confronting patients from other cultures who may also have underlying neuropsychiatric disorders.
RESUMO
Nodulisporic acid A (1) is a structurally complex fungal metabolite that exhibits systemic efficacy against fleas via modulation of an invertebrate specific glutamate-gated ion channel. In order to identify a nodulisporamide suitable for monthly oral dosing in dogs, a library of 335 nodulisporamides was examined in an artificial flea feeding system for intrinsic systemic potency as well as in a mouse/bedbug assay for systemic efficacy and safety. A cohort of 66 nodulisporamides were selected for evaluation in a dog/flea model; pharmacokinetic analysis correlated plasma levels with flea efficacy. These efforts resulted in the identification of the development candidate N-tert-butyl nodulisporamide (3) as a potent and efficacious once monthly oral agent for the control of fleas and ticks on dogs and cats which was directly compared to the topical agents fipronil and imidacloprid, with favorable results obtained. Multidose studies over 3 months confirmed the in vivo ectoparasiticidal efficacy and established that 3 lacked overt mammalian toxicity. Tissue distribution studies in mice using [(14)C]-labeled 3 indicate that adipose beds serve as ligand depots, contributing to the long terminal half-lives of these compounds.
Assuntos
Controle de Insetos , Inseticidas , Sifonápteros , Carrapatos , Tecido Adiposo/metabolismo , Administração Oral , Animais , Gatos , Cães , Feminino , Alcaloides Indólicos/síntese química , Alcaloides Indólicos/farmacocinética , Alcaloides Indólicos/farmacologia , Indóis , Inseticidas/administração & dosagem , Inseticidas/síntese química , Masculino , Camundongos , Distribuição TecidualRESUMO
A series of benzodiazepines and benzazepinones were synthesized and evaluated as potential sodium channel blockers in a functional, membrane potential-based assay. One member of the benzazepinone series, compound 47, displayed potent, state-dependent block of hNa(v)1.7, and was orally efficacious in a rat model of neuropathic pain.
Assuntos
Compostos Heterocíclicos com 3 Anéis/química , Compostos Heterocíclicos com 3 Anéis/uso terapêutico , Dor/tratamento farmacológico , Bloqueadores dos Canais de Sódio/classificação , Bloqueadores dos Canais de Sódio/farmacologia , Canais de Sódio/metabolismo , Animais , Compostos Heterocíclicos com 3 Anéis/administração & dosagem , Compostos Heterocíclicos com 3 Anéis/farmacologia , Estrutura Molecular , Canal de Sódio Disparado por Voltagem NAV1.7 , Ratos , Bloqueadores dos Canais de Sódio/química , Bloqueadores dos Canais de Sódio/uso terapêutico , Relação Estrutura-AtividadeRESUMO
Novel cyclopentane-based 3-phenyl-1-hydroxypropyl compounds were evaluated for inhibitory activity against the peripheral nerve sodium channel Na(V)1.7 and off-target activity against the cardiac potassium channel hERG. The stereochemistry of the hydroxyl group and substitution on the phenyl rings with either fluorinated O-alkyl or alkyl groups were found to be critical for conferring potency against Na(V)1.7. A benchmark compound from this series displayed efficacy in rat models of inflammatory and neuropathic pain.
Assuntos
Ciclopentanos/química , Ciclopentanos/farmacologia , Bloqueadores dos Canais de Sódio/síntese química , Bloqueadores dos Canais de Sódio/farmacologia , Canais de Sódio/metabolismo , Animais , Ciclopentanos/síntese química , Ciclopentanos/farmacocinética , Canais de Potássio Éter-A-Go-Go/metabolismo , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Ratos , Bloqueadores dos Canais de Sódio/química , Bloqueadores dos Canais de Sódio/farmacocinética , Relação Estrutura-AtividadeRESUMO
PURPOSE: PAMAM G5 dendrimer (P) was conjugated to Tat peptide (T), a cell penetrating peptide, in search of an efficient cellular delivery vehicle for antisense and siRNA oligonucleotides. METHODS: PAMAM G5 dendrimer was reacted with 4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-propionic acid, sulfosuccinimidyl ester, sodium salt (BODIPY) for visualization to yield the conjugate BP. Bifunctional sulfosuccinimidyl 6-[alpha-methyl-alpha-(2-pyridyldithio)toluamido]hexanoate (sulfo-LC-SMPT) was then used to conjugate primary amino groups of BP to cysteine derivatized Tat peptide to give the designed conjugate, BPT. This conjugate was complexed with antisense and siRNA oligonucleotides designed to inhibit MDR1 gene expression. NIH 3T3 MDR cells were used for the evaluation of biological activity of the conjugate. RESULTS: Both antisense and siRNA readily formed complexes with the synthesized BPT, introduced into NIH 3T3 MDR cells, and primarily accumulated in intracellular vesicles. MDR1 gene expression was partially inhibited by the antisense-BPT complex and weakly inhibited by the siRNA-BPT complex when both were tested at nontoxic levels of dendrimer. Conjugation with Tat peptide did not improve the delivery efficiency of the dendrimer. CONCLUSIONS: Dendrimer-oligonucleotide complexes were moderately effective for delivery of antisense and only poorly effective for delivery of siRNA. Conjugation of the dendrimer with the Tat cell penetrating peptide failed to further enhance the effectiveness of the dendrimer.
Assuntos
Dendrímeros , Sistemas de Liberação de Medicamentos , Produtos do Gene tat/química , Oligonucleotídeos/administração & dosagem , Poliaminas/química , RNA Antissenso/administração & dosagem , RNA Interferente Pequeno/administração & dosagem , Células 3T3 , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Animais , Compostos de Boro , Sobrevivência Celular/efeitos dos fármacos , Cromatografia em Gel , Corantes Fluorescentes , Genes MDR/genética , Camundongos , Microscopia Confocal , Ribonucleases/metabolismoRESUMO
Cholesterol modified mono-, di-, and tetrameric oligonucleotides were synthesized and hybridized with antisense oligonucleotides to study their incorporation in cationic liposomes together with the influence of this dendrimeric delivery system on biological activity. Electrostatic interactions seem to play the most important role during complexation with cationic lipids. This oligonucleotide formulation gives a small but significant increase in the inhibition of P-glycoprotein expression in a cellular system.
Assuntos
Colesterol/química , Lipídeos/química , Oligonucleotídeos Antissenso/administração & dosagem , Células 3T3 , Animais , Cátions , Transferência Ressonante de Energia de Fluorescência , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Camundongos , Oligonucleotídeos Antissenso/químicaRESUMO
A series of new voltage-gated sodium channel blockers were prepared based on the screening lead succinic diamide BPBTS. Replacement of the succinimide linker with the more rigid cyclic 1,2-trans-diamide linker was well tolerated. N-Methylation on the biphenylsulfonamide side of the amide moiety significantly reduced the clearance rate in rat pharmacokinetic studies.
Assuntos
Amidas/química , Amidas/farmacologia , Ciclopentanos/farmacologia , Dor/tratamento farmacológico , Bloqueadores dos Canais de Sódio/síntese química , Administração Oral , Amidas/síntese química , Amidas/uso terapêutico , Analgésicos/síntese química , Analgésicos/farmacologia , Animais , Compostos de Bifenilo/química , Ciclopentanos/síntese química , Ciclopentanos/uso terapêutico , Ativação do Canal Iônico/efeitos dos fármacos , Metilação , Mexiletina/farmacologia , Medição da Dor/efeitos dos fármacos , Ratos , Bloqueadores dos Canais de Sódio/farmacologia , Bloqueadores dos Canais de Sódio/uso terapêutico , Relação Estrutura-Atividade , Succinatos/química , Sulfonamidas/químicaRESUMO
A new series of voltage-gated sodium channel blockers with potential for treatment of chronic pain is reported. Systematic structure-activity relationship studies, starting with compound 1, led to identification of potent analogs that displayed use-dependent block of sodium channels, were efficacious in pain models in vivo, and most importantly, were devoid of activity against the cardiac potassium channel hERG.
Assuntos
Dor/tratamento farmacológico , Bloqueadores dos Canais de Sódio/uso terapêutico , Doença Crônica , Humanos , Conformação Molecular , Sondas Moleculares , Bloqueadores dos Canais de Sódio/químicaRESUMO
Antisense oligonucleotides are potentially powerful tools for selective control of cellular and viral gene expression. Crucial to successful application of this approach is the specificity of the oligonucleotide for the chosen RNA target. Here we apply DNA array technology to examine the specificity of antisense oligonucleotide treatments. The molecules used in these studies consisted of phosphorothioate oligomers linked to the Antennapedia (Ant) delivery peptide. The antisense oligonucleotide component was complementary to a site flanking the AUG of the MDR1 message, which codes for P-glycoprotein, a membrane ATPase associated with multidrug resistance in tumor cells. Using a DNA array of 2059 genes, we analyzed cellular responses to molecules comprised of Ant peptide-oligonucleotide conjugates, as well as to the Ant peptide alone. Besides the expected reduction in MDR1 message level, 37 other genes (approximately 2% of those tested) showed changes of comparable magnitude. The validity of the array results was confirmed for selected genes using Northern blots to assess messenger RNA levels. These results suggest that studies using antisense oligonucleotide technology to modulate gene expression need to be interpreted with caution.