RESUMO
Neurotrophins are a family of secreted proteins that play an important role in the development, differentiation, and survival of neurons. Studies also suggest that aberrant neurotrophin signaling may play a role in processes underlying disease states such as schizophrenia, Alzheimer's disease, and depression. Whereas the development of agents that selectively stimulate neurotrophin signaling has proven to be difficult, compounds have been identified that potentiate neurotrophin 3 (NT-3)-mediated activation of trk A. In the present studies, we extend those initial observations to identify compounds that also potentiate NT-3-mediated activation of trk B. Compound potentiation of NT-3 was observed using several readouts of transfected and endogenous trk receptor activity, including trk receptor phosphorylation, mitogen-activated protein kinase phosphorylation, reporter assay activity (beta-lactamase and luciferase), cell survival and neurite extension assays. Studies using chimeric trk receptors demonstrated that the extracellular domain is essential for compound potentiation and rule out interaction with intracellular signaling molecules as a mechanism of compound activity. Thus, the present studies demonstrate that trk B receptor activity can be potentiated by small-molecule compounds via the extracellular domain of the receptor and provide reagents for further evaluating the role of NT-3-mediated trk A and trk B activity in vivo.
Assuntos
Neurotrofina 3/farmacologia , Receptor trkB/agonistas , Animais , Western Blotting , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Cricetinae , DNA Complementar , Humanos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosforilação , Ratos , Receptor trkB/genética , Receptor trkB/metabolismo , Transdução de SinaisRESUMO
PURPOSE: The novel fluoro-substituted camptothecin analog, BMS-286309, and its prodrug, BMS-422461, were evaluated for their pharmacologic, toxicologic, metabolic and pharmacokinetic developmental potential. METHODS: In vitro and in vivo assays were used to assess the compounds for topoisomerase I activity, antitumor activity, gastrointestinal (GI) toxicity, and pharmacokinetic parameters. RESULTS: BMS-286309-induced topoisomerase I-mediated DNA breaks in vitro and was similar in potency to camptothecin. Both BMS-286309 and -422461 were comparable to irinotecan regarding preclinical antitumor activity assessed in mice bearing distal site murine and human tumors. BMS-422461 was also found to be orally active. Both analogs were >100-fold more potent in vivo than irinotecan and both were superior to irinotecan with respect to toxicological assessment of GI injury in mice. The generation of parent compound from BMS-422461 was qualitatively similar in mouse, rat and human blood and liver S9 fractions. The percentage of BMS-286309 remaining as the active lactone form at equilibrium was comparable in mouse and human plasma. The pharmacokinetic profile in rat blood demonstrated that BMS-422461 was rapidly cleaved to BMS-286309. CONCLUSIONS: The favorable in vivo metabolic activation of BMS-422461, and the pharmacokinetic characteristics of BMS-286309, suggest that the good efficacy of BMS-422461 is derived from robust in vivo release of BMS-286309 in rodents and the likelihood that this biotransformation will be preserved in humans. The comparable antitumor activity of BMS-422461 to irinotecan, as well as reduced preclinical GI toxicity, make this novel camptothecin analog attractive for clinical development.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Camptotecina/análogos & derivados , Camptotecina/farmacologia , Pró-Fármacos/farmacologia , Animais , Antineoplásicos Fitogênicos/farmacocinética , Camptotecina/síntese química , Camptotecina/farmacocinética , Carcinoma/tratamento farmacológico , Carcinoma/metabolismo , Carcinoma/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Feminino , Trato Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/metabolismo , Trato Gastrointestinal/patologia , Humanos , Irinotecano , Masculino , Neoplasias Mamárias Experimentais/tratamento farmacológico , Neoplasias Mamárias Experimentais/metabolismo , Neoplasias Mamárias Experimentais/patologia , Camundongos , Camundongos Endogâmicos C3H , Camundongos Nus , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Pró-Fármacos/farmacocinética , Ratos , Ratos Sprague-Dawley , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
A series of fluoroglycosylated fluoroindolocarbazoles was examined with respect to their topoisomerase I activity, cytotoxicity, and selectivity. The lead clinical candidate from this series, BMS-250749, displays broad spectrum antitumor activity superior to CPT-11 against some preclinical xenograft models, including curative antitumor activity against Lewis lung carcinoma.
Assuntos
Antineoplásicos/síntese química , Camptotecina/análogos & derivados , Camptotecina/farmacologia , Carbazóis/síntese química , Glucosídeos/síntese química , Indóis/síntese química , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Carbazóis/química , Carbazóis/farmacologia , Linhagem Celular Tumoral , Avaliação Pré-Clínica de Medicamentos , Resistencia a Medicamentos Antineoplásicos , Ensaios de Seleção de Medicamentos Antitumorais , Glucosídeos/química , Glucosídeos/farmacologia , Humanos , Técnicas In Vitro , Indóis/química , Indóis/farmacologia , Irinotecano , Camundongos , Microssomos Hepáticos/metabolismo , Inibidores da Topoisomerase I , Transplante HeterólogoRESUMO
[reaction: see text] Both 6'- and 4'-fluoro-glycosylated indolo[2,3-a]carbazoles are substrates for base-induced loss of fluorine as a leaving group from sp3 carbon. In the case of alpha-N-glycosylated substrate 3, loss of fluorine from the 6'-position leads to 3,6-anhydroglucose analogue 1. A novel N12,N13-bridged sugar analogue 2 results from loss of 4'-fluorine from beta-N-glycosylated analogue 4. Both analogues 1 and 2 display topo I inhibitory potencies similar to camptothecin.
Assuntos
Carbazóis/síntese química , Carbono/química , Inibidores Enzimáticos/síntese química , Flúor/química , Glicosídeos/síntese química , Compostos Heterocíclicos de Anel em Ponte/síntese química , Hidrocarbonetos Fluorados/síntese química , Indóis/síntese química , Inibidores da Topoisomerase I , Animais , Carbazóis/farmacologia , Inibidores Enzimáticos/farmacologia , Glicosídeos/farmacologia , Compostos Heterocíclicos de Anel em Ponte/farmacologia , Hidrocarbonetos Fluorados/química , Indóis/química , Leucemia P388 , Conformação Molecular , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
A series of fluoroindolocarbazoles were studied with respect to their topoisomerase I activity, cytotoxicity, selectivity, and in vivo antitumor activity. Emerging from this series was BMS-251873, a potential clinical candidate possessing a robust pharmacological profile including curative antitumor activity against prostate carcinoma.
Assuntos
Antineoplásicos/síntese química , Carbazóis/síntese química , Glucosídeos/síntese química , Neoplasias da Próstata/tratamento farmacológico , Inibidores da Topoisomerase I , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Carbazóis/química , Carbazóis/farmacologia , Glucosídeos/química , Glucosídeos/farmacologia , Masculino , Camundongos , Transplante de Neoplasias , Solubilidade , Relação Estrutura-Atividade , Água , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The synthesis and antifungal activity of 5'- and 5'-6'-substituted azasordarin derivatives are described. Modification of the 5'-position led to the discovery of the spirocyclopentyl analogue 7g, which is the first azasordarin to register single-digit MIC values versus Aspergillus spp. Further investigation identified the 5'-i-Pr derivative 7b, which displays superior pharmacokinetic properties compared to other azasordarins.
Assuntos
Antifúngicos/química , Antifúngicos/farmacocinética , Compostos Aza/síntese química , Compostos Aza/farmacocinética , Administração Oral , Animais , Antifúngicos/farmacologia , Aspergillus/efeitos dos fármacos , Compostos Aza/química , Compostos Aza/farmacologia , Glicosídeos/química , Indenos , Injeções Intravenosas , Camundongos , Testes de Sensibilidade Microbiana , Compostos de Espiro/química , Compostos de Espiro/farmacocinética , Compostos de Espiro/farmacologia , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
Compounds based on sordaricin were prepared via organometallic addition onto a fully protected sordaricin aldehyde. The fungal growth inhibition profiles for these compounds were established and the results are presented here. The synthesis of homologated sordaricin as well as ether and ester derivatives is presented, and structural rearrangement products upon oxidation. These compounds were evaluated as agents to inhibit fungal growth.
Assuntos
Antifúngicos/síntese química , Antifúngicos/farmacologia , Aldeídos/síntese química , Aldeídos/química , Aldeídos/farmacologia , Alquilação , Diterpenos , Fungos/efeitos dos fármacos , Hidrólise , Indicadores e Reagentes , Testes de Sensibilidade Microbiana , Oxirredução , Relação Estrutura-AtividadeRESUMO
Core-modified sordaricin derivatives were prepared via biotransformation followed by chemical modification and tested for antifungal activity. The antifungal activity proved to be very sensitive to modifications in the sterics and/or lipophilicity of the diterpene skeleton. Introduction of polar groups such as hydroxyl in the diterpene core results in loss of potency while small and lipophilic groups such as fluorine and the 7,8-olefin are well tolerated.
Assuntos
Antifúngicos/metabolismo , Antifúngicos/farmacologia , Antifúngicos/química , Biotransformação , Candida albicans/efeitos dos fármacos , Candida glabrata/efeitos dos fármacos , Diterpenos , Interações Hidrofóbicas e Hidrofílicas , Testes de Sensibilidade Microbiana , Nocardia/metabolismo , EstereoisomerismoRESUMO
The synthesis and biological activity of sordarin oxazepine derivatives are described. The key step features a regioselective oxidation of an unprotected triol followed by double reductive amination to afford the ring-closed products. The spectrum of antifungal activity for these novel derivatives includes coverage of Candida albicans, Candida glabrata, and Cryptococcus neoformans.
Assuntos
Antifúngicos/síntese química , Antifúngicos/farmacologia , Fungos/efeitos dos fármacos , Oxazepinas/síntese química , Oxazepinas/farmacologia , Candida albicans/efeitos dos fármacos , Candida glabrata/efeitos dos fármacos , Cryptococcus neoformans/efeitos dos fármacos , Ligação de Hidrogênio , Indenos , Testes de Sensibilidade Microbiana , Relação Estrutura-AtividadeRESUMO
Oxime derivatives of the sordarin aglycone have been identified as potent antifungal agents. The in vitro spectrum of activity includes coverage against Candida albicans and Candida glabrata with MICs as low as 0.06 microg/mL. The antifungal activity was established to be exquisitely sensitive to the spatial orientation of the lipophilic side chains.