RESUMO
Several tetrahydroimidazopyrimidines were prepared using silver assisted cyclization as the key step. The binding affinities of compounds thus prepared were evaluated in vitro toward hCRF(1)R. Initial lead compound 16 (K(i)=32 nM) demonstrated modest putative anxiolytic effects in the mouse canopy test. Further optimization using parallel synthesis provided compounds with K(i)'s <50 nM.
Assuntos
Desenho de Fármacos , Pirimidinas/síntese química , Pirimidinas/farmacologia , Receptores de Hormônio Liberador da Corticotropina/antagonistas & inibidores , Animais , Ciclização , Camundongos , Pirimidinas/químicaRESUMO
The enzyme gamma-secretase has long been considered a potential pharmaceutical target for Alzheimer disease. Presenilin (the catalytic subunit of gamma-secretase) and signal peptide peptidase (SPP) are related transmembrane aspartyl proteases that cleave transmembrane substrates. SPP and gamma-secretase are pharmacologically similar in that they are targeted by many of the same small molecules, including transition state analogs, non-transition state inhibitors, and amyloid beta-peptide modulators. One difference between presenilin and SPP is that the proteolytic activity of presenilin functions only within a multisubunit complex, whereas SPP requires no additional protein cofactors for activity. In this study, gamma-secretase inhibitor radioligands were used to evaluate SPP and gamma-secretase inhibitor binding pharmacology. We found that the SPP enzyme exhibited distinct binding sites for transition state analogs, non-transition state inhibitors, and the nonsteroidal anti-inflammatory drug sulindac sulfide, analogous to those reported previously for gamma-secretase. In the course of this study, cultured cells were found to contain an abundance of SPP binding activity, most likely contributed by several of the SPP family proteins. The number of SPP binding sites was in excess of gamma-secretase binding sites, making it essential to use selective radioligands for evaluation of gamma-secretase binding under these conditions. This study provides further support for the idea that SPP is a useful model of inhibitory mechanisms and structure in the SPP/presenilin protein family.
Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Anti-Inflamatórios não Esteroides/farmacologia , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Presenilinas/antagonistas & inibidores , Inibidores de Proteases/farmacologia , Sulindaco/análogos & derivados , Doença de Alzheimer/enzimologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/antagonistas & inibidores , Peptídeos beta-Amiloides/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Sítios de Ligação , Domínio Catalítico , Linhagem Celular , Humanos , Ligantes , Modelos Moleculares , Presenilinas/metabolismo , Sulindaco/farmacologiaRESUMO
8-Aryl-1,3a,7,8-tetraaza-cyclopenta[a]indenes represent a novel series of high-affinity corticotropin-releasing factor-1 receptor (CRF1R) antagonists. Herein we report the synthesis and SAR around the tricyclic core and the anxiolytic activity of an orally dosed exemplary compound 9d (K(i)=8.0 nM) in a mouse canopy model.
Assuntos
Receptores de Hormônio Liberador da Corticotropina/antagonistas & inibidores , Administração Oral , Animais , Antidepressivos/farmacologia , Compostos Aza/química , Depressão/tratamento farmacológico , Relação Dose-Resposta a Droga , Indenos/química , Cinética , Camundongos , Camundongos Endogâmicos BALB C , Modelos Químicos , Solubilidade , Relação Estrutura-Atividade , Fatores de Tempo , Água/químicaRESUMO
Methyltransferases form a large class of enzymes, most of which use S-adenosylmethionine as the methyl donor. In fact, S-adenosylmethionine is second only to ATP in the variety of reactions for which it serves as a cofactor. Several methods to measure methyltransferase activity have been described, most of which are applicable only to specific enzymes and/or substrates. In this work we describe a sensitive liquid chromatography/mass spectroscopy-based methyltransferase assay. The assay monitors the conversion of S-adenosylmethionine to S-adenosylhomocysteine and can be applied to any methyltransferase and substrate of interest. We used the well-characterized enzyme catechol O-methyltransferase to demonstrate that the assay can monitor activity with a variety of substrates, can identify new substrates, and can be used even with crude preparation of enzyme. Furthermore, we demonstrate the utility of the assay for kinetic characterization of enzymatic activity.
Assuntos
Catecol O-Metiltransferase/metabolismo , Cromatografia Líquida , Espectrometria de Massas em Tandem , Sequência de Aminoácidos , Catecol O-Metiltransferase/química , Catecol O-Metiltransferase/fisiologia , Ativação Enzimática , Humanos , Cinética , Dados de Sequência Molecular , S-Adenosil-Homocisteína/química , S-Adenosil-Homocisteína/metabolismoRESUMO
7-Aryl-6,7-dihydroimidazoimidazoles represent a novel series of high-affinity corticotropin-releasing factor 1 receptor antagonists. Here, we report their synthesis and SAR as well as behavioral activity of two exemplary compounds, 7b and 7k, in a mouse canopy model of anxiety.
Assuntos
Ansiolíticos/síntese química , Imidazóis/síntese química , Receptores de Hormônio Liberador da Corticotropina/antagonistas & inibidores , Animais , Ansiolíticos/farmacocinética , Ansiolíticos/farmacologia , Ansiedade/tratamento farmacológico , Barreira Hematoencefálica , Hormônio Liberador da Corticotropina , Humanos , Imidazóis/farmacocinética , Imidazóis/farmacologia , Camundongos , Ratos , Relação Estrutura-AtividadeRESUMO
2-arylamino-4-trifluoromethyl-5-aminomethylthiazoles represent a novel series of high-affinity corticotropin releasing factor-1 receptor (CRF(1)R) antagonists that are prepared in three steps in good overall yields. Herein, we report binding SAR as well as anxiolytic activity of an exemplary compound (7a, K(i)=8.6 nM) in a mouse canopy model.