RESUMO
An electrochemical Langmuir-Blodgett trough that permits an examination of local redox processes in a layer floating on the surface of water with a scanning tunneling microscopy-tip ultramicroelectrode has been constructed and tested on a layer of 1,1'-dicarbooctadecyloxyferrocene.
RESUMO
We synthesized several theophylline analogs and tested the hypothesis that these compounds may be nootropic or cognitive enhancers by examining their effects on evoked population spikes recorded extracellularly in the CA1 region of the rat hippocampus. Whereas the length of the carbon chain on N7 had no effect, different size of the terminal lactam ring strongly influenced neuroactivity. Our results suggest that hexahydroazepin-2-one analogs have potential for further development as cognitive enhancers.
Assuntos
Hipocampo/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Nootrópicos/síntese química , Nootrópicos/farmacologia , Teofilina/síntese química , Teofilina/farmacologia , Potenciais de Ação/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Eletrodos , Hipocampo/citologia , Hipocampo/fisiologia , Masculino , Estrutura Molecular , Neurônios/classificação , Neurônios/fisiologia , Ratos , Ratos Sprague-Dawley , Estereoisomerismo , Relação Estrutura-Atividade , Teofilina/análogos & derivados , Fatores de TempoRESUMO
Substituted pyrazolopyridines are potent inhibitors of phosphodiesterases and cyclin-dependent kinases. In this study, NMR was used to investigate the potential N1-H and N2-H tautomerism of 5-substituted pyrazolo[3,4-c]pyridine derivatives. Six compounds were fully characterized by using (1)H, (13)C, and (15)N chemical shifts and indirect (1)H--(13)C and (1)H--(15)N coupling constants. The (1)H NMR spectra were measured over a broad range of temperatures. All of the compounds were shown to exist predominantly in the N1-H tautomeric form. Complementary quantum-chemical calculations of the chemical shieldings and indirect spin-spin couplings support the structural conclusions drawn.
