RESUMO
We report the synthesis of three optical probes (Eu(3+)â1, Eu(3+)â2, and Eu(3+)â3) having a luminescent Eu complex (signaling unit) bonded in different positions to folic acid (FA), the folate receptor (FR) targeting unit. The structures of the two regioisomers Eu(3+)â1 and Eu(3+)â2 were assigned by mass spectrometric experiments. The optical properties and stability of these probes were assessed in phosphate-buffered saline, cell culture medium, rat serum, and cellular lysate, and results indicated that they are chemically and photophysically stable. Cytotoxicity was studied with ovarian cancer cells having high (SKOV-3), intermediate (OVCAR-3), low (IGROV-1), or null (A2780) expression of FRs. The internalized probe, evaluated in SKOV-3, IGROV-1, and A2780 cells, was in the order Eu(3+)â2 > Eu(3+)â1 > Eu(3+)â3. No internalization was observed for A2780 cells. Such results, together with those obtained in competition experiments of FA versus Eu(3+)â2 and FA or Eu(3+)â2 versus (3)H-FA, indicate that internalization is receptor-mediated and that Eu(3+)â2 shows high selectivity and specificity for FR.
Assuntos
Európio/química , Ácido Fólico/metabolismo , Substâncias Luminescentes/análise , Substâncias Luminescentes/química , Imagem Molecular/métodos , Sondas Moleculares/química , Compostos Organometálicos/química , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Estabilidade de Medicamentos , Európio/efeitos adversos , Európio/análise , Feminino , Ácido Fólico/efeitos adversos , Ácido Fólico/química , Humanos , Substâncias Luminescentes/efeitos adversos , Substâncias Luminescentes/síntese química , Sondas Moleculares/efeitos adversos , Sondas Moleculares/análise , Sondas Moleculares/síntese química , Estrutura Molecular , Compostos Organometálicos/efeitos adversos , Compostos Organometálicos/análise , Compostos Organometálicos/síntese química , Neoplasias Ovarianas/química , Neoplasias Ovarianas/metabolismo , Ratos , Relação Estrutura-Atividade , Especificidade por SubstratoRESUMO
We describe the application of molecular dynamics followed by principal component analysis to study the inter-domain movements of the ligand binding domain (LBD) of mGluR5 in response to the binding of selected agonists or antagonists. Our results suggest that the method is an attractive alternative to current approaches to predict the agonist-induced or antagonist-blocked LBD responses. The ratio between the eigenvalues of the first and second eigenvectors (R1,2) is also proposed as a numerical descriptor for discriminating the ligand behavior as a mGluR5 agonist or antagonist.
Assuntos
Aminoácidos/química , Ácido Glutâmico/química , Glicina/análogos & derivados , Simulação de Dinâmica Molecular , Fenilacetatos/química , Ácido Quisquálico/química , Receptores de Glutamato Metabotrópico/química , Xantenos/química , Sítios de Ligação , Glicina/química , Humanos , Ligantes , Análise de Componente Principal , Ligação Proteica , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Receptor de Glutamato Metabotrópico 5 , Receptores de Glutamato Metabotrópico/agonistas , Receptores de Glutamato Metabotrópico/antagonistas & inibidoresRESUMO
[reaction: see text] An original TiCl(4)/t-BuNH(2)-mediated hydroamination/annulation domino reaction of delta-keto-acetylenes is described. The synthesis of pyrrolo[1,2-a]indole-2-carbaldehydes, starting from 2-carbonyl-1-propargyl-1H-indoles runs under mild reaction conditions. A conceivable mechanism is also discussed. TiCl(4) has proved to be an effective multiactivity reagent: catalyst/Lewis acid/water scavenger. Some unpublished 2-carbonyl-1-propargyl-1H-indoles are prepared by means of Suzuki- and Negishi-type reactions.