RESUMO
A phosphine-mediated, well-designed Morita-Baylis-Hillman-type/Wittig cascade for the rapid assembly of a quinolinone framework from benzaldehyde derivatives is developed for the first time. By rationally combining I2/NIS-mediated cyclization, biologically relevant 3-(benzopyrrole/furan-2-yl) quinolinones were facilely synthesized in a one-pot process by starting from 3-styryl-quinolinones bearing an o-hydroxy/amino group, significantly expanding the chemical space of this privileged skeleton. Further utility of this protocol is illustrated by successfully performing this transformation in a catalytic manner through in situ reduction of phosphine oxide by phenylsilane.
Assuntos
Fosfinas , Quinolonas , Ciclização , FuranosRESUMO
A double junction interface was utilized to preserve separation efficiency and alleviate ion suppression from sulfated ß-cyclodextrin (S-ß-CD) in electrokinetic chromatography-electrospray ionization-mass spectrometry. The utility of the approach was demonstrated by chiral EKC-MS analysis of dihydroxyphenylalanine and methyldihydroxyphenylalanine enantiomers using either low concentration (counter-migration mode; 0.1% S-ß-CD) or high concentration (carrier mode; 2% S-ß-CD). In the counter-migration mode, S-ß-CD anions were supplied continuously from the junction reservoir to the separation column so that the effective separation length was preserved. This interface is especially useful under carrier mode in which high concentration of S-ß-CD will migrate toward the ESI source. With the use of the double junction interface, the S-ß-CD exited the separation column will remain in the junction reservoir, whereas the analyte will flow toward the ESI source through a connecting column. As a result, no ion suppression was observed and the sensitivity was improved significantly.
Assuntos
Cromatografia Capilar Eletrocinética Micelar/métodos , Espectrometria de Massas por Ionização por Electrospray/métodos , Cromatografia Capilar Eletrocinética Micelar/instrumentação , Di-Hidroxifenilalanina/análogos & derivados , Di-Hidroxifenilalanina/química , Di-Hidroxifenilalanina/isolamento & purificação , Modelos Químicos , Espectrometria de Massas por Ionização por Electrospray/instrumentação , Estereoisomerismo , beta-Ciclodextrinas/químicaRESUMO
Axons are long, slender processes of neurons that have various functions at different stages of development. Here, we report the use of a chip device to study the effects of various exogenous proteins on the growth and presynaptic differentiation of axons in a high-throughput manner. The device consists of a glass chip whose surface contains a protein-coated micropattern. When neurons are maintained on the chip, a specific region of the chip surface will be occupied exclusively by axons. The axons and clusters of release-competent synaptic vesicles, a presynapse-like specialization in the axon, can be quantified as the proportions of this specific region's area occupied respectively by these subcellular structures. By using chips with this specific region coated with different proteins, these proteins' effects on the growth and presynaptic differentiation of the axon were investigated by comparing the amounts of axons and clusters of release-competent synaptic vesicles in this region of the chip. We also demonstrate another application of this chip device by investigating the effective range of the signal produced by the interaction between neurons and neuroligin 1 in neurons. These results indicate the diverse applications of the chip device in exploring various issues pertaining to axonal functions.
Assuntos
Axônios , Moléculas de Adesão Celular Neuronais/metabolismo , Ensaios de Triagem em Larga Escala/métodos , Proteínas Imobilizadas , Neurônios , Animais , Axônios/efeitos dos fármacos , Axônios/metabolismo , Moléculas de Adesão Celular/química , Moléculas de Adesão Celular/metabolismo , Moléculas de Adesão Celular Neuronais/química , Moléculas de Adesão Celular Neuronais/farmacologia , Diferenciação Celular/efeitos dos fármacos , Desenvolvimento Embrionário , Matriz Extracelular/química , Matriz Extracelular/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Proteínas Imobilizadas/química , Proteínas Imobilizadas/farmacologia , Lisina/química , Neurônios/citologia , Neurônios/efeitos dos fármacos , Gravidez , Ligação Proteica , Mapeamento de Interação de Proteínas , Ratos , Ratos Sprague-Dawley , Vesículas Sinápticas/efeitos dos fármacos , Vesículas Sinápticas/metabolismoRESUMO
Compounds bearing fluorinated moieties are pervasive in a wide range of pharmaceuticals and agrochemicals. The installation of fluorinated units is a persistently vital task in synthetic chemistry, where facile and manipulable assays are highly demanding. Herein, we establish a general and programmable fluorination strategy for the modular assembly of mono- and difluoromethylarenes through the controllable deprotonation and fluorination of phosphonium ylides. Moreover, the rational combination of the reaction sequence allows the rapid construction of diversified fluorine-containing arenes.