RESUMO
Glyceraldehyde 3-phosphates are important intermediates of many central metabolic pathways in a large number of living organisms. d-Glyceraldehyde 3-phosphate (d-GAP) is a key intermediate during glycolysis and can as well be found in a variety of other metabolic pathways. The opposite enantiomer, l-glyceraldehyde 3-phosphate (l-GAP), has been found in a few exciting new pathways. Here, improved syntheses of enantiomerically pure glyceraldehyde 3-phosphates are reported. While d-GAP was synthesized by periodate cleavage of d-fructose 6-phosphate, l-GAP was obtained by enzymatic phosphorylation of l-glyceraldehyde. (1)H- and (31)P NMR spectroscopy was applied in order to examine pH-dependent behavior of GAP over time and to identify potential degradation products. It was found that GAP is stable in acidic aqueous solution below pH 4. At pH 7, methylglyoxal is formed, whereas under alkaline conditions, the formation of lactic acid could be observed.
Assuntos
Gliceraldeído 3-Fosfato/química , Gliceraldeído 3-Fosfato/síntese química , Glicerol Quinase/metabolismo , Cellulomonas/enzimologia , Técnicas de Química Sintética , Estabilidade de Medicamentos , Concentração de Íons de Hidrogênio , EstereoisomerismoRESUMO
The process for selecting potent and effective carbohydrate antigens is not well-established. A combination of synthetic glycan microarray screening, surface plasmon resonance analysis, and saturation transfer difference NMR spectroscopy was used to dissect the antibody-binding surface of a carbohydrate antigen, revealing crucial binding elements with atomic-level detail. This analysis takes the first step toward uncovering the rules for structure-based design of carbohydrate antigens.
Assuntos
Anticorpos/imunologia , Bacillus anthracis/imunologia , Mapeamento de Epitopos/métodos , Oligossacarídeos/imunologia , Anticorpos/química , Bacillus anthracis/química , Sítios de Ligação de Anticorpos , Espectroscopia de Ressonância Magnética/métodos , Análise em Microsséries/métodos , Modelos Moleculares , Oligossacarídeos/química , Ressonância de Plasmônio de Superfície/métodosRESUMO
By a stepwise synthesis strategy biofunctionalized Pyrrolopyrrole Cyanines (PPCy) with an asymmetric substitution pattern were obtained. These exhibit extremely strong and narrowband NIR absorption and fluorescence. Internalization of a peptide bound PPCy is demonstrated using live cell microscopy.
Assuntos
Corantes Fluorescentes/química , Pirróis/química , Células HeLa , Humanos , Microscopia de Fluorescência , Estrutura Molecular , Espectroscopia de Luz Próxima ao Infravermelho , EstereoisomerismoRESUMO
Three generations of bidentate phosphinated Pd(II) dendrimers are efficient catalysts in the absence of copper co-catalyst for the Sonogashira reaction and are, with two cyclohexyl substituents on the phosphorus atoms, recovered by precipitation and re-used.
