Survival and differentiation of neuroectodermal cells with stem cell properties at different oxygen levels.

Freeze-lesioned regions of the forebrain cortex provide adequate environment for growth of non-differentiated neural progenitors, but do not support their neuron formation. Reduced oxygen supply, among numerous factors, was suspected to impair neuronal cell fate commitment. In the present study, proliferation and differentiation of neural stem/progenitor cells were investigated at different oxygen levels both in vitro and in vivo.

A concise, total synthesis and antibacterial evaluation of 2-hydroxy-1-(1H-indol-3-yl)-4-methylpentan-3-one.

Treatment of racemic 2-hydroxy-3-(1H-indol-3yl)propionic acid methyl ester (5) with isopropyl magnesium chloride provided the title compound 1 and its isomer, 3-hydroxy-1-(indol-3-yl)-4-methylpentan-2-one (9). Both enantiomers (>96% ee) of each component were obtained via semi-preparative chiral supercritical fluid chromatography (SFC). In contrast to previous reports, these compounds, as well as their acetate derivatives, were not active or very weakly active against 16 bacterial strains, including Escherichia coli, Bacillus subtilis and Staphylococcus aureus.

Synthesis of a novel, recyclable, solid-phase acylating reagent.

In this paper, we describe the synthesis of N-(6-cyano-1,3-dimethyl-2,4-dioxo-5-substituted-1,3-dihydropyridino[2,3-d] pyrimidin-7-yl)imides 1. We will show the synthesis of 1 using both conventional heating and microwave techniques. In addition, the imide was attached to polystyrene and this immobilized imide was equally as effective at acylating various primary and secondary amines as its solution-phase counterpart.

Fast and quantitative high-performance liquid chromatography method for the determination of 9-fluorenylmethoxycarbonyl release from solid-phase synthesis resins.

Base catalyzed cleavage of 9-fluorenylmethoxycarbonyl (FMOC) group and subsequent analysis by UV spectrophotometry is a commonly used technique for measuring the loading of functional groups on solid supports. Recent works suggest that using 1,8-diazabicyclo[5,4,0]undec-7-ene (DBU) instead of piperidine makes it possible to use gas chromatography for quantitation, but due to the long deprotection time used, the method is not high-throughput. We observed that the dibenzofulvene released after DBU deprotection could be measured by reversed-phase (RP) HPLC.

Peptides as affinity surfaces for protein purification.

The tetrapeptide GPRP was previously shown to be an effective affinity ligand for fibrinogen when immobilized to Fractogel (Kuyas et al., 1990). The authors synthesized the GPRP peptide directly onto an aminefunctionalized POROS chromatographic resin to demonstrate the effectiveness of this approach for generating perfusive affinity media.