The first examples of unsymmetrical olefin cross-metathesis reactions in water, involving water-insoluble substrates, at room temperature and using commercially available catalysts are reported. The key to success is to include small percentages of the nonionic, vitamin E-based amphiphile "PTS". The nanometer micelles formed accommodate water-insoluble substrates, along with a readily available Ru-based metathesis catalyst. Reactions proceed at ambient temperatures with high efficiency and very high E-selectivity, and products are easily isolated.
Simply mixing a water-insoluble diolefinic substrate and Grubbs second generation catalyst in pure water containing small amounts of the amphiphile polyoxyethanyl a-tocopheryl sebacate (PTS) leads to efficient ring-closing metathesis.
<i>Objective:</i> A decline in the inhibitory neurotransmitter γ-aminobutyric acid (GABA) may enhance cytokine release in Alzheimer’s disease (AD) resulting in neuroinflammation. We investigated the GABA-mediated suppression of the synergistic release of interleukin (IL)-6 due to interleukin 1-β (IL-1β) and tumor necrosis factor-α (TNF-α). <i>Methods:</i> Rat C6 astrocytoma cells were treated with IL-1β and TNF-α in the absence and presence of GABA. Activation of p38, degradation of IĸB-α and total cellular IL-6 were determined by Western blot analysis. IL-6 release and gene expression were measured by ELISA and RT-PCR, respectively. <i>Results:</i> Although p38 and nuclear factor (NF)-ĸB are essential for the synergistic release of IL-6, GABA did not affect either p38 phosphorylation or IĸB-α degradation. Additionally, GABA suppressed IL-6 release but did not alter cytokine-driven synergistic increases in IL-6 gene expression. Western blot analysis revealed that co-treatments with IL-1β and TNF-α resulted in an increase in intracellular IL-6 that was prevented by GABA. <i>Conclusion:</i> GABA-induced inhibition of IL-6 release appears to coincide with a reduction in cellular IL-6. The GABA-induced suppression of IL-6 release may include inhibition of IL-6 gene translation.
Ruthenium-based metathesis catalysts are used in combination with PEG-600/α-tocopherol-based diester of sebacic acid (PTS)/H2O. The products are obtained with high efficiency and very high (E)-selectivities. -(LIPSHUTZ*, B. H.; AGUINALDO, G. T.; GHORAI, S.; VOIGTRITTER, K.; Org. Lett. 10 (2008) 7, 1325-1328;
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