RESUMEN
Apoptotic cells are known to suppress microglial inflammation in the brain by presenting phosphatidylserine. In this study, we newly designed polymeric particles that expose the anti-inflammatory site of phosphatidylserine to serve as an apoptotic cell-mimetic anti-inflammatory platform. The prepared anti-inflammatory particles showed no cytotoxicity and significantly inhibited the production of the inflammatory cytokine interleukin-6 against lipopolysaccharide stimulation in the microglia cell line MG6. This novel polymeric particle has potential for establishing a "cell-free" apoptotic cell-mimetic treatment for intracerebral inflammation.
RESUMEN
Treatment of dialkylbenzylsilanes (1) with trityl tetrakis(pentafluorophenyl)borate (TPFPB) afforded the corresponding silylium ions in equilibrium with their intra- or intermolecular π-complexes, which underwent dehydrogenative annulation with various alkenes to form 1,2,3,4-tetrahydro-2-silanaphthalenes (4) in up to 82% isolated yield. Sterically bulkier substituents on the silicon atom tended to increase the yield of cyclic products 4. The annulation products retained the stereochemistry in cases of the reactions using internal alkenes. The use of diisopropyl(1-naphthyl)silane (2) instead of 1 also resulted in annulation to obtain the 2,3-dihydro-1-sila-1H-phenalene derivatives 6. Electrophilic aromatic substitution at the 8-position was predominant, despite the two potentially reactive positions on the naphthyl group. The steric hindrance of the naphthyl group prevented addition of the cis-alkene to the silylium ion, which would considerably decrease yields of the desired products from 2 compared to those from 1.
