The highly enantioselective hydrogenation of 3-aryl-2H-1,4-benzoxazines was achieved using the (cyclooctadiene)iridium chloride dimer/(S)-SegPhos/iodine [Ir(COD)Cl]2/(S)-SegPhos/I2} system as catalyst with up to 92% ee. The 3-styryl-2H-1,4-benzoxazine derivatives were also hydrogenated by the iridium catalyst and Pd/C in two consecutive steps whereby 93–95% ee values were obtained.
使用(环辛二烯)铱氯化二聚物/(S)-SegPhos /碘[Ir(COD)Cl] 2 /(S)-SegPhos实现对3-芳基2 H -1,4-苯并恶嗪的高度对映选择性氢化/ I 2 }体系作为催化剂,ee最高可达92%。3-styryl-2 H -1,4-苯并恶嗪衍生物还通过铱催化剂和Pd / C在两个连续的步骤中进行氢化,从而获得93-95%ee值。
The tiliroside derivative, 3-O-[(E)-(2-oxo-4-(p-tolyl) but–3–en–1–yl] kaempferol produced inhibition of neuroinflammation and activation of AMPK and Nrf2/HO-1 pathways in BV-2 microglia
作者:Ravikanth Velagapudi、Faisal Jamshaid、Izabela Lepiarz、Folashade O. Katola、Karl Hemming、Olumayokun A. Olajide
DOI:10.1016/j.intimp.2019.105951
日期:2019.12
Neuroinflammation is now widely accepted as an important pathophysiological mechanism in neurodegenerative disorders, thus providing a critical target for novel compounds. In this study, 3-O-[(E)-(2-oxo-4-(p-tolyl)but-3-en-1-yl) kaempferol (OTBK) prevented the production of pro-inflammatory mediators TNF alpha, IL-6, PGE(2) and nitrite from BV-2 microglia activated with LPS and IFN gamma. These effects were accompanied by reduction in the levels of pro-inflammatory proteins COX-2 and iNOS. Involvement of NF-kappa B in the anti-inflammatory activity of OTBK was evaluated in experiments showing that the compound prevented phosphorylation, nuclear accumulation and DNA binding of p65 sub-unit induced by stimulation of BV-2 microglia with LPS and IFN gamma. Exposure of mouse hippocampal HT22 neurons to conditioned media from LPS + IFN gamma-stimulated BV-2 cells resulted in reduced cell viability and generation of cellular reactive oxygen species. Interestingly, conditioned media from LPS/IFN gamma-stimulated BV-2 cells which were treated with OTBK did not induce neuronal damage or oxidative stress. OTBK was shown to increase protein levels of phospho-AMPK alpha, Nrf2 and HO-1 in BV-2 microglia. It was further revealed that OTBK treatment increased Nrf2 DNA binding in BV-2 microglia. The actions of the compound on AMPK alpha and Nrf2 were shown to contribute to its anti-inflammatory activity as demonstrated by diminished activity in the presence of the AMPK antagonist dorsomorphin and Nrf2 inhibitor trigonelline. These results suggest that OTBK inhibits neuroinflammation through mechanisms that may involve activation of AMPK alpha and Nrf2 in BV-2 microglia.