• Title/Summary/Keyword: Michael Addition

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Studies on Synthesis and Heterocyclisation Reactions of Michael Products and Formation of New 1, 4-Thiazine Quinoxaline Derivatives

  • Mahgoub, S.A.
    • Archives of Pharmacal Research
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    • v.13 no.4
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    • pp.319-324
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    • 1990

  • Synthesis of $\alpha$-piperidino and $\alpha$-morphelino styryl quinoxalinone 2f, 2g respectively by facile one step method is reported. The Michael adducts (3a-d) obtained by the interaction of 2-styryl-2 (1H) quinoxalinone (2) and ethylacetoacetate have been treated with resorcino and hydroxylamine separately. With resorcinol the chromones (4) are obtained whereas with ydroxylamine isoxazoles (6) are the products. Michael addition of acetylacetone to 2 leads to 3-[1'-aryl-2'-(2'-hydroxy-3'-quinoxalinyl)ethyl]-2, 4-pentanediones (5) which undergo cyclisation with hydroxylamine to give isoxazoles (7). Addition of thiopenol and thioglycolic acid to 2 gives 3-$\alpha$[$\beta$-(phenyl)-$\beta$-(plenylthio)]ethyl-2(1H)-quinoxalinone (8) and 3-$\alpha$-[$\beta$-phenyl)-$\beta$-(hydroxycarbonylmethylithio)]-ethyl-2(1H)-qui noxalinone (9) respectively. 2-Bromomethyl-2(1H)-quinoxalinone (1b) reacts with thioglycolic acid to gives S-[2 (1H)-oxoquionoxaline-3-yl-methyl] mercaptoacetic acid (10) which on cyclisation with acetic anhydride/pyridine affords 1, 2, 5, 6-tetrahydro [1, 4]thiazino[4, 3-a] quinoxaline-1, 6-dione (11).

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Anti-inflammatory Effects of Phytochemicals Having Michael Addition Acceptors by the Modulation of Toll-like Receptor Signaling Pathways (Michael addition acceptor 그룹을 가지고 있는 phytochemicals의 toll-like receptor 신호전달체계 조절을 통한 항염증 효과)

  • Youn, Hyung-Sun
    • Korean Journal of Food Science and Technology
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    • v.41 no.5
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    • pp.477-482
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    • 2009

  • Toll-like receptors (TLRs) play a critical role in the induction of innate immune responses that are essential for host defense against invading microbial pathogens. In general, TLRs have two major downstream signaling pathways, namely MyD88- and TRIF-dependent pathways, leading to the activation of nuclear factor-${\kappa}B$ (NF-${\kappa}B$) and interferon regulatory factor 3 (IRF3) and the expression of inflammatory mediators. TLR4 dimerization is required for the activation of downstream signaling pathways and may be one of the first lines of regulation in activating TLR-mediated signaling pathways. In this paper, the molecular targets of curcumin, 6-shogaol, and cinnamaldehyde in TLR signaling pathways will be discussed. Curcumin, 6-shogaol, and cinnamaldehyde with ${\alpha},{\beta}$-unsaturated carbonyl groups inhibit the dimerization of TLR4 induced by lipopolysaccharide, resulting in the downregulation of NF-${\kappa}B$ and IRF3. These results suggest that phytochemicals with the structural motif conferring Michael addition inhibit TLR4 dimerization, suggesting a novel mechanism for the anti-inflammatory activity of phytochemicals.

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