Potential therapeutic antioxidants that combine the radical scavenging ability of myricetin and the lipophilic chain of vitamin E to effectively inhibit microsomal lipid peroxidation
摘要:
The flavonol myricetin, reacts with oxygen-centred galvinoxyl radicals 28 times faster than d-alpha-tocopherol (vitamin E), the main lipid-soluble antioxidant in biological membranes. Moreover, each myricetin molecule reduces twice as many such radicals as vitamin E. However, myricetin fails to protect vitamin E-deficient microsomes from lipid peroxidation as assessed by the formation of thiobarbituric acid reactive substances (TBARS). Novel and potentially therapeutic antioxidants have been prepared that combine the radical-scavenging ability of a myricetin-like head group with a lipophilic chain similar to that of vitamin E. C-6-C-12 alkyl chains are attached to the A-ring of either a 3,3',4',5'-tetrahydroxyflavone or a 3,2',4',5'-tetrahydroxyflavone head group to give lipophilic flavonoids (Clog P = 4 to 10) that markedly inhibit iron-ADP catalysed oxidation of microsomal preparations. Orientation of the head group as well as total lipophilicity are important determinants of antioxidant efficacy. MM2 models indicate that our best straight chain 7-alkylflavonoids embed to the same depth in the membrane as vitamin E. The flavonoid head groups are prepared by aldol condensation followed by Algar-Flynn-Oyamada (AFO) oxidation or by Baker-Venkataraman re-arrangement. The alkyl tails are introduced by Suzuki or Negishi palladium-catalysed cross-coupling or by cross-metathesis catalysed by first generation Grubbs catalyst, which tolerate phenolic hydroxyl and ketone groups. (C) 2004 Elsevier Ltd. All rights reserved.
A Facile and General Approach to 3-((Trifluoromethyl)thio)-4<i>H</i>-chromen-4-one
作者:Haoyue Xiang、Chunhao Yang
DOI:10.1021/ol502751k
日期:2014.11.7
A facile and efficient synthetic strategy to 3-((trifluoromethyl)thio)-4H-chromen-4-one was developed. AgSCF3 and trichloroisocyanuric acid were employed here to generate active electrophilic trifluoromethylthio species in situ. This reaction could proceed under mild conditions in a short reaction time and be insensitive to air and moisture.
开发了一种简便有效的合成3-((三氟甲基)硫代)-4 H -chromen-4-one的策略。这里使用AgSCF 3和三氯异氰尿酸原位产生活性的亲电子三氟甲硫基物质。该反应可在温和的条件下在短的反应时间内进行,并且对空气和湿气不敏感。
[EN] FLAVONOID COMPOUNDS AS THERAPEUTIC ANTIOXIDANTS<br/>[FR] COMPOSES FLAVONOIDES EN TANT QU'ANTIOXYDANTS THERAPEUTIQUES
申请人:ROWETT RES INST
公开号:WO2004007475A1
公开(公告)日:2004-01-22
Novel flavonoid compounds having anti-oxidant activity are described. Formula (1). The compounds have been shown to exhibit anti-oxidative properties in biological systems and their utility in a sunscreen or skincare composition or to treat conditions involving oxidative damage, especially curative or prophylactic treatment of Alzheimer's disease or ischaemia-reperfusion and injury, is described.
The formal [3+3] cyclization of 1,3-bis(silyloxy)buta-1,3-dienes with 1-aryl-3-ethoxyprop-2-en-1-ones, available by Heck reaction of benzoyl chlorides with ethyl vinyl ether, afforded a variety of 6-arylsalicylates. The reaction of the products with concentrated sulfuric acid resulted in the formation of fluorenones. 6-Alkylsalicylates were prepared by cyclization of 1,3-bis(silyloxy)buta-1,3-dienes
Synthesis of Multisubstituted 2-Aminopyrroles/pyridines via Chemoselective Michael Addition/Intramolecular Cyclization Reaction
作者:Xueyu Qi、Haoyue Xiang、Qian He、Chunhao Yang
DOI:10.1021/ol5018855
日期:2014.8.15
A facile and efficient synthetic strategy to construct polysubstituted 2-aminopyrroles/pyridines was developed via chemoselective Michaeladdition/intramolecular cyclization reaction under very mild conditions. It suggested that the chemoselectivity of the process could be controlled by the leaving ability of the halides.