γ-Hydroxyalkenals Are Oxidatively Cleaved through Michael Addition of Acylperoxy Radicals and Fragmentation of Intermediate β-Hydroxyperesters
摘要:
Oxidative cleavage of arachidonate (C-20) and linoleate (C-18) phospholipids generates truncated C-8 or C-12 gamma-hydroxyalkenal phospholipids as well as C-5 or C-9 carboxyalkanoate phospholipids, which are abundant in atherosclerotic plaques. The gamma-hydroxyalkenals promote foam cell formation by scavenger receptor CD36-mediated endocytosis. The carboxyalkanoates are potent regulators of endothelial cell functions that may promote atherogenesis. We now report an unexpected biosynthetic interconnection; the carboxyalkanoates can be generated through oxidative cleavage of the gamma-hydroxyalkenals with the loss of three carbons. This unprecedented transformation is shown to involve Michael addition of an acylperoxy radical and fragmentation of the resulting beta-hydroxyperester.
γ-Hydroxyalkenals Are Oxidatively Cleaved through Michael Addition of Acylperoxy Radicals and Fragmentation of Intermediate β-Hydroxyperesters
作者:Yuvaraju N. Balamraju、Mingjiang Sun、Robert G. Salomon
DOI:10.1021/ja048060i
日期:2004.9.1
Oxidative cleavage of arachidonate (C-20) and linoleate (C-18) phospholipids generates truncated C-8 or C-12 gamma-hydroxyalkenal phospholipids as well as C-5 or C-9 carboxyalkanoate phospholipids, which are abundant in atherosclerotic plaques. The gamma-hydroxyalkenals promote foam cell formation by scavenger receptor CD36-mediated endocytosis. The carboxyalkanoates are potent regulators of endothelial cell functions that may promote atherogenesis. We now report an unexpected biosynthetic interconnection; the carboxyalkanoates can be generated through oxidative cleavage of the gamma-hydroxyalkenals with the loss of three carbons. This unprecedented transformation is shown to involve Michael addition of an acylperoxy radical and fragmentation of the resulting beta-hydroxyperester.