An Alternative Pathway to Leukotriene B₄ Enantiomers Involving a 1,8-Diol-Forming Reaction of an Algal Oxylipin

Oxidized lipids function as tissue hormones in mammals. An important class of these oxylipins are the immunomodulatory leukotrienes (LTs). Besides mammals, marine algae produce bioactive oxylipins, including LTs. The novel acid-labile oxylipin, (5R,8S)-dihydroxy eicosatetraenoic acid, from the edible alga Gracilaria vermiculophylla rearranges via a 1,8-diol-forming mechanism to inflammatory LTB₄ enantiomers that exhibit an enantio-specific potency toward LTB₄ receptor 1. This alternative pathway to a well-known leukotriene may explain food poisoning after Gracilaria consumption.