ABSTRACT
Marine organisms are the source of an absolutely fantastic diversity of oxylipin structures, even greater than that found in their terrestrial counterparts. Over the last 30 years, research discoveries made with marine oxylipins have played many key roles in the development of eicosanoid research. Indeed, even the term “oxylipin,” which is now broadly utililized to describe the enzymatically oxidized lipids of higher plants and animals, was first proposed in the description of marine algal substances [1]. However, the marine dimension of oxylipin chemistry is not as well recognized as other areas within this broad field, perhaps because these organisms have relatively little societal impact and are sometimes difficult to access. The overwhelming majority of marine oxylipins derive from lipoxygenase (LOX) metabolism of polyunsaturated fatty acid (PUFA) precursors of a variety of carbon lengths (C-16 to C-22) and unsaturation patterns. Additional marine compounds of the oxylipin class derive from the metabolism of PUFA precursors by unique oxidative enzymes, and in a few cases, prostaglandin H synthase metabolism is implicated. However, it is the broad range of LOX metabolites produced by marine creatures, which is truly outstanding. These metabolites are notable both in the diversity of the substrates utilized, the site specificity of marine LOXs, and the secondary biosynthetic manipulations of the initially formed hydroperoxides, which, in turn, produce an enormous number of uniquely functionalized and cyclized structures. For example, naturally occurring halogenated (chloro-, bromo-, and iodo-) prostaglandin analogs, which derive from LOX metabolism, have been reported from marine corals and brown algae [2-5].
