Discovery of the mammalian insulin release modulator, hepoxilin B3, from the tropical red algae Platysiphonia miniata and Cottoniella filamentosa.

The insulin release enhancer, 10-hydroxy-11,12-trans-epoxy-5(Z),8(Z),14(Z)-icosatrienoic acid (hepoxilin B3), is a 12-lipoxygenase metabolite of arachidonic acid that has been found in various mammalian tissues. Although lipoxygenase pathways are well documented in terrestrial plants, this lipoxygenase product has never been isolated from the plant kingdom. Herein, we report the first isolation of this lipoxygenase product, hepoxilin B3, from two plants, the tropical red marine algae Platysiphonia miniata (C. Agardh) Børgesen and Cottoniella filamentosa Børgesen. Furthermore, through application of two-dimensional NMR methodology to the structural description of this algal natural product, we demonstrate the tremendous power of this technique in this chemical class.