11(R)-HEPE is produced by the oxidation of EPA by 11(R)-LO. This enzymatic activity and the resulting 11(R)-hydroxy acid have been isolated from the sea urchin S. purpuratus.
11(R)-HETE is biosynthesized by 11(R)-LOs of the sea urchin, S. purpuratus, and the fresh water hydra, H. vulgaris. The biological activity of 11(R)-HETE relates to oocyte maturation and tentacle regeneration, respectively, in these two species. 11(R)-HETE is also produced when aspirin-treated recombinant COX-2 is incubated with arachidonic acid. Stereochemical assignment of the (R) enantiomer is based on comparison of chiral HPLC retention times to published results.
Cyclic ADP-ribose (cADP-ribose) is a calcium mobilizing nucleotide that is biosynthesized from NAD+ by cADP-ribose synthases, including CD38. cADP-Ribose appears to activate calcium channels in intracellular membranes, which in turn activate ryanodine receptors. 8-bromo-cADP-Ribose is a stable, cell-permeable analog that blocks calcium release evoked by cADP-ribose in sea urchin egg homogenates with an IC50 value of 1.7 μM. It is commonly used to investigate intracellular signaling through cADP-ribose in isolated cells and tissues.
12(R)-HEPE, a monohydroxy fatty acid derived from EPA in the eggs of the sea urchin S. purpuratus, has a biological activity that, while not extensively documented, may resemble that of 12(R)-HETE (Catalog No.34560).