New C16 fatty-acid-based oxylipin pathway in the marine diatom Thalassiosira rotula

Abstract

An unprecedented series of C₁₆ oxylipins (1–8) has been characterized from the marine diatom Thalassiosira rotula. Absolute stereochemistry of the major alcohols 2 and 3 was determined to be 9S by spectroscopic and chemical methods. All the described products are formally derived by unprecedented enzymatic oxidation of C₁₆ fatty acids. Conversion of hexadeca-6,9,12-trienoic acid (C16:3 ω-4) into 3 unequivocally established the occurrence of (at least) a specific 9S-oxygenase activity. To the best of our knowledge, the present data reveal for the first time the existence of an organic network of oxygenase-mediated transformations that require C₁₆ fatty acids as substrates in living cells.