– Resolvin D1 is produced physiologically from the sequential oxygenation of docosahexaenoic acid by 15- and 5-lipoxygenase . It reduces human polymorphonuclear leukocyte transendothelial migration, the earliest event in acute inflammation, with an EC50 value of ~30 nM. RvD1 methyl ester is a methyl ester version of the free acid that may act as a lipophilic prodrug form that will alter its distribution and pharmacokinetic properties. The methyl ester moiety is susceptible to cleavage by intracellular esterases, leaving the free acid.