Resolvins are a family of potent lipid mediators derived from both eicosapentaenoic acid and docosahexaenoic acid . [1] In addition to being anti-inflammatory, resolvins promote the resolution of the inflammatory response back to a non-inflamed state.[2] Resolvin D5 (RvD5) is a DHA-derived resolvin generated by a double dioxygenation mechanism.[3] RvD5 has been identified in media from ionophore-stimulated trout brain cells, in human synovial fluid from patients with rheumatoid arthritis, and in exudates of bacterial infections in mice. [4][5][6] RvD5 stimulates the phagocytosis of E. coli by human macrophages, and RvD5 methyl ester enhances bacterial killing in mice inoculated with E. coli. [6] Analytical and biological comparisons of synthetic RvD5 with endogenously derived RvD5 have confirmed its identity as matching the natural product.[7]