17(S)-HDHA is a primary mono-oxygenation product of docosahexaenoic acid in human whole blood, human leukocytes, and mouse brain. 17(S)-HDHA serves as a precursor to 17(S)-resolvins and has intrinsic biological activity, such as the inhibition of TNF-α-induced interleukin-1β expression in human glioma cells and inhibition of TNF-α-induced leukocyte trafficking to the mouse air pouch.
(±)17-HDHA is an autoxidation product of docosahexaenoic acid in vitro. It is also produced from incubations of DHA in rat liver, brain, and intestinal microsomes. 17(S)-HDHA could be produced by enzymatic oxidation of DHA using soybean lipoxygenase (LO) and is the putative product of mammalian 15-LOs. 17(S)-HDHA was shown to be an inhibitor of U-46619 -induced rabbit and rat aortic smooth muscle contraction with IC50 values of 4.9 and 7.2 μM, respectively. (±)17-HDHA is a potential marker of oxidative stress in brain and retina where DHA is an abundant polyunsaturated fatty acid.
Resolvin conjugate in tissue regeneration 1 (RCTR1) is a specialized pro-resolving mediator (SPM) biosynthesized from docosahexaenoic acid by isolated human macrophages and apoptotic polymorphonuclear (PMN) neutrophils.1It has been found in human spleen and bone marrow.2RCTR1 is produced via lipoxygenase-mediated oxidation of DHA to 7(S)-8-epoxy-17(S)-HDHA, which is conjugated to glutathione.1,2,3RCTR1 (10 nM) increases phagocytosis ofE. colior apoptotic neutrophils in isolated human monocyte-derived macrophages.2It decreases chemotaxis induced by leukotriene B4in isolated human neutrophils when used at a concentration of 10 nM. RCTR1 (1 and 10 nM) accelerates tissue regeneration in planaria. Intraperitoneal administration of RCTR1 (100 ng/animal) shortens the inflammatory resolution period and decreases inflammatory exudate neutrophil infiltration in a mouse model ofE. coli-induced peritonitis. 1.Dalli, J., Ramon, S., Norris, P.C., et al.Novel proresolving and tissue-regenerative resolvin and protectin sulfido-conjugated pathwaysFASEB J.29(5)2120-2136(2015) 2.de la Rosa, X., Norris, P.C., Chiang, N., et al.Identification and complete stereochemical assignments of the new resolvin conjugates in tissue regeneration in human tissues that stimulate proresolving phagocyte functions and tissue regenerationAm. J. Pathol.188(4)950-966(2018) 3.Rodriguez, A.R., and Spur, B.W.First total synthesis of pro-resolving and tissue-regenerative resolvin sulfido-conjugatesTetrahedron Lett.58(16)1662-1668(2017)