(±)4-HDHA

(±)4-HDHA is an autoxidation product of docosahexaenoic acid (DHA) in vitro. It is also produced from incubations of DHA in rat liver, brain, and intestinal microsomes. Enzymatic transformation of DHA by RBL-1 cells also produces 4-HDHA. However, the enzymatic product is most likely the S-isomer. (±)4-HDHA is a potential marker of oxidative stress in brain and retina where DHA is an abundant polyunsaturated fatty acid.

22-HDHA is an oxidation product of docosahexaenoic acid . In vitro, it is formed upon incubation of rat liver microsomes with DHA and NADPH and also by the human cytochrome P450 (CYP) isoform CYP4F3B in BTI-TN-5B1-4 microsomes. Serum levels of 22-HDHA increase following dietary DHA supplementation in humans.

(±)10-HDHA is an autoxidation product of docosahexaenoic acid (DHA) in vitro.[1][2] It is also produced from incubations of DHA in rat liver, brain, and intestinal microsomes.[3][4][5] (±)10-HDHA is a potential marker of oxidative stress in brain and retina where DHA is an abundant polyunsaturated fatty acid. Reference：[1]. VanRollins, M., and Murphy, R.C. Autooxidation of docosahexaenoic acid: Analysis of ten isomers of hydroxydocosahexaenoate. J. Lipid Res. 25(5), 507-517 (1984).[2]. Reynaud, D., Thickitt, C.P., and Pace-Asciak, C.R. Facile preparation and structural determination of monohydroxy derivatives of docosahexaenoic acid (HDoHE) by α-tocopherol-directed autoxidation. Anal. Biochem. 214(1), 165-170 (1993).[3]. VanRollins, M., Baker, R.C., Sprecher, H., et al. Oxidation of docosahexaenoic acid by rat liver microsomes. J. Biol. Chem. 259(9), 5776-5783 (1984).[4]. Yamane, M., Abe, A., and Yamane, S. High-performance liquid chromatography-thermospray mass spectrometry of epoxy polyunsaturated fatty acids and epoxyhydroxy polyunsaturated fatty acids from an incubation mixture of rat tissue homogenate. J. Chromatogr. 652(2), 123-136 (1994).[5]. Kim, H.Y., Karanian, J.W., Shingu, T., et al. Sterochemical analysis of hydroxylated docosahexaenoates produced by human platelets and rat brain homogenate. Prostaglandins 40(5), 473-490 (1990).

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)