5(S),6(R)-DiHETE is a dihydroxy polyunsaturated fatty acid and a nonenzymatic hydrolysis product of leukotriene A4 (LTA4). Mouse liver cytosolic epoxide hydrolase catalyzes the conversion of LTA4 to 5(S),6(R)-DiHETE. It is a weak LTD4 receptor agonist in guinea pig lung membranes. It induces guinea pig ileum contraction with an ED50 value of 1.3 μM.
5(S),6(R)-11-trans DiHETE is a C-11 double bond isomer of 5(S),6(R)-DiHETE that is formed by the enzymatic isomerization of 5(S),6(R)-DiHETE by a membrane bound factor. 5(S),6(R)-11-trans DiHETE has been found in rat kidney homogenates and is potentially formed by the epoxide hydrolase pathway in this tissue. The isomerase activity responsible for the conversion of leukotriene B4 (LTB4) to 6-trans LTB4 in rat kidney homogenates has also been implicated in its formation. 5(S),6(R)-11-trans DiHETE is not a substrate for soybean lipoxygenase. The biological activity of 5(S),6(R)-11-trans DiHETE has not been reported.
Metabolism of 12(R)-HETE in corneal tissue produces predominantly the compound resulting from the loss of four carbon atoms through β-oxidation from C-1. This metabolite is 8(R)-hydroxy hexadecatrienoic acid (8(R)-HHxTrE) or 2,3,4,5-tetranor 12(R)-HETE.
12(R)-HEPE, a monohydroxy fatty acid derived from EPA in the eggs of the sea urchin S. purpuratus, has a biological activity that, while not extensively documented, may resemble that of 12(R)-HETE (Catalog No.34560).
Biosynthesis of 12(R)-HETE in invertebrates is via lipoxygenation of arachidonic acid . In mammals, 12(R)-HETE can be produced by 12(R)-LOs and also by CYP450 oxidation. The activity of 12(R)-HETE in mammals is predominantly proinflammatory. 12(R)-HETE exhibits dose-dependent leukocyte chemotaxis at concentrations as low as 100 nM, and lowers intraocular pressure in rabbits.
HG-12-6 is a type II inhibitor of IRAK4. HG-12-6 shows preferential binding to unphosphorylated inactive IRAK4 (IC50: 165 nM). HG-12-6 can modulate IRAK4 activity in autoimmunity and inflammation.