Ibuprofen Impurity K is a compound that serves as an impurity in Ibuprofen. Ibuprofen itself is an anti-inflammatory inhibitor specifically designed to targetCOX-1 and COX-2. It exhibits inhibitory activity with IC50 values of 13 μM and 370 μM for COX-1 and COX-2, respectively.
URB754 is a potent and noncompetitive inhibitor of monoacylglycerol lipase (MAGL), exhibiting an IC50 value of 200 nM for the recombinant rat brain enzyme. However, it does not inhibit human recombinant, rat brain, or mouse brain MAGL at concentrations up to 100 μM. There is evidence that the MAGL inhibitory activity of URB754 may be attributed to the impurity bis(methylthio)mercurane (IC50 = 11.9 nM for rat recombinant MAGL) that is found in commercial preparations. URB754 inhibits rat brain fatty acyl amide hydrolase (FAAH) with an IC50 value of 32 μM and binds weakly to the rat central cannabinoid (CB1) receptor with an IC50 value of 3.8 μM. It does not inhibit COX-1 or COX-2 at concentrations up to 100 μM. Inhibition of MAGL hydrolysis of 2-arachidonoyl glycerol (2-AG) is associated with enhanced stress-induced analgesia and may represent a novel drug target in pain and stress management.
15(R)-HETE, a monohydroxy fatty acid, is synthesized from arachidonic acid via aspirin-acetylated COX-2, leading to the formation of specialized pro-resolving mediators 15(R)-lipoxin A4 and B4 through a transcellular mechanism involving 5-lipoxygenase (5-LO). Additionally, this compound is produced by the cytochrome P450 (CYP) isoform CYP2C9 and can be generated from arachidonic acid by COX-1 in human mast cells, where it accumulates due to its resistance to conversion into 15-KETE by 15-hydroxyprostaglandin dehydrogenase (15-PGDH). As an agonist of PPARβ δ, 15(R)-HETE induces the expression of a target gene in NIH3T3 cells, demonstrating its biological significance.