(±)9-HETE is one of the six monohydroxy fatty acids produced by the non-enzymatic oxidation of arachidonic acid. The individual R and S isomers of racemic HETEs have been separated and identified using chiral phase HPLC. The racemic HETEs have been quantified as an index of lipid peroxidation using GC/MS.
9(R)-HETE is an enantiomer which makes up 50% of (±)9-HETE . At a concentration of 300 nM, 9(R)-HETE activates RXRγ-dependent transcription 1.5 fold relative to a control. Stereochemical assignment of the (R) enantiomer is based on comparison of chiral HPLC retention times to published results.
9(S)-HETE is an enantiomer which makes up 50% of (±)9-HETE . There are no reports of 9(S)-HETE occurring as an enzymatic lipoxygenation product. Whereas 12(S)-HETE promotes adhesion of several cell lines to endothelial cell monolayes, 9(S)-HETE and other positional HETEs are without effect. Stereochemical assignment of the (S) enantiomer is based on comparison of chiral HPLC retention times to published results.
19-HETE is one of the major cytochrome P450 (CYP450) metabolites of arachidonic acid that is released from the kidney in response to angiotensin II. When formed by the CYP2E1 isoform, 19-HETE is composed of 70% and 30% of the (S) and (R) stereoisomers, respectively. Both 19(S)- and 19(R)-HETE are potent vasodilators of renal preglomerular vessels. 19(S)-HETE stimulates both renal sodium-potassium ATPase and volume absorption in the rabbit proximal straight tubule.
CAY10770 is an inhibitor of the cytochrome P450 (CYP) isoform CYP4Z1 (IC50= 5.9 μM).1It is selective for CYP4Z1 over CYP4A11, CYP4F2, CYP4F3a, CYP4F3b (IC50s = 187-282 μM) but does inhibit CYP4F8 and CYP4F12 (IC50s = 167 and 91 μM, respectively). CAY10770 (3 μM) inhibits the production of 14(15)-EET, 19-HETE, and 14(15)-DiHET by 83, 86, and 80%, respectively, in T47D breast cancer cells expressing CYP4Z1.
1.Kowalski, J.P., McDonald, M.G., Pelletier, R.D., et al.Design and characterization of the first selective and potent mechanism-based inhibitor of cytochrome P450 4Z1J. Med. Chem.63(9)4824-4836(2020)