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.
(±)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.