Enantioselective Responses to a Phosphorothioate Analogue of Lysophosphatidic Acid with LPA3Receptor-Selective Agonist Activity

The metabolically stabilized LPA analogue, 1-oleoyl-2-O-methyl-rac-glycerophosphothioate (OMPT), is a potent agonist for the LPA(3) G-protein-coupled receptor. A new enantiospecific synthesis of both (2R)-OMPT and (2S)-OMPT is described. Calcium release assays in both LPA(3)-transfected insect Sf9 and rat hepatoma Rh7777 cells showed that (2S)-OMPT was 5- to 20-fold more active than (2R)-OMPT. Similar results were found for calcium release, MAPK and Akt activation, and IL-6 release in human OVCAR3 ovarian cancer cells.