MSI_000003374

PIP(20:0/20:3(5Z,8Z,11Z)-O(14R,15S)) is an oxidized phosphatidylinositol phosphate (PIP). As other PIPs, oxidized phosphatidylinositol phosphates are acidic (anionic) phospholipids that consist of a phosphatidic acid backbone, linked via the phosphate group to a phosphorylated inositol (hexahydroxycyclohexane). Phosphatidylinositol phosphates are generated from phosphatidylinositols, which are phosphorylated by a number of different kinases that place the phosphate moiety on positions 4 and 5 of the inositol ring, although position 3 can also be phosphorylated. Phosphatidylinositol phosphates can have many different combinations of fatty acids of varying lengths and saturation attached at the C-1 and C-2 positions. PIP(20:0/20:3(5Z,8Z,11Z)-O(14R,15S)), in particular, consists of one chain of eicosanoyl at the C-1 position and one chain of 14,15-epoxyeicosatrienoyl at the C-2 position. The most important phosphatidylinositol phosphate in both quantitative and biological terms is phosphatidylinositol 4-phosphate. Phosphatidylinositol and the phosphatidylinositol phosphates are the main source of diacylglycerols that serve as signaling molecules, via the action of phospholipase C enzymes. Phosphatidylinositol phosphates are usually present at low levels only in tissues, typically at about 1 to 3\\% of the concentration of phosphatidylinositol.