The identification of glycerophosphorylglycerol phosphate as the deacylation product of a new brain lipid.

When the water-soluble phosphate esters produced by mild alkaline methanolysis of rat brain lipids were separated on an anion exchange column, a fraction was observed which chromatographed between bis(glycerophosphoryl)glycerol and glycerophosphorylinositol phosphate. This compound did not correspond with the deacylation product from any phospholipid previously reported in brain. Evidence is presented here that the deacylation product is l-(L-3-glycerophosphoryl)-L-glycerol 3-phosphate,’ and it is proposed that it is derived from l-(phosphatidyl)L-glycerol 3-phosphate. Evidence that phosphatidylglycerol phosphate occurs in trace amounts in liver as an intermediate in the synthesis of phosphatidylglycerol has been reported (1).