MSI_000030265

PG(a-13:0/i-22:0) is a phosphatidylglycerol - a glycerophospholipid in which a phosphoglycerol moiety occupies a glycerol substitution site. As is the case with diacylglycerols, phosphatidylglycerols can have many different combinations of fatty acids of varying lengths and saturation attached at the C-1 and C-2 positions. Fatty acids containing 16, 18 and 20 carbons are the most common. PG(a-13:0/i-22:0), in particular, consists of one chain of anteisotridecanoic acid at the C-1 position and one chain of isodocosanoic acid at the C-2 position. Phosphatidylglycerol is present at a level of 1-2\\% in most animal tissues, but it can be the second most abundant phospholipid in lung surfactant (up to 11\\% of the total). It is well established that the concentration of phosphatidylglycerol increases during fetal development. Phosphatidylglycerol may be present in animal tissues merely as a precursor for cardiolipin synthesis.