1,2-Dipalmitoyl-sn-glycero-3-phosphoglycerol 1,2-Dipalmitoylphosphatidylglycerol 4537-77-3 DPPG Dipalmitoylphosphatidylglycerol Hexadecanoic acid, 1-((((2,3-dihydroxypropoxy)hydroxyphosphinyl)oxy)methyl)-1,2-ethanediyl ester