Lining at the air-liquid interface, pulmonary surfactant is a complex mixture of 90% lipids and 10% proteins. The major phospholipid (75%) is dipalmitoylphosphatidylcholine (DPPC) .

• 位于肺的液气交界面的肺泡表面活性物质由大约90%25的脂质和10%25的蛋白质组成，脂质中90%25为磷脂，主要(75%25)是二棕榈酰磷脂酰胆碱(dipalmitoylphosphatidylcholine，DPPC)使得肺泡呼气末表面张力较小。