... , triglycerides, andphospholipids (e.g., phosphatidylcholine, phosphatidylethanolamine, andphosphatidylinositol). However, in biochemistry, lecithin is usuallyused as a synonym for pure phosphatidylcholine, a phospholipid ... either egg yolk or soy beans from which it is mechanically orchemically extracted using hexane. Lecithin is commercially available in high purity ...