391836.fig.001a
(a)
391836.fig.001b
(b)
391836.fig.001c
(c)
391836.fig.001d
(d)
Figure 1: Chemical structure of choline, phosphocholine, sn-glycero-3-phosphocholine, and β,γ-dipalmitoyl-L-α-phosphatidylcholine (principal component of pulmonary surfactant).