PAF C-18:1 is a naturally occurring phospholipid produced by cells upon stimulation and plays a role in the establishment and maintenance of the inflammatory response. It is less potent than PAF C-16 and PAF C-18 in the induction of neutrophil chemotaxis, but is equipotent to PAF C-16 and PAF C-18 in promoting eosinophil migration. PAF C-18:1 activates the PAF receptor and has been used in antibody binding experiments to determine the importance of an acyl linkage at the sn-2 position for recognition at this receptor.
2-O-methyl PAF C-16 is a synthetic analog of platelet-activating factor (PAF) featuring a methyl group attached via an ether linkage at the sn-2 position. While the specific biological activities of 2-O-methyl PAF C-16 remain undercharacterized, studies with its C-18 counterpart have demonstrated its ability to modulate various biological processes. These processes include reducing plasma membrane fluidity and hindering the invasiveness of tumor cells in embryonic chick hearts. Furthermore, in rat astrocytes, the C-18 analog prompts the release of significant amounts of nitric oxide (NO) through a mechanism that involves the activation of nitric oxide synthase (NOS).