Lipids from strawberry fruits, leaves, achenes and pollen were separat
ed into classes by TLC, purified by HPLC and tested for biological act
ivity. A lipid fraction from fruits with the same chromatographic beha
viour as authentic platelet activating factor (PAF) showed identical b
iological activity, namely, dose-dependent aggregation of washed rabbi
t platelets, inhibition of aggregation by CV 3988, platelet desensitiz
ation to PAF and vice versa, and loss of activity by alkaline hydrolys
is and recovery of activity by reacetylation. The presence of PAF was
confirmed by FAB mass spectrometry. Lyso-phosphatidylcholines, includi
ng lyso-PAF, were also found in all the plant parts tested.