Compounds for determining the activity of phospholipase A.sub.2, are described herein, and include embodiments having formula (1) ##STR00001## wherein L.sub.1 is derived from an ether (R.sup.1--OR.sup.2).sub.m, wherein R.sup.1 and R.sup.2 are independently selected and are derived from a hydrocarbon having 1 to 12 carbon atoms, with m being an integer from 1 to 4, or from a hydrocarbon R having 1 to 20 carbon atoms; F is unsubstituted or substituted pyrene as a flouraphore; Q is a quencher, and L.sub.2 is C(O)-L.sub.1 or C(O)-L.sub.1-NH, wherein L.sub.1 is as defined above. These compounds may be used to determine the activity of phospholipase A.sub.2, in particular PAF-AH.