Biochem/physiol Actions MAFP is a selective, irreversible inhibitor of both calcium-dependent and calcium-independent cytosolic phospholipase A2, but not secretory phospholipase A2. MAFP is also a potent acetylcholinesterase inhibitor. Preparation Note To change the solvent, evaporate the methyl acetate under a gentle stream of nitrogen and immediately add the solvent of choice.