Synthesis and evaluation of a difluoromethylene analogue of sphingomyelin as an inhibitor of sphingomyelinase

A sphingomyelin analogue 2, in which the long alkenyl chain and the phosphodiester moiety of sphingomyelin were replaced by a phenyl and an isosteric difluoromethylenephosphonic acid, was prepared to evaluate its inhibitory potency to sphingomyelinase. The analogue non-competitively inhibited the neutral sphingomyelinase in bovine brain microsomes with an IC50 of 400 μM. The compound had the ability to suppress tumor necrosis factor α-induced apoptosis of PC-12 neurons at a low concentration of 0.1 μM.