Identification of small molecule sphingomyelin synthase inhibitors

Sphingomyelin synthase (SMS), which catalyzes ceramide as one of the substrates to produce sphingomyelin, is a critical factor in the sphingolipid biosynthesis pathway. Recent studies indicated that SMS could serve as a novel potential drug target for the treatment of various metabolic diseases such as insulin resistance and atherosclerosis. However, very few small-molecule inhibitors of SMS are known. In this study, we performed structure-based virtual screening in combination with chemical synthesis and bioassay and discovered a class of small-molecule SMS inhibitors. The most potent compound exhibited an IC50 value lower than 20 μM in an in vitro enzymatic assay. To the best of our knowledge, this is the first time that small-molecule SMS inhibitors with potency close to the micromolar range are publicly revealed. The structure-activity relationship demonstrated by this class of compounds provides insights into the structural features that are essential for effective SMS inhibition.