PDMP is a ceramide analog first prepared in a search for inhibitors of glucosylceramide synthase. PDMP has two adjacent chiral centers (C1 and C2) allowing for the formation of four possible isomers. PDMP contains all four of these stereoisomers. PDMP inhibits glucosylceramide synthase by 90% when used at a concentration of 0.8 μM in MDCK cell homogenates, however, the ability to inhibit glucosylceramide synthase has been found to reside in the D-threo (1R,2R) enantiomer. The D-threo PDMP enantiomer is also responsible for inhibition of β-1,4-galactosyltransferase 6 and prevention of lactosylceramide synthesis, which is a promotor of neuroinflammation in mice during chronic experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis. PDMP enhances curcumin-induced inhibition of proliferation, JNK activation, and Akt inhibition, as well as induction of apoptosis in WM-115 melanoma cells in vitro.