d-threo-pdmp

D-threo-PDMP is a potent inhibitor of glucoceramide synthase (GCS), effectively reducing cell surface glycosphingolipids by inhibiting glycosylation. Additionally, it decreases the axon plexus's total length and the number of axon branch points, ultimately inhibiting neurite growth.

(+)-D-threo-PDMP is a ceramide analog and is one of the four possible stereoisomers of PDMP . (+)-D-threo-PDMP is an inhibitor of glucosylceramide synthase. It inhibits glucosylceramide synthase by 50% when used at a concentration of 5 μM in an enzyme assay. (+)-D-threo-PDMP is the active component of racemic DL-threo-PDMP .

(-)-L-threo-PDMP is an enhancer of ganglioside biosynthesis. The (-)-L-threo-PDMP (1S,2S) isomer is the active stimulatory component of DL-threo-PDMP in contrast to (+)-D-threo-PDMP , which is an inhibitor of glucosylceramide synthetase. (-)-L-threo-PDMP upregulates GM3, GD3, and GQ1b synthase levels, which are glycosyltransferases involved in ganglioside biosynthesis, and increases ganglioside levels in cells. It increases neurite outgrowth and synapse formation in vitro and improves retention of a long-term memory learned prior to forebrain ischemia in rats when administered following ischemia at a dose of 40 mg/kg per day.

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.