This product is a high purity, well-defined, D-threo-dihydrosphingosine which demonstrates unique properties as compared with the natural D-erythro isomer and is therefore ideal for use in comparison studies of dihydrosphingosine. Sphinganine (dihydrosphingosine) is the precursor of dihydroceramide which is then desaturated to form ceramide. It is a critical intermediate in the synthesis of many complex sphingoid bases and ceramide analogs. It has been found that sphinganine can induce cell death in a number of types of malignant cells and is being tested for its pharmacological properties.1 While both D-threo and L-threo-C2-dihydroceramide induced apoptosis in cells neither D-erythro nor L-erythro-C2-dihydroceramide showed activity.2 A report has concluded that only the erythro isomers of dihydrosphingosine act as substrates for the enzyme sphingosine kinase with both of the threo isomers inhibiting its activity.3