dihydrosphinganine

Dihydrosphinganine, also known as dihydrosphingosine or sphinganine, is a saturated sphingoid base and a long-chain amino alcohol found in sphingolipids. It is typically described as 2-aminooctadecane-1,3-diol, a saturated 18-carbon backbone bearing an amino group at the second carbon and hydroxyl groups at the first and third carbons. As a core building block of sphingolipids, dihydrosphinganine serves as the direct precursor to dihydroceramides during lipid biosynthesis.

In de novo sphingolipid biosynthesis, serine palmitoyltransferase condenses serine with palmitoyl-CoA to form 3-ketosphinganine. This intermediate is then reduced by 3-ketosphinganine reductase to yield dihydrosphinganine. Subsequent N-acylation by ceramide synthases produces dihydroceramide, which can be desaturated to form ceramide. Thus, dihydrosphinganine occupies a central position as an immediate precursor in the pathway that generates the diverse family of sphingolipids.

Dihydrosphinganine is found across eukaryotic organisms as part of the sphingolipid metabolism that contributes to membrane structure and cellular signaling. In lipidomics, its levels reflect activity of the sphingolipid biosynthetic pathway, though the bioactive signaling often centers on ceramides, sphingosine, and their phosphorylated forms. Abnormal sphingolipid metabolism is associated with various diseases, making the study of dihydrosphinganine relevant for understanding lipid biochemistry and its physiological implications.