Structure. Sphingoid bases belong to the sphingolipids. Their structure consists of an amino alcohol with a single hydrocarbon chain. The hydrocarbon chain may contain further double bonds, hydroxylations, and other groups such as phosphates or sugar molecules. The number and position of double bounds, hydroxylations, and further substitutes in the hydrocarbon chain defines the sphingoid base lipid class.

Function. Sphingoid bases can be found in all animals and plants and may be present in some fungi and bacteria. They serve as the defining structural unit of sphingolipids and thus as key intermediates and biosynthetic precursors to more complex sphingolipids. Yet free sphingoid bases are also bioactive.

Sphingosine is the most abundant sphingoid base in animals and together with sphingosine-1-phosphate plays an important role in intra- and inter-cellular signaling. Sphinganine is the biosynthetic precursor to sphingosine. In humans, the accumulation of glycosylated sphingoid bases such as glucosylsphingosine and galactosylsphingosine is linked to devastating diseases like Gaucher and Krabbe disease.