Lysolipids

Lysolipids are derivatives of lipids resulting from hydrolytic removal of an acyl chain. In most cases, lyso- is used for glycerophospholipids when one of the two acyl groups has been removed. A number in front of lyso- indicates the site of hydrolysis, 2-lyso- designating hydrolysis at position 2, leaving a free hydroxyl group at this carbon atom. The “lyso-” term originated from the fact that these compounds may act as detergents and induce hemolysis (Levene et al. 1924). Apart from glycerophospholipids, lyso- is used for sphingolipids as, for example, lysosphingomyelin (sphingosylphosphorylcholine, removal of the amide-bound acyl chain) (Fig. 1). LIPID MAPS proposed a more general term (Fahy et al. 2005): “Lyso-” is denoting the position lacking a radyl group in glycerolipids and glycerophospholipids (“radyl-” is used when the type of substituent, i.e. acyl, alkyl, or alk-1’-enyl, at the glycerol backbone cannot be specified).

Fig. 1

LPA, LPC, SPC