Saccharolipids

From LipidomicsWiki

are compounds in which fatty acids are linked directly to a sugar backbone, forming structures that are compatible with membrane bilayers. In the SLs a sugar substitutes for the glycerol backbone that is present in glycerolipids and glycerophospholipids. SLs can occur as glycan or as phosphorylated derivatives. 

The most familiar saccharolipids are the acylated glucosamine precursors of the lipid A component of the lipopolysaccharides in Gram-negative bacteria. Typical lipid A molecules are disaccharides of glucosamine, which are derivatized with as many as seven fatty acyl chains. In some bacteria, the glucosamine backbone of lipid A is replaced by 2,3-diamino-2,3-dideoxyglucose; therefore, the class has been designated "Acylaminosugars". Included also in this class are the Nod factors of nitrogen-fixing bacteria, such as Sinorhizobium meliloti.

The Nod factors are oligosaccharides of glucosamine that are usually derivatized with a single fatty acyl chain. Additional SLs include fatty acylated derivatives of glucose, which are best exemplified by the acylated trehalose units of certain mycobacterial lipids. Acylated forms of glucose and sucrose also have been reported in plants.

SL classes and subclasses

Acylaminosugars

  Monoacylaminosugars
  Diacylaminosugars
  Triacylaminosugars
  Tetraacylaminosugars
  Pentaacylaminosugars
  Hexaacylaminosugars
  Heptaacylaminosugars

Acylaminosugar glycans Acyltrehaloses Acyltrehalose glycans Other