lipidclass

A lipid class is a category used to group lipids that share common structural features and, in many cases, similar biosynthetic origins. In biochemical and analytical contexts, organizing lipids into classes helps scientists describe their properties, functions, and roles in health and disease, and it provides a consistent framework for naming and data interpretation.

The major lipid classes recognized in modern lipidomics and biochemistry include fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, sterol lipids, prenol lipids, saccharolipids, and polyketides. Fatty acyls are long-chain carboxylic acids that form acyl chains. Glycerolipids, such as triacylglycerols and diacylglycerols, have a glycerol backbone and are key energy stores. Glycerophospholipids, including phosphatidylcholine and phosphatidylethanolamine, feature a glycerol backbone with phosphate-containing head groups and form major cellular membranes. Sphingolipids are built on a sphingoid base and include ceramides and sphingomyelins, important for signaling and membrane structure. Sterol lipids, such as cholesterol and plant sterols, have multi-ring ring systems. Prenol lipids derive from isoprenoid units and include ubiquinones and carotenoids. Saccharolipids (glycolipids) contain sugar moieties attached to lipid structures and are common in membranes of bacteria and plants. Polyketides are lipid-like compounds produced by polyketide synthases with diverse biological roles.

Classification into lipid classes is a practical convention; some molecules exhibit features of more than one class, and definitions can vary among databases. The term lipid class serves as a conceptual framework for characterizing lipid structure, metabolism, and function.