Nomenclature for steroid skeleton They have a fused polycyclic structure and vary in carbon side chains and / or presence or absence of a double bond (saturation). They are divided into 4,4-dimethyl<unk> s, 4-monomethyl<unk> s, and 4-desmethyl<unk> s based on the location of methyl groups at the carbon-4 position. Stanols are saturated sterols, having no double bonds in the sterol ring structure. The molecule in the article lead is β-sitosterol. The nomenclature is shown on the right. *By removing carbon 242, campesterol is obtained. *By removing carbons 241 and 242, cholesterol is obtained. *Removing a hydrogen from carbons 22 and 23 yields stigmasterol (stigmasta-5,22-dien-3β-ol). *By hydrogenating the double bond between carbons 5 and 6, β-sitostanol (Stigmastanol) is obtained. *By hydrogenating the double bond between carbons 5 and 6 and removing carbon 242, campestanol is obtained. *Removing carbon 242 and hydrogens from carbons 22 and 23, and inverting the stereochemistry at C-24 yields brassicasterol (ergosta-5,22-dien-3β-ol). *Further removal of hydrogens from carbons 7 and 8 from brassicasterol yields ergosterol (ergosta-5,7,22-trien-3β-ol). Important: Ergosterol is not a plant sterol. Ergosterol is a component of fungal cell membranes, serving the same function in fungi that cholesterol serves in animal cells. In addition: *Esterification of the hydroxyl group at carbon 3 with fatty/organic acids or carbohydrates results in plant sterol esters, i.e. oleates, ferulates and (acyl) glycosides. File:Sitosterol structure.β-sitosterol File:campesterol.Campesterol File:Stigmasterin.Stigmasterol File:Stigmastanol.Stigmastanol File:campestanol.Campestanol File:brassicasterol.Brassicasterol File:Cycloartenol.Cycloartenol File:cholesterol.Cholesterol Image:ergosterol.Ergosterol
Phytosterol
Ergosterol
Conjugated linoleic acid
Cholesterol
Lipoic acid
Cholic acid
Cerebroside
Oxycholesterol