Glyceride

Glycerol

Fatty acid

Triacetin, the simplest possible fat

Glycerides, more correctly known as acylglycerols, are esters formed from glycerol and fatty acids.

Glycerol has three hydroxyl functional groups, which can be esterified with one, two, or three fatty acids to form monoglycerides, diglycerides, and triglycerides.

Vegetable oils and animal fats contain mostly triglycerides, but are broken down by natural enzymes (lipases) into mono- and diglycerides and free fatty acids.

Soaps are formed from the reaction of glycerides with sodium hydroxide. The product of the reaction is glycerol and fatty acids. Fatty acids in the soap emulsify the oils in dirt, enabling the removal of oily dirt with water.

Partial glycerides are esters of glycerol with fatty acids, where not all the hydroxyl groups are esterified. Since some of its hydroxyl groups are free the molecule is polar. Short chain partial glycerides are more highly polarized, and have excellent solvent properties for many hard-to-solubilize drugs.