Sulfaation

Sulfaation is not a standard scientific term in chemistry or biochemistry, but it is sometimes used informally to refer to two related processes: sulfonation and sulfation. In a chemical context, sulfonation describes the introduction of a sulfonyl group (SO3H or SO3−) into a substrate, typically by electrophilic substitution. Aromatic sulfonation often uses sulfuric acid, oleum, or sulfur trioxide as the sulfonating agent, producing sulfonic acids such as benzenesulfonic acid. The reaction usually requires controlled temperature and can be reversible under certain conditions, a feature known as desulfonation when the sulfonic group is removed by heating or hydrolysis.

In a biological context, sulfation refers to the enzymatic transfer of a sulfate group to a molecule, forming a sulfate ester or a sulfated protein. This process is catalyzed by sulfotransferase enzymes and uses the universal sulfate donor 3'-phosphoadenosine-5'-phosphosulfate (PAPS). Sulfation modifies a wide range of substrates, including phenolic drugs, hormones, proteins, and carbohydrates, and plays a key role in solubility, activity, and molecular recognition. In the body, sulfation is common in the formation of glycosaminoglycans such as chondroitin sulfate and heparan sulfate, as well as in detoxification pathways that alter xenobiotics.

Distinctions are important: sulfonation (chemical) emphasizes the introduction of sulfonic groups to substrates, often in industrial synthesis; sulfation (biochemical) emphasizes enzymatic addition of sulfate groups in living systems. The term sulfaation is rarely used in technical literature and is typically clarified by context as either sulfonation or sulfation.