sulfation

Sulfation is the chemical process of introducing a sulfate group into another molecule. This modification commonly results in the formation of a sulfate ester or a sulfonated compound. Sulfation occurs in both chemical synthesis and biological systems, where it serves to alter solubility, reactivity, and biological activity.

In chemical terms, sulfation often involves strong sulfonating reagents such as sulfur trioxide–pyridine complexes, chlorosulfonic acid, or related activators. Alcohols, phenols, amines, and other nucleophiles can be converted to sulfate esters or sulfones, typically yielding products that are more polar and water-soluble. Reactions are used to produce functionalized materials, pharmaceuticals, and intermediates for further chemical transformations.

In biology, sulfation is a post-synthetic modification carried out by enzymes called sulfotransferases. These enzymes transfer a sulfo group from the universal donor 3'-phosphoadenosine-5'-phosphosulfate (PAPS) to substrates such as hormones, neurotransmitters, xenobiotics, carbohydrates, proteins, and lipids. The general reaction is substrate plus PAPS yielding a sulfated substrate plus PAP (3'-phosphoadenosine-5'-phosphate). Sulfation is a major pathway in Phase II metabolism, aiding detoxification and regulating biological signaling, receptor interactions, and the structure and function of glycosaminoglycans in the extracellular matrix.

Sulfation can be reversed by sulfatases in some contexts, and patterns of sulfation are tightly regulated in tissues, contributing to physiological and pathological processes.