Sulfation

Sulfation of calcium oxides Sulfation is a process used to remove "sulfur" from the combustion of fossil fuels. The goal is to minimize the pollution by the combusted gases. Combustion of sulfur-containing fuels releases sulfur dioxide, which, in the atmosphere, oxidizes to the equivalent of sulfuric acid, which is corrosive. To minimize the problem, the combustion is often conducted in the presence of calcium oxide or calcium carbonate, which, directly or indirectly, bind sulfur dioxide and some oxygen to give calcium sulfite. The net reaction is: :CaO + SO2 → CaSO3 :2 CaSO3 + O2 → 2 CaSO4 or the net reaction is sulfation, the addition of SO3: :CaO + SO3 → CaSO4 In the idealized scenario, the calcium sulfate (gypsum) is used as a construction material or, less desirably, deposited in a landfill. Other inorganic sulfations Detergents, cosmetics, etc. Sulfation is widely used in the production of consumer products such as detergents, shampoos, and cosmetics. Since the sulfate group is highly polar, its conjugation to a lipophilic "tail" gives surfacant-like properties. Well known sulfates are sodium lauryl sulfate and sodium laureth sulfate. Alkylsulfate are produced from alcohols by reaction with chlorosulfuric acid: :ClSO3H + ROH → ROSO3H + HCl Alternatively, alcohols can be sulfated to the half sulfate esters using sulfur trioxide. The reaction proceeds by initial formation of the pyrosulfate: : : Several million tons of fatty acid sulfates are produced in this way annually. The most common example is sodium dodecylsulfate (SDS) derived from lauryl alcohol. ==Sulfation in biology==

is used in the treatment of heart attacks. In biology, sulfation is typically effected by sulfotransferases, which catalyze the transfer of the equivalent of sulfur trioxide to substrate alcohols and phenols, converting the latter to sulfate esters. The source of the SO3 group is usually 3'-phosphoadenosine-5'-phosphosulfate (PAPS). When the substrate is an amine, the result is a sulfamate. Sulfation is one of the principal routes for post-translational modification of proteins. Sulfation is involved in a variety of biological processes, including detoxification, hormone regulation, molecular recognition, cell signaling, and viral entry into cells. Seagrasses Many edible seaweeds are composed on highly sulfated polysaccharides. The evolution of several sulfotransferases appears to have facilitated the adaptation of the terrestrial ancestors of seagrasses to a new marine habitat. ==See also==