Isethionic acid, taurine

Taurine is generally prepared from ox bile1 or the large muscle of the abalone.2 It has been synthesized from isethionic acid through chloroethanesulfonic acid followed by the action of aqueous ammonia 3 from ethyleneimine and sulfur dioxide 4 from 2-mercaptothiazoline by oxidation with bromine water 5 from bromoethylamine and ammonium sulfite 6 and from acetaldehyde by a complex set of reactions involving sulfonation, formation of the aldehyde ammonia and the imido sulfonic acid and finally reduction.7 The method given in the procedure has recently appeared in the literature.8... 

A quantitatively important pathway of cysteine catabolism in animals is oxidation to cysteine sulfinate (Fig. 24-25, reaction z),450 a two-step hydroxyl-ation requiring 02, NADPH or NADH, and Fe2+. Cysteine sulfinic acid can be further oxidized to cyste-ic acid (cysteine sulfonate),454 which can be decarbox-ylated to taurine. The latter is a component of bile salts (Fig. 22-16) and is one of the most abundant free amino acids in human tissues 455-457 Its concentration is high in excitable tissues, and it may be a neurotransmitter (Chapter 30). Taurine may have a special function in retinal photoreceptor cells. It is an essential dietary amino acid for cats, who may die of heart failure in its absence,458 and under some conditions for humans.459 In many marine invertebrates, teleosts, and amphibians taurine serves as a regulator of osmotic pressure, its concentration decreasing in fresh water and increasing in salt water. A similar role has been suggested for taurine in mammalian hearts. A chronically low concentration of Na+ leads to increased taurine.460 Taurine can be reduced to isethionic acid... 

Ammonolysis of Aminoalkyl Hydrogen Sulfates. Later, in discusdng the replacement of —OH groups, it will be shown that, when hydroxyethane-sulfonic (isethionic) acid is treated with ammonia, taurine is obtained by the preferential replacement of the hydroxyl group. 

Taurine from Hydroxyethanesulfonic Acid (Isethionic Acid). 

Taurin has acid properties and forms salts it is not attacked by H,S04, HXOa, or nitromuriatic acid, but is oxidized by nitrous acid, with formation of H,0, and isethionic acid. 

Taurine, /3-amino-ethanesulphonic acid, is found in combination with other substances in the bile of many animals. It can be prepared from isethionic acid by the steps indicated by the following formulas —... 

Antonucci, G. Spoto, and M. Materese, Isethionic acid as a taurine co-metabolite, "Taurine and Neurological Disorders," A. Barbeau and R.J. Huxtable, eds.. Raven Press, New York (1978). 

Taurides (or taurates) are acylamino alkane sulfonates which have chemical structures close to isethionates. They are prepared by the reaction of a fatty acid chloride with N-methyl taurine (CH3-NH-CH2-CH2-S03-Na). Oleic acid chloride or coconut fatty add chloride are suitable reactants. At variance with the above fatty acid isethionates, taurides are less prone to hydrolysis. Taurides have good foaming and emulsifying properties and are insensitive to water hardness. 

These are named as derivatives of taurine (2-aminoethanesulfonic acid) and are also called taurides. The typical synthetic route involves reaction of sodium bisulfite and ethylene oxide to form sodium isethionate, reaction of the isethionate with methylamine to form sodium iV-methyltaurate, then subsequent reaction with the acyl chloride of a fatty acid to give the iV-acyl-Al-methyltaurate. Taurates have good tolerance to water hardness and find specialty applications in textiles and in detergent bars and shampoos. Taurates are sometimes classified as amphoteric surfactants. 

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