Thioester

Definition

Thioesters are esters in which the linking oxygen atom is replaced by sulfur. They are the product of dehydration reaction between a carboxylic acid derivative and a thiol. Thioesters are common intermediates in biochemistry, for example, in acetyl-CoA, malonyl-CoA, acetoacetyl-CoA, and propionyl-CoA. Thioesters are intermediates in several key processes in which ATP is either used or regenerated. Thioesters are involved in the synthesis of all biological esters, including those found in lipids. They also participate in the synthesis of a number of other cellular components, including peptides, fatty acids, sterols, terpenes, and porphyrins. The carbonyl group in thioesters is electrophilic; thus, thioesters and amines combine to give amides:

$$ {\mathrm{R}\mathrm{NH}}_2+{\mathrm{R}}^{\prime }{\mathrm{SCOR}}^{{\prime\prime}}\to {\mathrm{R}\mathrm{NH}\mathrm{COR}}^{{\prime\prime} }+{\mathrm{R}}^{\prime}\mathrm{S}\mathrm{H} $$

(1)

The protons on the carbon atoms adjacent to...