Sugars esterification reactions

Reaction with Organic Compounds. Many organic reactions are catalyzed by acids such as HCl. Typical examples of the use of HCl in these processes include conversion of HgnoceUulose to hexose and pentose, sucrose to inverted sugar, esterification of aromatic acids, transformation of acetaminochlorobenzene to chloroaruHdes, and inversion of methone [1074-95-9]. 

Naoe et al. [239] used the sugar ester DK-F-110, a mixture of sucrose esters of fatty acids, as a nonionic surfactant along with isopropyl alcohol and hexane in a reverse micellar system to extract cytochrome C. This surfactant has a critical micellar concentration of 0.5 g/1 and HLB of 11. Aqueous phase pH was found to have a major role in the forward extraction and optimum extraction was achieved at pH 8.0. However, for optimum back extraction, addition of isopropyl alcohol at 20 vol.% was found to be very essential. Further, the esterification reaction rate of Rhizopus delemar lipase was found to be maximum in DK-F-110 systems and also higher than those obtained in AOT and lecithin-RMs at a water concentration of 0.25 mol l h... 

Most of lipase-catalyzed acylations of sugars in organic solvents have been reported as transesterification rather than esterification reactions. The displacement of the equilibrium towards products has been accomplished by using activated acyl donors [58] such as 2,2,2-trichloroethyl esters and, more often, enol esters. The use of enol esters, such as a vinyl or an isopropenyl ester, was, in fact, first reported in lipase-catalyzed reactions with sugars [59]. In the reaction, an unstable enol is liberated which instantaneously tautomerizes to the corresponding aldehyde or ketone, making the reaction irreversible. 

What are some important esterification reactions of sugars ... 

What are some important esterification reactions of sugars Esterification of sugars to phosphoric acid plays an important role in metabolism. 

Another advantageous feature of enzymes in an esterification reaction lies in their ability to distinguish a specific hydroxyl group of a complex polyalcohol like sugar derivatives. KUbanov et aL found that Bacillus subtilis protease (subtilirin) catalyzes the regioselective acylation disaccharides 16, as well as nucleosides and related compounds in N,N-dimethylformamide [40]. 

Esterification. The hydroxyl groups of sugars can react with organic and inorganic acids just as other alcohols do. Both natural and synthetic carbohydrate esters are important in various apphcations (1,13). Phosphate monoesters of sugars are important in metabohc reactions. An example is the enzyme-catalyzed, reversible aldol addition between dibydroxyacetone phosphate [57-04-51 and D-ylyceraldehyde 3-phosphate [591-57-1 / to form D-fmctose 1,6-bisphosphate [488-69-7],... 

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