Sugars, acylation

Epithio sugars acylation, 7, 171 hemiacetafs hydrolysis, 7, 170 Epitiostanol, 7, 182, 183 Epoxidations... 

There are about 17 anthocyanidins found in nature, but only 6 — cyanidin, delphinidin, petunidin, peonidin, pelargonidin, and malvidin—are ubiquitously distributed and of dietary importance. The variation of anthocyanins are due to (i) the number and position of hydroxyl and methoxy groups on the basic anthocyanidin skeleton (ii) the identity, number, and positions at which sugars are attached and (iii) the extent of sugar acylation and the identity of the... 

Polysaccharides, Sugars, acyl esters of, reaction with ammonia, 31,81-134... 

More recently, Gardner, Wenis, and Lee (41) reported on a series of sugar acyl, 4-hydroxybutyryl, and pantoyl derivatives of benzylhydrazine, a-methyl-phenethylhydrazine, and 4-dimethylaminobenzylhydrazine. Significant detoxification was obtained without corresponding loss in activity. For example, l-benzyl-2- (D-ribonoyl) hydrazine ... 

Polar solvents have a log P < 2, moderate solvents have a log P in the range 2apolar solvents log P > 4 (Table 1). Synthesis is best achieved in solvents of intermediate polarity that are able to partially solubilize both the sugar and enzyme, or in solvents with a log P value greater than 1.5 that do not affect the hydration shell of the enzyme and so denature the protein. Tertiary alcohols are particularly effective solvents in this respect as they cannot react with lipases due to steric hindrance at the hydroxy group and their boiling points facilitate their removal after reaction. tert-Butyl alcohol catalyzed by lipase has been employed for sugar acylations [40-42]. Other solvents that have been utilized include 2-pyrrolidone [43] for the synthesis of sorbitol ester derivatives. Pyridine and biphasic mixtures of solvents such as benzene/pyridine and tert-hvXy alcohol/hexane have also been used. 

Sugar Acyl substituent Phase transitions Refs. 

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