Glycosides acid hydrolysis

Compounds 2 and 3 were obtained as amorphous powders. The positive ion mode D/CI mass spectra of 2 and 3 gave the same quasimolecular ion adducts at m/z 450 [M+NH4] and the same fragment ion signals at m/z 288 [M-162+NH4] which also suggested them to be glycosides. Acidic hydrolysis of 2 and 3 yielded glucose as their sugar components. 

Cyanogemc glycosides are potentially toxic because they liberate hydrogen cyanide on enzyme catalyzed or acidic hydrolysis Give a mechanistic explanation for this behavior for the specific cases of... 

Nucleosides are much more water-soluble than the free bases because of the hydrophilicity of the sugar moiety. Like glycosides (see Chapter 7), nucleosides are relatively stable in alkali. Pyrimidine nucleosides are also resistant to acid hydrolysis, but purine nucleosides are easily hydrolyzed in acid to yield the free base and pentose. 

O-isopropylidene derivative (10) was then phosphorylated with phosphorous oxychloride to form the phosphate ester (11) from which the protecting groups were removed by mild acid hydrolysis. The 3-phos-phate (15) was obtained by phosphorylating the 4,6-benzylidene derivative (13) of the same glycoside with phosphorus oxychloride, followed by hydrolytic removal of the protecting groups, from the ester (14) thus obtained. 

Although the glycosidic bonds of uronic acid residues are usually more resistant to acid hydrolysis than those of neutral polysaccharides,218 these linkages in heparin are more readily cleavable then those between the hexosamine and the uronic acid residues. Disaccharides obtained by exhaustive hydrolysis of heparin with 0.5 MHC1 at 80° contained hexu-... 

Flavonoid aglycones (isolated by acid hydrolysis of the corresponding flavonoid glycosides)... 

The /3-orientation of the glycosidic group is indicated by the ease with which the reducing trimethylsugar is generated by aqueous acid hydrolysis, the hydrolysis being accompanied by an increase in dextro-... 

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