Thioglycoside hydrolysis

SCHEME 28. Selective thioglycoside hydrolysis mediated by NIS/H2S04-Si02. 

Anomeric center reactivity has been observed for the API lincomycin hydrochloride. Lincomycin HC1 contains a carbohydrate portion that undergoes thioglycoside hydrolysis at the carbohydrate anomeric center (Fig. 127) (177). 

Lincomycin undergoes thioglycoside hydrolysis and amide hydrolysis. 

Stability studies of lincomycin formulations don t appear to have been reported. However, the most probable degradation pathways are thioglycoside hydrolysis and amide hydrolysis (cf. 11.1). 

Partial hydrolysis of dithioacetals has been found useful for the preparation of anomers not obtained by the foregoing methods and also for preparation of fu-ranosidic 1-thioglycosides. 

Wolfrom and coworkers had found that the mercaptolysis of the crystalline calcium chloride double salt of streptomycin trihydrochloride yielded, after chromatographic purification, two anomeric forms of ethyl tetraacetylthiostreptobiosaminide diethyl mercaptal. Mercaptolysis of dihydrostreptomycin yielded an amorphous ethyl dihydrothio-streptobiosaminide hydrochloride which formed crystalline N-acetyl and pentaacetyl derivatives. The ability of the ring in this latter compound to resist hydrolysis and to form a thioglycoside instead of a thio-... 

Hepta-O-acetyl-a-lactosyl bromide was reported to give an unknown octasaccharide ( tetralactose ) in the presence of silver carbonate. Potassium benzenethiolate and hepta-O-acetyl-a-lactosyl bromide in alcohol, with sub-sequent de-O-acetylation, gave phenyl l-thio-/3-lactoside, in which the thioglycosidic bond is remarkably stable to acid hydrolysis." ... 

Krantz MJ, Lee YC (1976) Quantitative hydrolysis of thioglycosides. In Anal. Biochemistry 71 318-321... 

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