Enzymatic Hydrolysis of Glycosides

As already mentioned, the acid-unstable genuine dammarane sapo-genins can be obtained from the saponins by means of Smith degradation or its modifications. However, yields by this procedure are generally low and a 

Yosioka and coworkers reported that soil bacterial cultivation using a strain selected on a medium containing 6 g of a mixture of Rb, Rb2 and Rc as sole carbon source afforded 42 mg of (26) and 410 mg of a glucoside (50) 37, 38). The structure of (50) was established as 20-o-p-D-glucosyl-20(iS)-protopanaxadiol. 

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This important concept was rapidly absorbed by the research community, providing fine-tuning of both glycosidase categorization and inhibitor design. In particular, subtle differences of xylosidase and xylanase specificities were probed, and they provided useful insights into the complex and finely tuned enzymatic hydrolysis of glycosides. 

Preparation of pigments is based on their extraction with water, enzymatic hydrolysis of glycosides and reaction of aglycones with... 

G.C.H. Derksen, M. Naayer, T.A. van Beek, A. Capelle, I.K. Haaksman, H.A. van Doren and JE. Groot, Chemical and enzymatic hydrolysis of anthraquinone glycosides from madder roots, Phytochem. Anal., 14, 137 144 (2003). 

This type of reaction was used by Langenbeck24 to describe the mechanism underlying the enzymatic hydrolysis of a glycoside (Fig. 4). This... 

Black mustard is a light olive-brown powder obtained by grinding the dried ripe seeds of several varieties of plants of the Brassica genus moisture yields from this, through enzymatic hydrolysis of a contained glycoside, are about 0.6% of the volatile oil of mustard, which has as its main ingredient the irritant compound allyl isothiocyanate. Mustard is available in bulk and as the official plaster, the latter used only for the local irritant (counterirritant) properties it develops when applied to the skin after moistening with tepid water. 

The prevention of further deterioration requires arresting the chain scission reaction caused by acid or enzymatic hydrolysis of the glycosidic linkages. The reduction in DP through chain scission has a dual character to its negative effect upon properties. In addition to the inherent reduction in the tensile properties of the fibers, the lower DP enhances the opportunity for crystallization with resulting embrittlement. 

Nystrom, L. Moreau, R.A. Lampi, A.-M. Hicks, K.B. Piironen V. 2008. Enzymatic hydrolysis of steryl ferulates and steryl glycosides. Eur. Food Res. Tech. 227 727-733. 

Phospholipids also form complexes with proteins (e.g., vitellin in egg yoUc, animal and plant tissues, lipoproteins in blood serum, and milk), carbohydrates, glycosides, alkaloids, minerals, enzymes, cholesterol, and other substances. Lysophospholipids represent a special class of compounds resulting from the chemical or enzymatic hydrolysis of phospholipids. The role of phospholipases in normal and pathological conditions as well as in cell metabolism is of great biological significance (4). 

Polygalacturonic acid has been hydrolyzed by the enzyme pectinase in the preparation of D-galacturonic acid. When enzymatic hydrolysis of a polyuronide is possible, it is very useful since there is little decomposition of the products by this method. In addition it gives valuable information as to the type of glycosidic linkage present. 

XOS are manufactured by enzymatic hydrolysis of xylan from corn cobs, oat spelt xylan or wheat arabinoxylan [257]. Xylan, a principle t)q)e of hemicellulose exists as a linear polymer of -D-xylopyranosyl units linked by 1 4 glycosidic bonds. Depending on the origin, different substituents such as arabinfuranosyl, 4-0-methylglucuronosyl and acetyl groups are present. Typical raw materials for XOS production include hardwoods, com cobs, straws. 

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