P Glucoside

Emulsin (0-glycoaidase) almond nuts P-glucosides glucose and a non-carbohydrate 4I-4-5... 

Cellulose is the main component of the wood cell wall, typically 40—50% by weight of the dry wood. Pure cellulose is a polymer of glucose residues joined by 1,4-P-glucosidic bonds. The degree of polymerization (DP) is variable and may range from 700 to 10,000 DP or more. Wood cellulose is more resistant to dilute acid hydrolysis than hemiceUulose. X-ray diffraction indicates a partial crystalline stmcture for wood cellulose. The crystalline regions are more difficult to hydrolyze than the amorphous regions because removal of the easily hydrolyzed material has Htde effect on the diffraction pattern. 

Such evidence indicates that it might be unnecessary to reach the same intake of soy products as Japanese or other Asian populations to reach the same plasma levels of isoflavones. The rationale for such a difference could be a different bioavailability of the ingested isoflavones. Indeed, in most Asians a deficiency of an intestinal lactase, responsible for P-glucosides hydrolysis, might explain the lower isoflavones concentrations in the blood of the Japanese (Day et ai, 2000). 

As for anthocyanins, betalains are found in vacuoles and cytosols of plant cells. From the various natural sources of betalains, beetroot (Beta vulgaris) and prickly pear cactus (Opuntia ficus indica) are the only edible sources of these compounds. In the food industry, betalains are less commonly used as natural colorants from plant sources than anthocyanins and carotenoids, probably related to their more restricted distribution in nature. To date, red beetroot is the only betalain source exploited for use as a natural food coloring agent. The major betalain in red beetroot is betanin (or betanidin 5-0-P-glucoside). Prickly pear fruits contain mainly (purple-red) betanin and (yellow-orange) indicaxanthin and the color of these fruits is directly related to the betanin-to-indicaxanthin ratio (99 to 1, 1 to 8, and 2 to 1, respectively in white, yellow, and red fruits)." ... 

Synthesis of naturally occurring (J-D-glucopyranosides based on enzymatic P-glucosidation using -glucosidase from almond... 

The structures of all products were determined by either conversion to the corresponding acetates or direct comparison with the corresponding natural p-glucosides. Identification of the -configuration of the anomeric center was easily achieved via the analysis of the C-H/C-H coupling constant. The synthetic (3-D-glucosides (30, 33, 34, 35 and 36) were identical with... 

Glucosidase Cleavage of p-glucosides of alcohols and phenols Cycasin, rutin... 

The addition of phenyl sulfenyl choride and phenyl selenenyl chloride to glycals has been investigated, which provides another entry to the 2-deoxy-P-glucosides. As summarized by Roush et al. [156] (Scheme 5.53), the method gives the best selectiv-... 

Finally (pathway e, Scheme 5.56), triazoline 103 formed by cyclo addition of azide to glycal 1 can be photolytically converted into a 1,2-aziridine intermediate 104, from which 2-benzylamino-2-deoxy-P-glucosides can be formed on addition of an alcohol and catalytic scandium triflate [176]. 

Access to P-mannosides [209] is illustrated by the preparation of 179 from P-glucoside 178 by oxidation of the equatorial 2-OH followed by stereoselective reduction to give the axial alcohol an efficient indirect route to the a-mannosides [206] utilizes the P-thioglucoside 182, readily obtained from epoxide 173, proceeding via an oxidation-reduction protection sequence to give P-thiomannoside glycosyl donor 184, from which a-mannoside 185 can be stereoselectively prepared. 

Table 7.2 Synthesis of alkyl P-glucosides using P. dulcis kernel meal...

Hydrolysis of glycosides can also be achieved by the use of specific enzymes, e.g. P-glucosidase for P-glucosides and P-galactosidase for P-galactosides. 

G. Legler and H. Liedtke, Glucosylceramidase from calf spleen. Characterization of its active site with 4-n-alkylumbelliferyl P-glucosides and V-alkyl derivatives of 1-deoxynojirimycin, Biol. Chem. Hoppe Seyler, 366 (1985) 1113-1122. 

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