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Di saccharides

Cane sugar.—Melts, darkens, then chars, and finally burns, with a marked odour of burnt sugar. Typical of the changes given by mono- and di-saccharides. [Pg.320]

Mono- and di saccharides are colourless solids or sjrrupy liquids, which are freely soluble in water, practically insoluble in ether and other organic solvents, and neutral in reaction. Polysaccharides possess similar properties, but are generally insoluble in water because of their high molecular weights. Both poly- and di-saccharides are converted into monosaccharides upon hydrolysis. [Pg.453]

Fig. 40. — (a) Stereo view of two turns of the right-handed, 2-fold helix of Rhiz. trifolii capsular polysaccharide (47). The mono- and di-saccharide side chains (filled bonds) are involved in intrachain hydrogen bonds so that the molecule has the appearance of a double helix composed of an inner and outer strands. The vertical line represents the helix axis. [Pg.399]

Green coffee beans, as expected, contain storage polysaccharides such as starch, and structural support compounds such as cellulose and lignin. Mono- and di-saccharides are represented, as well as the related compounds quinic acid and myo inositol. [Pg.139]

In 2006, Milosavljevic and co-workers64 reported a study of the complete 4H and 13C NMR assignment of a new triterpenoid saponin, leucantho-side-A (13), from Cephalaria leucantha L. In the course of determining the structure and assigning the spectra, the authors made extensive use of the normal ensemble of 2D NMR experiments in use for the characterization of natural product structures HSQC, HMBC, DQF-COSY, TOCSY, and NOESY. The authors supplemented the aforementioned list of experiments with 2D /-resolved, DINE-(Double INEPT-Edited)-HSQC, and INADEQUATE spectra. The authors made no mention of the use of the connectivity information derived from the 1,1-ADEQUATE spectrum in the assembly of the triterpene nucleus of the molecule but reported extensive tabulations of the 1,1-ADEQUATE correlations that were used to sequence and assign the saccharide resonances of the tri- and di-saccharide sub-units, 14 and 15, respectively, linked to the triterpene nucleus. [Pg.240]

Fischer then examined the lactose yeast in the same manner as he did the Frohberg yeast and found it to contain both an invertin-like enzyme and a lactose-cleaving enzyme, which he termed lactase. From these results he concluded that the first step in the fermentation of lactose, as for the fermentation of sucrose and maltose, is the hydrolysis of the disaccharide to mono-sacharide. From this observation, he drew the landmark conclusion that he considered it most unlikely that any polysaccharide (the term included di-saccharides) can be fermented without first being hydrolyzed to hexose (31). [Pg.12]

Neutral mono-and di-saccharides Ionic mono- and di-saccharides... [Pg.327]

Bovine a-lactalbumin is one of the two enzymes in lactose synthetase, and its amino acid sequence shows striking similarities to that of lysozyme.118 A model based on the lysozyme model has been built, and the side-chain interactions found are convincing, showing that the model is essentially correct. The active cleft in the crystal is, however, shorter than that in the model, and is consistent with a mono- or di-saccharide as the substrate. Thus, the lysozyme structure may serve as a model for some enzymes that synthesize and hydrolyze carbohydrates. [Pg.98]

It is well known that sugars react with aqueous ammonia to produce heterocyclic compounds in low yield. The products of the reaction of the mono- and di-saccharides with concentrated, aqueous solutions of ammonia are dependent on three factors (I) the length of time during which the reaction proceeds, (2) the temperature of the reaction, and (3) the catalyst used. This matter has been briefly but comprehensively reviewed.1 The present article is more detailed it covers the literature to the end of July 1970, and has been prepared for the use of chemists who may not be specialists in the carbohydrate field, as well as of those who are. [Pg.311]

The similarity of the products obtained from the mono- and the di-saccharides supports the hypothesis of Jezo20 68 and Jezo and Luz k30 that the di- and poly-saccharides are first hydrolyzed to the monosaccharides. Although most glycosidic linkages are stable to... [Pg.333]

Ammonolysis of perbenzoylated derivatives of mono- and di-saccharides provides interesting examples of selective deacylation. Treatment of the benzoylated nitriles of D-galactonic, D-gluconic, and... [Pg.30]

As regards the l,l-bis(acylamido)-l-deoxyalditols, the first structural study was that of Fletcher and coworkers,69 who conducted oxidations with lead tetraacetate. These authors postulated an empirical relationship between the position of the oxidation curve in a graph and the number of hydroxyl groups present. They compared the curves afforded by a series of l,l-bis(acetamido)-l-deoxyalditols with those of alditols having the same number of free hydroxyl groups, and observed a close correspondence. At present, periodate oxidation is widely applied to these mono- or di-saccharide derivatives. Under controlled conditions, the methylation technique can also be applied.42... [Pg.109]

B. Giese, M. Hoch, C. Lamberth, and R. R. Schmidt, Synthesis of methylene bridged C-di-saccharides, Tetrahedron Lett. 29 1375 (1988). [Pg.258]

S. Hanessian and J. Banoub, Chemistry of the glycosidic linkage. An efficient synthesis of 1,2-/ranj-di-saccharides, Carbohydr. Res. 53 C13, (1977). [Pg.282]

Apart from the utilization of the common mono- and di-saccharides as metabolic substrates for growth and energy, there is little information on the growth effects of externally applied carbohydrates. Some, like D-mannose, D-galactose, and 2-deoxy-D-araWno-hexose, are inhibitory to root growth,718 possibly because they provide a high osmotic concentration in solution, from which they are only indifferently utilized, without being actively phytotoxic. [Pg.414]


See other pages where Di saccharides is mentioned: [Pg.404]    [Pg.186]    [Pg.398]    [Pg.371]    [Pg.153]    [Pg.283]    [Pg.165]    [Pg.165]    [Pg.43]    [Pg.233]    [Pg.218]    [Pg.71]    [Pg.366]    [Pg.575]    [Pg.6]    [Pg.32]    [Pg.32]    [Pg.32]    [Pg.33]    [Pg.33]    [Pg.57]    [Pg.60]    [Pg.62]    [Pg.15]    [Pg.34]    [Pg.396]    [Pg.320]    [Pg.39]    [Pg.93]    [Pg.421]    [Pg.14]    [Pg.38]    [Pg.76]   
See also in sourсe #XX -- [ Pg.144 ]

See also in sourсe #XX -- [ Pg.261 ]




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