Carbohydrates table

The seeds of dicotyledonous plants have two cotyledons, or seed leaves, which are part of the embryo. The cotyledons usually are the main storage tissue, although in some plants (such as castor bean) the endosperm also has a storage function. During development in the field, seeds gradually accumulate storage oils, proteins and carbohydrates (Table 3.1). In the seed, the cotyledon structure is relatively simple. The remainder of the embryo, the embryonic axis, consists mostly of undifferentiated cells, but provascular tissue can be detected that develops into vascular tissue in the seedling. 

The protein concentration in the field pea proteinate was only 87.7% due to the presence of significant quantities of ash, lipid and carbohydrate (Table I). Both refined starches were relatively pure, the protein levels being only 0.5%. The merits of producing protein and starch isolates as opposed to concentrates by the dry process would depend on their relative functional properties and the requirements of the end-user. 

Effect of Carbohydrate Table IV shows the effect of carbohydrates on the D.S. (%) of both lignin-carbohydrate complexes (LCC s) and DHP s... 

The reagent RuO /aq. Na(IO )/CCl oxidised a number of pyranoses and was the first catalytic Ru-based system for carbohydrates (Table 2.3) [2]. Although use of Na(10 ) as co-oxidant with RuO or RuClj is a common procedure for generating RuO in these reactions, it was noted that the use of the sparingly soluble K(IO ) in place of Na(10 ) as co-oxidant reduced over-oxidation [332] see also [330, 340, 341]. Conversion of pyranoses to lactones has been accomplished e.g. 2,4-di-O-benzyl-3-0-T)utyldiphenylsilyl-a,p-L-fucopyranose was oxidised by TPAP/NMO/ PMS/CHjCN to 2,4-di-0-benzyl-3-0- butyldiphenylsilyl-L-fuco-l,5-lactone (Fig. 2.17) [155]. 

Cellulosic phases as well as um.vlosic phases have been used extensively for enantiomeric separations recently. Most of the work in this area has been with various derivatives of the native carbohydrate. The cnanliorcsolving abilities of the derivatized cellulosic and amylosic phases are reported to be very dependent upon the types of substituents on the aromatic moieties that arc appended onto the native carbohydrate. Table 3 lists some of the cellulosic and amylosic derivatives that have been used. 

Hatley and Blair [3.69] presented mean Tg data for anhydrous carbohydrates (Table 3.1), which vary in the literature owing to measurement and interpretation differences. Small amounts of water may depress the data substantially. The physical stability of amorphous formulations below Tg is generally accepted, and a collapse can be avoided. This does not always apply to the chemical stability. If the temperature is reduced below T, the configurational entropy diminishes until it reaches zero. This T0 (also shown in Table 3.1) is called the zero mobility temperature at which the molecular motion stops. The authors define three areas of chemical reactions above Tg, chemical reactions are generally possible at T, reactions such as aggregation, which require substantial molecular motion, stop and between Tg and T0, reactions involv-... 

The transferrins contain varying amounts of carbohydrates (Table 7) and can be classified as glycoproteins. Williams (136) stated that ovotrans-ferrin and chicken serum transferrin differed only in carbohydrate contents. The ovotransferrin contains no sialic acid (44, 136). Serum transferrin, on the other hand, contains sialic acid. Williams (136), from the results of treating the serum transferrin with the enzyme neuraminidase, suggested that differences in the electrophoretic mobilities and isoelectric points of the multimolecular forms of serum transferrins may be due to differences in their contents of sialic acid. 

Three-center hydrogen bonds in the nucleic acid constituents occur as frequently as in the carbohydrates (see Thble 2.3). Because there are virtually no neutron diffraction studies available for this class of compounds, the analysis of the three-center bonds has to rely on data where the X-H bond lengths are normalized and are therefore to some extent less reliable than those of the carbohydrates (Table 8.3) which are based on neutron diffraction data. 

The addition of a C-2 (equation 1 R = H > alkyl, aryl > OMe NR2), C-3, or C-4 electron-donating substituent to a 1 -oxa-1,3-butadiene electronically decreases its rate of 4ir participation in a LUMOdiene-controlled Diels-Alder reaction (c/. Table 5). Nonetheless, a useful set of C-3 substituted l-oxa-l,3-buta-dienes have proven to be effective dienes ° and have been employed in the preparation of carbohydrates (Table 6). The productive use of such dienes may be attributed to the relative increased stability of the cisoid versus transoid diene conformation that in turn may be responsible for the Diels-Alder reactivity of the dienes. Clear demonstrations of the anticipated [4 + 2] cycloaddition rate deceleration of 1-oxa-1,3-butadienes bearing a C-4 electron-donating substituent have been detailed (Table 6 entry 4). >> "3 In selected instances, the addition of a strong electron-donating substituent (OR, NR2) to the C-4 position provides sufficient nucleophilic character to the 1-oxa-1,3-butadiene to permit the observation of [4 + 2] cycloaddition reactions with reactive, electrophilic alkenes including ketenes and sul-fenes, often in competition with [2 + 2] cycloaddition reactions. ... 

One-electron Chemistry of Carbohydrates Table 7.1 Unimolecular clock reactions. 

Table I showed that carbohydrates are an important part of the dissolved organic matter in subsurface seawater. Sieburth et al. (1976) have measured the concentrations of mono- and polysaccharides in screen microlayer and subsurface seawater samples from Block Island Sound and the North Atlantic. They find on average that 21% of the microlayer DOC and 16% of the subsurface DOC is accounted for by total carbohydrates. Table VIII gives their average results for nine samples, all of which were collected on slick-...

Most of the lactose in milk is lost in the whey during cheese manufacture and hence most cheese contain only trace amounts of carbohydrate (Table XIII). Furthermore, the residual lactose in cheese curd is usually fermented to lactic acid by starter bacteria. Thus, cheeses are suitable dairy foods for lactose-malabsorbing individuals who are deficient in the intestinal enzyme, lactase. 

The Crabtree effect does not operate in all species of the genus Saccharo-myces and is absent in Hansenula sp. and Candida sp. (Table 17.5). The effect is expressed in the presence of fructose as well as glucose but is less marked when maltose, mannose or galactose is the fermentable carbohydrate (Table 17.6). 

The clothes moth, Tineola, requires the usual B vitamins and a sterol but is able to grow normally in the absence of dietary fat and carbohydrate (Table 4), whereas Mahcosoma neustria requires carbohydrate.Aglaia... 

This is the main albumen protein, crystallized by Hofmeister in 1890. It is a glycophospho-protein with 3.2% carbohydrates (Table 11.5) and 0-2 moles of serine-bound phosphoric acid per mole of protein (ovalbumin components A3, A2 and Ai, approx. 3, 12 and 85%, respectively). 

This protocol has been successfully applied to various protected carbohydrates (Table 7.1), demonstrating its utility. 

Which Protecting Groups are Suitable for Carbohydrates (Table 2) ... 

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