Glucose chemical structure

Glc = glucose GlcA = glucuronic acid GulA = guluronic acid Man = mannose ManA = mannuronic acid Rha = rhamnose Xyl = xylose Fuc = fucose. Chemical structures and properties are available (19). 

Chemical Name Polymeric glucose (see structural formula) of molecular weight 40,000 Common Name —... 

FIGURE 9.20 Chemical structure of cellulose (a), which is a glucose polymer, and xylan (b), a typical component of hemicellulose. 

Its chemical structure, characterized by degradative chemical procedures in conjunction with spectroscopic and spectrometric techniques, corresponded to a pentasaccharide of jalapinolic acid with one unit of o-glucose and four L-rhamnoses. The structures of the intact dichrosides A-D remain unsolved (59). 

Although these definitions are vague, it appears that partial synthesis is restricted to those modifications which do not change the basic chemical structure, whereas ex-chiral-pool synthesis generally leads to a new type of compound. For instance, the introduction of new substituents into a steroid nucleus is partial synthesis , whereas the conversion of D-glucose into the pheromone e.vo-brevicomin is ex-chiral-pool synthesis . 

Figure 10 Chemical structures of ginsenosides. Abbreviations, glc, P-D-glucose rha, M-L-rhamnose ara, ot-L-arabinose p, pyranose /, furanose.

How does the chemical structure of the monosaccharide glucose differ from that of the monosaccharide fructose ... 

Describe, using chemical structural formulas, the reactions involved in the breakdown of glycogen to glucose 1-phosphate and the synthesis of glycogen from glucose 1-phosphate. 

Fig. 12 Cyclodextrin chemical structure and geometrical arrangement of the glucose units.

Saffron extract contains many carotenoids such as crocetin, crocetin di-glucose ester, crocetin gentiobiose glucose ester, and crocin (crocetin di-gentiobiose ester), whose chemical structures are shown in Figure 58.1. These carotenoids scavenge free radicals, especially superoxide anions, and so may protect cells from oxidative stress. Indeed, it has been demonstrated that these carotenoids are useful in sperm cryoconservation and in protecting heptocytes from toxins. 

FIGURE 58.1 Chemical structures of crocetin (A), crocetin diglucose ester (B), crocetin gentiobiose glucose ester (C), and crocin (D). 

The analytical utility of near-infrared spectroscopy can be demonstrated by an analysis of mixtures composed of glucose, lactate, urea, alanine, ascorbate, and triacetin in a pH 6.8 aqueous phosphate buffer.6 The chemical structures of these test compounds are presented in Figure 13.2. These components were selected to represent different classes of molecules expected in typical biological matrices. Glucose represents carbohydrates lactate represents small organic acids urea is a... 

Figure 13.2 Chemical structures of alanine, ascorbate, glucose, lactate, triacetin, and urea.

The chemical properties of monosaccharides are further complicated by the fact that they can exhibit tautomerism in aqueous basic solutions (Figure 1.15). This means that after a short time a basic aqueous solution of a monosaccharide will also contain a mixture of monosaccharides that will exhibit their characteristic chemical properties. For example, a solution of fructose will produce a silver mirror when treated with an ammoniacal solution of silver nitrate (Tol-len s reagent). This is because under basic conditions fructose undergoes tautomerism to glucose, whose structure contains an aldehyde group, which reduces Tollen s reagent to metallic silver. 

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