Sucrose chemical structure

Fig. 2.5.9 COSY spectra acquired at 600 MHz with an eight-coil probe along with the chemical structures of the compounds used. Each sample was a 10 mM solution in D20 loaded into the coil via the attached Teflon tubes, with the samples being (A) sucrose, (B) galactose, (C) arginine, (D) chloroquine, (E) cysteine, (F) caffeine, (G) fructose and (H)...

Challinor, Haworth and Hirst101 determined the chemical structure of the levan produced by the action of B. mesentericus on sucrose. Methylated levan appeared homogeneous when fractionally precipitated from mixed solvents. Fractional distillation of the hydrolytic products of methylated levan yielded tetramethyl-D-fructofuranose in an amount corresponding to a levan chain length of from ten to twelve fructofuranose units, joined as previously940 shown through the 2- and 6-positions. 

Sweet Taste. The mechanism of sweetness perception has been extensively studied because of its commercial importance. Many substances that vary in chemical structure have been discovered which are similar to the taste of sucrose. Commercial sweeteners include sucralose, acesulfame-K, saccharin, aspartame, cyclamate (Canada) and the protein thaumatin 4), Each sweetener is unique in its perceived sensation because of the time to the onset of sweetness and to maximum sweetness, ability to mask other sensations, persistence, aftertaste and intensity relative to sucrose [TABLE IT. For example, the saccharides, sorbitol and... 

H and 13C FT-NMR spectra of biomolecules. The lower spectra are for 1H showing a ppm scale of 0-10. TMS standard is at 0 ppm. The upper spectra are for 13C showing a ppm scale of 0-200. A L-Valine in D20 + DCI. Can you assign each peak to the correct protons and carbon atoms in the valine structure Hint The carboxyl carbon of valine has a peak at about 175 ppm. B Sucrose in D20. Carbon numbers in the chemical structure correspond to the following peaks in order from 0 to 120 ppm ... 

Emulsifiers. The chemical structures of emulsifiers, or surfactants, enable these materials to reduce the surface tension at the interface of two immiscible surfaces, thus allowing the surfaces to mix and form an emulsion. An emulsifier consists of a polar group, which is attracted to aqueous substances, and a hydrocarbon chain, which is attracted to lipids. Emulsifiers include mono- and diglycerides, lecithin, propylene glycol esters, luctylated esters, sorbttan and sorbitol esters, polysorbate.x, and sucrose esters. 

Fig. 2 Chemical structures of glycyrrhizin and of the sweet glycosides of Stevia rebaudiana Bert and relative sweetness of stevia glycosides compared to sucrose (4%) ...

The first Mexican substance searched for, found, and isolated based on old traditions, was the sesquiterpene hemandulcin from Lippia dulcis Trev. It was determined by a human taste panel to be more than 1000 times sweeter than sucrose. The structure of this sesquiterpene was determined and confirmed by chemical synthesis. It was nontoxic when administered orally to mice, and did not induce bacterial mutation.5 Further work has been carried out with some of the plants more frequently used (Table 12.3). The sesquiterpene alkaloids hippocrateine I, hippocrateine II, and emarginatine were identified in Hippocratea excelsa used in Mexican traditional medicine, and antimicrobial abietane type diterpenes were isolated from Salvia albocaerulea.6 7... 

The chemical structure of the most important nonnutritive sweeteners is shown in Figure 11-4. Saccharin is available as the sodium or calcium salt of orthobenzosulfimide. The cyclamates are the sodium or calcium salts of cyclohexane sulfamic acid or the acid itself. Cyclamate is 30 to 40 times sweeter than sucrose, and about 300 times sweeter than saccharin. Organoleptic comparison of sweetness indicates that the medium in which the sweetener is tasted may affect the results. There is also a concentration effect. At higher concentrations, the sweetness intensity of the synthetic sweeteners increases at a lower rate than that which occurs with sugars. This has been ascribed to the bitter-... 

The pure enzyme displayed the preference sucrose > raffinose > 1-kestose > nystose (in a ratio 100 24 10 6). Other carbohydrates such as turanose, cellobiose, melibiose, leucrose, methyl-a-D-glucopyranoside, and stachyose were also tested but their activity was negligible. Thus, the enzyme only recognized sugars containing a sucrose moiety in their chemical structure. The trisaccharide raffinose is equivalent to a sucrose molecule substituted at the C-6 hydroxyl group, whereas... 

Sulfuric acid, phosphate, and sucrose extracts of mouse and beef pancreas have also been compared chromatographically on Amberlite IRC-50 (154). For both species, the sulfuric acid extracts give two peaks which correspond to ribonucleases A and B. When prepared from supernatant free of zymogen granules and microsomes, phosphate and sucrose preparations give a third peak, (10-15 % of the total activity in the case of mouse 1 % in the case of beef) which can be converted into the previous ones by acid treatment. This treatment induces a two- to three-fold increase in activity and the dissociation of the acidic compound already referred to above. The chemical structure of mouse ribonuclease(s) is still unknown. 

Since Biot s discovery in 1815 of the optical rotatory powers of solutions of natural products such as sucrose, many people have studied the relationship between chemical structure and optical rotatory power. 

In reaction (b), which is catalyzed by a separate enzyme, the acceptor is D-fructose 6-phosphate and the resulting product is a phosphate of sucrose. The structure (8) assigned to this sucrose 6 -phosphate was deduced by chemical and enzymic analysis. ... 

One of the mysteries of the sweet taste sensation is the wide variety of molecules that tastes sweet. The chemical structure of common table sugar (called sucrose) is shown on the right. 

To date the ehemical struetures of dextrans synthesized by Leuconostoc species have been the most thoroughly investigated, although an increasing interest is being evinced in the chemical structures of dextrans produced by streptococci, because of their implication in the development of oral disease (see p. 433). Serological tests - have indicated that Lactobacilli convert sucrose into dextrans few confirmatory structural studies have, however, been reported. - ... 

HMF is an example for a potential bulk chemical obtainable from sucrose. The chemical structure of HMF, at first glance, does not immediately allow the... 

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