Sucrose preparation

The low-speed supernatants then are loaded onto 40% (w/w) sucrose prepared in a 40-mL tube for the SW28 rotor see Note 9). 

E. Fanton, J. Gelas, D. Horton, K. Karl, R. Khan, C. Knan Lee, and G. Paid, Kinetic acetonation of sucrose preparative access to a cbirally substituted 1,3,6-lrioxacyclooctane system, J. Org. Chem 46 4057 (1981). 

K. Y. Chang, S. H. Wu, and K. T. Wang, Regioselective enzymic deacetylation of octa-O-acetyl-sucrose Preparation of hepta-O-acetylsucroses, Carbohydr. Res., 222 (1991) 121-129. 

Chlorinated sugars have been used to study the mechanism of the sweetness of organic compounds, and certain of these have been found to be several orders of magnitude sweeter than sucrose. Preparation of several chlorinated analogues of sucrose revealed that halogen substitution on C-4, C-l and C-6 positions greatly increased the sweetness of sucrose. 

Olestra occurs as a solid, soft gel, or liquid at room temperature depending on the fatty acids used in manufacture. It is a mixture of the octa-, hepta-, and hexa-esters of sucrose prepared by the reaction of sucrose with edible C12 to C20 and higher fatty acid methyl esters. It is insoluble in water and soluble in common lipid solvents. 

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. 

Figure 4 Optimal freeze-drying pathways for the preparation of a low-moisture sucrose preparation. AB is the glass transition profile and CD the softening temperature profile as observed by DSC. Wj is the composition of the maximally freezeconcentrated solution ab is the ice sublimation at constant temperature bed is the ideal secondary drying path (- ) data from Shalaev and (O) data from Shalaev and Franks. For details, see text...

A monoester of sucrose prepared from a pure fatty acid methyl ester by transesterification is a mixture of positional isomers (15-20). Each isomer could behave differently in bread. Data in Figure 4 show a dramatic example of how positional isomers function differently in breadmaking (2) ). L-Ascorbyl 6-palmi-tate is an excellent dough strengthener, which showed a +92 cc volume response above a no-shortening control loaf (905 cc). On the other hand, L ascorbyl 2-palmi-tate decreased loaf volume 165 cc below the control. 

Enzymatic rearrangement of sucrose with Protoaminobacter rubrum CBS 574.77 performed on an industrial scale, affords isomaltulose (also named palatinose ) widely applied as artificial sweetener. Interesting optically pure derivatives (e.g. spiro-system f or analogs of nojirimycin 4) were obtained by hydrolysis of the glycosidic bond in functionalized sucroses. Sucralose (l, 4,6 -trideo)gr-l, 4,6 -trichloro-gaZarto-sucrose), prepared by chlorination of 6-0-acetylsucrose with S02Cl2/pyridine, represents an example in which the disaccharide skeleton is only slightly modified. 

Fig. 4.17 Plot of log,o(n/(mmol g ) against logfo (p7p) for the adsorption of benzene at 20°C on a series of progressively activated carbons prepared from sucrose. (Courtesy Dubinin.)...

Oxidation of Carbohydrates. Oxahc acid is prepared by the oxidation of carbohydrates (7—9), such as glucose, sucrose, starch, dextrin, molasses, etc, with nitric acid (qv). The choice of the carbohydrate raw material depends on availabihty, economics, and process operating characteristics. Among the various raw materials considered, com starch (or starch in general) and sugar are the most commonly available. Eor example, tapioka starch is the Brazihan raw material, and sugar is used in India. 

Pharmaceutical Applications. Sucrose has a long history in the manufacture of pharmaceuticals. It imparts body to symps and medicinal hquids and masks unpleasant tastes. Sucrose also functions as a diluent to control dmg concentrations in medicines, as an ingredient binder for tablets, and to impart chewiness to the latter. Sustained-release medications and protective tablet glazes are prepared using sucrose (41). Sucrose-based sugar pastes are used to promote wound healing (58). 

Sucralfate [54182-58-0] an aluminum salt of sucrose octasulfate, is used as an antacid and antiulcer medication (59). Bis- and tris-platinum complexes of sucrose show promise as antitumor agents (60). Sucrose monoesters are used in some pharmaceutical preparations (21). A sucrose polyester is under evaluation as a contrast agent for magnetic resonance imaging (mri) (61). Oral adrninistration of this substance opacifies the gastrointestinal tract and eliminates the need for purging prior to mri. 

Silyl Ethers. The preparation of per- O-trimethyl silyl ethers of sucrose is generally achieved by reaction with chi orotrimethyl sil ane and/or hexamethyldisila2ane in pyridine (25,26). However, this reaction is not selective and in general per-trimethyl silyl ethers are only used as derivatives for gas chromatographic studies. 

Acetylsucrose [63648-81-7] has been prepared in 40% yield by direct acetylation of sucrose using acetic anhydride in pyridine at 40° C (36). The 6-ester has subsequently been obtained in greater than 90% yield, by way of 4,6-cycHc orthoacetate. Other selective methods for the 6-acylated derivatives include the use of alkyl tin reagents such as dibutyl tin oxide (37) and of dibutyl stannolane derivatives (38). Selective acetylation of sucrose by an enzymic process has also been described. Treatment of sucrose with isopropenyl acetate in pyridine in the presence of Lipase P Amano gave, after chromatography, 6-0-acetylsucrose (33%) and 4/6-di-O-acetylsucrose (8%). The latter compound has been obtained in 47% yield by the prolonged treatment (39). 

A commercially interesting low calorie fat has been produced from sucrose. Proctor Gamble has patented a mixture of penta- to octafatty acid ester derivatives of sucrose under the brand name Olestra. It was approved by the FDA in January 1996 for use as up to 100% replacement for the oil used in preparing savory snacks and biscuits. Olestra, a viscous, bland-tasting Hquid insoluble in water, has an appearance and color similar to refined edible vegetable oils. It is basically inert from a toxicity point of view as it is not metabolized or absorbed. It absorbs cholesterol (low density Hpoprotein) and removes certain fat-soluble vitamins (A, D, E, and K). Hence, Olestra has to be supplemented with these vitamins. No standard LD q tests have been performed on Olestra however, several chronic and subchronic studies were performed at levels of 15% in the diet, and no evidence of toxicity was found. No threshold limit value (TLV), expressed as a maximum exposure per m of air, has been estabhshed, but it is estimated to be similar to that of an inert hpid material at 5 mg/m. ... 

Olestra is prepared by a solvenfless transesterification process in which sucrose is treated with methyl ester of fatty acids in the presence of sodium methoxide between 100—180°C for 14 hours (68). The manufacturing process involves removal of the unreacted fatty acid esters by enzymic hydrolysis... 

Phosphate Esters. The phosphorylation of sucrose using sodium metaphosphate has been reported (78). Lyoptulization of a sodium metaphosphate solution of sucrose at pH 5 for 20 hours followed by storage at 80°C for five days produced a mixture of sucrose monophosphates. These products were isolated by preparative hplc, with a calculated yield of 27% based on all organic phosphate as sucrose monoesters. Small proportions of glucose and fmctose were also formed. 

Monomethylacryloyl and vinylbenzyl derivatives of sucrose have been prepared as intermediates for polymers, and preparation of a range of copolymers of styrene and O-methjiacryloylsucrose has been described (114). Synthesis of 4- and 6-0-acryloylsucrose has been achieved by acid-catalyzed hydrolysis of 4,6-0-(l-ethoxy-2-propenyhdene)sucrose (76). These acryloyl derivatives have been polymerized and copolymerized with styrene (qv). 

Maple symp is prepared by concentrating (evaporation or reverse osmosis) sap from the maple tree to a concentrated solution containing predominantly sucrose. Its characteristic flavor and color are formed during evaporation. Maple symp is produced from the sap of several varieties of mature maple trees, eg, the sugar maple (/icer saccharum) and black maple A.cernigrunj). 

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