Sugar alcohols esters

Sugar esters or sugar alcohol esters with long chain fatty acids (lauric, palmitic, stearic and oleic) are produced industrially and are very important as surface-active agents. These include sorbitan fatty acid esters (cf. 8.15.3.3) and those of saccharose (cf. 8.15.3.2), which have diversified uses in food processing. 

The organic phase indudes aliphatic as well as aromatic adds, alcohols, esters, ethers, sugars and extractives (Table 6.3). Approximately 70 wt.% of the oil has been identified. The molecular weight of the individual components ranges from 18 up to 2000 gram mol-1. In some cases, the oil is an emulsion at microscopic level [58]. 

Sorbitol. Sorbitol is the sugar alcohol obtained by reduction of glucose and it can be dehydrated to either isosorbide or to 1,4- and 2,5-sorbitan in acid or base catalyzed processes, respectively. Using sulfonic acid functionalized MCM-41 type materials lauric acid esters of isosorbide can be achieved quite selectively starting from sorbitol (>95% selectivity towards isosorbide dilaurate at 33% lauric acid conversion) in a dehydration-esterification... 

One of the most impressive findings has been the discovery of lipid intermediates in the biosynthesis of polysaccharides (see Refs. 2 and 465.) At least two structurally different types of these compounds exist the intermediate may be an isoprenoid alcohol ester of the glycosyl pyrophosphate or the analogous derivative of the glycosyl phosphate. Derivatives of the first type are formed by reaction between the sugar nucleotide and the alcohol phosphate, for example, undecaprenyl phosphate (120), which participates in the biosynthesis of Salmonella lipopolysaccharide.466... 

Cachaqa and aguardente de cana are the most consumed distilled spirits in Brazil exclusively made from cane-sugar juice. Sugar and caramel maybe added for colour adjustment. The total content of congeners is between 200 and 650 mg 0.1 L p.e. Like other spirits, the flavour of cacha a is mainly characterised by the presence of fermentation by-products such as higher alcohols, esters, carboxylic acids, and carbonyl compounds [41-43]. 

In the first Section, the dolichol pathway of protein glycosylation is introduced, and the reader is made familiar with the various reactions in the formation of the lipid and carbohydrate moieties of lipid-linked saccharides. Three different classes of compound are known so far (a) isoprenoid alcohol esters of monosaccharide monophosphates, such as D-mannosyl and D-glucosyl (dolichol phosphate), (b) such isoprenoid alcohol esters of saccharide diphosphates as dolichol diphosphate linked to 2-acetamido-2-deoxy-D-glucose and to oligosaccharides, and (c) retinol (D-mannosyl phosphate). The dolichol-linked sugars occur in all eukaryotes. 

Mannitol hexanitrate is obtained by nitration of mannitol with mixed nitric and sulfuric acids. Similarly, nitration of sorbitol using mixed acid produces the hexanitrate when the reaction is conducted at 0—3°C and at —10 to —75°C, the main product is sorbitol pentanitrate (117). Xylitol, ribitol, and L-arabinitol are converted to the pentanitrates by fuming nitric acid and acetic anhydride (118). Phosphate esters of sugar alcohols are obtained by the action of phosphorus oxychloride (119) and by alcoholysis of organic phosphates (120). The 1,6-dibenzene sulfonate of D-mannitol is obtained by the action of benzene sulfonyl chloride in pyridine at 0°C (121). To obtain 1,6-dimethanesulfonyl-D-mannitol free from anhydrides and other by-products, after similar sulfonation with methane sulfonyl chloride and pyridine the remaining hydroxyl groups are acetylated with acetic anhydride and the insoluble acetyl derivative is separated, followed by deacetylation with hydrogen chloride in methanol (122). Alkyl sulfate esters of polyhydric alcohols result from the action of sulfur trioxide—trialkyl phosphates as in the reaction of sorbitol at 34—40°C with sulfur trioxide—triethyl phosphate to form sorbitol hexa(ethylsulfate) (123). 

Detergency - pETERGENCY] (Vol 7) -fatty acid esters ofhexitols [SUGAR ALCOHOLS] (Vol 23)... 

Emulsifiers - [PROPYLENE OXIDE] (Vol 20) -m defoamers [DEFOAMERS] (Vol 7) -in dye baths [DYE CARRIERS] (Vol 8) -as food additives [FOOD ADDITIVES] (Vol 11) -in paint removers [PAINT - PAINT AND FINISH REMOVERS] (Vol 17) -m papermaking [PAPERMAKING ADDITIVES] (Vol 18) -for pesticides [PESTICIDES] (Vol 18) -frompolyammes [DIAMINESAND HIGITERAMINES ALIPITATIC] (Vol 8) -sorbitan fatty esters as [SUGAR ALCOHOLS] (Vol 23) -sulfonated mat ls for [SULFONATION AND SULFATION] (Vol 23) -use m cosmetics [COSMETICS] (Vol 7) -use m dairy substitutes [DAIRY SUBSTITUTES] (Vol 7)... 

After benzoylation, it was possible to analyze together the food substances of varying chemical structures, such as alcohols, esters of 4-hydroxybenzoic acid, phenolic antioxidants, saccharides, and sugar alcohols. The method allowed the determination of these substances in different matrices by the same analytical procedure, using the same cleanup. The preservatives were separated on an RP-18 column. Acetonitrile-water (50 35) or acetonitrile-water-butylmethyl ether (110 35 40) were used as mobile phases. Detection was UV at 230 nm (71). 

Obviously, these methods are inapplicable to esterification of free sugars and of alkali-labile glycosides and esters (including the resultant sulfonic esters), but may be employed with sugar alcohols, non-reducing di- and oligo-saccharides, and alkali-stable glycosides and acetals (e.g., certain-O-isopropylidene derivatives). 

Studies on sulfonic esters of sugar alcohols have revealed that sulfonic... 

Sulfonic esters of sugar alcohols often react similarly with ammonia thus, l,4 3,6-dianhydro-2,5-di-0-tosyl-D-mannitol and -sorbitol give326 the corresponding 2,5-diamino-2,5-dideoxy derivatives. However, 1,4 3,6-dianhydro-L-iditol affords326 a compound thought to be 1,4 3,6-dianhydro-2,5-dideoxy-2,5-imino-D-mannitol. 

Benzyl ethers.2 Benzyl ethers of sugar alcohols can be obtained in 82-98% isolated yield by reaction with 1 and catalytic amounts of triflic acid under these conditions isopropylidene and benzylidene acetal groups are stable, as well as ester and imide groups. The reagent thus is comparable to benzyl triflate (6,44). 

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