Sucrose ester group

Two groups of sucrose derivatives of herbicidal acids have been reported. The herbicidal properties of the sucrose esters of (2,4-dichlorophenoxy)-acetic acid and other analogs differed somewhat from the salts of the free herbicide acids. This could be accounted for as being due to differences in solubility and penetration, since it is unlikely, by analogy to the fatty acid esters, that the sucrose esters would remain intact in the plant. 0 The second set of sucrose esters were water-soluble sirups, having surfactant properties, prepared from reaction products of hydroxyethyl ethers of sucrose or diglycidyl ethers of poly(oxyetbylene glycol) with (2,4,5-tri-chlorophenoxy) acetic acid or other herbicidal acids. 1... 

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. 

The Alkylglycosides (AGs) and Sucrose esters of fatty acids (SEFAs) are families of nonionic glycosurfactants that have been used for their ability to gently extract membrane proteins with a minimal loss of functionality. These compounds can be synthesized and purified economically, with a worldwide production of thousands of tons per year. Chemically, AGs and SEFAs are a group of uncharged amphipathic compounds that consist of an aliphatic hydrocarbon chain attached to a sugar moiety. Certain AGs and SEFAs such as dodecanoyl sucrose have enjoyed widespread use as food-grade emulsifiers and in cosmetic preparations. 

The most common nonionic surfactants are those based on ethylene oxide, referred to as ethoxylated surfactants. Several classes can be distinguished alcohol ethoxylates, alkyl phenol ethoxylates, fatty acid ethoxylates, sorbitan ester ethoxylates, fatty amine ethoxylates, and ethylene oxide-propylene oxide copolymers (sometimes referred to as polymer surfactants). Another important class of nonionics are the multihydroxy products such as glycol esters, glycerol (and polyglycerol) esters, glucosides (and polyglucosides), and sucrose esters. Amine oxides and sulfinyl surfactants represent nonionic with a small head group. 

Sucrose esters can be tailored to specific needs by the number of hydrocarbon chains that are attached to the sucrose and these surfactants find applications in foods because they are colourless, odourless, and tasteless. For example, to produce a low fat spread with a high water content, then three fatty acid groups might be required to get the right surfactant to blend the margarine and water to a smooth consistency. 

By analogy with the polysorbate ester reaction, similar surfactant ester feedstocks that feature a free hydroxyl function can undergo oxyethylation to materials of higher HLB and these include glycerol, polyglycol and sucrose esters. In addition, many naturally occurring fats and oils can react with ethylene oxide to raise their water solubility. Castor oil is a common base for oxyethylation and the obvious site is the hydroxyl group in the ricinoleic... 

Sucrose Esters. Sucrose has eight free hydroxyl groups, which are potential sites for esterification to fatty acids. Compounds containing six or more fatty acids per sucrose molecule have been proposed for use as noncaloric fat substitutes under the name Olestra this material acts like a triglyceride fat and has no surfactant properties. Compounds containing one to three fatty acid esters, on the other hand, do act as emulsifiers and are approved for food use in that capacity. They are manufactured by the following steps ... 

The preparation of well defined sucrose polyurethanes has been investigated in studies with partially protected sucrose esters [54]. Regioselectivity observations on the carbamoylation of sucrose in DMF showed in the case of alkylisocyanates a clear preference for the reaction position at the 2-OH in the glucose part. When phenylisocyanate is used the most favored reaction position is the 6-OH-group followed by the 2-OH-group [55, 56]. Similar regioselectivities could also be found for the reaction of the respective diisocyanates with sucrose [56]. 

Glycerides, glucosides, saccharides, sorbitan derivatives, Tweens and Spans, etc. also belong to the class of nonionic surfactants. Mono- and diesters of fatty acids and multiatomic alcohols are oil soluble surfactants with low solubility in water. Sulfoesterification of these compounds followed by subsequent neutralization allows one to obtain water soluble surfactants. Many representatives of this group, such as sucrose esters, are non-toxic, tasteless and odorless, which makes them attractive for use in the pharmaceutical, food and perfume industries. 

Though a phosphate of fructose is involved in this reaction it is the 6-phosphate, and so the phosphate ester group remains intact and does not play a direct part in the glycosyl transfer. The second step is to remove this phosphate, by way of a specific sucrose phosphatase, thereby generating free sucrose, at the expense of a certain amount of Gibbs free energy. 

Sucrose esters are non-ionic surface-active materials which could be utilized as emulsifiers and fat replacers.They are synthesized by esterification linking lipophilic fatty acids to the hydrophilic sucrose. Especially the three primary OH groups of sucrose are more easily substituted through fatty acids compared to the secondary ones, thus leading preferably to mono-, di- and tri-esters. These lower-substituted sucrose esters are well suited for application as food emulsifiers especially in dressings and sauces, confectionery, icings and bakery fillings. Cosmetics are another important field of application. 

The inheritance of glandular trichomes in S, berthaultii and in crosses with 5. tuberosum has been studied by several groups (11. 35-371. Type B trichome density, droplet size and presumably the presence of sucrose esters appear to be controlled by relatively few recessive genes. Heritability estimates ranged from 20-30% for density of Type A and B trichomes and 60% for Type B droplet size. The presence of polyphenoloxidase in type A trichomes is controlled by a single dominant gene (381. The inheritance of sesquiterpenes in type A trichomes has not been studied. 

We identified eight different general types of sucrose esters and two types of glucose esters (Table IV). The glucose esters are further complicated by the presence of a- and p forms. All types characterized to date have a complex mixture of to fatty acids attached to the 2,3 and 4 positions of the glucose moiety. These acids consist of normal chains, and iso- and anteiso methyl-branched isomers. For most species the major acyl group on the glucose moiety were methyl-branched to isomers. 

The chemical shifts of the twelve carbons in sucrose have been assigned by three groups of investigators (22-24). Furthermore, Horton et al., found that the chemical shifts of sucrose in water were practically identical to those in methyl sulfoxide (23). We therefore, can compare the data on sucrose esters in methyl sulfoxide to those found in water. 

The properties of the fatty acid esters of the glycosides of sorbitol, like those of lactitol and maltitol are comparable with those of the known sucrose esters. Sucrose has 8 hydroxyl groups which can be esterified, whereas lactitol and maltitol contain 9 hydroxyl groups. 

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