Acylated starch

The acylation of hydrolyzed starch with acid anhydrides in pyridine2063-2065 gave products of interest for medical and cosmetic use, as well as applications similar to those of acylated starches 2066... 

Acylated starch can be copolymerized to yield materials for films, lacquers, and fibers.2111 Starch acetate copolymerized with epichlorohydrin was extruded to give cold-water swelling products with a high degree of friability.2112 Epichlorohydrin-crosslinked starch has been acylated with 2,3-di-O-benzoyl-L-threaric anhydride.2113 The reaction proceeded either in /V,/V-dimethy 11 ormam ide or in toluene, and the non-crosslinked product has also been reported.2114... 

AGs and APGs are produced completely with renewable feedstocks such as glucose and fatty alcohols derived from starch and palm kernel oil [34]. AGs, which are mainly the two homologues C12- and C14-1V-methyl glucamide, are manufactured by reductive amination of glucose followed by acylation with fatty acid derivatives [35],... 

In starch chemistry and technology, extrusion is used for cooking as well as for preparation of starch complexes with such guest molecules as gluten6511 and lipids.651 Acylation of starch with cyclic anhydrides of dioic acids on extrusion has been demonstrated the reaction provides anionic starches.651... 

Dahlia tubers, inulin from, II, 254 Dambonitol, III, 46 Damson gum, I, 343 IV, 246, 247 structure of, IV, 253 blood group activity of, IV, 50, 52 Deamination, mechanism of, II, 62 Degradation, of acylated nitriles of al-donic acids, IV, 119-151 of aldonic acids, III, 149 of aldose sugars, I, 254 enzymatic, of starch and glycogen, III, 251-310... 

Biswas A, Shogren RL, Stevenson DG et al (2006) Ionic liquids as solvents for biopolymers acylation of starch and zein protein. Carbohydr Polym 66 546-550... 

The limited solubility of starch and its modified products may affect the reversibility of many reactions. This may explain several, apparently unusual, reactions reported in starch chemistry. There are, for example, reports of starch esterification with sodium hydrogenphosphates, acylation of starch with acyl amides (which is equivalent to the transformation of an amide into an ester), and the formation of alkali-metal starchates upon treatment of starch with alkali (a reaction which fails for simple alcohols). A specific property of starch is its ability to form surface sorption and helical inclusion-complexes with many inorganic and organic guest molecules.4... 

Phosphation can occur simultaneously with acylation. Such reaction of starch in a mixture of 87% phosphoric acid and acetic acid with acyl anhydrides produced a gummy substance, which transformed into an amorphous solid upon purification.1593... 

Acylation with methoxalic anhydride (the anhydride of the monmethyl ester of oxalic acid) in pyridine produced starch monomethoxalate.1907... 

Anhydrides of unsaturated acids could react in pyridine, as shown in the preparation of methacrylic esters.1908 1909 As with acetic anhydride, higher aliphatic acyl anhydrides produced triesters,1910 but benzoic anhydride produced only a diester. Subsequent acylation with benzoic and acetic anhydrides provided a mixed acetyldibenzoyl starch.1911... 

Various anhydrides show significant differences in reactivity. For instance, acetic anhydride reacted with starch in the presence of formamide, whereas phthalic anhydride required pyridine to react. This property was utilized in preparation of starch esters carrying two different acyl groups simultaneously.19181919 Mixed starch esters may also be prepared by using a mixture of various anhydrides in... 

The reactivity of acyl chlorides determines the selectivity of the reaction.1938 Benzoyl chloride provided disubstituted products rather than triesters,1946-1948 but maltodextrins formed triesters. However, by adjusting the reaction conditions, mono- and di-esters of fatty acids could also be prepared.1949 On the other hand, acetylation usually led to the triacetate.1438 Chlorides of unsaturated acids, when treated with pregelatinized starch, did not require any solvent other than water. In this case, dissolved alkali played the role of catalyst. Mixed esters were also formed when mixtures of acyl chlorides1950-1953 or acyl anhydrides were used.1954 1955... 

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