Beta-dextrin

Inclusion compounds of the Cg aromatic compounds with tris((9-phenylenedioxy)cyclotriphosphazene have been used to separate the individual isomers (43—47). The Schardinger dextrins, such as alpha-cyclodextrin, beta-dextrin, and gamma-dextrin are used for clathration alpha-dextrin is particularly useful for recovering PX from a Cg aromatic mixture (48,49). PyromeUitic dianhydride (50) and beryllium oxybenzoate (51) also form complexes, and procedures for separations were developed. 

Table X 4 summarizes similar data for the hydrolysis by maltase-free malt alpha amylase of beta dextrins obtained from arrowroot starch by the action of beta amylase. The beta dextrins were precipitated with alcohol from the reaction mixture of arrowroot starch after it had reached a limit in the hydrolysis at 60% theoretical maltose. The beta dextrins were hydrolyzed extensively by malt alpha amylase. Glucose was liberated in very small amounts even in the later stages of the hydrolysis of these beta dextrins maltose was liberated in appreciable amounts and, at equivalent hydrolyses, appeared to be formed somewhat more rapidly from the beta dextrins (Table X) than from the untreated starch (Table IX). Upon hydrolysis with malt alpha amylase the molecular weights of the beta dextrins dropped appreciably but not as extensively as when arrowroot starch was hydrolyzed directly by malt alpha amylase.

Products Formed by Malted Barley Alpha Amylase from Beta Dextrine Formed from Arrowroot Starch by Beta Amylase (Data of Myrbiicku)... 

A Comparison of the Action of Purified Maltase-free Alpha Amylase from Malted Barley upon Corn Amylose, Corn Starch and upon Beta Dextrins Formed from Corn Starch by the Action of Beta Amylase (Data of Myrbdck and Thorsellu)... 

Corn amylose Corn starch Beta dextrine ... 

An interesting comparison is also given in Table XI86 of the action of malted barley alpha amylase upon corn starch, beta dextrins obtained from corn starch by the action of beta amylase, and upon corn amylose prepared according to the method of Meyer.6 90 These data show that, with equivalent amounts of enzyme, amylose was hydrolyzed much more rapidly and more extensively than unfractionated corn starch. Although the beta dextrins were hydrolyzed by this amylase, they were hydrolyzed much more slowly and less extensively than either of the other two substrates. These results are similar to those already considered for pancreatic amylase.41 64... 

Freudenberg later concurred with French s results, after studying the X-ray measurements of Borchert and also his and Cramer s optical rotation data. He also proposed that the gamma dextrin consisted of eight d-glucosyl residues joined by a linkages in a cyclic structure, as in the case of the alpha and beta dextrins. 

P-Cyclodextrin beta-cycloamylose beta-dextrin Cavamax W7 Pharma cycloheptaamylose cycloheptaglucan cyclo-maltoheptose Kleptose. 

Practically all workers in the field have noted that different starchy substrates differ in their behavior with B. macerans amylase, both as regards the total yields of Schardinger dextrins and also with respect to the relative proportions of alpha and beta dextrins. 

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