Maltotriose production

Likewise, complete synthesis of acarbose was conveniently accomplished by use of the anhydro derivative 392b prepared from maltotriose. Condensation of 392b with optically active 359 afforded two products, one of which was, after deprotection, shown to be identical to an authentic sample of acarbose. 

Oligosaccharides are condensation products of two to ten monosaccharides maltotriose is an example. 

Solutions of 1% (w/v) maltotriose, maltotetraose, maltopentaose, maltohexaose, and maltoheptaose were incubated at 60 C with purified enzyme (0.05 U/ml). Products were analyzed after 72 hours by HPTLC (Whatman HP-K). Plates were developed with n-BuOH EtOH H20 (3 3 2, v/v) at 25 C and the products detected with a mixture of 0.2% (w/v) orcinol in MeOH and 20% H2SO4 in MeOH (1 1, v/v). 

Figure 1. Photograph of a paper chromatogram of the products liberated from maltotriose by glucoamylase...

On the radioautogram of the hydrolytic products initially produced from the tetrasaccharide, the maltotriose was labeled, but the glucose was not. As the concentration of the maltotriose increased in the incubation mixture, a hydrolysis of the trisaccharide occurred to yield labeled maltose and non-labeled glucose. On prolonged incubation the tetrasaccharide was completely converted to glucose by the glucoamylase. 

In these a-amylase reactions, glucose is not the primary product. Glucose is formed as a secondary product in the hydrolysis of maltotriose, maltotetraose and branched dextrins. Using 14C-reducing end labeled maltodextrins, G3 to G8, Robyt and French19 showed that porcine pancreatic a-amylase has different specificities for hydrolyzing the different linkages of the maltodextrins. The different frequencies for... 

Starting with a feedstock of 65-70% maltose, made by one of the methods previously described, the liquor is passed through an adsorption separation column. This results in a product with a maltose level of approximately 98% which may be crystallized, leaving a predominately maltotriose fraction which is purified as a syrup. 

The enzyme most commonly used is a-amylase. Optimal pH and temperature are 6.5 and 70 to 90°C, respectively. Hydrolysis can be carried out to obtain a product consisting mostly of maltose with small amounts of glucose or vice versa. The sweet-taste intensity of starch hydrolysates depends on the degree of saccharification and ranges from 25 to 50 percent of that of sucrose. Table 6.2 provides an average composition on some hydrolysis products. The wide range of starch syrups starts with those with a low DE value of 10 to 20 (maltotriose) and ends with a high DE value of 96 (dextrose)[7]. 

The unusual utility of this adsorbent has been demonstrated by its role in the preliminary isolation of isomaltose,maltotriose, maltotetra-086, = and panose > from the hydrolytic products of starch in the preparation of n-xylo-biose, -trio.se, -tetraose, -pentaose, -hexaose, and -heptaose from a partially hydrolyzed xylan in the resolution of bi-molecular dianhydrides of L-sorbose < and D-fructose < > in an improved procedure for the preparation of stachyose and in the preparation of a series of maltodextrins (as high as maltoheptaose) from the partial, acid... 

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