Maltose crystalline

In the structure for maltose shown in Example 2.23, no configuration is given for the anomeric carbon of the glucose unit on the right the structure represents the state of maltose in solution—a mixture of a and (3 anomers. In crystalline maltose, the anomeric hydroxyl is a, and maltose can be described as a-D-glucosyl-(l — 4)-a-D-glucose. 

Crystalline maltose is used as a direct-compression tablet excipient in chewable and nonchewable tablets. ... 

Excipient Crystalline maltose Manufacturer SPI Pharma Group Lot No. 8K110947 Magnification lOOx... 

Crystalline maltose, e.g. Advantose 100 (SPI Pharma Group), is spray-dried to produce spherical particles with good flow properties. The material is also nonhygroscopic and is highly compressible. 

Bowe KE, Billig JL, Schwartz JB, et al. Crystalline maltose a direct compression pharmaceutical excipient. Pharm Technol Eur 1998 10(5) 34, 36, 37, 40. 

PROBLEM 16.13 When crystalline maltose is dissolved in water, the initial specific rotation changes and gradually reaches an equilibrium value. Explain. 

Both maltose and lactose, being reducing sugars, give osazones which differ from one another and from glucosazone in crystalline form. Sucrose (G-r-r-F), having no potential aldehyde or ketone grouping, does not form an osazone. 

The approximate times of osazone formation in minutes are given in Table 111,139. The product from mannose is the simple hydrazone and is practically white. Arabinose osazone separates first as an oil, whilst that from galactose is highly crystalline. Lactose and maltose give no precipitate from hot solution. 

Hydrogenation of high maltose symps gives a mistuie of sugar alcohols, from which maltitol [585-88-6J (4) can be isolated in crystalline form. Maltitol is almost as sweet as sucrose (0.9 times) and has been promoted as a sweetener in various food apphcations (33). 

This particular trimethylglucose is unique in that it was separated in crystalline form from the hydrolyzates of the methyl ethers of several naturally-occurring glucose polymers almost two decades before it was synthesized from glucose. These natural sources, which still furnish the most convenient routes for the preparation of 2,3,6-trimethyl-D-glucose, include maltose,124-128 cellobiose,127,128 lactose,122-181 starch,71,182 glycogen,188,184 cellulose,185-187 and lichenin. 188,189 The literature pub-... 

When maltose was treated with 8 molar equivalents of benzoyl chloride in pyridine at —40°, it afforded octa-0-benzoyl-/3-maltose, l,2,6,2, 3, 4, 6 -hepta-0-benzoyl-/3-maltose, and l,2,6,2, 3, 6 -hexa-0-benzoyl-/3-maltose in yields of 3, 79, and 12%, respectively.69 Similar treatment of methyl /3-maltoside with 7 molar proportions of benzoyl chloride in pyridine gave crystalline methyl 2,6,2, 3, 4, 6 -hexa-0-benzoyl -/3 - maltoside and methyl 2,6,2, 3, 6 -penta-O -benzoyl -/3 -maltoside in yields of 71 and 23%, respectively.69 Analysis of the relative yields of the products of these reactions suggests that, after HO-3, the 4 -hydroxyl group in maltose and methyl /3-maltoside is the most hindered. Benzoylation of methyl 4, 6 -0-benzylidene-/3-maltoside with 10 molar proportions of reagent gave 2,6,2, 3 -tetra-0-benzoyl-4, 6 -0-benzylidene-/3-maltoside (71%) and an equimolar mixture (22%) of the 2,6,2 - and 2,6,3 -tribenzoates. These results indicated that the order of reactivity of the hydroxyl groups towards acid halides in pyridine is HO-2, HO-6 > HO-2 HO-3 > HO-3. 

The importance of sugar sulfonates as synthetic intermediates has been widely recognized.77,78 Selective methanesulfonylation and p-toluenesulfonylation of maltose and its derivatives has been studied. Umezawa and coworkers used sequential p-toluenesulfonylation and acetylation to obtain crystalline l,2,3,2, 3, 4 -hexa-0-acetyl-6,6 -di-0-p-tolylsulfonyl-/3-maltose in 45% yield.79 Dimolar methanesulfonylation of methyl /3-maltoside followed by acetylation afforded crystalline methyl 2,3,2, 3, 4 -penta-0-acetyl-6,6 -di-0-(methylsulfonyl)-/3-maltoside. The mother liquor also yielded a small proportion of a... 

The cyclic acetals of sugars constitute an important class of compounds, and their value as synthetic intermediates is well recognized.100 The reaction of methyl /3-maltoside with benzaldehyde in the presence of zinc chloride has been reported to give the crystalline methyl 4, 6 -0-benzylidene-/3-maltoside.52 Similar benzylidenation of l,6-anhydro-/8-maltose affords the corresponding 4, 6 -0-benzylidene derivative in 63% yield.82... 

The kinetic-acetonation procedure previously reported,107 employing alkyl isopropenyl ethers in N,N-dimethylformamide, and applied to the common pentoses and hexoses, has been extended to various hexuloses, oligosaccharides, and other sugar systems.108 Maltose gave the 4, 6 -monoacetal, isolated as the crystalline hexaacetate, on treatment with isopropenyl methyl ether inN,N-dimethylformamide in the presence of p-toluenesulfonic acid. 

Using the pure anomers of maltose in the same way, we found that crystalline hog pancreatic a-amylase causes the very rapid synthesis of maltotetraose from a-maltose but not from /3-maltose whereas, crystalline sweet potato /3-amylase causes the very rapid synthesis of the same compound, specifically from /3-maltose. Configurational inversion again marks this latter condensation as glycosyl-hydrogen interchange, or glycosyl transfer. 

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