Maltose hydrate

Maltose (hydrated). Maltose (anliydrous) 165 loot + 130 206 Octa-acetate, a- 125, p 160... 

French500 has collected together unit-cell data for maltose hydrate and some poly-O-acylsaccharides in the hope that some packing information might be obtained which could be applied to the problem of starch structure. 

Glattfeld and Hanke applied this procedure to the oxidation of maltose hydrate. An aqueous solution of the sugar was shaken with lead carbonate and bromine since lead bromide separated from the reaction mixture, only aeration was necessary to remove the excess bromine, and treatment with silver oxide and hydrogen sulfide removed the last bromide, silver and lead ions. The maltobionic acid was isolated as the calcium salt. Here the neutralization of the hydrobromic acid was beneficial in preventing any hydrolysis of the aldobionic acid. 

Results of the maltose hydrate adhesion on original PC and PC-EB teeth after 50 days of storage in a saliva model solution at 37°C are shown in Table 12.3. The content of adhesion decreases with a dose of EB irradiation, but the decay saturates at higher doses. For reference, the adhesion on polyamide (PA nylon) is higher than PC. In the mouth, maltose is formed by enzyme affection... 

Figure 7 Refractive index detection in liquid chromatography. (A) Dual-triangular section flow cell for detector based on Snell s law. (B) Separation of detection of carbohydrates with LC and refractive index detection. Sample 4ng each of (1) xylose, (2) fructose, (3) sucrose, (4) maltose hydrate, and (5) lactose. (Reproduced with permission from Munk M (1993) Refractive index detection. In Parriott D (ed.) A Practical Guide to HPLC Detection. San Diego Academic Press.)...

Raffinose hyd Maltose hydrate D-Fructose D-Mannose D-Glucose (ankyd.) D-Glucose (hyd.) L-Arabinose D-Galactose Sucrose... 

The greater volume of A was taken to be an indication of greater hydration. It was suggested that the unit cell contained two maltose units of a chain of D-glucose units. 

For maltose, lactose (hydrated) and raffinose (hydrated), the normal weights are respectively 12-55 (or 12-58) grams, 37-88 (or 32-95) grams,2 and 16-545 (or 16-576) grams, according as the volume is measured in true (or Mohr) c.c. 

Here we compare the thermodynamic parameters of trehalose, maltose and sucrose because they have the same chemical formula (C12H22O11) and mass (molecular weight 342.3), but different structures which could be responsible for their different hydration properties. The anomaly of hydration of trehalose is understood from the following observation [10]. Namely, the amount of water used for the preparation of 1.5 M trehalose solution is smaller than the amount used for the preparation of other sugar solutions. In a 1.5 M solution, trehalose itself occupies 37.5% of the volume of the solution. However, in a 1.5 M solution, sucrose occupies 13% and maltose occupies 14%. These data suggest that trehalose has a larger hydrated volume than the other sugars. This hypothesis can be demonstrated from various thermodynamic parameters as shown in Table 12.1. 

The cooperative, infinite chains and cycles formed by O-H 0 hydrogen bonds in the a-cyclodextrin hydrates are a characteristic structural motif [109]. As with the simpler carbohydrate crystal structures described in Part II, Chapter 13, the hydrogen bonds can be traced from donor to acceptor in the cyclodextrin hydrate crystal structures. Networks of O-H 0-H 0-H interactions are observed in which the distribution of hydrogen bonds follows patterns with two characteristic motifs. One are the "infinite chains which run through the whole crystal lattice, and the others are the loops or cyclically closed patterns (a special case of the "infinite chains). As in the small molecule hydrates, such as a-maltose monohydrate, the chains and cycles are interconnected at the water molecules to form the complex three-dimensional networks illustrated schematically in Fig. 18.5, with some sections shown in more detail in Fig. 18.7 a, b, c. 

Fig. 13.—Chromatograms, on Hydrated Magnesium Acid Silicate, of (a) a- and (3-n-Glucopyranose Pentaacetates and of (b) -Gentiobiose Octaacetate and/S-Maltose Octaacetate.

Dextrates is a purified mixture of saccharides resulting from the controlled enzymatic hydrolysis of starch. It is either anhydrous or hydrated. In addition to dextrose, dextrates contains 3-5% w/w maltose and higher polysaccharides. 

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