Sugar polyols

Etherification. The reaction of alkyl haUdes with sugar polyols in the presence of aqueous alkaline reagents generally results in partial etherification. Thus, a tetraaHyl ether is formed on reaction of D-mannitol with aHyl bromide in the presence of 20% sodium hydroxide at 75°C (124). Treatment of this partial ether with metallic sodium to form an alcoholate, followed by reaction with additional aHyl bromide, leads to hexaaHyl D-mannitol (125). Complete methylation of D-mannitol occurs, however, by the action of dimethyl sulfate and sodium hydroxide (126). A mixture of tetra- and pentabutyloxymethyl ethers of D-mannitol results from the action of butyl chloromethyl ether (127). Completely substituted trimethylsilyl derivatives of polyols, distillable in vacuo, are prepared by interaction with trim ethyl chi oro s il an e in the presence of pyridine (128). Hexavinylmannitol is obtained from D-mannitol and acetylene at 25.31 MPa (250 atm) and 160°C (129). 

Joost H-G, Thorens B (2001) The extended GLUT-family of sugar/polyol transport facilitators - nomenclature, sequence characteristics, and potential function of its novel members. Mol MembrBiol 18 247-256... 

The organic solutes shown to be related to stress adaptation include sugars, polyols, tertiary N compounds, amino acids and organic acids. Of particular note are compounds such as proline, glycine betaine and reducing... 

Joost, H. G., et al. Nomenclature of the GLUT/SLC2A family of sugar/ polyol transport facilitators. Am. J. Physiol. 2002, 282, E974-E976. 

It has long been recognized that boron is required by higher plants [61, 62], and recent research indicates the involvement of boron in three main aspects of plant physiology cell wall structure, membrane function, and reproduction. In vascular plants, boron in solution moves in the transpiration stream from the roots and accumulates in the stems and leaves. Once in the leaves, the translocation of boron is limited and requires a phloem transport mechanism. The nature of this mechanism was only recently elucidated with the isolation of a number of borate polyol compounds from various plants [63-65]. These include sorbitol-borate ester complexes isolated from the floral nectar of peaches and mannitol-borate ester complexes from the phloem sap of celery. The implication is that the movement of boron in plants depends on borate-polyol ester formation with the particular sugar polyol compounds used as transport molecules in specific plants. 

Numerous compounds can provide general cryoprotection to proteins, when used at concentrations of several hundred millimolar. These include sugars, polyols, amino acids, methylamines, and salting-out salts (e.g., ammonium sulfate) [59,61,68-70]. Based on the results of freeze-thawing experiments with LDH and PFK and a review of the literature on protein freezing. Carpenter and Crowe [59] have proposed that this cryoprotection can be explained by the same universal mechanism that Timasheff and Arakawa have defined for solute-induced protein stabilization in nonfrozen, aqueous solution (reviewed in [4,70,78,79]). 

Non-Reducing Sugar (Polyol) Monosaccharides of Commercial Importance. 848... 

Monosaccharides Reducing sugar Polyol Food products Abbreviations... 

Protein denaturation has been observed during spray drying due to the dehydration process and the use of excipients to replace hydrogen bonded water is often needed (e.g., sugars, polyols, amino acids) in the protein formulation (3.57.58). 

Several methods have been applied in the field of stabilizing enzymes against losses during drying and subsequent storage and handling. The bulk of these applications are concerned with the addition of carbohydrates and, more specifically, sugars, polyols, and salt components to the enzyme concentrate [9]. 

Chen K, Tamura M, Yuan Z, Nakagawa Y, Tomishige K (2013) One pot conversion of sugar and sugar polyols to n-alkanes without C-C dissociation over Ir-ReOx/Si02 catalyst combined with H-ZSM-5. ChemSusChem 6 613-621... 

Co-solvents such as ethanol, sugars, polyols, propylene glycol and glycerol, also have preservative properties if they are present in sufficient concentration (see also Sect. 23.3). Propylene glycol at 15 % is not quite as effective as sorbic acid or methyl parahydroxybenzoate and tastes unpleasant. Glycerol 85 % in concentration 30 % preserves less well than propylene glycol but tastes slightly sweet. 

Gallic acid is almost invariably found in plant tissues, associated with sugars, polyols, glycosides and other phenols, in ester form. Methods of structure determination have been amply documented in recent... 

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