Glycerol mannitol

Its acidity is considerably enhanced by chelation with polyhydric alcohols (e.g. glycerol, mannitol) and this forms the basis of its use in analytical chemistry e.g. with mannitol p T drops to 5.15,... 

Several polyols (i.e. molecules displaying multiple hydroxyl groups) have found application as polypeptide stabilizing agents. Polyols include substances such as glycerol, mannitol, sorbitol and PEG, as well as inositol (Table 6.9 and Figure 6.22). A subset of polyols is the carbohydrates, which are listed separately (and thus somewhat artificially) from polyols in Table 6.9. Various polyols have been found to stabilize proteins in solution directly, and carbohydrates in particular are also often added to biopharmaceutical products prior to freeze-drying in order to provide physical bulk to the freeze-dried cake. 

Protein drugs have been formulated with excipients intended to stabilize the protein in the milieu of the pharmaceutical product. It has long been known that a variety of low molecular weight compounds have the effect of preserving the activity of proteins and enzymes in solution. These include simple salts, buffer salts and polyhydroxylated compounds such as glycerol, mannitol, sucrose and polyethylene glycols. Certain biocompatible polymers have also been applied for this purpose such as polysaccharides and synthetic polymers such as polyvinyl pyrrolidone and even nonionic surfactants. 

The initial pH of the medium was adjusted to 7.0. All chemicals were of analytical grade. The carbon sources (commercial sugar-sucrose, sugarcane juice and molasses, sugarcane juice alcohol stillage, glycerol, mannitol, soybean oil) were added in order to establish an initial substrate concentration of 20 g/L. In some cases, the medium was also aseptically supplemented with 0.1% (w/v) yeast extract and 0.001% (w/v) Na EDTA previously and separately sterilized by filtration through a Millipore membrane with a pore size of 0.22 pm. 

Another class of polyol compounds that have been widely used as sugar substitutes is that of sugar alcohols. The most important of these sugar substitutes are erythritol, glycerol, mannitol (hexane-1,2,3,4,5,6-hexol), and sorbitol. Figure 1 shows the molecular models of glycerol and sorbitol. It can be appreciated that sorbitol has a chemical constitution very similar to that of monosaccharides, yet it has been used as sugar substitute since the body metabolizes it slowly. 

The economic feasibility of a lipid production process is determined by the cost of the raw materials as well as the fermentation processes itself. Glucose is the most commonly employed carbon source, but substrates like xylose, lactose, mannose, glycerol, mannitol, L-arabinose, ethanol, as well as wastewaters derived from animal fat treatment and olive oil mills are considered for single-cell oil production in yeast (reviewed in [67]). 

One of the earliest methods for modification of a PMMA surface for medical applications is based on chemical conversion of the wall rather than on addition of a new layer [9]. The conversion of PMMA consists of reesterificatitMi of PMMA with polyfunctional hydroxyl compounds, such as ethylene glycol, glycerol, mannitol, or saccharose. First, the PMMA surface is covered with ethylene glycol or another polyalcohol, which is allowed to diffuse inside the polymer body. Then the surface is treated with hot sulfuric acid to perform reesterification and replace the methanol in PMMA with ethylene glycol. After neutralization with sodium bicarbonate, a hydrophilic, transparent layer is formed on the surface of the PMMA. 

Lactic acid is mainly prepared in large quantities (around 200 kT per year) by the bacterial fomentation of carbohydrates. These fermentation processes can be classified according to the type of bacteria used (i) the hetero-fermentative method, which produces less than 1.8 mol of lactic acid per mole of hexose, with otho- metabolites in significant quantities, such as acetic acid, ethanol, glycerol, mannitol and carbon dioxide (ii) the homo-fomentative method, which leads to greater yields of lactic acid and lower levels of by-products, and is mainly used in industrial processes [3]. The convo-sion yield from glucose to lactic acid is more than 90 per cent. 

Adding polyhydroxy compounds, such as glycerol, mannitol, and glucose, to hydroxypropylmethylcel-lulose (HPMC) matrix can remarkably enhance the resolution of DNA fragments. Some intercalating dyes (e.g., ethidium bromide, YOYO, TOTO, and 9-aminoacri-dine) " can also enhance the resolution of DNA separation by modifying the DNA helix or persistence length. 

Studies of specific heat capacities and volumes suggest that polyols bind to proteins and stabilize their natural conformations, and studies of a-amino-acids in aqueous solutions of glycerol, mannitol, or glucitol have also been made to clarify this structural interaction. ... 

Some polyols (1,2-propanediol, glycerol, mannitol, sorbitol) have distinct hygroscopic... 

---