Sorbitol, purification

When the benzylidenation of sorbitol is carried out under slightly different conditions, a dibenzylidene-D-sorbitol (m. p. 219-221°, after purification via its dibenzoate) is obtained.29 116 Wolfe, Hann and Hudson29 demonstrated that oxidative scission of the diacetal resulted in the consumption of one molecular equivalent of lead tetraacetate and in the production of formaldehyde, together with a dibenzylidene-aldehydo-pentose, which yielded L-xylose when heated with aqueous... 

Summary Sorbitol hexantrate is easily prepared by nitrating sorbitol with mixed acid of nitric and sulfuric. After the reaction, the crude product is decanted, washed, and then dissolved in 95% ethanol. This mixture is then added to warm water, which causes the solid product to precipitate. The product is then recrystallized from fresh 95% ethanol for purification. Commercial Industrial note For related, or similar information, see Serial No. 310,926, March 18th, 1930, by E.I. Dupont de Nemours Company, to Rank H. Bergeim, Leonia, NJ. Part or parts of this laboratory process may be protected by international, and/or commercial/industrial processes. Before using this process to legally manufacture the mentioned explosive, with intent to sell, consult any protected commercial or industrial processes related to, similar to, or additional to, the process discussed in this procedure. This process may be used to legally prepare the mentioned explosive for laboratory, educational, or research purposes. 

Fig, 3, It should be emphasized that a careful examination of the cyclodextrin derivatives must be performed after the final purification. Several authors have indicated that incomplete derivatization may be the reason for irreproducible results. Except for thorough NMR investigations ( H- and C-NMR), the "reductive cleavage" of cyclodextrin derivatives and subsequent quantitative gas chromatographic analysis of the 1,5-anhydro-sorbitol derivatives as developed by Mischnick-Lubbecke and Krebber (35) have proved a sensitive and reliable method to detect even traces of under-or over-alkylated derivatives. 

Dextrose and sorbitol undergo a catalytic condensation reaction with an acid. Further purification may be performed to... 

Peel-off masks are applied in a uniform layer on the skin and upon drying and removal produce a sensation of skin tightness and cleansing action. Peel-off masks are marketed to consumers with normal, oily, combination, and acne-prone skin types. These masks are believed to perform the functions of skin exfoliation, hydration, and purification. They are based on plasticized polyvinyl alcohol. Hydrophilic emollients (e.g., ethoxylated fatty acid or alcohol derivatives, dimethicone copolyol) and humectants (e.g., glycerin, propylene glycol, sorbitol) are added to prevent moisture loss and cracking of polyvinyl alcohol film. Solvents... 

Polysaccharides like dextrin, sugars, sugar-alcohols like sorbitol and mannitol, glycerol and ethylene glycol are sometimes used as stabilizers. Some peptides and amino acids are useful excipients for purification. Compounds with a similar structure to that of the substrate are generally effective as stabilizers and are used as fillers for storage. 

In Table 13.4 the characteristics of some rigid polyether polyols based on a sorbitol -glycerol mixture are presented. The initial starter mixture is solution of sorbitol (70%) and glycerol. After water vacuum distillation, the mixture of sorbitol - glycerol containing 0.1-0.5% water, is propoxylated in the presence of a KOH catalyst, followed by the usual purification. These polyether polyols are transparent viscous liquids, which are colourless or slightly yellow polyols ... 

The second most important polyol is mannitol. It is used, for example, in chewing gum and in pharmaceutical preparations [17]. Mannitol can be prepared by catalytic hydrogenation of the keto group of o-fructose followed by purification by crystallization, because sorbitol is also formed [1]. The aqueous solubility of mannitol is much lower than that of sorbitol, enabling selective crystallization (Scheme 3). Production methods for o-mannitol have been reviewed by Makkee [18]. 

Raney catalysts are used in a broad range of industrial hydrogenations. These include reductions of nitriles and dinitriles (e.g. for nylon intermediates), aldehydes (e.g. for sorbitol or alkane diols), olefins and alkynes (e.g. for monomer purification) and aromatic nitro compounds (e.g. for urethane intermediates). 

Adipic acid, 1,8-octanediol, sorbitol and glycerol were all purchased from Aldrich in the highest possible purity and were used without further purification. Novozyme-435 (specified activity 7000PLU/g) was a gift from Novozymes. 

D-sorbitol. The oxidation rate of D-sorbitol decrease drastically, which lead to the low concentration of L-sorbose in broth. Thereby, it will increase the downstream cost of the separation and purification. Control of initial concentration of sorbitol with 200 g/L, the production and yield of L-sorbose were 200 g/L and 14.2 g/L/h (Giridhar and Srivastava 2002). Besides this, with constant speed feeding of 600 g/L D-sorbitol, the concentration of L-sorbose was 1.6 times greater than batch fermentation whereas 272.37 g/L L-sorbose achieved with linear feeding strategy (Giridhar and Srivastava 2001) exponential feeding of 700 g/L D-sorbitol after 10 h batch fermentation with 200 g/L D-sorbitol made 290 g/L L-sorbose (Srivastava and Lasrado 1998). 

Dihexanoylphoshatidylcholine (dC(6)PC) (> 99%) was obtained from Avanti Polar Lipids Inc. (Alabaster, AL, USA). The purity was monitored by thin-layer chromatography (TLC). The sample gave a single spot on a TLC plate and it was, therefore, used without further purification. Sorbitol was obtained from Towa Kasei Kogyo Co. (Tokyo, Japan) with a specified purity better than 99.9%. The purity was checked by the manufacturer by means of liquid chromatography. 

To obtain a good yield of intact jojoba plastids, a high osmolarity of the isolation medium was maintained using 0.5 M sorbitol. Then purification was performed according to Guillot-salomon et al, (1987). 

For purification of HMGR, stem and leaf tissue were ground with buffer containing 10 mM K phosphate, 0.4 M sorbitol, 30 mM EDTA, 10 mM DTE, and 10% w/w insoluble PVP, pH 7.2. The filtered extract was centrifuged as described in Fig. 1. Pellets were resuspended in 0.1 M K phosphate, 30 mM EDTA, 10... 

Shinagawa E, Matsushita K, Adachi O, Ameyama M (1982) Purification and characterization of D-sorbitol dehydrogenase from membrane of Gluconobacter suboxydans var. alpha. Agric Biol Chem46(l) 135-141... 

---