Stabilization, salt

Polymer Cost 3 Viscosity0 (cps). 40 lb/1000 gal Shear0 at 300 rpm Stability Salte Tolerance Acidf Stability Enzyme9 Stability Residue1 in Broken Gel Applications... 

The problem of homogeneity-heterogeneity mentioned in Section 18.2.2 arises also here in the cases of using a simple metal salt instead of a ligand-stabilized salt (see [70, 71]). 

The use of stabilized diazonium salts is a recent modification, and the exact limits of this reaction have not yet been established. It has been found to be particularly good for nitroanilines (4-nitrobiphenyl is obtained in 70% yield from p-nitroaniline) and for coupling with nitrobenzene. Coupling of the stabilized salt of aniline failed with toluene, biphenyl, naphthalene, and 1-nitronaphthalene, and the stabilized salt of /3-naphthylamine gave no /3-phenylnaphthalene when coupling with ben-... 

Conversion of stabilized diazo compounds to hydrocarbons does not depend upon the reducing action of ethyl alcohol, for the reaction takes place smoothly in acetone, ether, nitrobenzene, benzene, chloroform, apd carbon tetrachloride. No acetaldehyde is produced when ethanol is the solvent. In the absence of metals, however, when the stabilized salts of diazotized a-naphthylamine are treated with ethyl alcohol, acetaldehyde, naphthalene, a-ethoxynaphthalene, and tar are obtained. 

In [13], based on a one-dimensional model, it was shown that the observed parameters of the NBML in the Black Sea are defined by the buoyancy fluxes balance between the destabilizing geothermal heat flux and stabilizing salt flux supplied with the waters of the Sea of Marmara penetrating to great depths. 

High concentrations of stabilizing salts such as NaCl and Na2S04 were reported to increase, and chaotropic salts to decrease, the affinity of bacterial and fungal cellulases to crystalline cellulose. Denaturing agents are capable of eluting cellulases from the cellulosic substrate (Otter et al., 1989). 

Phosphorylation of the activation loop appears to drive the equilibrium towards a catalytically active conformation due to the abUity of the phosphorylated residue to form stabilizing salt bridges with a series of lysine or arginine residues. However, it should be noted that, based on the evidence to date, the activation loop can occupy a range of conformations including one dose to an active conforma-... 

Although many of the substituted cyclopropenyl ions are marvels of stability, salts of the parent ion darken rather rapidly on heating and exposure to atmospheric moisture causes rapid decomposition. The hexachloroantimonate salt is stable for a long period at — 20° C and for a few hours at room temperature. As might be expected, the cyclopropenyl salts are soluble in polar solvents such as acetonitrile and dimethylformamide, but are insoluble in non-polar solvents. They, of course, react with protic solvents as described earlier. In aqueous solution the equilibrium of equation 24 is established. The pH required to... 

Lowering the Km value of a fuel-oxidizing enzyme is one of the many challenges faced when utilizing natural wild-type enzymes for EFC applications. Other issues, depending on the intended application, include enzyme immobilization and orientation, temperature and pH stability, salt inhibition, and substrate specificity. 

The ions to the left in the series exert a stabilizing effect on proteins. The ions to the right may bind to the protein surface and thereby destabilize the protein. The effect of the ions is additive. Ammonium sulfate is a stabilizing salt often used for precipitation of proteins (2-3-M solution). Gdn-sulfate is a stabilizing salt, while Gdn-chloride is a strong denaturant. 

Nowadays, there are many HALS stabilizers commercial of which the majority is based on 2,2,6,6-tetra-methyl-4-piperidinyl moieties. The first commercial type (LMW-HALS-1) is relatively low in molecular weight, which caused that due to its high volatility it is not suitable for thin applications. To overcome this problem oligomeric HALS types were developed. One of the drawbacks of the piperidinyl moiety of HALS stabilizers is that it is basic causing that it can react with acids and forms a not stabilizing salt. Consequently, the effectiveness of HALS in systems where acids are present or can be formed is limited. To beat this problem less basic HALS types as, for example, N-O-R types were developed. 

The [Ph3P=N=PPh3] ion (commonly abbreviated to [PPN]" ) is related to [Cl3P=N=PCl3], and is often used to stabilize salts containing large anions. We return to this topic in Box 24.2. 

The oxygen- and sulfur-stabilized salts show remarkable differences in reactions with nucleophiles. Compound 11 reacts with water to give 16 containing an oxygen-bridged dication. On reaction of 12 with water quantitative decomposition into the protonated pincer ligand and a polysiloxane is observed (Scheme 2). 

After days or weeks, depending on the bacterium- or fungus-type production organism, when the product titer (concentration), yield, or rate, sometimes combined, are maximal, the fermenter is ready for harvest. Before harvest, in some case, stabilizing salts are added, or temperature and pH parameters are adjusted. 

The characterization of the lab-produced quaternary anunonitun resins were investigated, including the density of active site, thermal stability, salt effect, imbibed solvent composition in the resin and the reuse of the resin. Meanwhile, the effect of base and temperature for the reactivity of the model reaction was conducted to achieve the optimum coniUtion. 

Evidence for the involvement of salt links in the stabilization of bakers yeast jS-o-fructofuranosidase has been obtained from studies of immobilization of the enzyme on cellulose, derivatives of Sephadex and insolubilized con-canavalin A, and modification with citraconic anhydride, methyl acetimidate, or ethylene diamine. The general stability to such treatments was offered as the evidence, since modification of either amino- or carboxy-groups would result in loss of conformational stability, unless the stabilizing salt linkages were present. 

Prell JS, O Brien JT, Steill JD, Oomens J, Williams ER (2009) Structures of protcmated dipeptides the role of arginine in stabilizing salt bridges. J Am Chem Soc 131 11442-11449... 

Under the influence of LDA 5-formyl-l,3,6-trimethyluracil forms a stabilized salt which can participate in cycloaddition reactions. Hence, with aldehydes, pyrano[4,3-d]pyrimidines are obtained, with high regio-and stereo-specificity. Since the Diels-Alder reaction occurs in a disrotatory manner (thermal) R and OH are cis to each other in (57). 

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