Sodium acetate hydrolysis

Due to phase variation, there are fluctuations in expression levels of certain enzymes in bacteria, therefore, not all colonies or cells make the same structure of lipid A species. A micro-extraction method for extraction of lipid A from a single colony has been developed (Zhou et al., 2009). This method uses microwave-assisted enzymatic digestion and sodium acetate hydrolysis, suitable to analyze lipid A from both cell samples and an individual colony. Because the clean up of SDS is very time-consuming, and the contaminated SDS would seriously interfere with the analysis by mass spectrometry, the proteinase K, instead of SDS, is used to disrupt the cells. Using this method, the entire process for lipid A preparation only takes about 2 h with a detection limit to 1 (xg. 

The disadvantages attending the use of acetic anhydride alone are absent when the acetylation is conducted in aqueous solution according to the following procedure. The amine is dissolved in water containing one equivalent of hydrochloric acid, slightly more than one equivalent of acetic anhydride is added to the solution, followed by enough sodium acetate to neutralise the hydrochloric acid, and the mixture is shaken. The free amine which is liberated is at once acetylated. It must be pointed out that the hydrolysis of acetic anhydride at room temperature is extremely slow and that the free amine reacts much more readily with the anhydride than does the water this forms the experimental basis for the above excellent method of acetylation. 

The addition of active methylene compounds (ethyl malonate, ethyl aoeto-acetate, ethyl plienylacetate, nltromethane, acrylonitrile, etc.) to the aP-double bond of a conjugated unsaturated ketone, ester or nitrile In the presence of a basic catalyst (sodium ethoxide, piperidine, diethylamiiie, etc.) is known as the Michael reaction or Michael addition. The reaction may be illustrated by the addition of ethyl malonate to ethyl fumarate in the presence of sodium ethoxide hydrolysis and decarboxylation of the addendum (ethyl propane-1 1 2 3-tetracarboxylate) yields trlcarballylic acid ... 

Bromination of quinaldine (I) (Section V,2) with bromine in glacial acetic acid in the presence of anhydrous sodium acetate aflFords dilute sulphuric acid gives quinaltiinic acid (III). 

Sodium acetate reacts with carbon dioxide in aqueous solution to produce acetic anhydride and sodium bicarbonate (49). Under suitable conditions, the sodium bicarbonate precipitates and can be removed by centrifugal separation. Presumably, the cold water solution can be extracted with an organic solvent, eg, chloroform or ethyl acetate, to furnish acetic anhydride. The half-life of aqueous acetic anhydride at 19°C is said to be no more than 1 h (2) and some other data suggests a 6 min half-life at 20°C (50). The free energy of acetic anhydride hydrolysis is given as —65.7 kJ/mol (—15.7 kcal/mol) (51) in water. In wet chloroform, an extractant for anhydride, the free energy of hydrolysis is strangely much lower, —50.0 kJ/mol (—12.0 kcal/mol) (51). Half-life of anhydride in moist chloroform maybe as much as 120 min. Ethyl acetate, chloroform, isooctane, and / -octane may have promise for extraction of acetic anhydride. Benzene extracts acetic anhydride from acetic acid—water solutions (52). 

The production of triphenyl tin hydroxide [76-87-9] and triphenyl tin acetate [900-95-8] start with triphenyl tin chloride, which is prepared by the Kocheshkov redistribution reaction from tetraphenyltin and tin tetrachloride. The hydroxide is prepared from the chloride by hydrolysis with aqueous sodium hydroxide. The acetate can be made directiy from the chloride using sodium acetate or from the hydroxide by neutrali2ation with a stoichiometric quantity of acetic acid. 

The azlactones of a-benzoylaminocinnamic acids have traditionally been prepared by the action of hippuric acid (1, Ri = Ph) and acetic anhydride upon aromatic aldehydes, usually in the presence of sodium acetate. The formation of the oxazolone (2) in Erlenmeyer-Plochl synthesis is supported by good evidence. The method is a way to important intermediate products used in the synthesis of a-amino acids, peptides and related compounds. The aldol condensation reaction of azlactones (2) with carbonyl compounds is often followed by hydrolysis to provide unsaturated a-acylamino acid (4). Reduction yields the corresponding amino acid (6), while drastic hydrolysis gives the a-0X0 acid (5). ... 

In contrast to this, consider next a solution of sodium acetate. From vSec. 09 we know that in such a solution the thermal agitation raises a certain number of protons from the solvent molecules to the vacant proton levels of the (CH GOO) ions. In the aqueous solution of such a salt, this process is known as the hydrolysis of the salt and is traditionally regarded as a result of the self-ionization of the water. In Fig. 36, however, it is clear that in the proton transfer... 

The hydrolysis of the sodium salt of a weak acid can be treated similarly. Thus for a solution of sodium acetate... 

Example 11. Calculate (i) the hydrolysis constant, (ii) the degree of hydrolysis, and (iii) the hydrogen ion concentration of a solution of sodium acetate (0.01 mol L-1) at the laboratory temperature. 

Treatment with NCS in carbon tetrachloride converted the parent into the 2,3-dichloro derivative. The 2,3-dibromo compound was made similarly with NBS (74BSF2239), or with bromine in chloroform in the presence of sodium acetate (72CHE13). Monobromination is possible, but generally mixtures form with 2- and 3-bromo products in ratios of the order of 1 3 (72CHE13). It was possible to prepare 3-bromobenzo[h]sele-nophene by reaction of the 2,3-dibromo derivative with butyl lithium followed by hydrolysis. Four moles of bromine gave the 2,3,6-tribromo derivative from benzo[h]selenophene (74BSF2239). 

Neutral PET hydrolysis usually takes place under high temperature and pressure in die presence of alkali metal acetate transesterification catalysts.28 It is diought diat the catalytic effect observed on the part of zinc salts is the result of electrolytic changes induced in die polymer-water interface during the hydrolysis process. The catalytic effect of zinc and sodium acetates is thought to be due to die destabilization of die polymer-water interface in the hydrolysis process. 

A mixture of acetic anhydride/polyphosphoric acid/sodium acetate was used to carry out cyclodehydrations. The water treatment at the end of the reaction caused an extremely violent hydrolysis. 

Aryloxy-l,2-diarylethanones can be cyclodehydrated to diarylbenzofurans by heating with sodium acetate and acetic anhydride in polyphosphoric acid. Quenching the hot reaction mixture with water leads to initially violent acid-catalysed hydrolysis of the excess anhydride. 

This reaction does not take place to a great degree as should be expected from the fact that both an acid (HC2H302) and a base (OH-) are produced in the same reaction. The result is that a 0.1 M solution of sodium acetate has a pH of 8.89, which means that the solution is basic, but not strongly so. Another way to look at this reaction is to say that OH- is a strong base but HC2H302 is a weak acid. Therefore, the solution should be basic, and it is. On the other hand, a 0.1 M solution of NaCl or NaN03 has a pH of 7, because the hydrolysis represented by the equation... 

Methyl-2-cyclohexenone has been prepared (a) by the action of ni-t rosyl chloride on 1-methylcydohexene, followed by dehydrohalogena-I ion with sodium methoxide4 or sodium acetate,6 and hydrolysis of the resulting oxime (b) in an impure condition by several methods 6-12... 

The conversion of D-mannose (20) into L-gulose (9) was reported by Evans and Parrish,15 and is shown in Scheme 4. D-Mannose (20) was converted into 21 by condensation with acetone, methanol, and 2,2-di-methoxypropane in the presence of an acid, and mild hydrolysis of 21 afforded 22. Methanesulfonylation of 22 provided 23, which was transformed into 24 with sodium acetate in refluxing N,N-dimethyl-formamide. The overall yield of 24 from D-mannose was >50%. Base hydrolysis, followed by acid hydrolysis, afforded L-gulose (9). 

Alkylation of 7V-benzyl-p-toluenesulfonamide (12a) with a threefold excess of fra j-l,4-dichloro-2-butene (ila) gives the allylic chloride 11b. which is treated with sodium acetate in DMF followed by hydrolysis to afford the allylic alcohol 10a in an overall 68% yield. 

NaCl is added to the solution Explain, b. What will happen to the degree of hydrolysis of 0.02-molar sodium acetate if NaCl is added Explain. 

Since protein adsorption to an anion exchange resin is reversible and does not constitute a classical immobilization, the ability of the resins to retain activity under various conditions must be determined. Macrosorb KAX DEAE bound -D-glucosidase was tested with solutions of primary interest for their final application. Several batch washes of a 1% w/v slurry were required to ensure complete equilibrium elution for a given concentration, as determined from the absence of pNPG units in subsequent washes. Several salt solutions of typical fermentation media components were tested. These included 3 mM to 50 mM solutions of MgSO, KHgPO, NaQ, and sodium acetate. Also, incubations with cellulase solutions were tested to determine if the proteins present in a cellulose hydrolysis would displace the -D-glucosidase. Both of these displacement studies were carried out at 22°C and 40 C. 

The operational stability of the IME was determined by the performance of the IME in a real cellulose hydrolysis reactor. 50-mL tubes were charged with 2.5 g a-cellulose (50 g/L) in 10 mM sodium acetate pH 4.8. Tetracycline and cycloheximide... 

CGTase Activity Assay. Aaivity was measured by the Pharmacia Phadebas Amylase Assay at pH 6.0, 60 C in O.IM sodium acetate (100 ppm Ca+ " ) for 15 minutes using B, stearothermophilus alpha-amylase as a standard. Alpha-amylase preparations were assayed under the same conditions. One Phadebas unit is defined as the amount of enzyme that will catalyze the hydrolysis of 1.0 micromole of glucosidic linkages of Lintner starch per minute at 6OOC, pH 6.0. 

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