Assay hydrolysis

Burkholderia cepacia Fabric, PET trimer HPLC, water absorption assays Hydrolysis, increased hydrophilicity [38, 51]... 

For undetermined reasons, the optical density of DNA is less than the sum of the densities of the component nucleotides.Since DNA is a very long polymer, with a molecular weight of approximately 1,000,000, there is a decrease in viscosity on hydrolysis. The binding of basic dyes is characteristic only of large polymers, and has been used to assay hydrolysis. The most widely used assays, as with ribonuclease, measure either acid produced by hydrolysis of phosphate diesters or the formation of acid-soluble nucleotides. ... 

An approach based on molecular modeling and screening resulted in a library of structures that resemble NeuSAc only because they contain a carboxylate function [64]. For compound 107 IC50 = 0.15 mM was determined (assay hydrolysis of MU-Neu5Ac). 

The use of mutant 34486 of Neurospora crassa for the microbiological assay of ch oline has been described (8). A physiological method has also been used in which the ch oline is extracted after hydrolysis from a sample of biological material and acetylated. The acetylcholine is then assayed by a kymographic procedure, in which its effect in causing contraction of a piece of isolated rabbit intestine is measured (33). 

The crude ketal from the Birch reduction is dissolved in a mixture of 700 ml ethyl acetate, 1260 ml absolute ethanol and 31.5 ml water. To this solution is added 198 ml of 0.01 Mp-toluenesulfonic acid in absolute ethanol. (Methanol cannot be substituted for the ethanol nor can denatured ethanol containing methanol be used. In the presence of methanol, the diethyl ketal forms the mixed methyl ethyl ketal at C-17 and this mixed ketal hydrolyzes at a much slower rate than does the diethyl ketal.) The mixture is stirred at room temperature under nitrogen for 10 min and 56 ml of 10% potassium bicarbonate solution is added to neutralize the toluenesulfonic acid. The organic solvents are removed in a rotary vacuum evaporator and water is added as the organic solvents distill. When all of the organic solvents have been distilled, the granular precipitate of 1,4-dihydroestrone 3- methyl ether is collected on a filter and washed well with cold water. The solid is sucked dry and is dissolved in 800 ml of methyl ethyl ketone. To this solution is added 1600 ml of 1 1 methanol-water mixture and the resulting mixture is cooled in an ice bath for 1 hr. The solid is collected, rinsed with cold methanol-water (1 1), air-dried, and finally dried in a vacuum oven at 60° yield, 71.5 g (81 % based on estrone methyl ether actually carried into the Birch reduction as the ketal) mp 139-141°, reported mp 141-141.5°. The material has an enol ether assay of 99%, a residual aromatics content of 0.6% and a 19-norandrost-5(10)-ene-3,17-dione content of 0.5% (from hydrolysis of the 3-enol ether). It contains less than 0.1 % of 17-ol and only a trace of ketal formed by addition of ethanol to the 3-enol ether. 

Alkaline (and also acidic) ester hydrolysis of /3-poly(L-malate) is accompanied by side reactions leading to the formation of fumarate, maleate and/or racemiza-tion, especially at elevated temperatures. The above assays thus underestimate the polymer contents due to the formation of small amounts of 2-4% fumarate (unpublished results). This fraction of fumarate increases for the hydrolysis of more concentrated polymer solutions. 

CH2 CH.CH2.OH mw 58.09 OB to C02 -220.35% colorl, mobile liq with a pungent odor mp —129° bp 96.9°, d 0.8520g/cc at 20/4° RI 1.4127, 1.4133, 1.4135 (Sep values). V sol in w, ethanol and ether. Prepn is by the high temp chlorination of propene, followed by hydrolysis of allyl chloride. Thus,. . Allyl chloride is hydrolyzed at 200psi pressure, 150°C and a pH range of 10—12. Injection of steam forms a water-allyl alcohol azeotrope, which is then treated with diallyl ether to remove water. Final purification by distn leads to a 98% min assay. . (Ref 2). Using procedures such as the above, ... at least two American companies (Shell Chemical Co and Dow Chemical Co) produce a total of several million lbs per year... (Ref 2)... 

The versatility of the reagent system in the assay of small peptides is nicely illustrated in Figures 3 through 5. Neurotensin, a polypeptide composed of 13 amino acids, and three fragments from partial hydrolysis were derivatized with NDA/CN and separated by... 

The activity of enzymes in the film was estimated in the following way In order to test the activity of urease, we utilized a calorimetric assay based on urea hydrolysis the enzymatic reaction was followed at 590 nm, the suitable wavelength for bromcresol purple (Chandler 1982). Urea concentration was 1.67 ts 10 M. 

Epimerization of 4 at C-2 provided 5a-carba-a-DL-galactopyranose (6). When the pentaacetate IS was heated in acetic acid containing sulfuric acid, epimerization occurred at C-2 through an intermediary cyclic acetoxonium ion (18), with anchimeric assistance of the vicinal, axial acetoxyl group. After acetylation, 5a-carba-a-DL-galactopyranose pentaacetate (19) was obtained in a yield of 14% it was converted into 6 by hydrolysis. The antimicrobial activity of the racemate 6 was found to be about half that of the natural antibiotic 7 in the same assay system, indicating that the L-antipode is probably inactive. " ... 

Whole cell OPH activity was measured by following the increase in absorbancy of p-nitrophenol from the hydrolysis of substrate (0.1 mM Paraoxon) at 400 nm (sm = 17,000 M cm ). Samples of culture (1 ml) were centrifuged at 10,000 g and 4 C for 5 min. The cells were washed, resuspended with distilled water, and 100 pi was added to an assay mixture containing 400 pi 250 mM CHES [2-(N-cyclohexylamino)ethane-sulfonic acid] buffer, pH 9.0, 100 pi 1 mM Paraoxon, and 400 pi distilled water. One unit of OPH activity was defined as pmoles Paraoxon hydrolyzed per min. Each value and error bar represents the mean of two independent experiments and its standard deviation. 

A viscometric assay and identification of hydrolysis products were used to determine the mechanism of action of PG. An endo-PG is characterized by a strong reduction in viscosity (e.g. 50%) with a concomitantly low (e.g. 1-3%) release of reducing groups [9]. The time required for 50% decrease in viscosity of a 3.0% (w/v) sodium polypectate solution at 25°C was approximately 10 min, at which time about 1.5% of the total galacturonide bonds had been hydrolysed (data not shown). These results reveal a random mechanism of hydrolysis of sodium polypectate and the enzyme was a poly oc(l,4)-D-galacturonide glycanohydrolase (EC 3.2.1.15) or endo-PG. 

A or colorimetry Test for related substances by UV 20A Assay by hydrolysis rate... 

Oxime carbamates are not directly amenable to gas chromatography (GC) because of their high thermal instability, which often leads to their breakdown at the injection port or in the column during analysis. Analysis of oxime carbamates by GC with sulfur detection or flame photometric detection involves oxidation of the intact insecticides or alkaline hydrolysis to form the more volatile but stable oxime compound. Enzymatic techniques have been reported for the analysis of these compounds. Enzyme-linked immunosorbent assay (ELISA) has been used to determine aldicarb and its sulfone and sulfoxide metabolites and methomyl in water, soil, and sediment samples. 

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