Trichloroacetic acid phenol

Proteins coextracted by salt or alkaline solutions can be precipitated with the usual reagents, such as phosphotungstic acid, phosphomolybdic acid, picric acid, etc., or denatured with Sevag s reagent, followed by precipitation of the polysaccharide with alcohol. Trichloroacetic acid, phenol or acetic acid extractions have also been used with success. 

The rate of stripping or the stripabiUty on cataly2ed urethane and epoxy resin finishes can be increased by adding formic acid, acetic acid, and phenol. Sodium hydroxide, potassium hydroxide, and trisodium phosphate [10101-89-0] may be added to the formula to increase the stripabiUty on enamel and latex paints. Other activators include oleic acid [112-80-17, trichloroacetic acid [76-85-9], ammonia, triethanolamine [102-71-6], and monoethyl amine. Methylene chloride-type removers are unique in their abiUty to accept cosolvents and activators that allow the solution to be neutral, alkaline, or acidic. This abihty gready expands the number of coatings that can be removed with methylene chloride removers. 

Most of the chemistry of PA is determined by its acidic nature. It is a strong acid whose ionization constant of 1.6 x 10"1 (Ref 31) makes it comparable in acid strength to pyrophosphoric acid and trichloroacetic acid. PA readily forms salts with bases and esters with alcohols. The salts are known as Picrates. Many of them are expl and will be described in a separate article in this Vol. The esters are phenol ethers, eg, Trinitro-anisolc (see Vol t, A450-L)... 

Bifunctional catalysis in nucleophilic aromatic substitution was first observed by Bitter and Zollinger34, who studied the reaction of cyanuric chloride with aniline in benzene. This reaction was not accelerated by phenols or y-pyridone but was catalyzed by triethylamine and pyridine and by bifunctional catalysts such as a-pyridone and carboxylic acids. The carboxylic acids did not function as purely electrophilic reagents, since there was no relationship between catalytic efficiency and acid strength, acetic acid being more effective than chloracetic acid, which in turn was a more efficient catalyst than trichloroacetic acid. For catalysis by the carboxylic acids Bitter and Zollinger proposed the transition state depicted by H. 

The phenols pyrocatechol, resorcinol and hydroquinone can be detected with all chloramine T reagents. The detection sensitivity is about the same with chloramine T - sodium hydroxide and chloramine T - trichloroacetic acid. In all cases the detection limits are ca. 75 ng substance per chromatogram zone after the plate has been subsequently dipped in a paraffin oil solution. Somewhat less favorable detection limits of 150 to 200 ng substance per chromatogram zone are obtained after treatment with chloramine T - hydrochloric acid and chloramine T - sulfuric acid. 

Stagnone GJ, Orgel MB, Stagnone JJ (1987) Cardiovascular effects of topical 50% trichloroacetic acid and Baker s phenol solution. J Dermatol Surg Oncol 13 999-1002... 

Trichloroacetic acid and phenol peels (see peel sections) have been used extensively to treat photodamage [60, 61]. However, TCA peels in concentrations above 35% are unpredictable. Albeit efficacious for severe photodamage, phenol peels are associated with myriad side effects [61]. Hence, combination medium-depth peeling agents have become increasingly popu-... 

In Goiffon s method (G3) peptides are precipitated with phospho-tungstic acid from a trichloroacetic acid filtrate. The precipitate is dissolved and color is developed by a reaction with Folins phenol reagent. This method, however, is not only specific for peptides and a separate assay of uric acid has to be made since this substance also reacts with Folin s reagent. 

CI3C-COOH Trichloroacetic acid CI3C-COO- 0.66 CgHg-OH Phenol CgHs-O- 9.9... 

The nature of the association between membrane and teichoic acid is unknown, and it is possible that these teichoic acids are chemically attached to other components of the cell. Samples obtained by extraction with phenol appear to have appreciably higher molecular weight than has the purified teichoic acid obtained by extraction with trichloroacetic acid, and it is likely that the prolonged, acid treatment used in earlier work may have caused hydrolysis of some of the phosphodiester linkages. It is noteworthy that this comment on earlier studies does not apply to ribitol teichoic acids. Detailed examination of preparations of membrane teichoic acid obtained by less drastic conditions is highly desirable, in order to confirm the supposed size of the naturally occurring polymers, as well as... 

The incubation digest (7.0 ml) contained 1 ml of 0.022 M phenyl phosphate 2.5 ml of 0.1 M acetate buffer, pH 5.0 0.5 ml of test enzyme solution and 3.0 ml of solutions of acceptors giving a final concentration as shown in the third column. Incubation time, 30 min. Digests were inactivated by 3.0 ml of 10% trichloroacetic acid solution and were analyzed for phenol and inorganic phosphate. In the case of the standard acceptor, 1,4-butanediol, the expected transfer product, 1,4-butanediol phosphate, was isolated in a yield of 35% from a large-scale experiment. The hydrolysis of this phosphate ester by prostatic acid phosphatase liberated approximately equimolar amounts of 1,4-butanediol and inorganic phosphate. 

The vaccine formulation comprises a mixture of the outer-membrane lipopolysaccharides from bacteria of the seven different serotypes. The lipopolysaccharides may be obtained from cultures of each of the seven types by the standard procedure of Westphal (11), involving phenol—water extraction of the cells. However, for large-scale purposes, the older procedure of Boivin, (12) involving extraction of the cells with trichloroacetic acid, was... 

Subsequent studies show that iodoalkanes of 1-4 carbons (2388) and chloroacetic acids form abiotically in soil (413), in addition to their well-known biogenic enzymatic formation. An abiotic source of CH3Br is suggested for the emission of this gas from ash (Fraxinus excelsior) and saltwort (Batis maritima), plants having known bromine content (2389). The emissions are a function of both temperature increase and bromine concentration. The natural formation of chloroethyne (58) in soil is also proposed to involve a Fenton reaction (382), as is the production of dichloroacetic and trichloroacetic acids from phenols and soil humic acid (413). 

The condensation of allylic alcohols with phenolic compounds in the presence of an acid catalyst yields allylphenols. This reaction was used 86 in a synthesis of vitamin K (LXXVa) by condensing phytol with 2-methyl-l,4-naphthohydroquinone in dioxane with oxalic or trichloroacetic acid as catalyst the hydroquinone first formed was oxidized to... 

Since the discovery of LPS (Shear, 1941), various methods for the extraction of LPS have been developed. These include extraction with trichloroacetic acid (Ribi et al., 1961), with ether (Galanos et al., 1969), with water (Robert et al., 1967), with pyridine (Goebel et al., 1945), with phenol (Westphal and Jann, 1965), with butanol (Morrison and Leive, 1975), and with sodium dodecyl sulfate (SDS) (Darveau and Hancock, 1983). A few of these methods can chemically alter the structure of LPS (Nowotny et al., 1966 Tsang et al., 1974 Wober and Alaupovic, 1971). Among these methods, the most used are the phenol-water extraction (Westphal and Jann, 1965) and the ether extraction (Galanos et al., 1969). The former is most efficient for the extraction of S-LPS, while the latter for R-LPS. A method which could efficiently extract both S-LPS and R-LPS has also been developed (Darveau and Hancock, 1983). 

Rats weighing 200-300 g are starved for 24 hours, with free access to water before the experiment. They are treated orally or subcutaneously with the test compound 15 min prior to oral administration by gavage of 1.5 ml 0.07% phenol red in 2% car-boxymethylcellulose solution. 15 min later the animal is sacrificed and the stomach is immediately removed. The whole stomach including the stomach content is alkalized with 1 N NaOH and homogenized. The homogenate is filtered, and after precipitation of the protein with 10% trichloroacetic acid, centrifuged for 15 min at 3000 rpm. The concentration of phenol red in the supernatant is measured colorimetrically in a photometer at 546 nm. 

Pa = Concentration of phenol red in the initial solution after addition of equal volumes of 1 N NaOH and trichloroacetic acid ( xg/ml)... 

Perchloroethylene in end-exhaled air Perchloroethylene in blood Trichloroacetic acid in urine Phenol... 

This hypothesis is in close agreement with the results and views presented by Barnard et al. (1954). It is also significant that salts of anions shown by Steinhardt et al. (1941, 1942a) to have a high affinity for wool are able to superciontract the fiber, whereas little or no contraction is obtained with anions of low affinity. The sodium salts of trichloroacetic acid (Crewther and Dowling, 1956) and nitrated phenols (Crewther, 1959) are examples of the former acetate is an example of the latter. 

The iodometric method was then modified (G23, G24) by changing the final concentration of trichloroacetic acid from 8% to 3.3%, leaving more proteose-like substances in the filtrate, and quantitating the mucosubstances in the filtrate colorimetrically by the Folin-Ciocalteu reaction with the phenol reagent, instead of iodometric titration. This colorimetric reaction determines the tyrosine and tryptophan content after alkaline hydrolysis of the total dissolved mucin. 

Phthalein type dyes have been prepared from 2,3-dicarboxypyrazine by heating with phenols or aromatic amines and zinc chloride. For example, compound (25) was obtained with resorcinol (1353). Efforts to prepare 2,6-diaminopyrazine through a Curtius-Schmidt reaction on 2-acetamido-6-carboxypyrazine (with sodium azide, sulfuric acid, and trichloroacetic acid) proved unsuccessful (434). The preparation of bicyclic heterocyles from 2-amino-3-carboxypyrazines has been described in Section VIII. 1D(6). 

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