Neutral phenolics, fractionation

We found that the ether and ethyl acetate extracts of chicory roots exhibited the best nematicidal activities. The extracts were separated according to their acidity to give organo-acidic, phenolic, basic and neutral fractions. The phenolic fraction was found... 

Figure 5. Infrared absorption spectra of the acidic furnish extract fraction fractionated further by sequential extraction into aldehydic (bisulfite), hydroxyl (bicarbonate), phenolic (hydroxide), and aliphatic (neutral residual) fractions...

A fractionation method for separation of neutral phenols from the acidic ones by using two 300-mg C18 cartridges was proposed. The operative procedure is summarized in the scheme in Figure 2.12 (Lee and Jaworski, 1987). 

The tumorigenic effect of benzo[a]pyrene was retarded by the creosote oil, neutral distillate, neutral residue, and phenolic fractions. However, in three instances this effect was apparently related to skin damage associated with the treatments rather to a specific inhibitory effect. Only the phenolic fraction seemed to exhibit a primary antagonistic effect. Three other fractions (basic, neutral, and a low concentration of neutral distillate) exhibited apparent tumor promoting effects. 

It is a relatively recent observation that Colchicum species contain numerous chemical constituents of diverse chemical properties. Recognition of this fact has led to more efficient methods of isolation. In addition to neutral, phenolic, and basic alkaloids, 0. autumnale contains fatlike substances which are removed by a preliminary ligroin extraction of the pulverized, dry material. From such an extraction of the flowers of C. autumnale, Santavy and Herout (293) have isolated a paraffin, Ca7-28H5g 58, m.p. 58-60° an alcohol, CaaH450H, m.p. 66-67° and a phytosterol, m.p. 139-140°. Benzoic, salicylic, and 2-hydroxy-6-methoxybenzoic acids may be separated from the alkaloid mixture by virtue of their solubility in ether and aqueous base (294). The alkaloids themselves may be separated into neutral, phenolic, or basic fractions by standard extraction techniques. Pure alkaloids may be obtained from each fraction by fractional crystallization and chromatography on... 

Identified by Andrade-Aispuro and Crouzet (1983) using original laboratory and pilot units allowing recovery of the volatiles produced during coffee roasting, with a system based on an absorption column equipped with Raschig rings and a countercurrent flow of water. The condensate was fractionated by chemical extraction into basic, acid, neutral and phenolic fractions. The constituents were separated and... 

Neutral and phenolic fractions 49 g Washings (addle fraction)... 

Description Cumene is oxidized (1) with air at high efficiency (-i-95%) to produce cumene hydroperoxide (CHP), which is concentrated (2) and cleaved (3) under high-yield conditions (-i-99%) to phenol and acetone in the presence of an acid catalyst. The cleavage mixture is neutralized and fractionated to produce high-purity products (4-8), suitable for all applications. AMS is hydrogenated to cumene and recycled to oxidation or optionally recovered as a pure byproduct. 

As stated above, the protocol can be interrupted either after the obtainement of the first (step 1) or the second (step 3) pellet of mitochondria. If the crude fraction is used, it is recommanded to resuspend the mitochondria and centrifuge them again prior the lysis. The pellet is gently lysed with 0.5 ml of SDS 1% or 2% at room temperature for. 10 min. The clear lysate is transferred into a 1.5 ml microcentrifuge tube. Proteins are extracted with 0.5 ml of neutralized phenol. Spin for 5 min at 12,000 g. Adjust the aqueous supernatant to a final concentration of 0.3 M NaAc. Add 2.5 vol of absolute alcohol, mix (by inversion of the tube), keep at -20°C overnight. Centrifuge mtDNA, wash the pellet with 70° ethanol, dry under vacuum, dissolve in appropriate vol of TE. 

In the third step in the synthesis of phenol, the cumene hydroperoxide undergoes cleavage to phenol and acetone. This is usually accomplished by feeding the hydroperoxide, with sulphuric acid as catalyst, continuously into previously decomposed material maintained at about 50—90 C. The product is then neutralized and fractionated by distillation. The cleavage reaction possibly proceeds as follows ... 

Because phenols are weak acids, they can be freed from neutral impurities by dissolution in aqueous N sodium hydroxide and extraction with a solvent such as diethyl ether, or by steam distillation to remove the non-acidic material. The phenol is recovered by acidification of the aqueous phase with 2N sulfuric acid, and either extracted with ether or steam distilled. In the second case the phenol is extracted from the steam distillate after saturating it with sodium chloride (salting out). A solvent is necessary when large quantities of liquid phenols are purified. The phenol is fractionated by distillation under reduced pressure, preferably in an atmosphere of nitrogen to minimise oxidation. Solid phenols can be crystallised from toluene, petroleum ether or a mixture of these solvents, and can be sublimed under vacuum. Purification can also be effected by fractional crystallisation or zone refining. For further purification of phenols via their acetyl or benzoyl derivatives (vide supra). 

A mixture of monolauryl phosphate sodium salt and triethylamine in H20 was treated with glycidol at 80°C for 8 h to give 98% lauryl 2,3-dihydro-xypropyl phosphate sodium salt [304]. Dyeing aids for polyester fibers exist of triethanolamine salts of ethoxylated phenol-styrene adduct phosphate esters [294], Fatty ethanolamide phosphate surfactant are obtained from the reaction of fatty alcohols and fatty ethanolamides with phosphorus pentoxide and neutralization of the product [295]. A double bond in the alkyl group of phosphoric acid esters alter the properties of the molecule. Diethylethanolamine salt of oleyl phosphate is effectively used as a dispersant for antimony oxide in a mixture of xylene-type solvent and water. The composition is useful as an additive for preventing functional deterioration of fluid catalytic cracking catalysts for heavy petroleum fractions. When it was allowed to stand at room temperature for 1 month it shows almost no precipitation [241]. 

Isolation of Antimicrobial Alkaloids from Tertiary Non-phenolic Base Fraction - A 2 g portion of the crude nonphenolic base fraction was dissolved in chloroform and chromatographed over 200 g of aluminum oxide (Woelm, neutral, grade III). The solvents used were 300 ml of chloroform, 500 ml of 1Z methanol in chloroform, 300 ml of 2Z metha-... 

The arene sulphonyl chloride (0.11 mol) in PhH (50 ml) is added dropwise at 20°C to a two-phase system of the alcohol (or phenol) (0.1 mol) and TEBA-Cl (0.91 g, 4 mmol) in PhH (100 ml) and aqueous NaOH (30%, 50 ml). The mixture is stirred at 20°C for 5-8 h, and the organic phase is then separated, washed well with HzO until the washings are neutral, dried (Na2S04), and fractionally distilled to yield the sulphonic ester. 

Elforts have been made to characterize the nature and content of individual components that are present in the low-molecular-mass fraction of the total mill effluents, which include the spent chlorination and alkali extraction stage liquors [2,4]. Approximately 456 types of compounds have been detected in the conventional bleach effluents, of which 330 are chlorinated organic compounds [22]. The compounds may be lumped into three main groups, namely, acidic, phenolic, and neutral (Table 2). Acidic compounds are further divided into the five categories of acids fatty, resin, hydroxy, dibasic, and aromatic acids. The most important fatty acids are formic and acetic acids. The dominant resin acids are abietic and dehydroabietic acids. Among the hydroxy acids identified, glyceric acid predominates. Dibasic acids such as oxalic, malonic, succinic, and mafic acids are derived from the lignin and carbohydrate fraction... 

Among the numerous applications of SPE are separations of phenolic acids and flavonoids from wines and fruit juices. Sep-Pak Cig cartridges have been used for the fractionation of flavonol glycosides and phenolic compounds from cranberry juice into neutral and acidic parts before HPLC analysis. Antimutagenic flavonoids were identified in aqueous extracts of dry spinach after removal of lipophilic compounds by SPE. ... 

Eor obtaining neutral fraction the column was eluted with water firstly. The acidic fractions were obtained by elution of linear NaCI gradient (0-1.4 M) in water. The carbohydrate elution profile was determined using the phenol-sulphiric acid method, finally two column volumes of a 2 M sodium chloride solution in water were eluted to obtain the most acidic polysaccharide fraction. The relevant fractions based on the carbohydrate profile were collected, dialysed and lyophilized. 

Here S is the solubility of the lignin in neutral water, X is the fraction of phenolic groups that have been ionized, and Ka is the dissociation constant of the phenolic groups. The pKa was determined to be approximately 11.4 from light scattering results and the solubility limit was measured to be about 0.16 mass fraction. A reasonable fit of the permeate concentration from ultrafilter experiments with a 10,000 molecular weight cutoff (MWCO) was obtained. 

An alternative cleanup procedure is the partition of the raw extract, which often contains considerable amounts of lipid material, between an organic and an aqueous sodium hydroxide phase. With this partitioning scheme, the analytes are further fractionated into estrogens and nonestrogens. The presence of phenolic groups in the molecules of estrogens such as diethylstilbestrol and zeranol ensures their complete extraction from organic phases such as chloroform or tert.-butyl methyl ether into the aqueous sodium hydroxide phase (435, 438, 447). Further purification could be accomplished by neutralization of the sodium hydroxide solution and back-extraction of the contained diethylstilbestrol into diethyl ether (435), or adjustment of the pH of the sodium hydroxide solution to 10.6-10.8 and back-extraction of the contained zeranol into a chloroform phase (447). 

In some instances, combinations of Cig and silica columns are also used for better purification of the crude extracts (431, 445). A combination of Cg, silica, and amino solid-phase extraction columns has been successfully employed to fractionate anabolic and catabolic steroid hormone residues from meat in polar and nonpolar neutral and phenolic compounds, and to purify further each fraction effectively (452). Another combination of two solid-phase extraction columns, one using a graphitized carbon black sorbent and the other Amberlite resin in the hydroxyl form, allowed neutral anabolics to be isolated and separated from acidic anabolics and their metabolites (453). A combination of basic alumina column placed in tandem with an ion-exchange column has also been applied for the purification of the crude extracts in the determination of diethylstilbestrol and zeranol (427), and estradiol and zeranol in tissues (450). 

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