Acetone-Soluble Fats

The aldehyde of 8-hydroxybutyric acid, acetaldol, has been reported as one of the products of metabolism of human tubercle bacilli by Kasuya it is present particularly in the acetone-soluble fat moiety. 

Acetone-soluble fats, from lipids of M. tuberculosis, III, 326, 327 Acetophenone, phytochemical reduction of, IV, 83... 

Phospholipids were first identified by Hammerschlag and Kresling. Long and Campbell concluded that the waxy substance present in M. tuberculosis was a difficultly hydrolyzable ester of an alcohol of high molecular weight. A systematic and thorough examination of the lipids of the bacilli has been undertaken by Anderson and coworkers. He was able to differentiate between four main lipid fractions (1) phosphatides (2) acetone-soluble fats (3) waxes (4) firmly bound lipids. 

It is necessary to isolate the dehydrohalogenated methoxychlor from the nonsaponi-fiable portion of the fats and waxes. To do this, advantage is taken of the fact that both methoxychlor and its dehydrohalogenated product are readily soluble in acetone, whereas fats are relatively insoluble. The residue is first dissolved in hot acetone, and then the acetone is chilled to —15° C., which causes precipitation of the fats. After the fats are filtered off, the acetone is removed by evaporation. 

The acetone-soluble fraction was known to contain a large percentage of free fatty acids in addition to the fatty esters. Some of these fatty acids were found by Anderson to be of a type hitherto unknown. In common with the waxes, this fat did not contain any free glycerides. Alkaline hydrolysis of the fat derived from human strain bacilli yielded a water-soluble carbohydrate. This was identified as trehalose by isolation of the crystalline sugar. Corresponding fats isolated from the bovine and avian strains of bacilli were examined. The presence of glycerol could not be detected nor could the carbohydrate components be identified. 

The physical properties of methylene chloride are Hsted in Table 1 and the binary a2eotropes in Table 2. Methylene chloride is a volatile Hquid. Although methylene chloride is only slightly soluble in water, it is completely miscible with other grades of chlorinated solvents, diethyl ether, and ethyl alcohol. It dissolves in most other common organic solvents. Methylene chloride is also an excellent solvent for many resins, waxes, and fats, and hence is well suited to a wide variety of industrial uses. Methylene chloride alone exhibits no dash or fire point. However, as Htde as 10 vol % acetone or methyl alcohol is capable of producing a dash point. 

Traditionally, dried or powdered plant material is used and extracts can be obtained by mixing the material with food-grade solvents like dichloromethane or acetone followed by washing, concentration, and solvent removal. The result is an oily product that may contain variable amounts of pheophytins and other chlorophyll degradation compounds usually accompanied by lipid-soluble substances like carotenoids (mainly lutein), carotenes, fats, waxes, and phospholipids, depending on the raw material and extraction techniques employed. This product is usually marketed as pheophytin after standardization with vegetable oils. 

The most critical decision to be made is the choice of the best solvent to facilitate extraction of the drug residue while minimizing interference. A review of available solubility, logP, and pK /pKb data for the marker residue can become an important first step in the selection of the best extraction solvents to try. A selected list of solvents from the literature methods include individual solvents (n-hexane, " dichloromethane, ethyl acetate, acetone, acetonitrile, methanol, and water ) mixtures of solvents (dichloromethane-methanol-acetic acid, isooctane-ethyl acetate, methanol-water, and acetonitrile-water ), and aqueous buffer solutions (phosphate and sodium sulfate ). Hexane is a very nonpolar solvent and could be chosen as an extraction solvent if the analyte is also very nonpolar. For example, Serrano et al used n-hexane to extract the very nonpolar polychlorinated biphenyls (PCBs) from fat, liver, and kidney of whale. One advantage of using n-hexane as an extraction solvent for fat tissue is that the fat itself will be completely dissolved, but this will necessitate an additional cleanup step to remove the substantial fat matrix. The choice of chlorinated hydrocarbons such as methylene chloride, chloroform, and carbon tetrachloride should be avoided owing to safety and environmental concerns with these solvents. Diethyl ether and ethyl acetate are other relatively nonpolar solvents that are appropriate for extraction of nonpolar analytes. Diethyl ether or ethyl acetate may also be combined with hexane (or other hydrocarbon solvent) to create an extraction solvent that has a polarity intermediate between the two solvents. For example, Gerhardt et a/. used a combination of isooctane and ethyl acetate for the extraction of several ionophores from various animal tissues. 

Very sparingly soluble in water (less than 1%) freely soluble in oils and fats, gasoline, kerosene, acetone, carbon tetrachloride, alcohol, PS, and FM. Miscible with DP, L, ED, PD and the organophosphorus nerve agents. 

Soluble in acetone, acetic acid, alcohol (Weast, 1986), glycols, and fat solvents (Windholz et al,... 

Fig. 37A shows the chromatogram obtained in isocratic conditions for a mixture of homogeneous TG standards. The mobile phase is a mixture of CHC13 and acetonitrile (49 51). Tribehenin (BBB) is eluted easily in 18 min, while tristearin (SSS) could not be eluted without serious difficulties in previous studies where acetone/acetonitrile mixtures were used. This is certainly due to the use of a strong eluent, containing about half CHC13, a solvent in which fats are known to be very soluble. 

Soluble in Petroleum ether, 50% or higher alcohols, propylene glycol, fats, oils Toluene, alcohols, methyl ethyl ketone, acetone, petroleum ether, benzene, fats, oils Ethanol, oils, ether, fats, oils Oil... 

Chloroform-methanol is used to extract lipid and lipoprotein material according to Folch et al. [147], with the addition of aqueous KC1 to isolate lipid and lipoproteins. Alternatively, if lipid material is not to be investigated, fats can be removed with acetone with little co-extraction of Se. The presence of fats is not desirable as lower aqueous extraction efficiencies are obtained and nondefatted samples can degrade HPLC performance. Extraction with phosphate buffer will remove cytosol-soluble Se, while extraction with phosphate buffer containing SDS will release and solubilize membrane-bound Se. Phenylmethane sulfonyl fluoride or a similar reagent needs to be added to buffers to retard proteolytic... 

Bohenin occurs as a white to light tan, waxy solid. It is a triglyceride containing behenic acid at the 1- and 3-positions and oleic acid at the 2-position. Behenic acid is a saturated fatty acid that occurs naturally in peanuts, most seed fats, animal milk fat, and marine oils. It is produced by the interesterification of triolein and ethyl behenate in the presence of a suitable lipase enzyme preparation. It melts at approximately 52°. It is insoluble in water soluble in hexane, in chloroform, and in acetone and slightly soluble in hot ethanol. 

Diacetyl Tartaric Acid Esters of Mono- and Diglycerides occur over a range in appearance from sticky, viscous liquids through a fatlike consistency to a waxy solid, depending on the iodine value of the oils or fats used in their manufacture. They are the reaction product of partial glycerides of edible oils, fats, or fat-forming fatty acids with diacetyl tartaric anhydride. The diacetyl tartaroyl esters are miscible in all proportions with oils and fats. They are soluble in most common fat solvents, in methanol, in acetone, and in ethyl acetate, but are insoluble in other alcohols, in acetic acid, and in water. They are dispersible in water and resistant to hydrolysis for moderate periods of time. The pH of a 3% dispersion in water is between 2 and 3. 

All-rac-a-Tocopherol occurs as a yellow to amber, clear, viscous oil. It is a form of vitamin E. It oxidizes and darkens in air and on exposure to light. It is insoluble in water freely soluble in alcohol and miscible with acetone, with chloroform, with ether, with fats, and with vegetable oils. 

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