Liquid squalene

Thiourea inclusion compounds have also found recent applications as diverse as the separation of liquid crystal isomers 84 ), isolation of petroleum constituents 85,86), and the recovery of squalene during olive oil refining87), to cite just a few examples. 

Millson [113] investigated components of sewage sludge and found elementary sulphur in the hydrocarbon fractions eluted from liquid adsorption columns. By using a solid adsorbent such as alumina, silica gel, or Florisil, and heptane as eluent, the sulphur could be separated from weakly adsorbed hydrocarbons, e.g. squalene or biphenyl, but not from more strongly adsorbed hydrocarbons such as phenyldodecane. 

The condensable products were analyzed by gas-liquid chromatography using columns containing either l,2,3-tris(2-cyanoethoxy) -propane or di-2-cyanoethyl ether supported on Embacel. Hydrocarbons were determined on columns containing either dimethylsulfolane or a combination of propylene carbonate, squalene, and silicone oil on Embacel (3). 

In a subsequent study [30], cholesteryl-substituted 18C6 derivative 11 and diaza [18]crown-6 12 (Scheme 6) were used to create solid-supported bilayer lipids. The liquid crystalline crown derivatives 11,12 were dissolved in chloroform and mixed with squalene or squalene saturated with cholesterol. The solid-supported bilayers were prepared in freshly cut stainless steel wires. A 10-4 to 10-1 mol L-1 solution of MCI (M = Li, Na, K, Rb, Cs) or MgCl2 was used as aqueous phase. Measurement of the membrane potential revealed a Nemst response to the concentration of M+ in solution. It was possible to differentiate between the different cations which might be used for the preparation of new ion sensors. For the detection of K+ and Rb+, aza crown derivative 12 proved to be the most selective. A problem was the presence of traces of Fe2+/3+ that made the measurements difficult. It was also not... 

Figures 2 to 7 present simulation results of the quantity recovered of each component (except fatty acids) in the liquid and vapor phases in relation to its quantity in the feed stream (%) vs the operating temperature (°C) for feed flow rates ranging from 0.5 to 1.0 kg/h using the DISMOL simulator. Since fatty acids are the most volatile components and are recovered first at a lower temperature (approx 125°C), they were omitted in order to facilitate understanding the obtained results. By increasing the temperature, it is possible to recover tocopherols in the vapor phase with the diglyceride and the squalene. Phytosterols are recovered in the liquid phase, also called residue. Thermal decomposition was not calculated because, in these cases, it is very small.

When the solubility of various minor lipid components were compared with that of selected components of other major lipid classes, it was found that a-tocopherol, oleic acid (a liquid fatty acid), and squalene were the most soluble solutes and p-carotene had the lowest solubility in SCCO2 (Figure 5, solubility isotherms constructed using Equation 2). 

PE is a crystalline polymer with many grades, with a wide variety of crystallinity and molecular weight. A porous PE membrane is more drug-permeable than non-porous membranes of low-crystalline PE, both of which are available for the reservoir system. EVA, as a copolymer of ethylene and vinyl acetate with 9-40 wt.% vinyl acetate, is favorably used for the reservoir membrane. However, it should be noted that EVA, especially the copolymer with high vinyl acetate content, is resistant to hydrophilic liquid substances such as water and glycerin. But this copolymer swells and deforms itself in lipophilic liquid substances. Hence, paraffin, squalene, and IPM could not be used as reservoir liquids in combination with EVA. 

Dubois, J.-E., Chretien, J.R., Sojdk, L. and Rijks, J.A. (1980a). Topological Analysis of the Behaviour of Linear Alkanes up to Tetradecenes in Gas-Liquid Chromatography on Squalene. J.Chromat., 194,121-134. 

The stereoisomeric mixture of -hydroxyalkyl selenides resulting from the reaction of the a-selenoalkyllithium and the carbonyl compound has been often cleanly and easily separated into its constituents by liquid chromatography on silica gel (Schemes 124,133,134, and 170 172).200.206.222,226,229,258 59 jj,jg has, therefore, allowed the synthesis of each of the two stereoisomers of various di- and tri-substituted alkenes (Schemes 124,170 and 171 Scheme 172, a) and epoxides (Scheme 124 Scheme 172, b), which are otherwise obtained as intractable mixtures of stereoisomers through the conventional phosphorus or sulfur ylide methods. Last but not least, 2-lithio-2-methylselenopropane can be used as the precursor of various compounds bearing gem dimethyl substituted carbons, such as squalene, oxido-squalene, lanosterol and cholesterol. Use of commercially available perdeuterated or Ci or — 2 acetone allows the straightforward synthesis of the corresponding labelled compounds... 

The aim of this work was to develop a simple, environmentally sound and fltst method for the extraction and determination of squalene in an olive biomass using the PFE technique, and investigate if this technique could be a viable processing technology for the extraction of squalene from olive oil pomace. The effects of different solvents and mixtures of solvent, extraction temperature and extraction time were also evaluated for their influence on yield of squalene. Squalene in the olive biomass extracts were quantified by liquid chromatography with UV absorbance and fluorescence detection. In addition, the proposed method was used to determine the content of a-tocopherol in the olive biomass. 

Several attempts have been made to simplify the comparisons of retention times from column to column and compound to compound. The first and simplest is by E. Kovats Helv. Chim. Acta, 41, 1915, 1958) involving the use of hydrocarbons. The next was by L.J. Rohrschneider (J. Chromatog., 22, 6, 1966), who used benzene, ethanol, methylethyl ketone, nitromethane, and pyridine to characterize liquid phases. W.O. McReynolds J. Chromatog. Sci., 8, 685, 1970) improved upon this by using 10 compounds to relate over 200 liquid phases to squalene. The results indicated that many of the liquid phases behaved nearly the same and that really just a few were needed to separate all of the compounds. Kovats introduced a retention index, I, which is defined as ... 

The HETS is strongly dependent on the type of system (and of the type of separation equipment). According to our experiments, the HETS for the squa-lene-tocopherol-sterol system is in the range of 2.5-0.7m. The HETS decreases with increasing liquid loading of the column, and consequently increases with increasing gas loading. The main reason for the different HETS values for fatty acid ethyl esters and squalene-tocopherol-sterol mixtures is, most probably, the very different viscosities of the gas-saturated liquid phase. The viscosity of the liquid phase of the ethyl ester system is 60 X 10" Pas (at 140 bar, 100°C), and for the squalene-tocopherol system is 400 X 10 Pas (300 bar, 100°C). 

Group I. Liquids which spread upward, exhibiting a primary film and a secondary film with nearly constant slope at the leading edge (n-hexadecane, pristane, squalane, squalene, polychlorobiphenyl, and the polymer liquids poly methyl siloxane, polyisobutylene, and polytrichloroethylene). 

Pfizer reported the discovery of a new class of structurally complex alkyl carboxylic acids, as exemplified by CP-225917 and CP-263114 (Figure 20), that are weak and non-selective inhibitors of squalene synthase and FPTase. These compounds were isolated by acid base liquid-liquid partition, Sephadex LH20 chromatography and reverse phase HPLC from ethyl acetate extracts of an unidentified fungus that also produced zaragozic acid A [97]. 

Squalene is a precursor for steroid biosynthesis and may have cardioprotective and cancer-preventative properties. Though nuts are known to contain squalene, the limited literature available indicates that the pine nut contains a relatively low amount of squalene compared to other nuts [8]. Reverse-phase high-performance liquid chromatography (HPLC) analysis showed that pine nut oil had a squalene content of about 40mg/100g oil, which is approximately 23mg/100 nuts. Thus, they would not be a likely choice for a squalene-based nutraceutical however, this study did not report the species of pine nut measured, and variability between species of other compounds of interest may indicate that a different species could provide higher squalene content. 

Harris and Prausnitz, using a conventional analytical gas-liquid chromatograph, have determined the activity coefiicients of 22 polar solutes (including ketones, acetates, and nitriles) in solvents squalane, squalene, octadecane, and benzyldiphenyl. The results were used to obtain an approximate scale of relative Lewis acidities similar to that of Brown. The experimental accuracy is very difficult to assess because surface effects were not determined. A comparison with the literature values for three systems indicates reliability within a few per cent. 

The phase behavior of monoglycerol fatty acid esters with different alkyl chain length in liquid paraffin oil, squalane, and squalene is described first, then the phase behavior in the dilute regions of the monoglycerol fatty acid esters in linear chain alkanes is discussed. This section is based on Ref. [64], and [69], respectively. 

Phase Behavior In Liquid Paraffin, Squalane, and Squalene... 

Figure 2.1 Phase diagrams of homologous series of monoglycerol fatty acid ester surfactants in different nonpolar oils liquid paraffin, squalane and squalene (S = solid, I = isotropic single liquid phase, and II = isotropic two-liquid phases).

In the preceding section, it was seen that the monoglycerol fatty acid esters could not form any liquid-crystalline phases in liquid paraffin, squalane, and squalene. Phase-behavior studies have shown that the surfactants of this class do not form any liquid-crystalline phases in n-alkanes also. At normal room temperature, there is a solid phase in equilibrium with an excess oil phase in glycerol a-monolaurate... 

In this section, the nonaqueous phase behavior of homologous series of diglycerol fatty acid esters in a variety of nonpolar oils will be discussed. The binary phase behavior of these surfactants in liquid paraffin, squalane, and squalene will be described first and then the phase behavior in -alkanes and aromatic oils. The data presented in this section are rendered from Ref. [9] and [65], respectively. 

The phase behavior of diglycerol fatty acid esters (C G2, m = 12, 14, and 16) in liquid paraffin oil, squalane, and squalene is discussed. This section compares the nonaqueous phase behavior of mono- and diglycerol-based nonionic surfactants in different oils. Phase diagrams of surfactant/oil binary systems for the C ,G2 (m = 12-16) surfactants in a wide range of temperature and concentration at atmospheric pressure are shown in Figure 2.2. Gontrary to the G G) surfactants, the G ,G2 surfactants form a variety of self-assembled structures in nonpolar oils liquid paraffin oil, squalane, and squalene. 

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