Abstract  Predisafe (rabbit cornea broblast cells culture) is an alternative method developped by Biopredic to determine the occular irritating potential. Cell layer was exposed to pure solution of perhydrosqualen (animal squalan) and cytotoxicity was evluated by neutral red colorimetric method. The results show an ocular tolerance inferior to 15, the substance is considered as slightly irritant for eyes.

Abstract  Assessment of mutagenic activity of squalane was conduced on "Salmonella typhimurium his-" and "Escherichia coli WP2(uvrA)" strains according to the OECD guideline n°471. There is no signicant difference between the number of spontaneaous reversions, the number of reversions obtained in the positive controls (with or without metabolica cativation), and the mean of corresponding experimental historic values obtained in the laboratory. There is no evidence of any increase of number of revertant colonies in the presence of the test substance (5000, 1000, 500, 100 and 50 µg) with or without metabolic activation for bacterial strains in Salmonella typhimurium TA1535, TA97a, TA98, TA100 and Escherichia coli WP2(uvrA).

Abstract  On the basis of ongoing research conducted on the clarification of processes responsible for lubricant degradation in the environment of piston grooves in exhaust gas recirculation (EGR) diesel engines, an experimental investigation was aimed to develop a kinetic model, which can be used for the prediction of lubricant oxidative degradation correlated with endurance test conducted on engines. Knowing that base oils are a complex blend of paraffins and naphthenes with a wide range of sizes and structures, their chemistry analysis during the oxidation process can be highly convoluted. In the present work, investigations were carried out with the squalane (C30H62) chosen for its physical and chemical similarities with the lubricant base oils used during the investigations. Thermo-oxidative degradation of this hydrocarbon was conducted at atmospheric pressure in a tubular furnace, while varying temperature and duration of the tests in order to establish an oxidation reaction rate law. The same experimental procedures were applied to squalane doped with two different phenolic antioxidants usually present in engine oil composition: 2,6-di-tert-butyl-4-methylphenol and octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate. Thus, the effect of both antioxidants on the oxidation rate law was investigated. Data analysis of the oxidized samples (Fourier transform infrared spectroscopy and gas chromatography/mass spectrometry) allowed rationalization of the thermo-oxidative degradation of squalane. The resulting kinetic modeling provides a practical analytical tool to follow the thermal degradation processes, which can be used for prediction of base oil hydrocarbon aging. If experiments confirmed the role of phenolic additives as an effective agent to lower oxidation rates, the main results lie in the observation of a threshold temperature where a reversed activity of these additives was observed. [DOI: 10.1115/1.3155797]

Abstract  The Ocean Anoxic Event 1 (OAE-1) in central sites of the Basque-Cantabrian Basin exhibits very reducing depositional conditions of sedimentation. These sedimentation events have left a distinct mixture of hydrocarbons that are represented by C22-C30 n-alkanes with a predominance of the even-carbon-number homologues, high relative proportions of squalane and C16-C24 n-alkylcyclopentanes predominated by n-undecyl-, n-tridecyl- and n-pentadecylcyclopentane. Other minor compounds encompass a series of C18-C21 n-alkylcyclohexanes and C18-C24 dimethyl n-alkylcyclohexanes maximized by the even-carbon-number homologues as well as iso- and anteiso-alkanes. This unusual distribution of n-alkanes in this environment provides a new case for comparison with previously reported hypersaline and phosphorite sedimentary deposits where the occurrence of similar n-alkane distributions was reported. In the present case, these major n-alkanes and squalane are indicative of transformation under strong reducing conditions. In contrast, the occurrence of the alkylcyclopentanes, irrespective of the presence of even-carbon-number n-alkanes or squalane, suggests that reductive cyclization of fatty acids is less dependent on strong reducing conditions.

Abstract  Squalene is a polyunsaturated hydrocarbon with a formula of C₃₀H₅₀. Squalene can be found in certain fish oils, especially shark liver oil, in high amounts and some vegetable oils in relatively smaller amounts. Human sebum also contains 13% squalene as one of its major constituents. Squalane is a saturated derivative of squalene and also found in these sources. Interest in squalene has been raised after its characterization in shark liver oil which is used as a traditional medicine for decades. Several studies exhibited results that prove certain bioactivities for squalene and squalane. Up to date, anticancer, antioxidant, drug carrier, detoxifier, skin hydrating, and emollient activities of these substances have been reported both in animal models and in vitro environments. According to promising results from recent studies, squalene and squalane are considered important substances in practical and clinical uses with a huge potential in nutraceutical and pharmaceutical industries.

Abstract  This study was conducted to better understand the processes of carbonaceous deposits formation in the piston grooves of direct injection Diesel engines. An experimental investigation of parameters affecting the engine oil degradation in the first groove of a Diesel engine was carried out to shed light on the formation of these carbonaceous deposits. A dedicated reactor was designed to reproduce the parameters that exist in the first groove of a Diesel engine used under exhaust gas recirculation conditions, and squalane was used to model the lubricant. The relationship between oil degradation and environmental conditions (temperature, pressure, time, oxygen content and components of the gas in the groove) was clarified by characterizing the degradation levels of the squalane molecule. A general mechanism was proposed to explain the formation of carbon deposits in the first piston grooves of Diesel engines depending on the surrounding atmosphere. The influence of pressure on degradation conditions usually investigated under atmospheric conditions was proposed for the first time to understand processes responsible for carbonaceous deposit formation.

Abstract  This paper investigated the use of Bacillus coagulans W-15 immobilized on carriers in a bio-contact oxidation reactor to treat oilfield produced water. It researched the effect of hydraulic retention time (HRT) on the removal efficiencies of chemical oxidation demand (COD) and total organic carbon (TOC). The results showed that, when the HRT was 24 and 32 h, the COD of effluent water were less than or equal to 352 mg/L, the removal efficiencies of COD and TOC were greater than or equal to 75% and 68%, respectively. The degradation efficiencies in the bio-contact oxidation reactor immobilized with W-5 were estimated to be 73% for total oil, and 86% for the gas chromatography resolved compounds. The quality of the effluent water met the professional emission standard of petrochemical industry of China.

Abstract  The adsorption of the phospholipid (PL) 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) dissolved in the oil phase squalene or squalane was studied at the interface with water. Dynamic interfacial tension was measured by profile analysis tensiometry (PAT). Two different setups were considered, a buoyant oil drop surrounded by water or a pendant water drop in oil. For the proof of methodology the interfacial tensions of water in chloroform and chloroform in water interfaces were measured. From the equilibrium interfacial tensions of different PL concentrations, the Gibbs adsorption isotherm was determined. These isotherms allow the extraction of the minimal areas per lipid molecule as well as critical aggregation concentration (CAC). We found significant differences in the results obtained for both setups. By means of PAT, the CAC determined for water drops in oil was smaller than for oil drops in water. Photon correlation spectroscopy (PCS) and nuclear magnetic resonance (NMR) were used to verify the determined CACs. We concluded the setup-dependent differences to be caused by depletion effects when initially dissolving the surface active component in the small drop volume. We recommend the reversed setup where the surface active component is dissolved in the surrounding bulk phase to avoid corrections of bulk concentrations. (C) 2015 Elsevier B.V. All rights reserved.

Abstract  Squalene (SQ), the sterol precursor in all cell types, is a functional lipid of high importance, as currently an array of benefits to human health are recognized. It has chemopreventive and photooxidative properties, it protects human from coronary heart diseases and is also used to maintain skin health. Technological properties of SQ have been widely appreciated in fields beyond human consumption. Moreover, SQ forms stable nanoemulsions and, as found in several conformations, it forms SQ-drug conjugates with improved properties and potentially can be used as an important bioactive ingredient carrier. As far as food applications are concerned, its thermal stability and contribution in the stability of frying oils are well established. All of the above properties increased both food and non-food SQ applications so that its current demand in food, pharmaceuticals and cosmeceuticals is getting higher. Sharks, the richest SQ source, are endangered species. Consequently, the need for search of new SQ sources, mainly of plant origin, is increased. Biotechnology gives also some interesting alternatives. In this review article, the most recent patents regarding SQ extraction, production as well as its food-related applications are presented. Squalane, the hydrogenated counterpart of squalene, is also discussed.

Abstract  In the present work, we focused on the aging behavior of stabilized and unstabilized polyolefins using the solvent squalane as a polypropylene-mimicking model. It was found that squalane as well as polypropylene show aging-induced photoluminescence emissions at elevated temperatures. To separate and identify the photoluminescent species from other aging-induced degradation products, a high performance liquid chromatography method using photoluminescence detection (lambda(Ex) = 375 nm, lambda(Em) = 410 nm) was developed. Comparison of the integrated photoluminescence intensities allowed performing a stabilizer efficacy rating of different squalane-antioxidant formulations. For characterization and structure elucidation of the photoluminescent degradation products, the liquid chromatogaphic method was adapted for coupling to a high resolution Orbitrap mass spectrometer. It was possible to assign the observed masses to (multiple) unsaturated carbonyl compounds, which is in accordance to previous investigations. (C) 2015 Elsevier Ltd. All rights reserved.

Abstract  The interaction of hydrocarbon chains at aqueous interfaces is a major factor in defining the interfacial structures of monolayers and membranes formed by surfactants. The intermolecular pair potentials which can be expressed in the two-dimensional second virial coefficients (B-2(T)) are basic to understanding these structures. In this report, measurements of the adsorption of hexane vapor on water as a function of the partial vapor pressure are reported for a static system in which the vapor pressure is controlled by mixing liquid hexane with either hexadecane or squalane. The B-2(T) for hexane at the water/vapor interface is approximately estimated at one temperature. The results confirm that the extensive published data on the adsorption of alkanes on water obtained in a vapor now system are incorrect, presumably due to inadequate vapor saturation.

Abstract  IPA COPYRIGHT: ASHP The toxicity of 26 cosmetics excipients was evaluated using a rabbit test. The ocular and cutaneous effects were evaluated using official French methods with some additions. The results show that 13 samples gave adverse reactions after repeated skin exposures; 8 of them appeared to be significantly more irritant--4 isopropyl myristates and 4 oleyl alcohols each from different sources. Eleven excipients were well tolerated when applied undiluted during 60 days and 2 gave uncertain results. Compounds tested included squalane, caprylic triglycerides, isopropyl myristate and palmitate, decyl oleate, octyl palmitate and stearate, oleyl alcohol and polyoxyethylene sorbitan stearate.

Abstract  The accumulation of persistent lipophilic organic pollutants like dioxins and PCBs in human body is of great concern since many of these compounds may elicit adverse health effects on humans. To reduce dioxins and PCBs with long half-lives that are absorbed into the human body, we need to work actively to minimize accumulation of dioxins and PCBs taken. Lot of manner has been tested such as foods containing dietary fibers and chlorophyll, lipids (squalane etc) and anion exchange resins. Cholestyramine, a cholesterol lowering agent, was no efficacy in humans. Authors have conducted a pilot study to demonstrate the effect lowering dioxin in human bodies using colestimide. Nine patients on cdestimide for 6 months, showed mean 20% decrease respectively in both dioxin and PCB levels, and the maximum percentage decrease was approximately 40%. From a standpoint to avoid the influence on high-risk group and high-risk life stage other than next generation, the world-wide cooperation for reducing environmental chemicals is greatly appealed.

Abstract  Model experiments on laboratory animals (guinea pigs) were carried out to test the possible allergy reaction (possibility or sensitization) to the repeated administration of an experimental lipoid adjuvant (ELA) prepared on the basis of isopropylpalmitate. No significant differences were observed between the animals senzitized-provoked with ELA and the control animals. In older to evaluate the local tissue reactivity (local reactogenicity), also with regard to the process dynamics, to the administration of ELA and to carry out comparisons with other types of lipoid adjuvants, as well as aluminium hydroxide, comparative patho-anatomical and patho-histological examinations of tissues were carried out in the location of adjuvant administration. The examinations indicated very low local reactogenicity of the experimental lipoid adjuvant prepared in our laboratory.