Unsaturated Aliphatic Chains Research Articles

DOUBLE SOLUBILITY OF KEROGEN AND CARBONATES FROM TARFAYA OIL SHALE (MOROCCO) BY POTABLE WATER, DISTILLED WATER OR SEAWATER FROM THE ATLANTIC OCEAN

The solubility of the materials contained in oil shale has often been questioned. Ordinary water coming directly from purification stations or partially distilled water are of primary interest in the energy industry for exploitation or research. Similarly, given that a large proportion of the Tarfaya oil shale is immersed in the Atlantic Ocean, we thought it would be interesting to study the effect of these types of water on the solubility of kerogen under physical conditions of moderate temperature. Ultra-violet and infra-red spectroscopy was used in this work. As the identification energy of the ultraviolet is fairly high compared with the infrared and visible. We were able to follow the evolution of heavy matter from kerogen. The effect of temperature was also highlighted. Spectroscopic identification uses radiation of varying energies depending on the compounds to be detected. For example, for infrared, the energy used to identify substituted unsaturated aliphatic is higher than that used to identify substituted unsaturated monocyclic. As far as our work is concerned, the energy used for identification by UV is sufficiently higher than that for infrared, which means that the compounds to be detected from oil shale can only be heavy hydrocarbons (branched and multisubstituted unsaturated aliphatic chains). Similarly, supercritical fluid extraction using water and other solvents such as toluene is often used to determine the different fractions of organic compounds in oil shale. We are going to use three analytical methods to highlight this solubility in seawater (subsequently the solubility in distilled water), which are ultra-violet spectroscopy, infra-red spectroscopy and the determination of carbonates (mineral matter) by complexometry.

Theoretical Study on Abstraction and Addition Reaction Kinetics for a Medium-Size Unsaturated Methyl Ester: Methyl-3-hexenoate + H/OH Radicals.

Combustion chemistry of methyl esters with long alkyl chains and different degrees of unsaturation has been of particular interest for biodiesel combustion. Methyl-3-hexenoate (mhx3d) with a medium-size unsaturated aliphatic chain is regarded as a valuable surrogate of biodiesel components. Here, the abstraction and addition reaction kinetics of mhx3d + H/OH radicals are comprehensively investigated. An accurate and efficient exchange-correlation density functional M06-2X/ma-TZVP is validated by the DLPNO-CCSD(T)/CBS(T-Q) benchmark calculations and is used for the multistructural search, geometry optimization, potential energy profiles, and direct dynamic calculations. The multistructural torsional (MS-T) anharmonicity, variational effects, and tunneling effects including one-dimensional Winger tunneling, multidimensional zero-curvature tunneling (ZCT), and small-curvature tunneling (SCT) are also evaluated in rate coefficient calculations. The existence of reactant complexes of the abstraction and addition reactions is neglected for mhx3d + H due to weak van der Waals interaction but is considered for mhx3d + OH. Therefore, a pre-equilibrium model is employed to obtain the rate coefficients for mhx3d + OH. The calculation results show that the MS-T factor ranges from 0.29 to 11.41, the tunneling transmission coefficient calculated by SCT is in the range of 1.0-4.0, and the recrossing transmission coefficient is between 0.65 and 1.0. Moreover, the two OH-addition reactions exhibit negative temperature coefficient behavior. The branching ratios show that the H/OH-addition reactions are dominant at lower temperature, especially for mhx3d + H. Rate coefficients of the title reactions are fitted in terms of a modified three-parameter Arrhenius expression.

Development of Solvent-Free Co-Ground Method to Produce Terbinafine Hydrochloride Cyclodextrin Binary Systems; Structural and In Vitro Characterizations.

Molecular complexation with cyclodextrins (CDs) has long been a known process for modifying the physicochemical properties of problematic active pharmaceutical ingredients with poor water solubility. In current times, the focus has been on the solvent-free co-grinding process, which is an industrially feasible process qualifying as a green technology. In this study, terbinafine hydrochloride (TER), a low solubility antifungal drug was used as a model drug. This study aimed to prepare co-ground products and follow through the preparation process of the co-grinding method in the case of TER and two amorphous CD derivatives: (2-hydroxypropyl)-β-cyclodextrin (HPBCD); heptakis-(2,6-di-O-methyl)-β-cyclodextrin (DIMEB). For this evaluation, the following analytical tools and methods were used: phase solubility studies, differential scanning calorimetry (DSC), X-ray powder diffractometry (XRPD), hot-stage X-ray powder diffractometry (HOT-XRPD), Fourier-transform infrared (FT-IR), Raman spectroscopy, and Scanning Electron Microscopy (SEM). Furthermore, in vitro characterization (dissolution and diffusion studies) was performed in two kinds of dissolution medium without enzymes. In the XRPD and SEM studies, it was found that the co-grinding of the components resulted in amorphous products. FT-IR and Raman spectroscopies confirmed the formation of an inclusion complex through the unsaturated aliphatic chain of TER and CDs. In vitro characterization suggested better dissolution properties for both CDs and decreased diffusion at higher pH levels in the case of HPBCD.

Facile adjusting the concentration of siliceous seed to obtain different HZSM-5 zeolite catalysts for effective catalytic depolymerization reaction of lignin

To improve lignin depolymerization reaction performance of HZSM-5 zeolite catalyst, we reported the effective catalytic depolymerization of rice husk lignin (RHL) to lignin phenolic monomer (LP) products over the different Si/Al mole ratios of HZSM-5 zeolite catalyst. Firstly, five samples comprising different Si/Al mole ratio of HZSM-5 zeolite catalyst were prepared by the physical method. The X-ray powder diffraction (XRD), scanning electron microscope (SEM), Brunauer–Emmett–Teller (BET), pyridine adsorption Fourier transform infrared spectroscopy (FT-IR), and temperature-programmed desorption of ammonia (NH3-TPD) were used to characterize various catalysts. Secondly, gas chromatography–mass spectrometry (GC-MS), 2D heteronuclear single quantum coherence (2D-HSQC), and gel permeation chromatography (GPC) were used to characterize various catalytic depolymerization products. The effect of different Si/Al molar ratios on the lignin conversion to LP products and the structural changes of residual lignin were analyzed. Finally, according to the results of LP products, we discovered that after the use of different Si/Al molar ratios of HZSM-5 zeolite catalysts, the content of acid in the different catalysts which increased with decreasing the Si/Al mole ratios. Among them, the A4P PM products (A4P: having a saturated or unsaturated aliphatic side chain in C4 position) increased from 0.58% (SA560, Si/Al: 560) to 1.83% (SA70, Si/Al: 70), the C6P PM products (C6P: having no side chain in C4 position of G, S, and H structure) increased from 1.53% (SA560, Si/Al: 560) to 3.41% (SA70, Si/Al: 70). Finally, the highest 6.05% PM products yield appeared in the SA70 (Si/Al: 70) catalytic system. It is worth noting that PM products produced by this HZSM-5 zeolite catalyst SA70 have great potential to be a promising renewable alternative to fossil resources.

Efficient anti-tumor nano-lipoplexes with unsaturated or saturated lipid induce differential genotoxic effects in mice

Cationic lipids are well-known excipients for nanometric liposomal gene delivery systems. However, because of the suspected, collateral toxicity in normal cells, the use of cationic lipids for the treatment of human tumor is largely limited. Recently, we developed a glucocorticoid receptor (GR)-targeted liposomal, anticancer delivery system (DXE nano-lipoplex), which carried cationic lipid of saturated twin aliphatic chains. It exhibited efficient anti-tumor effect in aggressive and drug-resistant tumor models. Toward exploring lipoplex’s human clinical use, we incorporated another nano-lipoplex (D1XE) group that carried cationic lipid with one of its aliphatic chain carrying unsaturation and compared in vivo genotoxicological profiling-based safety assessment and the respective anti-tumor efficacy of the lipoplexes. Thus, both the lipoplexes differ only by the chemical identity of one of their constituent cationic lipid. Unsaturated aliphatic chains in lipid generally impart efficient cell surface fusogenic property in lipid formulations. Herein, we report that nanoplex with unsaturated cationic lipid (D1XE) exhibited better physical appearance with less flocculent behavior than nanoplex with saturated lipid (DXE). Upon multiple injections, D1XE nanoplex imparted better tumor regression but most importantly, exhibited much lower overall toxicity (e.g. genotoxicity, weight loss, etc.) than DXE nanoplex. With a higher antitumor effect but a lower genotoxic effect, D1XE is proved to be a better nanoplex than DXE for the potential clinical trial. Thus, this study clearly delineates the importance of incorporating a constituent lipid that carries a single unsaturated aliphatic chain toward developing efficient anti-tumor nano-lipoplexes with reduced genotoxicity.

Synthesis and properties of UV-curable cardanol-based acrylate oligomers with cyclotriphosphazene core

Multiarm cardanol-based oligomers with a cyclotriphosphazene core were prepared through a nucleophilic substitution reaction; the structures of oligomers were fully characterized and confirmed through Fourier transfer infrared spectrometry, 1H nuclear magnetic resonance (NMR), 31P NMR, and gel permeation chromatography. The designed multiarm bio-based acrylates (AECC) were successfully prepared by epoxidizing the unsaturated aliphatic chain of cardanol segments with m-chloroperoxybenzoic acid and acrylating epoxy groups. The synthesized oligomers contain rigid phosphazene/benzene rings as “hard cores” and long aliphatic chains as “flexible shells.” Compared with commercial hyperbranched polyurethane acrylate (CN2302) and acrylated epoxidized soybean oil, cured AECC coatings and films exhibited not only greater hardness, excellent adhesion, higher glass transition temperatures, and excellent mechanical properties but also good thermal stability and biodegradability. We successfully obtained a high-performance UV-curing resin that has a high biorenewable material content and can meet basic daily requirements.

Synthesis, Characterization, Metal ion intake and Antibacterial Activity of Schiff base Complexes of Cu(II), Ni(II)and Co(II) using di-α-formylmethoxy bis (3 pentadecenylphenyl) methane (DFMPM) and aniline

Cardanol, a naturally occurring C15 unsaturated aliphatic chain substituted phenol derived from cashew nut shell liquid (CNSL) was used for the preparation of Schiff base ligand using aniline. This preparation involved (a) the conversion of cardanol into bis (3-pentadecenyl phenol) methane (BPPM) using formaldehyde. (b) bis (3-penta decenyl phenol) methane into di-α-formylmethoxy bis (3-pentadecenyl phenyl methane). DFMPM on treatment with epichlorohydrin followed by the action of sodium periodate. (c) DFMPM to Schiff base ligand with aniline and finally (d) Schiff base complexes with Cu (II), Ni (II) and Co (II) metal salts. The ligand and complexes were characterized by IR, UV-Visible, 1H NMR and elemental analysis, melting point, conductivity, metal ion intake and the antibacterial activity was studied. The conductance measurements indicate that all the complexes of non electrolytes. The infrared spectra indicate the coordination of imino nitrogen and M-N bonds. UV-Visible spectra provide structural details of these complexes. 1H NMR data is also consistent with IR spectral data. The results indicate that the complexes of Cu (II), Ni (II), Co (II) are hexa coordinated and have moderate antibacterial activity.

Enzymatic Synthesis of Sorboyl-Polydatin Prodrug in Biomass-Derived 2-Methyltetrahydrofuran and Antiradical Activity of the Unsaturated Acylated Derivatives.

Efficient and highly regioselective synthesis of the potential 6′′-O-sorboyl-polydatin prodrug in biomass-derived 2-methyltetrahydrofuran (2-MeTHF) was achieved using Candida antarctica lipase B for the first time. Under the optimal conditions, the initial reaction rate, maximum substrate conversion, and 6′′-regioselectivity were as high as 8.65 mM/h, 100%, and 100%, respectively. Kinetic and operational stability investigations evidently demonstrated excellent enzyme compatibility of the 2-MeTHF compared to the traditional organic solvents. With respect to the antioxidant properties, three unsaturated ester derivatives showed slightly lower DPPH radical scavenging activities than the parent agent. Interestingly, further studies also revealed that the antiradical capacities of the acylates decreased with the elongation of the unsaturated aliphatic chain length from C4 to C11. The reason might be attributed to the increased steric hindrance derived from the acyl residues in derivatives.

High quality lard with low cholesterol content produced by aqueous enzymatic extraction and β‐cyclodextrin treatment

New food processing technology is required for food production with high quality and healthfulness. In this study, a novel application was developed to extract lard from pig fatback, a by‐product of the slaughter plant, by an aqueous enzymatic extraction method (AEE). Various proteases with different properties including Alcalase 2.4 L, Neutrase 1.5 MG, Flavourzyme 1000 L, and Protamex were evaluated for their efficiency in oil release and lard qualities. Alcalase 2.4 L was more effective for oil extraction with a yield of 95.19%. A high quality of lard was produced by AEE in comparison with lards produced by conventional extraction methods in aspects of color, acid value, peroxide value, phospholipids, cholesterol, and oxidation stability. A further refinement to reduce cholesterol from lard by β‐cyclodextrin (β‐CD) was developed and the optimal conditions were established. The optimal conditions were 7% β‐CD addition (w/w) to a mixture of equal amount of lard and distilled water at reaction temperature 50°C for about 60 min. The cholesterol content of lard from this refinement process was about 3.2 mg/100 g which was about 93.7% reduction from 51.2 mg/100 g. This simple process by AEE and cholesterol reduction did not affect the composition of fatty acids and construction of triglyceride. Factors that were components of lard or produced during the lard extraction processes were evaluated for their influence on the cholesterol removal. Phospholipids could slightly enhance cholesterol removal, while free fatty acids with saturated or unsaturated aliphatic chains would have inhibitory effects because of their competition with cholesterol for β‐CD.Practical applications: An excellent quality of lard was produced by a novel application of an aqueous enzymatic extraction method (AEE). This lard could be further refined by β‐cyclodextrin for cholesterol reduction. This procedure would be a promising technology to obtain healthy lard and explore animal by‐products for the food industry. This lard with high nutrients could have very broad applications such as in baking, cooking, deep fat frying in food industry.Lard obtained by combination of aqueous enzymatic extraction and β‐cyclodextrin treatment presented high quality and very low cholesterol.

Antibacterially active phenolic lipid derivatives from Comarum salesovianum (Steph.) Aschers. et Gr.

The antibacterial activity-guided purification of the dichloromethane fraction of the aerial parts of Comarum salesovianum (Steph.) Aschers.et Gr. led to the isolation and elucidation of three phenolic lipid derivatives: 6-(non-8-enyl) salicylic acid (1), 6-nonyl salicylic acid (2) and 3-(non-8-enyl) phenol (3), which were found for the first time in the natural source. The equal mixture of compounds 1 and 2 exhibited potent inhibitory activity against all tested Gram-positive bacterial strains (Enterococcus faecalis, Micrococcus luteus, Staphylococcus epidermidis and Staphylococcus aureus) with inhibitory zones of 12.2–22.1mm, whereas each single compound showed weaker activity than the mixture of 1 and 2. However, compound 3 strongly inhibited (29.9±1.8) the growth of M. luteus. The presence of salicylic acid with the unsaturated aliphatic side chain is essential for the antibacterial activity strength of phenolic lipid molecules.

Synthesis and Characterization of Bio Active Transition Metal Complexes of Cu(II) Co(II) and Ni(II) using Natural Sources

Cardanol a naturally occurring C15 unsaturated aliphatic chain substituted phenol derived from cashew nut shell liquid (CNSL) was used for the preparation of Schiff base ligand using Glutamine. Di-α-formylmethoxybis(3pentadecenylphenyl)methane (DFMPM) is prepared from cardanol using standard methods. The ligand formed Schiff base complexes with Cu(II), Co(II) and Ni(II) ions. The ligand and complexes were characterized by UV-visible, IR, and the elemental analysis, melting point, metal ion intake, SEM, XRD antibacterial and antifungal activity were studied. The result indicate that the complexes of Cu(II), Co(II) and Ni(II) are hexaco-ordinated and have moderate antibacterial and antifungal activity. The metal ion intake indicated the ligand can be used for the removal of these metals from water. The SEM and XRD studies revealed the nano crystalline nature of the complexes.

Aspergillus oryzae CsyB Catalyzes the Condensation of Two β-Ketoacyl-CoAs to Form 3-Acetyl-4-hydroxy-6-alkyl-α-pyrone

The type III polyketide synthases from fungi produce a variety of secondary metabolites including pyrones, resorcinols, and resorcylic acids. We previously reported that CsyB from Aspergillus oryzae forms α-pyrone csypyrone B compounds when expressed in A. oryzae. Feeding experiments of labeled acetates indicated that a fatty acyl starter is involved in the reaction catalyzed by CsyB. Here we report the in vivo and in vitro reconstitution analysis of CsyB. When CsyB was expressed in Escherichia coli, we observed the production of 3-acetyl-4-hydroxy-α-pyrones with saturated or unsaturated straight aliphatic chains of C9-C17 in length at the 6 position. Subsequent in vitro analysis using recombinant CsyB revealed that CsyB could accept butyryl-CoA as a starter substrate and malonyl-CoA and acetoacetyl-CoA as extender substrates to form 3-acetyl-4-hydroxy-6-propyl-α-pyrone. CsyB also afforded dehydroacetic acid from two molecules of acetoacetyl-CoA. Furthermore, synthetic N-acetylcysteamine thioester of β-ketohexanoic acid was converted to 3-butanoyl-4-hydroxy-6-propyl-α-pyrone by CsyB. These results therefore confirmed that CsyB catalyzed the synthesis of β-ketoacyl-CoA from the reaction of the starter fatty acyl CoA thioesters with malonyl-CoA as the extender through decarboxylative condensation and further coupling with acetoacetyl-CoA to form 3-acetyl-4-hydroxy-6-alkyl-α-pyrone. CsyB is the first type III polyketide synthase that synthesizes 3-acetyl-4-hydroxy-6-alkyl-α-pyrone by catalyzed the coupling of two β-ketoacyl-CoAs.

CNSL: an environment friendly alternative for the modern coating industry

Considering ecological and economical issues in the new generation coating industries, the maximum utilization of naturally occurring materials for polymer synthesis can be an obvious option. In the same line, one of the promising candidates for substituting partially, and to some extent totally, petroleum-based raw materials with an equivalent or even enhanced performance properties, is the Cashew Nut Shell Liquid (CNSL). This dark brown-colored viscous liquid obtained from shells of the cashew nut can be utilized for a number of polymerization reactions due to its reactive phenolic structure and a meta-substituted unsaturated aliphatic chain. Therefore, a wide variety of resins can be synthesized from CNSL, such as polyesters, phenolic resins, epoxy resins, polyurethanes, acrylics, vinyl, alkyds, etc. The present article discusses the potential of CNSL and its derivatives as an environment friendly alternative for petroleum-based raw materials as far as polymer and coating industries are concerned.

PKC Activation by Resveratrol Derivatives with Unsaturated Aliphatic Chain

Resveratrol (1) is a naturally occurring phytoalexin that affects a variety of human disease models, including cardio- and neuroprotection, immune regulation, and cancer chemoprevention. One of the possible mechanisms by which resveratrol affects these disease states is by affecting the cellular signaling network involving protein kinase C (PKC). PKC is the family of serine/threonine kinases, whose activity is inhibited by resveratrol. To develop PKC isotype selective molecules on the resveratrol scaffold, several analogs (2–5) of resveratrol with a long aliphatic chain varying with number of unsaturated doubled bonds have been synthesized, their cytotoxic effects on CHO-K1 cells are measured and their effects on the membrane translocation properties of PKCα and PKCε have been determined. The analogs showed less cytotoxic effects on CHO-K1 cells. Analog 4 with three unsaturated double bonds in its aliphatic chain activated PKCα, but not PKCε. Analog 4 also activated ERK1/2, the downstream proteins in the PKC signaling pathway. Resveratrol analogs 2–5, however, did not show any inhibition of the phorbol ester-induced membrane translocation for either PKCα or PKCε. Molecular docking of 4 into the activator binding site of PKCα revealed that the resveratrol moiety formed hydrogen bonds with the activator binding residues and the aliphatic chain capped the activator binding loops making its surface hydrophobic to facilitate its interaction with the plasma membrane. The present study shows that subtle changes in the resveratrol structure can have profound impact on the translocation properties of PKCs. Therefore, resveratrol scaffold can be used to develop PKC selective modulators for regulating associated disease states.

Abstract 190: Targeting ceramide and endoplasmic reticulum-stress in vitamin E induced apoptosis in human breast cancer cells

Abstract Vitamin E consists of eight plant-derived forms classified as tocopherols (α, β, Δ, γ) and tocotrienols (α, β, Δ, γ) which have a chromanol ring and a saturated and unsaturated aliphatic side chain, respectively. The anti-cancer actions of tocopherols and tocotrienols are limited to the gamma and delta forms. Here, we report that both γ-tocopherol (γT) and γ-tocotrienol (γT3) display potent anti-cancer actions with γT3 being more potent. Both forms target similar pro-apoptotic and anti-apoptotic pathways. γT and γT3 induced apoptosis in human breast cancer cells by enhancing death-receptor DR5 mediated activation of caspase-8 and mitochondria dependent caspase-9, as well as by activating ER-stress markers: GADD153/ C/EBP homologous protein (CHOP), GRP-78, ATF-4 and eIF2α. JNK and CHOP are involved in DR5 mediated apoptosis triggered by both vitamin E forms. γT and γT3 decreased protein levels of anti-apoptotic factors c-FLIP, BCl-2 and survivin. Since ceramide is a known upstream inducer of ER-stress and downstream mediator of death receptor apoptotic pathway mediators, treatments with γT and γT3 were conducted in the presence of specific inhibitors of sphingomyelin hydrolysis, de novo ceramide pathways and ER-stress in order to distinguish between the pathways modulated by the vitamin E forms. Data show that both γT and γT3 induced apoptosis via activation of sphingomyelin hydrolysis and the de novo ceramide pathways; however, activation of the ER-stress pathway contributed to apoptosis induced by γT3 only. Taken together, our data suggest that γT3s more potent apoptotic effects in comparison to γT are due to the ability of γT3 to activate ER stress pathways. This better understanding of the anti-cancer properties and mechanistic actions by these two natural occurring agents in vitro provides the necessary impetus to test them in combination with other known anti-cancer agents in pre-clinical xenograft studies to identify novel and safer therapeutic strategies. Research funded by The Clayton Foundation for Research. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 190. doi:10.1158/1538-7445.AM2011-190

Pro-apoptotic activity of lipidic α-amino acids isolated from Protopalythoa variabilis

Lipidic α-amino acids (LAAs) have been described as non-natural amino acids with long saturated or unsaturated aliphatic chains. In the continuing prospect to discover anticancer agents from marine sources, we have obtained a mixture of two cytotoxic LAAs ( 1a and 1b) from the zoanthid Protopalythoa variabilis. The anti-proliferative potential of 14 synthetic LAAs and 1a/ 1b were evaluated on four tumor cell lines (HCT-8, SF-295, MDA-MB-435, and HL-60). Five of the synthetic LAAs showed high percentage of tumor cell inhibition, while 1a/ 1b completely inhibited tumor cell growth. Additionally, apoptotic effects of 1a/ 1b were studied on HL-60 cell line. 1a/ 1b-treated cells showed apoptosis morphology, loss of mitochondrial potential, and DNA fragmentation.

Update of the CHARMM all-atom additive force field for lipids: validation on six lipid types.

A significant modification to the additive all-atom CHARMM lipid force field (FF) is developed and applied to phospholipid bilayers with both choline and ethanolamine containing head groups and with both saturated and unsaturated aliphatic chains. Motivated by the current CHARMM lipid FF (C27 and C27r) systematically yielding values of the surface area per lipid that are smaller than experimental estimates and gel-like structures of bilayers well above the gel transition temperature, selected torsional, Lennard-Jones and partial atomic charge parameters were modified by targeting both quantum mechanical (QM) and experimental data. QM calculations ranging from high-level ab initio calculations on small molecules to semiempirical QM studies on a 1,2-dipalmitoyl-sn-phosphatidylcholine (DPPC) bilayer in combination with experimental thermodynamic data were used as target data for parameter optimization. These changes were tested with simulations of pure bilayers at high hydration of the following six lipids: DPPC, 1,2-dimyristoyl-sn-phosphatidylcholine (DMPC), 1,2-dilauroyl-sn-phosphatidylcholine (DLPC), 1-palmitoyl-2-oleoyl-sn-phosphatidylcholine (POPC), 1,2-dioleoyl-sn-phosphatidylcholine (DOPC), and 1-palmitoyl-2-oleoyl-sn-phosphatidylethanolamine (POPE); simulations of a low hydration DOPC bilayer were also performed. Agreement with experimental surface area is on average within 2%, and the density profiles agree well with neutron and X-ray diffraction experiments. NMR deuterium order parameters (S(CD)) are well predicted with the new FF, including proper splitting of the S(CD) for the aliphatic carbon adjacent to the carbonyl for DPPC, POPE, and POPC bilayers. The area compressibility modulus and frequency dependence of (13)C NMR relaxation rates of DPPC and the water distribution of low hydration DOPC bilayers also agree well with experiment. Accordingly, the presented lipid FF, referred to as C36, allows for molecular dynamics simulations to be run in the tensionless ensemble (NPT), and is anticipated to be of utility for simulations of pure lipid systems as well as heterogeneous systems including membrane proteins.

Phospholipid Monolayers Probed by Vibrational Sum Frequency Spectroscopy: Instability of Unsaturated Phospholipids

The surface specific technique vibrational sum frequency spectroscopy has been applied to in situ studies of the degradation of Langmuir monolayers of 1,2-diacyl-phosphocholines with various degrees of unsaturation in the aliphatic chains. To monitor the degradation of the phospholipids, the time-dependent change of the monolayer area at constant surface pressure and the sum frequency intensity of the vinyl CH stretch at the carbon-carbon double bonds were measured. The data show a rapid degradation of monolayers of phospholipids carrying unsaturated aliphatic chains compared to the stable lipids carrying fully saturated chains when exposed to the ambient laboratory air. In addition, the degradation of the phospholipids can be inhibited by purging the ambient air with nitrogen. This instability may be attributed to spontaneous degradation by oxidation mediated by various reactive species in the air. To further elucidate the process of lipid oxidation in biological membranes artificial Langmuir monolayers probed by a surface specific spectroscopic technique as in this study can serve as a model system for studying the degradation/oxidation of cell membrane constituents.

Oil, micronutrient and heavy metal contents of tomatoes

In this study, oils, micronutrients and heavy metal contents of tomato seeds and tomato (Lycopersicon esculentum) fruits from different Turkish resources were determined. The tomato seed oil contains more than 84% unsaturated fatty acids, such as oleic acid, linoleic acid and linolenic acid. The fatty acid composition of tomato seed oil was similar to that of soybean oil. Under supercritical conditions, partial thermal degradation occurs on the double bonds of unsaturated aliphatic carbons chains in fatty acids. Linoleic acid was the major unsaturated fatty acid in tomato seed oil. The concentrations of metals (Pb, Cd, Fe, Cu, Zn, Na, K, Ca and Mg) were determined in tomato samples.

Oil from Tea Seed by Supercritical Fluid Extraction

Green tea seed oil (Camellia sinensis L. Kuntze) samples were used in this work. The tea seed oil contains more than 84% unsaturated fatty acid, such as oleic acid, linoleic acid, and linolenic acid. The most current research on oil extraction is focused on producing biodiesel from vegetable oils. The biodiesel from tea seed oil in itself is not significantly different from biodiesel produced from vegetable oils. Tea seed oils as well, as different vegetable oils, have lower pour point and lower viscosity. Supercritical fluid extraction of tea seed oil was performed to study the effects of various parameters such as pressure, temperature, extraction time, and solvent (methanol) on the yield and composition of the oil. Under supercritical conditions, partial thermal degradation occurs on the double bonds of unsaturated aliphatic carbon chains in fatty acids. Oxidation of methyl esters resulted in the formation of hydroperoxides. Unsaturated fatty acid, such as oleic acid, linoleic acid, linolenic acid, and gadoleic, reach as high as 85.6%. The content of linoleic and linolenic acids in the tea seed oil is 20.5%, while these acids account for 15.9% of the total fatty acids in the supercritical methanol extracts. Partial thermal degradation of the linoleic and linolenic acids may occur in the supercritical methanol extraction due to high temperature (< 513 K). The high temperature had a much greater effect on the polyunsaturated fatty acids than saturated and mono saturated fatty acids.