Nonglyceride complex of the seed oil ofOnopordum acanthium

Extraction of the comminuted seeds has yielded an oil from which have been isolated: C₃₃-C₂₅, C₁₈ and C₁₇ paraffinic hydrocarbons, C_18:1, C_18:2, C_18:3, C_17:1, C_17:2 and C_17:3 olefinic hydrocarbons, ethyl esters of C_32:0, C_31:0, C_30:0, C_29:0, and C_28:0 fatty acids, sterols with molecular weights of 414, 412, and 400, and the alcohols α-amyrin and lupeol with their natural acetates. Extraction of the uncomminuted seeds has shown that the paraffinic hydrocarbons, ethyl esters, and alcohol acetates pass into the oil from the husks of the seeds. This is the first time that the C_31:0 and C_29:0 fatty acids have been detected as natural compounds, and it is the first time that the ethyl esters of C₃₄, C₃₃, C₃₂, C₃₁, and C₃₀ fatty acids have been isolated from seed oils of higher plants.     

The use of sulfated tin oxide as solid superacid catalyst for heterogeneous transesterification of <Emphasis Type="Italic">Jatropha curcas</Emphasis> oil

This work presents the use of sulfated tin oxide enhanced with SiO₂ (SO₄²⁻/SnO₂-SiO₂) as a superacid solid catalyst to produce methyl esters from Jatropha curcas oil. The study was conducted using the design of experiment (DoE), specifically a response surface methodology based on a threevariable central composite design (CCD) with α = 2. The reaction parameters in the parametric study were: reaction temperature (60°C to 180°C), reaction period (1 h to 3 h), and methanol to oil mole ratio (1: 6 to 1: 24). Production of the esters was conducted using an autoclave nitrogen pressurized reactor equipped with a thermocouple and a magnetic stirrer. The maximum methyl esters yield of 97 mass % was obtained at the reaction conditions: temperature of 180°C, reaction period of 2 h, and methanol to oil mole ratio of 1: 15. The catalyst amount and agitation speed were fixed to 3 mass % and 350–360 min⁻¹, respectively. Properties of the methyl esters obtained fell within the recommended biodiesel standards such as ASTM D6751 (ASTM, 2003).     

Thermal analysis of lipids isolated from various tissues of sheep fats

The physical–chemical properties and fatty acid composition of sheep subcutaneous, tallow, intestinal, and tail fats were determined. Sheep fat types contained C_16:0, C_18:0, and C_18:1 as the major components of fatty acid composition (19.56–23.40, 20.77–29.50, 32.07–38.30%, respectively). Differential scanning calorimetry (DSC) study revealed that two characteristic peaks were detected in both crystallization and melting curves. Major peaks (T _peak) of tallow and intestinal fats were similar and determined as 31.25–24.69 and 7.44–3.90 °C, respectively, for crystallization peaks and 15.36–13.44 and 45.98–44.60 °C, respectively, for melting peaks in DSC curves; but those of tail fat (18.29 and −2.13 °C for crystallization peaks and 6.56 and 33.46 °C for melting peaks) differed remarkably from those of other fat types.     

Structure and Applications of a Rhamnolipid Surfactant Produced in Soybean Oil Waste

Soybean oil soapstock was utilized as an alternative carbon source for the production of rhamnolipids by Pseudomonas aeruginosa LBI strain. The chemical composition and properties of the rhamnolipid mixture obtained were determined to define its potential applications. The chemical characterization of the rhamnolipid has revealed the presence of ten different homologues. The monorhamnolipid RhaC₁₀C₁₀ and the dirhamnolipid Rha₂C₁₀C₁₀ were the main components of the mixture that showed predominance of 44% and 29%, respectively, after 144-h of cultivation. The biosurfactant was able to form stable emulsions with several hydrocarbons and showed excellent emulsification for soybean oil and chicken fat (100%). The rhamnolipid removed 67% of crude oil present in sand samples and presented antimicrobial activity against Bacillus cereus and Mucor miehei at 64 μg/mL and inhibition of Neurospora crassa, Staphylococcus aureus, and Micrococcus luteus at 256 μg/mL. The results demonstrated that the rhamnolipid produced in soybean oil soapstock can be useful in environmental and food industry applications.     

Thermophysical properties of biodiesel and related systems: (Liquid + liquid) equilibrium data for soybean biodiesel

This work reports (liquid + liquid) equilibrium (LLE) data for the systems of interest in soybean biodiesel production. Numerical data for LLE were obtained for binary, ternary and quaternary systems comprising fatty acid methyl esters (FAME) and fatty acid ethyl esters (FAEE) from soybean oil, water, glycerol, methanol, and ethanol at temperatures of (303.15, 318.15, and 333.15) K. Quantification of compounds in equilibrium in both phases was determined by analytical methods whereas solubility curves (binodal) were obtained by the cloud-point method. For all systems investigated, good alignments were obtained between phase compositions and the initial as well as overall compositions hence indicating low deviations from the mass balance. Experimental results were correlated using the UNIQUAC model with satisfactory agreement between experiment and theory.     

Chiroptical properties and conformation of some 2-alkyl substituted dicarboxylic acids

CD spectra in EPA (a mixture of ethanol, isopentane and diethyl ether) at 25° and -185° were measured for the following acids and their methyl esters: (R)-2-methyl-, (R)-2-ethyl-, (R)-2-n-propyl-, (R)-2-n-butyl-, (R)-2-n-hexyl-, (R)-2-isobutyl-, (S)-2-isopropyl- and (S)-2-cyclohexylsuccinic acids, (R)-2-methylglutaric acid, (R)-2-methylsuberic acid, (R,R)-2,3-dimethyl-succinic acid and (+)-trans-Caronic acid (3,3-dimethyl-1,2-cyclopropane-dicarboxylic acid). The CD data are explained in terms of the conformation around the C₁C₂, C₂C₃ and C₃C₄ bonds.     

Evaluation of vinasses from sugarcane molasses distillation as a new source of sugarcane wax

Molasses, a by-product of sugar manufacturing, are the most common raw material for rum manufacturing. During the fermentation and distillation process, vinasses are produced in large quantities and disposed in landfills. In this study, they were evaluated as a new source of sugarcane wax. The chemical composition of the wax was studied by GC-Mass spectroscopy. A series of n-alkanes (C₂₃–C₃₃) and ethyl and methyl esters of fatty acids (palmitate and oleate are the predominant), of phytosterols (stigmasterol, β-sitosterol, campesterol), free fatty acids (C_12:0–C_36:0), and triglycerides constitute the main components. In addition, 2-ketones (C₂₇–C₃₃), aldehydes (C₂₈, C₃₂, C₃₄), ketosteroids (derivatives of stigmasterol, β-sitosterol, and campesterol), and fatty alcohol acetates (alcohol moiety: C₂₈, C₃₀, C₃₂) were found as minor products. Published in Khimiya Prirodnykh Soedinenii, No. 5, pp. 448–450, September-October, 2008. Original article submitted March 19, 2007.     

Polyesters by lipase-catalyzed polycondensation of unsaturated and epoxidized long-chain α,ω-dicarboxylic acid methyl esters with diols

Long-chain, symmetrically unsaturated α,ω-dicarboxylic acid methyl esters (C₁₈, C₂₀, C₂₆) were obtained by the catalytic metathetical condensation of 9-decenoic, 10-undecenoic, and 13-tetradecenoic acid methyl esters, respectively, with the homogeneous Grubbs catalyst bis(tricyclohexyl phosphine) benzylidene ruthenium dichloride dissolved in methylene chloride. The dicarboxylic acid esters were epoxidized chemoenzymatically with H₂O₂/methyl acetate with Novozym 435^®, an immobilized lipase B from Candida antarctica. Polyesters from symmetrically unsaturated or epoxidized α,ω-dicarboxylic acid methyl esters with 1,3-propanediol or 1,4-butanediol, respectively, were achieved by enzymatic polycondensation with the same biocatalyst applied. With 1,3-propanediol as a substrate, the linear unsaturated and epoxidized polyesters had molecular weights of 1950–3300 g/mol and melting points of 47–75 °C, whereas with 1,4-butanediol as a substrate, the resulting polyesters showed higher molecular weights, 7900–11,600 g/mol, with similar melting points of 55–74 °C. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1601–1609, 2001     

Nonglyceride complex of the seed oil ofOnopordum acanthium

Extraction of the comminuted seeds has yielded an oil from which have been isolated: C₃₃-C₂₅, C₁₈ and C₁₇ paraffinic hydrocarbons, C_18:1, C_18:2, C_18:3, C_17:1, C_17:2 and C_17:3 olefinic hydrocarbons, ethyl esters of C_32:0, C_31:0, C_30:0, C_29:0, and C_28:0 fatty acids, sterols with molecular weights of 414, 412, and 400, and the alcohols -amyrin and lupeol with their natural acetates. Extraction of the uncomminuted seeds has shown that the paraffinic hydrocarbons, ethyl esters, and alcohol acetates pass into the oil from the husks of the seeds. This is the first time that the C_31:0 and C_29:0 fatty acids have been detected as natural compounds, and it is the first time that the ethyl esters of C₃₄, C₃₃, C₃₂, C₃₁, and C₃₀ fatty acids have been isolated from seed oils of higher plants.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 612–615, September–October, 1979.     

Melt processed polyethylene/fullerene nanocomposites with highly improved thermo-oxidative stability

The thermo-oxidative stability of melt processed polyethylene composites with the two fullerenes C₆₀ and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) was studied with the aim of comparing the stabilization effect of both fullerenes on three different polyethylenes (PE). The results obtained show that, irrespective of the specific polyethylene being considered, C₆₀ loadings as low as 1.0 wt% cause a dramatic increase in the thermo-oxidative stability of the corresponding composites (up to 64.8 °C at T2% and 113.8 °C at T5%, TX% being the temperature corresponding to a mass loss of X wt%), in agreement with previous reports. Furthermore, and more importantly, this work shows for the first time that the thermo-oxidation stability effect caused by PCBM is even higher than that of C₆₀, the difference between both being particularly significant in the early stages of degradation, i.e. for mass losses ≤2 wt%. For example, polyethylene composites with 1.0 wt% PCBM show T2% values which are systematically higher than those of the corresponding composites with 1.0 wt% C₆₀, the difference between the T2% values of the two composites being 38.8 °C, 67.1 °C and 26.4 °C in the three different polyethylenes considered. Therefore, when compared with C₆₀, PCBM is particularly more effective at delaying the beginning of the thermo-oxidative degradation. According to our results, PCBM loadings as low as 1.0 wt% can increase the thermo-oxidative stability of polyethylene composites by more than 130 °C and these are, as far as we know, the highest thermo-oxidative stability results induced by nanoparticles ever reported in the literature for polyethylene.     

The interaction between some ethyl esters of aminoacids and acetic acid in carbon tetrachloride

The dimerization constant, K₁ of acetic acid in CCl₄ is determined by an IR spectrometric method and is found to have a value of 2252M⁻¹ at 20°. The association constants, K₂, for the interaction between the acetic acid monomer and some aminoacid ethyl esters are determined by the same method and found to have the values given (in M⁻¹ at 20°) for the esters of the following aminoacids: glycine (282 ± 24), dl-alanine (236 ± 33), dl-α-aminobutyric acid (139 ± 11), α-aminoisobutyric acid (172 ± 18). dl-norvaline (104 ± 13), dl-valine (150 ± 8), dl-leucine (108 ± 18) and 3-phenyl-dl-alanine (140 ± 21). A correlation of these experimental values with some structural parameters related to the steric effect of the substituents on the esters is proposed.     

Characterization of fatty acid methyl esters by thermal analysis

The thermal stability of selected straight-chain (C₆-C₁₄) esters of fatty acids has been studied by TG-DTG and DTA analysis. In DTG, a peak is detected between 84° and 125° C followed by a main effect in the range 105°–215°C, whereas in DTA only an exothermic peak appears in the range of 126.5° to 187°C (onset temperatures). The temperatures of these effects have been related with ignition points, molecular weights and boiling points. The characteristics of melting and recrystallization of the above fatty acid methyl esters and those with carbon numbers between C₁₄ and C₂₄ have been established by DSC along the melting range between ?83° and 50°C. Polymorphism appears in caproic, heptanoic, palmitic and stearic acid methyl esters.     

Isolation and Characterization of a Novel Thermophilic-Organic Solvent Stable Lipase From <Emphasis Type="Italic">Acinetobacter baylyi</Emphasis>

The benzene tolerant Acinetobacter baylyi isolated from marine sludge in Angsila, Thailand could constitutively secrete lipolytic enzymes. The enzyme was successfully purified 21.89-fold to homogeneity by ammonium sulfate precipitation and gel-permeable column chromatography with a relative molecular mass as 30 kDa. The enzyme expressed maximum activity at 60°C and pH 8.0 with p-nitrophenyl palmitate as a substrate and found to be stable in pH and temperature ranging from 6.0-9.0 to 60-80°C, respectively. A study on solvent stability revealed that the enzyme was highly resisted to many organic solvents especially benzene and isoamyl alcohol, but 40% inhibited by decane, hexane, acetonitrile, and short-chain alcohols. Lipase activity was completely inhibited in the presence of Fe²⁺, Mn²⁺, EDTA, SDS, and Triton X-100 while it was suffered detrimentally by Tween 80. The activity was enhanced by phenylmethylsulfonyl fluoride (PMSF), Na⁺, and Mg²⁺ and no significant effect was found in the presence of Ca²⁺ and Li⁺. Half of an activity was retained by Ba²⁺, Ag⁺, Hg⁺, Ni²⁺, Zn²⁺, and DTT. The enzyme could hydrolyze a wide range of p-nitrophenyl esters, but preferentially medium length acyl chains (C₈-C₁₂). Among natural oils and fats, the enzyme 11-folds favorably catalyzed the hydrolysis of rice bran oil, corn oil, sesame oil, and coconut oil in comparison to palm oil. Moreover, the transesterification activity of palm oil to fatty acid methyl esters (FAMEs) revealed 31.64 ± 1.58% after 48 h. The characteristics of novel A. baylyi lipase, as high temperature stability, organic solvent tolerance, and transesterification capacity from palm oil to FAMEs, indicate that it could be a vigorous biocatalyzer in the prospective fields as bioenergy industry or even in organic synthesis and pharmaceutical industry.     

Optimization of biodiesel production via transesterification of soybean oil using α-MoO3 catalyst obtained by the combustion method

A catalyst based on MoO₃ was synthesized by a simple and fast pilot-scale combustion reaction method and applied to the conversion of soybean oil to biodiesel via transesterification. For that, the statistical analysis of the catalyst amount and temperature, factors that influence the process, was evaluated by means of central composite design 2². MoO₃ was characterized in terms of structure by X-ray diffraction (XRD), textural characterization Brunauer-Emmett-Teller (BET), density by helium pycnometry (DE), particle size analysis (DG) and acidity tests by temperature-programmed desorption of ammonia (NH₃-TPD), chemical analysis by X-ray fluorescence (EDX), morphology by scanning electron microscopy (SEM) and catalytic properties. The transesterification products were characterized by gas chromatography (GC), acidity index (AI) and kinematic viscosity (KV). The results indicate the catalyst formation with a surface area of 1.36 m²g^?1, and density of 4.5 g/cm³ which consists of a single crystalline phase of orthorhombic configuration, with total NH₃ acidity of 33.61 μ.mol/g. Morphological characterization revealed that the catalyst is formed by irregular plates of various sizes and shapes, with a wide sizes range of agglomerated particles. In the soybean oil transesterification reactions, the catalyst was active showing 96.9% conversion to ethyl esters. The experimental design was meaningful and predictive, with a reliability level of 95%. The statistical analysis identified temperature as a significant variable for the adopted planning. To conclude, a new single-phase catalyst (α-MoO₃) has been developed and successfully applied to the biodiesel Synthesis from soybean oil. These results have a positive and promising impact for biodiesel production by transesterification of soybean oil against ethanol.     

Catalytic conversions in green aqueous media: Part 4. Selective hydrogenation of polyunsaturated methyl esters of vegetable oils for upgrading biodiesel

This study deals with the influence of operating parameters on the selective hydrogenation of crude polyunsaturated methyl esters of linseed, sunflower and soybean oils in order to achieve high selectivities up to 79.8 mol% of monounsaturated (C18:1) fatty acid methyl esters (FAME) which is 1st generation biodiesel of increased oxidative stability, energy and environmental performance at a low pour point employing water-soluble Rh/TPPTS catalytic complexes [TPPTS = P(C₆H₄-m-SO₃Na)₃] in green aqueous/organic two-phase systems. This study also discloses the great potential of biphasic selective catalytic hydrogenation to produce 2nd generation biodiesel from polyunsaturated FAME of alternative, non-food oil feedstocks which are originally not suitable for biodiesel production or give poor quality biodiesel but combine the advantage that they would not affect food production. Because the mixture of methyl esters of linseed oil mainly consists of C18:3 FAME it constitutes a good model to investigate the effects of parameters on the whole spectrum of the stepwise hydrogenation: C18:3 (linolenates) → C18:2 (linoleates) → C18:1 (oleates)  C18:0 (stearate) and to obtain first information on the selective hydrogenation of alternative, non-food oils with a high C18:3 FAME content to make them suitable for 2nd generation biodiesel formulations.     

Biphasic alcoholysis coupled with high-speed countercurrent chromatography for high performance on separating phorbol from Croton tiglium Linn extracts

Phorbol is a tetracyclic diterpenoid found in Euphorbia tirucalli, Croton tiglium, and Rehmannia glutinosa, and is nuclear of various phorbol esters. The rapid obtaining of phorbol with high purity highly contributes to its application, such as synthesizing phorbol esters with designable side chains and particular therapeutic efficacy. This study introduced a biphasic alcoholysis method for obtaining phorbol from croton oil by using polarity imparity organic solvents in both phases and established a high-speed countercurrent chromatography method for simultaneous separation and purification of phorbol. The optimized operation conditions of biphasic alcoholysis were a reaction time of 91 min, a temperature of 14°C, and a croton oil-methanol ratio of 1:30 (g:ml). The phorbol during the biphasic alcoholysis was 3.2-fold higher in content than that obtained in conventional monophasic alcoholysis. The optimized high-speed countercurrent chromatography method was using the ethyl acetate/n-butyl alcohol/water at 4.7:0.3:5 (v:v:v) with Na₂SO₄ at 0.36 g/10 ml as the solvent system, using the mobile phase flow rate of 2 ml/min, the revolution of 800 r/min, under which the retention of the stationary phase was achieved at 72.83%. The crystallized phorbol following high-speed countercurrent chromatography was obtained as high purity of 94%.     

Optimization of alkaline transesterification of soybean oil and castor oil for biodiesel production

This article reports experimental data on the production of fatty acid ethyl esters from refined and degummed soybean oil and castor oil using NaOH as catalyst. The variables investigated were temperature (30–70°C), reaction time (1–3 h), catalyst concentration (0.5–1.5 w/wt%), and oil-to-ethanol molar ratio (1:3–1:9). The effects of process variables on the reaction conversion as well as the optimum experimental conditions are presented. The results show that conversions >95% were achieved for all systems investigated. In general, an increase in reaction temperature, reaction time, and in oil-to-ethanol molar ratio led to an enhancement in reaction conversion, whereas an opposite trend was verified with respect to catalyst concentration.     

A new enzymatic strategy for the preparation of (2R,3S)-3-phenylisoserine: a key intermediate for the Taxol side chain

Burkholderia cepacia lipase PS-IM catalysed the hydrolysis of racemic ethyl 3-amino-3-phenyl-2-hydroxypropionate with excellent enantioselectivity (E >200), when the reaction was performed with added H₂O as a nucleophile, in iPr₂O, at 50 °C. The hydrolysis of the less reactive enantiomeric ethyl 3-amino-3-phenyl-2-hydroxypropionate with 18% HCl afforded the corresponding enantiomerically pure (2R,3S)-3-amino-3-phenyl-2-hydroxypropionic acid hydrochloride, a key intermediate for the Taxol side chain.     

An improved derivatization method for sensitive determination of fatty acids by high-performance liquid chromatography using 9-(2-hydroxylethyl)-carbazole as derivatization reagent with fluorescence detection

Summary Tagging techniques with reagents used for fluorescent detection for short and long-chain fatty acids using high-performance liquid chromatography are evaluated in terms of the tagging reactions, handing, flexibility, stability of the reagents. Emphasis is given to the applications of the tagging techniques to relatively high molecular mass fatty acids. The fatty acids or carboxylic compounds were derivatized to their corresponding esters with 9-(2-hydroxy ethyl)-carbazole (HEC) in acetonitrile at 60°C with N, N′-carbonyldiimidazole (CDI) as a coupling agent in the presence of 4-dimethylaminopyridine (DMAP). A mixture of esters of C₁−C₂₀ fatty acids was completely separated with 45 min using gradient elution on a reversed-phase C₁₈ column. The maximum fluorescence emission for the derivatized fatty acids is at 365 nm (λ_ex 293 nm). Studies on derivatization conditions indicated that fatty acids react rapidly and smoothly with HEC in the presence of CDI and DMAP in acetonitrile to give the corresponding sensitively fluorescent derivatives. The application of this method to the analysis of long chain fatty acids in plasma is also investigated. The LC separation shows good selectivity and reproducibility for fatty acids derivatives. The relative standard deviations (n=6) for each fatty acid derivative are <5.0%. The detection limits are at 38–57 fmol levels for C₁₄−C₂₀ fatty acids and lower levels for <C₁₄ fatty acids.     

Kinetics of enzyme-catalyzed alcoholysis of soybean oil in n-hexane

This work investigated the production of fatty acid ethyl esters (FAEEs) from soybean oil using n-hexane as solvent and two commercial lipases as catalysts, Novozym 435 and Lipozyme IM. A Taguchi experimental design was adopted considering the variables temperature (35–65°C), addition of water (0–10 wt/wt%), enzyme (5–20 wt/wt%) concentration, and oil-to-ethanol molar ratio (1:3–1:10). It is shown that complete conversion in FAEE is achieved for some experimental conditions. The effects of process variables on reaction conversion and kinetics of the enzymatic reactions are presented for all experimental conditions investigated in the factorial design.