Analytical Characterization of Fatty Acids Composition of Datura alba Seed Oil by Gas Chromatography Mass Spectrometry

Methyl ester derivatives of fatty acids were analyzed for the determination of the constituents of Datura alba seed oil. Gas chromatography coupled to mass spectrometer was used for these analyses. Results delivered that there were saturated as well as unsaturated fatty acids in Datura alba seed oil. Total of 15 different fatty acid components were identified and quantified. Methyl linoleate was found in highest concentration (16.22%) among the identified analytes of interest. In addition methyl esters of Palmitic acid (6.59%), Oleic acid (5.41%) and Stearic acid (1.35%) were found. Concentrations of rest of the detected fatty acids were less than 1%. From the literature it appears that no such work has been performed for the determination of fatty acids in Datura alba seed oil.     

Characterization and purification of polyunsaturated fatty acids from microalgae by gas chromatography-mass spectrometry and countercurrent chromatography

Summary The present study was undertaken in order to characterize then to purify fatty acids from marine phytoplankton. From a crude mixture of fatty acid methyl esters it was possible to isolate by countercurrent chromatography a mixture of four polyunsaturated fatty acid methyl ester identified as being hexadecatrienoic acid methyl ester, octadecatetraenoic acid methyl ester, eicosapentaenoic acid methyl ester and docosahexaenoic acid methyl ester by gas chromatography coupled with mass spectrometry in electron impact and in positive-ion chemical ionization mode. The four polyunsaturated fatty acids are in different ratios in mixtures from the two microorganisms:Skeletonema costatum andIsochrysis galbana.     

Isolation of 6,9,12,15-Hexadecatetraenoic Fatty Acid (16:4n-1) Methyl Ester from Transesterified Fish Oil by HSCCC

Fish oil is considered a healthy food due to the presence of large amounts of polyunsaturated fatty acids (PUFAs), especially in the form of n-3 fatty acids 5,8,11,14,17-eicosapentaenoic acid (20:5n-3; EPA) and 4,7,10,13,16,19-docosahexaenoic acid (22:6n-3; DHA). However, fish oil is known to contain many other PUFAs, some of which are uncommon and whose bioactivity is scarcely investigated. In this study, we isolated the rare PUFA 6,9,12,15-hexadecatetraenoic fatty acid (16:4n-1) which bears a double bond on the terminal carbon from fish oil in form of its methyl ester. We used high-speed counter-current chromatography (HSCCC) for the fractionation of 500 mg-portions of fatty acid methyl esters prepared from a fish oil capsule and investigated the fractions by GC/MS. Twenty-eight 13-mL fractions were collected and fatty acid methyl esters were detected in fractions 11–23. The elution was carried out in normal phase mode, providing the long-chained saturated and monoenoic fatty acids first. More than 100 fatty acids ranging from 10:0 to 26:0 could be identified in the HSCCC fractions, and most of them were polyunsaturated. The reproducibility of the HSCCC method was shown by repeated injection of the fish oil and the fractions containing 6,9,12,15-hexadecatetraenoic fatty acid (16:4n-1). The late eluting 16:4n-1 methyl ester was isolated in pure form and its structure was verified.

     

Analytical Characterization of Fatty Acids Composition of Bioactive Stem Oil of Maytenus royleanus by Gas Chromatography Mass Spectrometry

The significant inhibition and selectivity for human solid tumor cell by oily fraction of Maytenus royleanus, was subjected to GC‐MS analysis for determination of its chemical constituents. GC‐MS profile of methyl ester derivatives of fatty acids, showed that Palmitic acid (35.41%), Oleic acid (10.91%), Stearic acid (5.31%), Margaric acid (5.13%), Behenic acid (5.18%) and Hexanoic acid (4.97%) were the major components in the isolated oily fraction, while rest of the other fatty acids were present in minor concentration. The literature revealed that no such work has been done for the determination of fatty acids in M. royleanus stem oil.     

Determination of fatty acid methyl esters derived from algae Scenedesmus dimorphus biomass by GC–MS with one‐step esterification of free fatty acids and transesterification of glycerolipids

Algae can synthesize, accumulate and store large amounts of lipids in its cells, which holds immense potential as a renewable source of biodiesel. In this work, we have developed and validated a GC–MS method for quantitation of fatty acids and glycerolipids in forms of fatty acid methyl esters derived from algae biomass. Algae Scenedesmus dimorphus dry mass was pulverized by mortar and pestle, then extracted by the modified Folch method and fractionated into free fatty acids and glycerolipids on aminopropyl solid‐phase extraction cartridges. Fatty acid methyl esters were produced by an optimized one‐step esterification of fatty acids and transesterification of glycerolipids with boron trichloride/methanol. The matrix effect, recoveries and stability of fatty acids and glycerolipids in algal matrix were first evaluated by spiking stable isotopes of pentadecanoic‐2,2‐d₂ acid and glyceryl tri(hexadecanoate‐2,2‐d₂) as surrogate analytes and tridecanoic‐2,2‐d₂ acid as internal standard into algal matrix prior to sample extraction. Later, the method was validated in terms of lower limits of quantitation, linear calibration ranges, intra‐ and inter‐assay precision and accuracy using tridecanoic‐2,2‐d₂ acid as internal standard. The method developed has been applied to the quantitation of fatty acid methyl esters from free fatty acid and glycerolipid fractions of algae Scenedesmus dimorphus .     

Composition of the lipophilic extract from the sponge <Emphasis Type="Italic">Axinella carteri</Emphasis> collected from the Bay of Bengal of the Orissa coast

The composition of the lipophilic extract from the two specimen of the sponge Axinella carteri (Dendy) collected from two different depths of the Bay of Bengal of the Orissa coast were investigated. Fatty acids, as well as volatile compounds and sterols, were identified. A high concentration of polyunsaturated fatty acids was identified from depth species compared to the species collected from shallow water. The presence of a high concentration of a polymethyl-branched fatty acid, i.e., phytanic acid, and a demospongic acid (C26:2, Δ 5,9) were identified in both specimen, but the % composition of both acids were more in the species collected from depth than the species collected from shallow water. Important polyunsaturated fatty acids like 5,8,11,14-eicosatetraenoic acid and 5,8,11,14,17-eicosapentaenoic acid (EPA) were also found in depth species which were absent in the species collected from shallow water. Antimicrobial screening of the lipid extracts of A. carteri was also studied against different pathogens. Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 224–227, May–June, 2008.     

Investigation of kernel oils of <Emphasis Type="Italic">Quercus robur</Emphasis> and <Emphasis Type="Italic">Quercus cerris</Emphasis>

The kernel oils of Quercus robur and Quercus cerris were obtained by Soxhlet extraction using petroleum ether. Oil yields were found to be 5.2–5.6% and 4.3–4.8% for Q. robur and Q. cerris kernel, respectively (expressed in g per 100 g of dried plant material). The physical and chemical constants, unsaponifiable matter and total fatty acids were determined. The total fatty acid composition of oils was determined by GC in the methyl ester form. Considering the composition and content of fatty acids, the examined kernel oils were very similar. Seven fatty acid components were identified in both oils: palmitic, stearic, arachidic, palmitoleic, oleic, linoleic, and -linolenic. In Q. robur and Q. cerris kernel oils the principal acids were oleic (44.3% and 43.0%, respectively) and linoleic (37.2% and 32.6%, respectively), followed by a significant amount of palmitic acid.Published in Khimiya Prirodnykh Soedinenii, No. 5, pp. 347–348, September–October, 2004.     

Proton affinities of saturated aliphatic methyl esters

The kinetic method was used to determine the proton affinities of methyl esters of several saturated fatty acids. Decompositions of the proton-bound dimers of the methyl esters, AHB⁺, were observed under different conditions with two instruments. The proton affinities (PAs) of the methyl esters increase continually with increasing carbon number in the acid. Equilibrium and initial rate experiments were performed with a Fourier transform ion cyclotron resonance mass spectrometer on the methyl ester of the C₂₂ saturated acid (methyl behenate). These experiments give values for PA (methyl behenate) that are perhaps slightly lower than those obtained with the kinetic method. The PAs of the methyl esters of the fatty acids could be correlated with the equation: PA (ester) = (40.0 ± 2.5)*log(n) + (784.7 ± 3.9) kJ/mol or PA (ester) = (864 ± 2) − (479 ± 41)/n, wheren = number of atoms in the molecule. Proton affinities of smaller sets of 1-alkylamines and 1-alkanols can be fit to similar equations.     

Production of biodiesel by immobilized Candida sp. lipase at high water content

A new process for enzymatic synthesis of biodiesel at high water content (10–20%) with 96% conversion by lipase from Candida sp. 99–125 was studied. The lipase, a no-position-specific lipase, was immobilized by a cheap cotton membrane and the membrane-immobilized lipase could be used at least six times with high conversion. The immobilized lipase could be used for different oil conversion and preferred unsaturated fatty acids such as oleic acid to staturated fatty acids such as palmitic acid. The changes in concentration of fatty acids, diglycerides, and methyl esters in the reaction were studied and a mechanism of synthesis of biodiesel was suggested: the triglycerides are first enzymatically hydrolyzed into fatty acids, and then these fatty acids are further converted into methyl esters.     

Characterization of <Emphasis Type="Italic">Opuntia ficus indica</Emphasis> seed oil from Tunisia

The lipid fraction of Opuntia ficus indica seeds was extracted and analyzed for its chemical and physical properties such as acid value, free fatty acid percentage (% FFA), iodine index, peroxide value, and saponification value as well as refractive index and density. The yield of seed oil was calculated as 11.75%. The acid and free fatty acid values indicated that the oil has a fairly low acidity. The triacylglycerols, fatty acids, sterols, and tocopherols were identified and their concentrations determined. The main TAGs were LLL (25.60%), OLL (21.53%), PLL (15.53%), and POL + SLL (12.73%). Linoleic acid (60.69%) was the dominant fatty acid, followed by oleic (21.42%) and palmitic (12.76%) acids, respectively. A high level of sterols making up 16.06 g/kg seed oil was present. The sterol marker, β-sitosterol, accounted for 71.60% of the total sterol content in the seed oil. Among the tocopherols present in the oil, γ-tocopherol (421.08 mg/kg) was the main constituent.     

Fatty acid composition of Viscum album subspecies from Turkey

The lipophylic extracts of three Viscum album subspecies growing on different host plants in Turkey were comparatively analyzed for derived methyl esters of their fatty acids by capillary gas chromatography-mass spectrometry (GC-MS). The sample of V. album ssp. album growing on apricot trees was remarkably rich in palmitic acid (11.47%). Arachidic acid was found in only ssp. austriacum and ssp. abietis samples. The unsaturated fatty acids, mainly oleic and linoleic acids, were identified in nine lipophylic extracts obtained from V. album samples belonging to ssp. album. The amounts of linoleic and oleic acid were the highest in the sample of ssp. album growing on apricot trees (12.18 and 9.19%, respectively). Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 523–525, November–December, 2006.     

大果白刺游离脂肪酸的柱前衍生高效液相色谱-荧光检测法分析

采用2-（11H-苯[a]咔唑）乙基对甲苯磺酸酯（BCETS）为柱前荧光衍生试剂,通过梯度洗脱使得18种脂肪酸在BDS-C8柱上得到良好的分离.方法应用于大果白刺不同部位中游离脂肪酸的分析,结果表明大果白刺的果皮果肉和叶子中均含有大量的不饱和脂肪酸,其总不饱和脂肪酸含量分别为70.74%和73.47%.大果白刺种子中不饱和脂肪酸的含量相对较少,仅占总脂肪酸含量的57.21%,其不饱和脂肪酸组成主要是C18∶1（油酸）和C18∶2（亚油酸）.其中,大果白刺的果皮果肉中,不饱和脂肪酸主要是C18∶1、C18∶2和C18∶3（亚麻酸）.其叶子中的不饱和脂肪酸主要是C18∶3,所占总脂肪酸比例为48.34%.首次对大果白刺中的脂肪酸进行了分析,可以为大果白刺在食品、药品中的进一步开发应用和质量控制提供一定的数据支持.     

Unusual Δ5cis-fatty acids in seed oils of Cimicifuga species

A range of unusual fatty acids with cis-5-unsaturation had been reported in the seed oil of Caltha palustris. Seed oils of Cimicifuga spp. have now been found to contain the same unusual fatty acids as are present in Caltha, plus several other minor fatty acids to give a more complex and more unsaturated seed oil fatty acid pattern. The gas chromatographic fatty acid patterns found seem to be consistent and chemotaxonomically significant, because essentially the same pattern was found in several species of the genus Cimicifuga. These findings may shed a new light on the relation of Cimicifuga to Caltha, and to other genera in the plant family Ranunculaceae. The situation is illustrated by capillary GLC seed oil fatty acid methyl ester “fingerprints” obtained from Cimicifuga and Caltha, and is discussed in relation to other genera. The occurrence in nature of several of these unusual fatty acids, and their chemotax-onomic significance is discussed. The close relation of GLC fatty acid patterns of Caltha and Cimicifuga could indicate monophyly and/or their belonging to the same tribe or subtribe. These observations are not in accordance with the phylogenetic systematic schemes of the genera in this plant family as published by various authors.     

Physicochemical Properties and Composition of Lipids from Capsicum annuum Seeds

The mass of 1000Capsicum annuum(Solanaceae) seeds and their moisture, oil and ash contents were determined. The lipid composition and acid components were studied. Low-molecular-weight fatty acids, concentrated in the ester fraction, were detected     

Vapor–liquid equilibria and densities of CO2 with four unsaturated fatty acid esters at elevated pressures

In this study experimental P–T–x–y equilibrium data for four binary mixtures over a wide range of pressure (10.44–23.54 MPa) were determined at 313 K and 333 K. Liquid and vapor densities of carbon dioxide + four fatty acid ester systems, including oleic acid methyl ester, linoleic acid methyl ester, eicosapentaenoic acid ethyl ester, and docosahexaenoic acid ethyl ester were measured by using two circulating systems consisting of two vibrating tube densitometers. The vapor-phase density was observed to increase more significantly with pressure than the liquid-phase density at constant temperature. Experimental equilibrium constants of oleic acid methyl ester and linoleic acid methyl ester were found to be larger than those of eicosapentaenoic acid ethyl ester, docosahaxaenoic acid ethyl ester, linoleic acid, triolein, and tocopherol. This indicates that the two methylated fatty acids would be extracted easier than the other compounds in a separation process using supercritical CO₂ extraction. The equilibrium data were successfully correlated using the Peng–Robinson and modified Soave–Redlich–Kwong equations of state with quadratic (two parameters), Panagiotopoulos–Reid (three parameters), and Adachi–Sugie (three parameters) mixing rules. In general, the Soave–Redlich–Kwong equation of state with the Panagiotopoulos–Reid mixing rules and the quadratic mixing rules give the best correlation for methylated fatty acids and ethylated fatty acids, respectively.     

Fatty acid composition of two Athamanta turbith subspecies

The fruit oils of Athamanta turbith ssp. hungarica and Athamanta turbith ssp. haynaldii were obtained by Soxhlet extraction using petroleum ether. The fatty acid composition of oils was determined by GC in the methyl ester form. Considering the composition and content of fatty acids, the examined oils were very similar. Petroselinic acid was the principal one (45.6 and 46.2%, respectively), followed by a significant amount of linoleic acid (26.9 and 29.1%, respectively). In both oils, myristic, pentadecanoic, palmitic, palmitoleic, stearic, petroselinic, oleic, linoleic, α-linolenic, arachidic, and behenic acid were identified. Lignoceric acid was detected only in A. turbith ssp. hungarica oil. Published in Khimiya Prirodnykh Soedinenii, No. 4, pp. 319–320, July–August, 2006.     

Isolation of chlorinated fatty acid methyl esters derived from cell-culture medium and from fish lipids by using an aminopropyl solid-phase extraction column

An aminopropyl-based solid-phase extraction technique was used for isolation of chlorinated fatty acids in lipids. A range of different chlorinated fatty acids was eluted in a small volume of solvent (4 ml) and the recoveries of the different species and isomers were quantitative. Only 1% of the vastly dominating unchlorinated fatty acid methyl esters were recovered in the fractions containing the chlorinated fatty acid methyl esters. This method makes it possible to isolate and detect > or = 1 microg of a chlorinated fatty acid methyl ester in 1 g of lipid.     

Study of the inhibitory effect of ferulic acid on short-chain fatty acids in milk samples by dispersive liquid–liquid micro-extraction in combination with fluorescence derivatization

A sensitive high-performance liquid chromatography (HPLC) method was developed to study the influence of ferulic acid on the formation of volatile fatty acids and lactic acid in milk and soybean milk samples. Volatile fatty acids were extracted by liquid–liquid micro-extraction using chloroform and acetonitrile as the extraction and disperser solvents, respectively. The analytes were derivatized with 2-(5-benzoacridine)ethyl-p-toluenesulfonate that showed excellent fluorescence property and made the sensitive HPLC analysis of short-chain fatty acids become possible. The optimized HPLC sensitivity was in the range of 1.1–1.9?µg?L^?1. Ferulic acid was added in milk and soybean milk samples to study its preservative effect. The results indicated that ferulic acid with concentration of 0.2% (m/v) could effectively reduce the formation of short-chain fatty acids.     

Determination of Free Fatty Acids in Natural Oils and Alkyd Resins by High Performance Liquid Chromatography

Abstract

Mixtures of free fatty acids in natural oil and alkyd resin samples have been analyzed using a μBondapak Free Fatty Acid column in conjunction with a ternary mobile phase. Variation of the mobile phase composition allows ‘‘fingerprinting'’ as well as quantitation of the fatty acid components. Samples can be analyzed in ten minutes by this method. The results of the application of this technique to the identification of oil sources of fatty acids as well as the production of fatty acids during alkyd resin synthesis are given. Good agreement is observed for fatty acid compositions determined via HPLC with those obtained by gas chromatographic methyl ester analysis.     

Occupational exposure to low levels of organic and inorganic substances in a chemical plant for the production of terephtalic acid dimethyl ester

The aim of our study was the evaluation of personal exposure to chemical pollutants in workers employed in a plant for the production of terephtalic acid dimethyl ester. Chemical agents have been included in the monitoring program on the basis of the industrial process. In the plant, the oxidation of p-xylene is performed by air and the resulting acid is esterified with methyl alcohol. Purified terephtalic acid dimethyl ester is then utilized for the production of polyethylene terephtalate. The environmental monitoring included terephtalic acid dimethyl ester, p-toluic acid methyl ester, terephtalic acid, p-xylene, methylacetate, methylbenzoate, formic acid, acetic acid, methanol, and the catalysts cobalt acetate and manganese (II) acetate tetrahydrate. Personal exposure to the cited airborne substances was performed in the breathing zone of six workers. Air samplings were carried out by drawing air through glass fibre filters (terephtalic acid dimethyl ester, p-toluic acid methyl ester and terephtalic acid aerosols), by active adsorption (methanol, formic and acetic acids vapours). p-Xylene, methylacetate and methylbenzoate vapours were collected by passive sampling. Cellulose nitrate filters were used for cobalt and manganese salts samplings. Analyses were performed by UV detection high-performance liquid chromatography (terephtalic acid dimethyl ester, p-toluic acid methyl ester and terephtalic acid), flame ionization detection gas chromatography (p-xylene, acetic acid methyl ester and benzoic acid methyl ester), ion chromatography (formic and acetic acids) and inductively coupled plasma-mass spectrometry (cobalt and manganese). The results were evaluated according to the threshold limit values (TLVs) of the American Conference of Governmental Industrial Hygienists (ACGIH) and indicated that the environmental levels of the workplace pollutants were well below the threshold limit values-time weighed average (TLV-TWA) adopted by the American Conference of Governmental Industrial Hygienists for 2002, although for three substances the TLVs were not available.