Lipids and flavolignans from <Emphasis Type="Italic">Silybum marianum</Emphasis>

Lipids from the air-dried aerial part (AP) and seeds of Silybum marianum (L.) Gaerth. (Asteraceae) were studied. The class and fatty acid compositions of neutral lipids (AP, seeds) and glyco- and phospholipids (AP) were determined. Neutral lipids (NL) with a complicated set of lipophilic components, mainly triterpenols, sterols, and their esters predominated in the AP. The fatty acids of the AP were dominated by 16:0, 18:2 (glycolipids), and 18:3 (neutral lipids, phospholipids); of seed NL, by 18:2 and 18:1. The content and composition of flavolignans isolated from defatted seeds and the content of total protein in the meal were found.     

Improvement of a solid phase extraction method for analysis of lipid fractions in muscle foods

The most used method for muscle lipid fractionation into major lipid classes was modified for improving its separation efficiency. Extracted lipids from a masseter muscle of one Iberian pig were separated into neutral lipids (NL), free fatty acids (FFA) and polar lipids (PL) using aminopropyl minicolumns, following the extensively used method of Kaluzny et al. [1] (old method-OM-) and a method based on that, developed by Pinkart et al. [2] with some (modifications modified method–MM). Obtained lipid classes were further analysed by TLC and lipid fractions were identified. TLC evidenced the presence of a certain amount of PL in the NL fraction obtained with the OM. On the other hand, using the MM only an almost undetectable presence of PL was evidenced in the NL fraction. Fatty acid composition of NL, PL and FFA obtained with each method was studied by gas chromatography. Fatty acid profile of NL was strongly influenced by the separation method used. Thus, NL obtained using the OM showed higher amounts of saturated fatty acids (SFA) and polyunsaturated fatty acids (PUFA) and lower of monounsaturated fatty acids (MUFA) than those obtained using the MM. Moreover, NL obtained using the OM showed the presence of fatty alcohols, constituents of phospholipids (PhL) absent or present only in trace amounts in acylglycerols. This profile reflects the coelution of PL in the NL fraction. Fatty acid profile of FFA and PL fractions was also influenced by the solid phase extraction (SPE) method used, but to a lesser extent.     

Lipids Containing Polyunsaturated Fatty Acids Synthesized by Zygomycetes Grown on Glycerol

Several strains of Zygomycetes cultivated on glycerol produced mycelia rich in lipids containing higher amounts of neutral lipids (NL) than glycolipids plus sphingolipids and phospholipids (P), while biosynthesis of P in Mortierella ramanniana, Mucor sp., and Cunninghamella echinulata occurred though NL accumulation process was in progress. Polyunsaturated fatty acids (PUFA) concentration gradually decreased in all lipid fractions of M. ramanniana during growth. In contrast, in C. echinulata concentration of both linoleic and γ-linolenic acids increased with time, especially in P. Taking for granted that the main function of PUFA is associated to their participation in mycelial membranes, we could suppose that biosynthesis of these fatty acids is associated to mycelial growth. However, this is accurate only for some Zygomycetes, e.g., M. ramanniana. On the contrary, PUFA biosynthesis in C. echinulata persists after growth cessation, suggesting that in this species biosynthetic ability is not a strictly growth-associated process. Phosphatidyl-inositol and phosphatidyl-choline were the major P classes in C. echinulata and M. ramanniana, respectively. In M. ramanniana, a decrease of PUFA concentration was noticed even when mycelia were incubated in low temperature (conditions that normally favor PUFA biosynthesis), indicating that PUFA biosynthesis in this fungus is associated to primary metabolism.     

Lipids from <Emphasis Type="Italic">Halostachys caspica</Emphasis> and <Emphasis Type="Italic">Halocharis hispida</Emphasis>

The composition of lipids from the aerial parts of two species of halophytes from the family Chenopodiaceae, Halostachys caspica C. A. Mey. and Halocharis hispida Bge. was determined. Neutral lipids (NL, 62.1 and 54.2%, respectively) dominated the total lipids (TL) of these plants. More than a third of the NL were esters of aliphatic alcohols and phytosterols (FAE). Fatty acids 16:0, 18:1, and 18:2 dominated the acids of FAE; 16:0, 18:1, and 18:3, the phospholipids. The principal fatty acids of glycolipids were unsaturated acids (68.3 and 75.1%) with linolenic acid dominating (44.9 and 43.5%). Presented at the 7th International Symposium on the Chemistry of Natural Compounds, Tashkent, October 16–18, 2007. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 276–278, May–June, 2009.     

Lipids from leaves ofEphedra equizetina

The content and composition by class and fatty acid of neutral (NL), glyco- (GL), and phospholipids (PL) in leaves ofEphedra equizetina Bunge (Ephedraceae) are determined. The acid composition of NL, GL, and PL includes saturated 12∶0–32∶0 acids and unsaturated 15∶1, 16∶1, 18∶1, 18∶2, and 18∶3 acids. Unsaponified components of the total lipids also contained biologically active substances such as α-tocopherol, carotenoids, high-molecular-weight fatty alcohols, triterpenes, and sterols. Academician S. Yu. Yunusov Institute of the Chemistry of Plant Substances. Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (371) 120 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 718–721, November–December, 1999.     

Integrative Chemical Biology Approaches for Identification and Characterization of “Erasers” for Fatty‐Acid‐Acylated Lysine Residues within Proteins

Acylation of proteins with fatty acids is important for the regulation of membrane association, trafficking, subcellular localization, and activity of many cellular proteins. While significant progress has been made in our understanding of the two major forms of protein acylation with fatty acids, N‐myristoylation and S‐palmitoylation, studies of the acylation of lysine residues, within proteins, with fatty acids have lagged behind. Demonstrated here is the use of integrative chemical biology approaches to examine human sirtuins as de‐fatty‐acid acylases in vitro and in cells. Photo‐crosslinking chemistry is used to investigate enzymes which recognize fatty‐acid acylated lysine. Human Sirt2 was identified as a robust lysine de‐fatty‐acid acylase in vitro. The results also show that Sirt2 can regulate the acylation of lysine residues, of proteins, with fatty acids within cells.     

Polyunsaturated fatty acids from several plant species of the family Boraginaceae

Lipids from seeds of the plants Cynoglossum officinale (1), Echium vulgare (2), and Lappula squarrosa (3) of the family Boraginaceae growing in the Republic of Bashkortostan were studied. Four polyunsaturated acids, linoleic (LA), γ-linolenic (GLA), α-linolenic (ALA), and stearidonic (SA), were identified among the fatty acids. The principal acids of the neutral lipids (NL) were 18:1 and 18:2 in 1, ALA in 2 and 3, and GLA in approximately equal amounts in all three samples. The highest amount of SA (16.8 %) was found in 3. Unsaponified components of NL samples were identified by GC/MS. Alkaloids were observed in the pulp and polar lipids.     

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.     

Analysis of the Dynamic Decomposition of Unsaturated Fatty Acids and Tocopherols in Commercial Oils During Deep Frying

The decomposition of unsaturated fatty acids and tocopherols in 10 commercial edible oils during deep frying was investigated. The dominant tocopherol in oils rich in polyunsaturated fatty acids (PUFAs) was γ-tocopherol, except for natural perilla oil (δ-tocopherol dominant), and the main tocopherol in oleic acid-rich oils was α-tocopherol. The PUFA-rich oils had higher tocopherol contents than the oleic acid-rich oils. Both the reduction rate of total unsaturated fatty acid (TUFA) and total tocopherol (TToc) were linear with frying time (t). The decomposition rate of TToc is faster than that of TUFA since the slope values obtained from fitting equations (Y?=?k t) k_TToc (1.520–14.483) were obviously larger than for k_TUFA (0.155–0.270). By establishing a dynamic decomposition index, unsaturated fatty acids and tocopherol in oils showed dynamic decomposition over multiple frying cycles. The obtained results showed that decomposition characteristics of oils are related to their fatty acid compositions.     

A Novel Labeling Reagent of 2-(12-Benzo[b]acridin-5-(12H)-yl)-acetohydrazide for Determination of Saturated and Unsaturated Fatty Acids in Traditional Chinese Herbs by HPLC-APCI-MS

A new fluorescence labeling reagent 2-(12-benzo[b]acridin-5(12H)-yl)-acetohydrazide (BAAH) has been designed for fatty acids labeling. Eleven fatty acids containing seven saturated and four unsaturated fatty acids were used to evaluate the analytical potential of this reagent. The labeling reaction of BAAH with fatty acids was completed at 85 °C for 60 min using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC·HCl) as the condensing agent. Separation of the derivatized fatty acids was carried out on a reversed-phase Thermo Hypersil Gold C18 column (4.6 mm × 250 mm, 5 μm) in combination with a gradient elution with a good baseline resolution. The fluorescence excitation and emission wavelengths were set at λ_ex 280 and λ_em 510 nm, respectively. The identification was carried out by the online APCI-MS in positive-ion detection mode. Linear correlation coefficients for all fatty acid derivatives were of >0.9994. Detection limits, at a signal-to-noise ratio of 3:1, were 3.89–12.5 nmol L⁻¹ for the labeled fatty acids. The developed method was successfully applied to the accurate determination of fatty acids in five traditional Chinese herbs with satisfactory results.

     

Separation of dietary omega‐3 and omega‐6 fatty acids in food by capillary electrophoresis

A lower dietary omega‐6/omega‐3 (n‐6/n‐3) fatty acid ratio (<4) has been shown to be beneficial in preventing a number of chronic illnesses. Interest exists in developing more rapid and sensitive analytical methods for profiling fatty acid levels in foods. An aqueous CE method was developed for the simultaneous determination of 15 n‐3 and n‐6 relevant fatty acids. The effect of pH and concentration of buffer, type and concentration of organic modifier, and additive on the separation was investigated in order to determine the best conditions for the analysis. Baseline separations of the 15 fatty acids were achieved using 40 mM borate buffer at pH 9.50 containing 50 mM SDS, 10 mM β‐cyclodextrin, and 10% acetonitrile. The developed CE method has LODs of <5 mg/L and good linearity (R² > 0.980) for all fatty acids studied. The proposed method was successfully applied to the determination of n‐3 and n‐6 fatty acids in flax seed, Udo® oils and a selection of grass‐fed and grain‐fed beef muscle samples.     

LC‐MS identification of derivatized free fatty acids from adipocere in soil samples

Free fatty acids were derivatized as amides (DFFA) by reaction with (R)‐(+)‐1‐phenylethylamine, using a simple, fast and robust reaction scheme. A HPLC method with diode array and ESI MS detection was developed for the analysis of the derivatized substances. Six fatty acids were used in the method development: myristic, linoleic, palmitic, oleic, margaric and stearic acids. Under these conditions the elution of the DFFA are well resolved with retention times raging from 6.9 to 16.0 min. Fatty acids were extracted from cemetery soil and from adipocere formation experimental soils using a Soxhlet extraction, using as solvent ether/dichloromethane (1:1). Each DFFA is characterized by three m/z peaks: molecular weight of the substance; molecular weight of a dimer of the substance; the molecular weight of the dimer plus the atomic mass of sodium. The analysis of soil samples detected the six fatty acids used in the method developed plus palmitoleic and pentadecanoic. Beside this set of eight fatty acids other 13 fatty acids were detected in trace quantities or only in some soils and some were tentatively assigned as: 10‐hydroxystearic, myristoleic, heptadecenoic and arachidic acids.     

Fatty acid composition of some Astragalus species from Turkey

In this study, the fatty acid contents of some Astragalus L. (Fabaceae) species from Turkey were determined by GC and GC-MS techniques. The seed oils of Astragalus sp. (A. echinops Aucher ex. Boiss., A. subrobustos Boriss., A. jodostachys, Boiss. & Buhse., A. falcatus Lam., A. fraxinifolius DC.) contained linolenic (between 23–41.%), linoleic (23–37%), and oleic acids (8–19%) as the major components. Fatty acid composition of the studied Astragalus taxa showed uniform fatty acid patterns. Palmitic and stearic acids were the major saturated fatty acids in the seed oils. The amounts of unsaturated fatty acids were higher than saturated fatty acids. Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 526–528, November–December, 2006.     

Functional properties and fatty acids profile of different beans varieties

Dried seeds of four varieties of Phaseolus vulgaris, three of Vigna unguiculata ssp. unguiculata and two of Vigna angularis grown and marketed in Italy, Mexico, India, Japan, Ghana and Ivory Coast were analysed for fatty acids content. In oils from seeds of P. vulgaris, the main fatty acids were linolenic (34.7–41.5%) and linoleic (30.7–40.3%), followed by palmitic (10.7–16.8%). The first three aforementioned fatty acids in the lipid fraction of V. unguiculata varieties were 28.4, 28.7 and 26.2%, respectively; while in V. angularis varieties, main fatty acids were linoleic (36.4–39.1%) and palmitic (26.9–33.3%), followed by linolenic (17.9–22.2%). Statistical analyses indicate that botanical species play a rule in bean fatty acids distribution, while the same was not verified for geographical origin. Furthermore, the atherogenic index (AI) and the thrombogenic index (TI) were investigated for health and nutritional information. The results showed that these wide spread legumes have functional features to human health.     

Decrease of glutathione and fatty acids during iron-induced lipid peroxidation inEhrlich ascites tumor cells

In order to investigate a possible relationship between the intensity of lipid peroxidation (LP) in tumor cells and their proliferative activity various methods to quantify LP are desirable. In this study the decrease in the contents of fatty acids and glutathione was measured by established methods inEhrlich ascites tumor (EAT) cellsin vitro, in which LP was stimulated by the addition of ferrous iron, either as free ion or as histidinate chelate.When EAT cells were incubated for 30 min at 37 °C in the presence of 5 mM FeSO₄ the following changes were observed in comparison to appropriate control cells: The content of reduced glutathione (GSH) and total glutathione (GSH+2 GSSG) decreased significantly by 24 and 30% respectively. The decrease of 4 unsaturated (C 18:1; C 18:2; C 20:4; C 22:6) and 2 saturated fatty acids (C 16:0; C 18:0) by about 15% on the average was statistically significant only for C 16:0 and C 20:4).More pronounced effects were observed with 5 mM Fe(II)-histidinate. GSH and GSH+2 GSSG decreased by 54% and 40%, resp. The decrease of fatty acids by about 40% on the average was significant for all of the 6 fatty acids tested. These results are in agreement with previous studies on LP in EAT cells showing Fe(II)-histidinate to be a more powerful promoter of LP compared with free ferrous ion. The observation, that the content not only of GSH but also of total glutathione was decreased in iron-treated tumor cells is in contradiction to the hypothesis that GSH may act as a mere redox mediator of LP under the conditions used and points to a consumption of GSH by several possible pathways. The finding of decreased levels of unsaturated as well as saturated fatty acids in the presence of Fe(II)-histidinate underlines the extraordinary potency of iron as an initiator and catalyst of LP.This work was supported by the Association for International Cancer Research, St. Andrews, U.K.     

Evaluation of gas chromatographic methods for the determination of <Emphasis Type="Italic">trans</Emphasis> fat

Consumption of trans fat has been associated with increased risk of coronary heart disease. For nutrition labeling purposes, the US Food and Drug Administration (FDA) defines trans fat as the sum of all the fatty acids with at least one nonconjugated double bond in the trans configuration. The FDA regulation states that label declarations of trans fat are not required for products that contain less than 0.5 g of trans fat per serving if no claims are made about fat, fatty acids or cholesterol. While attenuated total reflection Fourier-transformed infrared spectroscopy (ATR-FT-IR) provides reproducible measurements for samples containing more than 5% trans fat, methods based on gas chromatography (GC) are needed to measure lower trans fat levels. Trans fat quantitation by GC has recently been updated by considering more fatty acids, focusing more attention on fatty acids present in low amounts, and by using 100-m high-polarity capillary columns for optimal separation. The consistently high interlaboratory relative standard deviations (RSD, e.g., 21% at 1% trans fatty acids (TFA), 60% at 0.17% TFA), and intralaboratory RSD values (e.g., 10% at 1% TFA, 16% at 0.17% TFA) for trans fat at 1% or less of total fat reported in the collaborative study data for American Oil Chemists Society Official Method Ce 1h-05 suggest the need to carefully define the parameters associated with GC analysis of fatty acids.     

Determination of 30 Free Fatty Acids in Two Famous Tibetan Medicines by HPLC with Fluorescence Detection and Mass Spectrometric Identification

A simple and sensitive high-performance liquid chromatographic (HPLC) method with fluorescence detection and mass spectrometric identification has been developed for analysis of 30 long-chain and short-chain free fatty acids (FFAs). The fatty acids were derivatized to their esters with 1-[2-(p-toluenesulfonate)ethyl]-2-phenylimidazole-[4,5-f]-9,10-phenanthrene (TSPP) in N,N-dimethylformamide (DMF) at 90 °C with anhydrous K₂CO₃ as catalyst. A mixture of C₁–C₃₀ fatty acids was completely separated within 60 min by gradient elution on a reversed-phase C₈ column. Qualitative identification of the acids was performed by atmospheric-pressure chemical ionization mass spectrometry (APCI–MS) in positive-ion mode. The fluorescence excitation and emission wavelengths were 260 and 380 nm, respectively. Quantitative determination of the 30 acids in two Tibetan medicines Gentiana straminea and G. dahurica was performed. The results indicated that the medicines contained many FFAs. Linear correlation coefficients for the FFA derivatives were >0.9991. Relative standard deviations (RSDs, n = 6) for the fatty acid derivatives were <3%. Detection limits (at a signal-to-noise ratio of 3:1) were 3.1–38 fmol. When the fatty acid derivatives were determined in the two real samples results were satisfactory and the sensitivity and reproducibility of the method were good.     

Determination of fatty acids in the seeds of Lepidium apetalum Willdenow,Descurainia sophia (L.) Webb ex Prantl,and Draba nemorosa L. by ultra-high-performance liquid chromatography equipped with a charged aerosol detector

Both the contents of fatty acids and the ratios of unsaturated to saturated fatty acids are important parameters for determining the nutritional values of oils. Thus, we herein evaluated the fatty acids present in the seed oils of Lepidium apetalum Willdenow, Descurainia sophia (L.) Webb ex Prantl, and Draba nemorosa L. as sources of Lepidii seu Descurainiae Semen seeds in Northeast Asian Countries. We developed a method based on ultra-high-performance liquid chromatography using a charged aerosol detector for the quantitative analysis of fatty acids in the seed oils. This technique is less time-consuming than previous methods as derivatization of the oils is not required. Our method was developed though the comparison of a UV detector with a charged aerosol detector, and various stationary phases and gradient programs were tested. In addition, method validation was carried out according to the International Conference on Harmonization guidelines with respect to linearity, precision, and accuracy. We found that the quantities of unsaturated fatty acids (6.051–282.376?mg/g) were higher than those of saturated fatty acids (0.855–12.548?mg/g) in all plant seed oils. The proposed method is reproducible and convenient, and therefore, is suitable for the quantitative analysis of fatty acids in plant oils.     

Antioxidant activity and fatty acids quantification in Sicilian purslane germplasm

Abstract

Portulaca oleracea is an annual succulent herb in the family Portulacaceae. It is a nutritious vegetable with high antioxidant properties and, it is among the richest plant source of ω-3 fatty acids, as well as a rich source of ω-6 fatty acids, ascorbic acid, tocopherols and beta-carotene. In the present study, three purslane populations under different Mediterranean environmental conditions for two years, for future valorization as novel food sources of omega-3 fatty acids, were evaluated. In particular, biomorphological characteristics, total phenols and fatty acids content were determined. The antioxidant activities were evaluated using 2,2-diphenyl-1-picrylhydrazyl assay. The population “Cas” appears to have higher antioxidant activity than the other two populations (“Cal” and “S. Ven”).The saturated fatty acid content is influenced only by the year of collection, while the polyunsaturated fatty acid by the populations. The most abundant unsatured fatty acids are linoleic and linolenic acids and “Cas” attained the highest contents.     

Seed Oil Fatty Acids of Mongolian Compositae: The trans‐Fatty Acids of Heteropappus hispidus,Asterothamnus centrali‐asiaticus and Artemisia palustris

Seed oils from the Compositae plant family are known to contain a variety of unusual fatty acids. Subsequent to the recent discovery of γ‐linolenic acid in Saussurea and Youngia, further Mongolian Compositae species were investigated for their seed oil fatty acid composition. A number of δ3trans‐fatty acids (16 : 1δ3t, 18 : 1δ3t and 18 : 3δ3t, 9c, 12c) were found in the seed oils of Heteropappus hispidus and Asterothamnus centrali‐asiaticus. The latter fatty acid, but not the trans‐monoenes, was also found in one species of Artemisia. These unusual fatty acid isomers were characterized by capillary gas‐liquid chromatographic (GLC) separations in combination with other chromatographic techniques (analytical thin layer chromatography, TLC and preparative argentation TLC), and infrared spectrocsopy (IR). Their identity was further confirmed by co‐chromatography with other seed oils known to contain these trans‐fatty acids. The fact that within the Compositae plant family there are apparently two or three distinct groups of genera containing δ3trans‐fatty acids is discussed.