Serum fatty acid profiles and potential biomarkers of ankylosing spondylitis determined by gas chromatography–mass spectrometry and multivariate statistical analysis

Ankylosing spondylitis (AS) is a common chronic inflammatory rheumatic disease. Early and accurate detection is essential for effective disease treatment. Recently, research has focused on genomics and proteomics. However, the associated metabolic variations, especially fatty acid profiles, have been poorly discussed. In this study, the gas chromatography–mass spectrometry (GC‐MS) approach and multivariate statistical analysis were used to investigate the metabolic profiles of serum free fatty acids (FFAs) and esterified fatty acids (EFAs) in AS patients. The results showed that significant differences in most of the FFA (C12:0, C16:0, C16:1, C18:3, C20:4, C20:5, C22:5 and C22:6) and EFA (C12:0, C16:1, C18:0, C18:1, C18:2, C18:3, C20:4 and C22:6) concentrations were found between the AS patients and healthy controls (p < 0.05). Principal component analysis and partial least squares discriminant analysis were performed to classify the AS patients and controls. Additionally, FFAs C20:4, C12:0, C18:3 and EFAs C22:6, C12:0 were confirmed as potential biomarkers to identify AS patients and healthy controls. The present study highlights that differences in the serum FFA and EFA profiles of AS patients reflect the metabolic disorder. Moreover, FFA and EFA biomarkers appear to have clinical applications for the screening and diagnosis of AS. Copyright © 2014 John Wiley & Sons, Ltd.     

Change of Lipid Composition of Mucor miehei as a Function of Cultivation Temperature

Lipids of the thermophilic fungus Mucor miehei,strain UzLT-3, cultivated at 26 and 42 C are studied. The lipids of this strain contain isomeric 18:2 (9,12) and (6,9) fatty acids and polyene acids - and -18:3, which are uncharacteristic of thermophilic fungi. Cultivation at 26°C increases the fraction of phospholipids (PL), glycolipids (GL), and isomeric 18:3 fatty acids in the total lipids. It is hypothesized that the liquid-crystalline state of the membranes of this strain at reduced temperature are due to activation of desaturases ¹² and ¹⁵ and possibly ⁶ , which are present in the fungus and participate in the biosynthesis of unsaturated acyl lipids.     

在线热辅助甲基化-气相色谱法分析棉籽仁中的脂肪酸组成

建立了分析棉籽仁中脂肪酸组成的在线热辅助甲基化-气相色谱法。将0.3 mg棉籽仁样品与2 μ L三甲基氢氧化硫（0.2 mol/L）加入裂解器,在350℃下进行甲基化反应,通过气相色谱仪进行分离分析,共检测到8种脂肪酸甲酯成分,分别为亚油酸（C18：2）、油酸（C18：1）、棕榈酸（C16：0）、硬脂酸（C18：0）、肉豆蔻酸（C14：0）、棕榈油酸（C16：1）、花生酸（C20：0）和二十二酸（C22：0）,不饱和脂肪酸的相对含量为66.30%~72.54%,其中亚油酸的相对含量为43.20%~53.61%,相对峰面积的相对标准偏差（RSD）小于10%（n=5）。通过分析5组棉籽仁样品与3种食用油中的脂肪酸组成,结果表明不同产地的棉籽仁中的脂肪酸组成差异不明显,且棉籽仁中的脂肪酸组成与玉米油最为接近,相似度为0.960~0.992。该方法简单、快速、准确,适合分析棉籽仁中的脂肪酸组成。     

Characterization of the Fatty Acid Composition in Cultivated Atlantic Bluefin Tuna (Thunnus thynnus L.) Muscle by Gas Chromatography-Mass Spectrometry

Abstract

A previously established gas chromatography-mass spectrometry method was applied for the determination of the fatty acid composition in the muscles of Atlantic bluefin tuna (Thunnus thynnus L). The fish were collected in the Mediterranean Sea and cultivated for several months. The goal of the study was to demonstrate the feasibility of these measurements and to improve knowledge about the influence of size and gender on the fatty acid composition. Although no significant differences were found with respect to gender, males and females showed different correlations of fatty acid composition with weight. In the males, a statistically significant linear correlation was found for 14:0, 16:0, 18:1n9, 20:1n9, 22:1n9 (positive correlation), and for 20:4n6, 20:5n3 22:6n3 (negative correlation). In the females, a statistically significant polynomial correlation for specific fatty acids was highlighted: specimens with medium size showed the lowest content of 20:1n9 and 22:1n9 and the highest content of 20:4n6, 20:5n3, and 22:6n3. Therefore, males smaller than 150?kg and females from 150 to 250?kg appeared to have the highest greater nutritional value. This study demonstrated the practicality of the analytical methodology and enhanced the knowledge of the influence of size on the fatty acid composition of Atlantic bluefin tuna muscle, reporting a newly established gender difference and representing a starting point to produce the best nutritional characteristics for farmed tuna.     

Determination of cuticular and internal fatty acids of Chorthippus brunneus males and females using HPLC‐LLSD and GC–MS

Insects are of growing significance in veterinary medicine and human healthcare; therefore, an understanding of their biology is very important. The cuticular and internal fatty acid compositions of Chorthippus brunneus males and females have been studied for the first time. The lipids of males and females were separated into classes of compounds using high‐performance liquid chromatography with a laser light scattering detector. The free fatty acid (FFA) fractions obtained by HPLC were silylated and then analyzed by GC–MS. The cuticular lipids of males contained 15 saturated, four unsaturated with even‐numbered and two unsaturated with odd‐numbered carbon chains, FFAs ranging from C8 to C25. The major free fatty acids in males were C16 (20.8%), C18:2 (8.5%), C18:1 (32.9%) and C18 (24.4%). The cuticular lipids of females contained 17 saturated, four monounsaturated and two diunsaturated free fatty acids ranging from C8 to C30. The major cuticular fatty acids in females were C16 (25.1%), C18:2 (6.2%), C18:1 (23.7%) and C18:0 (33.2%). The internal FFAs of males consisted of 20 compounds ranging from C8 to C26. Four of these compounds were detected as major compounds: C16 (14.1%), C18:2 (21.6%), C18:1 (38.0%) and C18 (22.5%). Among 18 internal free fatty acids of females, C16 (22.3%), C18:2 (10.9%), C18:1 (40.2%) and C18 (20.5%) were the most abundant compounds. The following cuticular fatty acids present in the lipids of females were absent in the lipids of males: C26, C27 and C30. On the other hand, only C24 was absent from the cuticular lipids of females. Only C10 and C24 internal fatty acids present in the lipids of males were absent in the lipids of females. Copyright © 2016 John Wiley & Sons, Ltd.     

碱催化法衍生化气相色谱/质谱法分析青海湖裸鲤鱼油中的脂肪酸

用碱催化法将青海湖裸鲤鱼油甲酯化,以气相色谱/质谱法分析鱼油中的脂肪酸。青海湖裸鲤可食用部分中鱼油含量为25.13%。从鱼油中共鉴定出47种脂肪酸,包括直链、单支链、多支链饱和脂肪酸,单不饱和、多不饱和脂肪酸,环丙烷基、呋喃基脂肪酸等。不饱和脂肪酸含量为73.6%,其中多不饱和脂肪酸含量为25.4%,以C18∶2(4.9%),C18∶3(3.1%),C20∶4(1.3%),C20∶5(二十碳五烯酸（EPA）, 9.4%)和C22∶6(二十二碳六烯酸（DHA）, 6.7%)为主。单不饱和脂肪酸含量为48.2%,主要由C16∶1(20.3%),C18∶1(25.9%)构成。饱和脂肪酸含量为25.7%,主要有C14∶0(3.4%),C16∶0 (19.4%)和C18∶0(1.1%)。青海湖裸鲤鱼油中还存在不常见的环丙烷基和呋喃基脂肪酸及多种奇数碳链和支链脂肪酸。因此,青海湖裸鲤是功能性脂肪酸的重要膳食来源。     

牙菌斑有机酸的气相色谱-质谱分析

采用ＧＣ／ＭＳ联用技术分析了正常人牙菌斑内有机酸成分。发现了１４种有机酸,其中有８种直链饱和脂肪酸、４种直链非饱和脂肪酸、２种芳香酸。含量最多的是Ｃ１６∶０,Ｃ１８∶０,Ｃ１８∶１３种脂肪酸。其中苯乙酸、苯丙酸及十五碳酸等３种成分是第１次在牙菌斑中检测出。     

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.     

Fatty Acids from the Sponge <Emphasis Type="Italic">Tedania dirhaphis</Emphasis>

The fatty acid (FA) composition of total lipids from the marine sponge Tedania dirhaphis from the Sea of Okhotsk was studied. GC and GC-MS identified 50 acids, particular attention being paid to components with 14–22 C atoms. Acids 16-Me-19:0, 10,14-Me₂-15:1(Δ6), 18:1(Δ6), 18:1(Δ8), and 22:1(Δ16) were observed and identified for the first time in sponges. The main FA in lipids from T. dirhaphis was 28:3(Δ5,9,21), the relative content of which reached 63.3%.__________Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 233–236, May–June, 2005.     

Comparative study on fatty acid composition of olive (Olea europaea L.), with emphasis on phytosterol contents

The present study was designed to determine the fatty acid composition and phytosterol contents of Turkish native olive cultivars, namely Kilis Yağlık and Nizip Yağlık cv. In this context, olive fruits from 34 locations were sampled and then screened for their components in comparison. Fifteen different fatty acids were found in both olive oils. In the order of abundance, the most important ones were oleic acid (18:1) > palmitic acid (16:0) > linoleic acid (18:2) > stearic acid (18:0). Significant differences were observed in the contents of oleic acid (18:1), palmitic acid (16:0), linoleic acid (18:2) but not for stearic acid content in comparison both oils (p < 0.01). There were significant differences in terms of unsaturated fatty acids, saturated fatty acids and polyunsaturated fatty acids (p < 0.01). The seven phytosterols – cholesterol, campesterol, stigmasterol, β ‐sitosterol, Δ‐5‐avenasterol, Δ‐7‐stigmastenol and Δ‐7‐avenasterol – were studied in both oil sources. The predominant sterols were β ‐sitosterol, Δ5‐avenasterol and campesterol in the samples analysed. However, no significant differences were found in the levels of the phytosterols between the two olive cultivars.     

Survival of Freeze-dried Leuconostoc mesenteroides and Lactobacillus plantarum Related to Their Cellular Fatty Acids Composition during Storage

Lactic acid bacteria strains Lactobacillus plantarum CWBI-B534 and Leuconostoc ssp. mesenteroïdes (L. mesenteroïdes) Kenya MRog2 were produced in bioreactor, concentrated, with or without cryoprotectants. In general, viable population did not change significantly after freeze-drying (p?>?0.05). In most cases, viable population for cells added with cryoprotectants was significantly lower than those without (p?16:0), palmitoleic (C_16:1), stearic (C_18:0), oleic (C_18:1), linoleic (C_18:2), and linolenic (C_18:3) acids were identified. Four of them, C_16:0, C_16:1, C_18:0, and C_18:1, make up more than 94% or 93% of the fatty acids in L. mesenteroides and L. plantarum, respectively, with another one, namely, C18:3, making a smaller (on average 5–6%, respectively) contribution. The C_18:2 contributed very small percentages (on average?≤?1%) to the total in each strain. C_16:0 had the highest proportion at most points relative to other fatty acids. Moisture content and water activity (a _w) increased significantly during the storage period. It was observed that C_16:1/C_16:0, C_18:0/C_16:0 and C_18:1/C_16:0 ratios for freeze-dried L. mesenteroides or L. plantarum, with or without cryoprotectants, did not change significantly during the storage period. According to the packaging mode and storage temperatures, C_18:2/C_16:0 and C_18:3/C_16:0 ratios for freeze-dried L. mesenteroides and L. plantarum with or without cryoprotectants decreased as the storage time increased. However, a higher C_18:2/C_16:0 or C_18:3/C_16:0 ratio for L. mesenteroides and L. plantarum was noted in the freeze-dried powder held at 4 °C or under vacuum and in dark than at 20 °C or in the presence of oxygen and light.     

Profiling of ornithine lipids in bacterial extracts of Rhodobacter sphaeroides by reversed-phase liquid chromatography with electrospray ionization and multistage mass spectrometry (RPLC-ESI-MS)

Ornithine lipids (OLs), a sub-group of the large (and of emerging interest) family of lipoamino acids of bacterial origin, contain a 3-hydroxy fatty acyl chain linked via an amide bond to the α-amino group of ornithine and via an ester bond to a second fatty acyl chain. OLs in extracts of Rhodobacter sphaeroides (R. sphaeroides) were investigated by high-performance reversed phase liquid chromatography (RPLC) with electrospray ionization mass spectrometry (ESI-MS) in negative ion mode using a linear ion trap (LIT). The presence of OLs bearing both saturated (i.e, 16:0, 17:0, 18:0, 19:0 and 20:0) and unsaturated chains (i.e., 18:1, 19:1, 19:2 and 20:1) was ascertained and their identification, even for isomeric, low abundance and partially co-eluting species, was achieved by low-energy collision induced dissociation (CID) multistage mass spectrometry (MSⁿ, n = 2–4). OLs signatures found in two R. sphaeroides strains, i.e., wild type 2.4.1 and mutant R26, were examined and up to 16 and 17 different OL species were successfully identified, respectively. OLs in both bacterial strains were characterized by several combinations of fatty chains on ester-linked and amide-linked 3-OH fatty acids. Multistage MS spectra of monoenoic amide-linked 3-OH acyl chains, allowed the identification of positional isomer of OL containing 18:1 (i.e. 9-octadecenoic) and 20:1 (i.e. 11-eicosenoic) fatty acids. The most abundant OL ([M−H]⁻ at m/z 717.5) in R. sphaeroides R26 was identified as OL 3-OH 20:1/19:1 (i.e., 3-OH-eicosenoic acid amide-linked to ornithine and esterified to a nonadecenoic chain containing a cyclopropane ring). An unusual OL (m/z 689.5 for the [M−H]⁻ ion), most likely containing a cyclopropene ester-linked acyl chain (i.e., OL 3-OH 18:0/19:2), was retrieved only in the carotenoidless mutant strain R26. Based on the biosynthetic pathways already known for cyclopropa(e)ne ring-including acyl chains, a plausible explanation was invoked for the enzymatic generation of this ester-linked chain in R. sphaeroides.     

Simultaneous quantification of total eicosapentaenoic acid,docosahexaenoic acid and arachidonic acid in plasma by high‐performance liquid chromatography–tandem mass spectrometry

A method for the simultaneous quantification of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and arachidonic acid (AA) in human plasma by HPLC–tandem mass spectrometry (HPLC‐MS/MS) was developed and validated. Free and esterified forms of fatty acids were hydrolysed from plasma samples in the presence of an internal standard and subjected to liquid–liquid extraction. The chromatographic run time was 3.5 min per sample. The assay was linear from 0.5 to 300 mg/L (r² > 0.997, n = 18). Based on matrix addition, accuracy deviation was <15%, except for AA at 10 mg/L (30–90%), whereas precision was <8% for all fatty acids studied. The method was applied to the measurement of these omega‐3 fatty acids in a fish oil supplement study with healthy volunteers. Healthy males (n = 4) were administered a supplement containing 465 mg EPA and 375 mg DHA per capsule (Omacor®). A dose of two capsules was given daily over a 4 week period. Pre‐treatment concentrations varied between subjects for EPA (17–68 mg/L), DHA (36–63 mg/L) and AA (121–248 mg/L). During the dosing period EPA increased 460–480% from the baseline concentration, while DHA increased 150–160%. The EPA–AA ratio increased from 0.07–0.56 to 0.3–3.1 after 4 weeks of dosing. In conclusion, the method described could be suitable for monitoring EPA, DHA and AA in clinical studies that may aid in achieving optimal concentrations of these fatty acids in patients who could be at risk of sudden cardiac death. Copyright © 2010 John Wiley & Sons, Ltd.     

Lipids and lipophilic components of Viburnum opulus fruits during maturation

The variation of the composition of neutral and polar lipids and lipophilic components during maturation of guelder rose (V. opulus L., fam. Caprifoliaceae) fruits was investigated. During fruit ripening, all lipid groups are accumulated, the highest accumulation rate being observed in the first period of maturation. In nonpolar lipids, this is due to a substantial increase in the content of triacylglycerides, whereas the contents of free fatty acids, methyl esters of fatty acids, monoacylglycerides, and especially esters of triterpenoid compounds decrease. During early maturation, all acyl-containing classes of lipids contain large amounts of saturated fatty acids (mainly, 16:0), whose content decreases during ripening, while the contents of unsaturated 18:1 and 18:2 acids increase.     

大鼠肝过氧化物酶体中脂肪酸的分析

 用双 (2 乙基己基 )酚酞酸酯 (DEHP)诱导大鼠肝过氧化物酶体增殖 ,再用蔗糖密度梯度离心法分离大鼠肝细胞过氧化物酶体 ,并用十七烷酸作内标 ,以毛细管气相色谱法在非极性SPB 1石英毛细管柱上对其中的 11种脂肪酸进行分离测定。正常组和诱导组的大鼠肝过氧化物酶体中的不饱和脂肪酸和长链脂肪酸所占总脂肪酸的比例及总脂肪酸的统计结果是 :诱导组的不饱和脂肪酸的含量高于正常组的 (P <0 0 5 ) ,而两个组的脂肪酸总量及长链脂肪酸的含量无明显差别。结果提示 :诱导组的大鼠肝过氧化物酶体的脂肪酸成分发生了变化 ,其膜结构与正常组的不相同。     

Analysis of plasma free fatty acid cyanomethyl derivatives by GC-NPD for the diagnosis of mitochondrial fatty acid oxidation disorders

Summary Early diagnosis of fatty acid oxidation (FAO) disorders is important to reduce severe morbidity and mortality. Although analysis of plasma free fatty acids (FFAs) is frequently performed using stable isotope-dilution gas chromatography-mass-spectrometry (GC-MS), there are institutions where the required instrumentation is not available to support a rapid work-up of acutely ill patients. For this reason, we have developed a novel cyanomethyl derivatization method for FFAs which is followed by GC analysis of the resulting esters using nitrogen-phosphorus detector (NPD) for the rapid diagnosis of mitochondrial fatty acid oxidation disorders. FFAs were extracted from plasma and derivatized to the cyanomethyl ester by heating with bromoacetonitrile at 60°C for 30 min GC-NPD analysis was then performed. The mean recoveries of C6:0-C18:0FFAs were between 87% abd 96%. The method detection limits (S/N=3) were 0.1–0.5 ng for C6:0-C14:0 FFAs, and 0.001–0.01 ng for C16:0-C18:0 FFAs. We succesfully performed differential diagnosis of representative FAO disorders from the confimed patient's plasmas. This simple method offers cost-effective and time-saving alternative to GC-MS for the biochemical diagnosis of selected FAO disorders.     

Determination of free fatty acids in milk and cheese procedures for extraction,clean up,and capillary gas chromatographic analysis

A rapid, reliable and precise capillary gas chromatographic method for routine quantification of short- and long-chain free fatty acids (FFA) in milk and cheese is described. Procedures of (1) lipid extraction, (2) isolation of the FFA from milk and cheese extracts, and (3) capillary gas chromatographic analysis were developed and optimized. FFA can be extracted from cheese for 95–100% with ether-heptane after grinding with sodium sulfate and addition of 2.5 M sulfuric acid. From milk, 95–100 % of the FFA (≤ C8:0) are also extracted with ether-heptane after addition of ethanol and 2.5 M sulfuric acid. Internal standards are used to compensate for the losses of lower FFA (C2:0–C8:0) in the aqueous phase. In view of the excellent recovery (98–100 %) and a considerable saving of time, the use of an aminopropyl column is preferred for the isolation of the FFA from lipid-extracts. The underivatized FFA are separated directly by capillary gas chromatography making use of columns which enable accurate and rapid (≤ 40 min) determination of FFA C2:0–C20:0. With the method described, all major FFA (C2:0–C18:3) in milk and cheese can be quantified with good repeatability (rsd less then 2 %). The method is also applicable to the analysis of short-chain fatty acids in other products.     

Urinary Fatty Acid Composition and Biomarkers Discovery for Type 2 Diabetic Patients Based on Ultra-Performance Liquid Chromatography-Quadrupole/Time of Flight Mass Spectrometry and Multivariate Statistical Analysis

A strategy of high sensitive assay method of urine fatty acid profiles was established based on ultra-performance liquid chromatography-quadrupole time of flight-mass spectrometry (UPLC/Q-TOF) and applied in metabolomics research of diabetes mellitus. In this way, 19 fatty acids including two pair of hard-resolved isomers were separated well in only 13 minutes, and Q-TOF mass spectrometry reduced the matrix interference of urine samples by high resolution and accurate molecular weights. Under the optimal conditions, fatty acid profiles of 93 cases of urine samples were analyzed. Fatty acid profiles of type 2 diabetes mellitus showed large differences from health controls based on multivariate data analysis; C16:0, C18:0, C18:2, C20:5, and C22:6 were screened as potential clinical biomarkers. This work is complementary to the clinical diagnosis of diabetes mellitus; additionally, noninvasive testing of urine samples made it more convenient for examination while reducing the patient's pain and improving their living conditions.     

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.     

杏仁油的物化性能及其脂肪酸组成的分析

用３种不同溶剂萃取杏仁得到杏仁油,并对其物化常数进行测定。杏仁油用饱和氢氧化钾 甲醇皂化,再用甲醇 硫酸（体积比为４∶１）甲酯化后,将乙醚萃取液作气相色谱分析。太原杏仁油中脂肪酸的主要成分为油酸（Ｃ１８∶１,质量分数约６８％）和亚油酸（Ｃ１８∶２,质量分数约２５％）,少量棕榈酸（Ｃ１６∶０）、棕榈烯酸（Ｃ１６∶１）和硬脂酸（Ｃ１８∶０）,微量花生酸（Ｃ２０∶０）。