An improved method of characterizing fatty acids by equivalent chain length values

Fatty Acids in Cnidaria: Distribution and Specific Functions

The phylum Cnidaria comprises five main classes-Hydrozoa, Scyphozoa, Hexacorallia, Octocorallia and Cubozoa-that include such widely distributed and well-known animals as hard and soft corals, sea anemones, sea pens, gorgonians, hydroids, and jellyfish. Cnidarians play a very important role in marine ecosystems. The composition of their fatty acids (FAs) depends on food (plankton and particulate organic matter), symbiotic photosynthetic dinoflagellates and bacteria, and de novo biosynthesis in host tissues. In cnidarian lipids, besides the common FA characteristics of marine organisms, numerous new and rare FAs are also found. All Octocorallia species and some Scyphozoa jellyfish contain polyunsaturated FAs (PUFAs) with 24 and 26 carbon atoms. The coral families can be distinguished by specific FA profiles: the presence of uncommon FAs or high/low levels of common fatty acids. Many of the families have characteristic FAs: Acroporidae are characterized by 18:3n6, eicosapentaenoic acid (EPA) 20:5n3, 22:4n6, and 22:5n3; Pocilloporidae by 20:3n6, 20:4n3, and docosahexaenoic acid 22:6n3 (DHA); and Poritidae by arachidonic acid (AA) and DHA. The species of Faviidae show elevated concentrations of 18:3n6 and 22:5n3 acids. Dendrophylliidae, being azooxanthellate corals, have such dominant acids as EPA and 22:5n3 and a low content of DHA, which is the major PUFA in hermatypic corals. The major and characteristic PUFAs for Milleporidae (class Hydrozoa) are DHA and 22:5n6, though in scleractinian corals, the latter acid is found only in trace amounts.

Pathogenic fungus uses volatiles to entice male flies into fatal matings with infected female cadavers

To ensure dispersal, many parasites and pathogens behaviourally manipulate infected hosts. Other pathogens and certain insect-pollinated flowers use sexual mimicry and release deceptive mating signals. However, it is unusual for pathogens to rely on both behavioural host manipulation and sexual mimicry. Here, we show that the host-specific and behaviourally manipulating pathogenic fungus, Entomophthora muscae, generates a chemical blend of volatile sesquiterpenes and alters the profile of natural host cuticular hydrocarbons in infected female housefly (Musca domestica) cadavers. Healthy male houseflies respond to the fungal compounds and are enticed into mating with female cadavers. This is advantageous for the fungus as close proximity between host individuals leads to an increased probability of infection. The fungus exploits the willingness of male flies to mate and benefits from altering the behaviour of uninfected male host flies. The altered cuticular hydrocarbons and emitted volatiles thus underlie the evolution of an extended phenotypic trait.

Occurrence of Cis-11,12-Methylene-Hexadecanoic Acid in the Red Alga Solieria pacifica (Yamada) Yoshida

Fatty acids in marine algae have attracted the attention of natural chemists because of their biological activity. The fatty acid compositions of the Solieriaceae families (Rhodophyceae, Gaigartinales) provide interesting information that unusual cyclic fatty acids have been occasionally found. A survey was conducted to profile the characteristic fatty acid composition of the red alga Solieria pacifica (Yamada) Yoshida using gas chromatography-mass spectrometry (GC-MS), infrared spectroscopy (IR), and proton nuclear magnetic resonance spectroscopy (¹H-NMR). In S. pacifica, two cyclopentyl fatty acids, 11-cyclopentylundecanoic acid (7.0%), and 13-cyclopentyltridecanoic acid (4.9%), and a cyclopropane fatty acid, cis-11,12-methylene-hexadecanoic acid (7.9%) contributed significantly to the overall fatty acid profile. In particular, this cyclopropane fatty acid has been primarily found in bacteria, rumen microorganisms or foods of animal origin, and has not previously been found in any other algae. In addition, this alga contains a significant amount of the monoenoic acid cis-11-hexadecenoic acid (9.0%). Therefore, cis-11,12-methylene-hexadecanoic acid in S. pacifica was likely produced by methylene addition to cis-11-hexadecenoic acid.

[The influence of sinusoidal modulated currents on the fatty acid composition of plasma and blood erythrocytes in the patients presenting with chronic cholecystitis]

The objective of the present study was to evaluate the effectiveness of the treatment with sinusoidal modulated currents on lipid metabolism in the patients presenting with chronic cholecystitis in the state of remission.

PATIENTS AND METHODS

The study included 25 patients with chronic non-calculosis cholecystitis in phase of remission and 20 healthy subjects (controls). We studied the serum lipid spectrum as well as the fatty acid composition of plasma and blood erythrocytes before and after therapy with sinusoidal modulated currents applied to the right-sided hypochondrium region.

RESULTS AND DISCUSSION

The treatment of the patients with chronic cholecystitis in remission with the use of sinusoidal modulated currents produced moderate lipid-modulatory and membranotropic effects mediated through the activation of the processes of lipid metabolism that may result in the depletion of the pool of essential polyunsaturated fatty acids.

CONCLUSION

The results of this study give evidence that it is advisable to treat the patients presenting with chronic cholecystitis by sinusoidal modulated currents in the combination with the oral intake of exogenous polyunsaturated fatty acids.

Efficient Separation and Analysis of Triacylglycerols: Quantitation of β-Palmitate (OPO) in Oils and Infant Formulas

A high-efficiency, convenient, and reliable method for the separation of structurally similar triacylglycerols is detailed and applied in the quantitative analysis of 1,3-dioleoyl-2-palmitoylglycerol (OPO) in infant formulas and OPO oils. OPO is an important lipid component in "humanized" infant formula. A fast preparative isolation of an OPO-containing fraction from the crude complex mixture, by nonaqueous reversed phase HPLC, followed by Ag(+)-HPLC with detection at 205 nm allowed fine separation and detection of the desired fraction. OPO was quantitated independently of its regioisomer 1,2-dioleoyl-3-palmitoylglycerol (OOP) and isomers of stearoyl-linoleoyl-palmitoyl glycerol that might be present in infant formulas. For samples with low OPO content, an evaporative light-scattering detector (ELSD) was more preferable than UV detection, with a calculated LOD of 0.1 μg of OPO injected and LOQ of 0.3 μg. The method, which showed high reproducibility (RSD < 5%), was suitable for both high OPO content oils and low OPO products such as unenriched infant formula. A number of possible interference issues were considered and dealt with.

Detection and molecular cloning of CYP74Q1 gene: identification of Ranunculus acris leaf divinyl ether synthase

Enzymes of the CYP74 family, including the divinyl ether synthase (DES), play important roles in plant cell signalling and defence. The potent DES activities have been detected before in the leaves of the meadow buttercup (Ranunculus acris L.) and few other Ranunculaceae species. The nature of these DESs and their genes remained unrevealed. The PCR with degenerate primers enabled to detect the transcript of unknown P450 gene assigned as CYP74Q1. Besides, two more CYP74Q1 isoforms with minimal sequence variations have been found. The full length recombinant CYP74Q1 protein was expressed in Escherichia coli. The preferred substrates of this enzyme are the 13-hydroperoxides of α-linolenic and linoleic acids, which are converted to the divinyl ether oxylipins (ω5Z)-etherolenic acid, (9Z,11E)-12-[(1'Z,3'Z)-hexadienyloxy]-9,11-dodecadienoic acid, and (ω5Z)-etheroleic acid, (9Z,11E)-12-[(1'Z)-hexenyloxy]-9,11-dodecadienoic acid, respectively, as revealed by the data of mass spectrometry, NMR and UV spectroscopy. Thus, CYP74Q1 protein was identified as the R. acris DES (RaDES), a novel DES type and the opening member of new CYP74Q subfamily.

Composition of fatty acids in plasma and erythrocytes and eicosanoids level in patients with metabolic syndrome

BACKGROUND

Disturbances of the fatty acids composition in plasma and red blood cells and eicosanoid synthesis play an important role in the metabolic syndrome (MS) formation.

METHODS

The observation group included 61 people with metabolic syndrome (30 patients with MS and normal levels of insulin, 31 people with MS and insulin resistance--IR). The parameters of carbohydrate and lipid metabolism in blood serum were examined. The composition of nonesterified fatty acids (NEFA), fatty acid (FA) of red blood cells lipids was analyzed by gas-liquid chromatography. Eicosanoids level in MS patients blood serum was studied by enzyme immunoassay.

RESULTS

In MS patients in the absence of glucose-insulin homeostasis disturbances and in patients with IR the accumulation of polyunsaturated fatty acids (18:2 n6, 18:3 n3, 22:4 n6) and lower pool of saturated FA (12:0, 14:0, 16: 0, 17:0) in plasma were discovered. A deficit of polyunsaturated FA (18:3 n3, 20:4 n6) with a predominance of on-saturated FA (14:0, 18:0) in erythrocyte membranes was revealed. In MS patients regardless of the carbohydrate metabolism status high levels of leukotriene B4 and 6-keto-prostaglandin-F1α in serum were found. The development of IR in MS patients leads to increased synthesis of thromboxane A2.

CONCLUSION

The results revealed a disturbance in nonesterified fatty acids of plasma lipids and red blood cells, eicosanoid synthesis in MS patients. The breach of the plasma and cell membranes fatty acids compositions, synthesis of vasoactive and proinflammatory eicosanoids is an important pathogenetic part of the MS development.

Non-polar lipid components of human cerumen

Human cerumen was separated by column chromatography into the following groups of compounds: hydrocarbons, squalene, wax esters and cholesterol esters, triacylglycerols, free fatty acids, free fatty alcohols, monoacylglycerols, free cholesterol, free sterols, and free hydroxy acids. The groups of compounds obtained were examined in detail by gas chromatography and gas chromatography-mass spectrometry. In total, about one thousand compounds have been identified.

Modification of fatty acids composition in erythrocytes lipids in arterial hypertension associated with dyslipidemia

BACKGROUND

Modification of fatty acids (FA) composition in erythrocytes lipids as an early indicator of the development of arterial hypertension (AH) and lipid disorders.

METHODS

We included 34 patients with arterial hypertension and 11 healthy individuals. Each patient was examined the lipid composition of serum. From erythrocytes by gas chromatography were identified fatty acids. The quantitative composition of the erythrocyte lipids FA in patients with AH presented with saturated and polyunsaturated monoenic acids with carbon chain lengths from C12 to C22.

RESULTS

In all hypertensive patients is disturbed lipid FA composition of erythrocytes. The patients with a normal level of serum lipids revealed deficiency of polyunsaturated acids n6-linoleic (18:2 n6), arachidonic (20:4 n6), dokozatetraenic 14.4% (22:4 n6). The patients with dislipidemia installed more profound restructuring of the lipid matrix of the membrane of erythrocytes. A decrease in polyunsaturated fatty acids family n3: dokozapentaenovoy (22:5 n3), docosahexaenoic PUFA (22:6 n3), the total value of n3 PUFA in 1,3 times was revealed.

CONCLUSION

Thus, modification of erythrocyte FA are fairly subtle indicator of pathology of lipid metabolism, which manifest themselves much earlier than changes in the lipoprotein of blood plasma.

Muscle and hepatic fatty acid profiles and α-tocopherol status in African catfish (Clarias gariepinus) given diets varying in oxidative state and vitamin E inclusion level

On termination of a 56-day feeding trial, the effect of dietary oxidized oil and all-rac-α-tocopheryl acetate on fatty acid and α-tocopherol status of juvenile African catfish (Clarias gariepinusj muscle and liver was investigated. Clarias of mean initial weight 15·8 (s.e. 0·29) g were given food at -proportionately 0·03 body weight per day on diets of two oxidative states (fresh or oxidized) at two levels of supplemental α-tocopheryl acetate (20 or 100 mg/kg dry matter).

As well as having a significant detrimental effect on final body weight (P < 0·001), oxidation of the dietary lipid source was responsible for decreasing muscle but not hepatic polyunsaturated fatty acids (PUTAs). Liver tissue was suspected of actively synthesizing longer chain PUT As in response to consumption of oxidized oils, as indicated by decreases in the proportions of linoleate (18:2 n-6) and linolenate (18:3 n-3) and the increased abundance of eicosatetraenoic acid (20:4 n-6, arachidonate) and docosahexaenoic acid (22: 6 n-3, DHA). This phenomenon has not been described in fish nutrition and therefore possible mechanisms are discussed. Additionally, oxidized oils in catfish diets caused significant depletion of a-tocopherol from both muscle and liver (P < 0·05).

Modulation of the effects of oxidized lipids was achieved at the higher dietary tocopherol concentration. Appearance of an unknown aliphatic compound (equivalent chain length (ECL) = 13·1), believed to be a product of lipid peroxidation, demonstrated that catfish given rancid/low-tocopherol diets had been subjected to heightened oxidative nutritional stress. Values obtained for this peak were significantly correlated with dietary regime (P < 0·02), Once more, dietary α-tocopheryl acetate moderated this effect. It was concluded that elevated inclusion of all-rac-α-tocopheryl acetate into diets for African catfish could abrogate the effects of oxidized dietary lipids on muscle and liver fatty acids and α-tocopherol.

Gas chromatographic retention data of wax esters

Higher wax esters within the range of C24 to C44 (205 standards) were analyzed by means of gas chromatography and Kováts indexes (I) and reduced Kováts indexes (RKI) were calculated. The dependences of these retention data on number of carbon atoms and on number and position of double bonds in acid and in alcohol moieties of esters were plotted.

Prediction of equivalent chain lengths from two-dimensional fatty acid retention indices

A recently introduced two-dimensional fatty acid retention index system (2D-FARI) was used as basis for prediction of equivalent chain lengths (ECL) of fatty acid methyl esters (FAME) on a BPX-70 stationary phase. Models for the relationship between 2D-FARI data and ECL values of a calibration sample with 30 common fatty acids were established by a simple multivariate regression. The models were thereafter applied on 2D-FARI data for other FAMEs and used to predict the ECLs for these compounds. The 2D-FARI values for the fatty acids in the calibration sample are given by definition. Thus, the only information necessary to calculate the ECL value for a compound run under identical conditions as the calibration sample is the 2D-FARI values for the compound, which can be acquired from literature data. The method was validated with test sets analysed with different temperature and flow programs. ECLs of various marine FAME and trans isomers of Eicosapentaenoic and Docosahexaenoic acid were predicted with root mean squared error of prediction from 0.002 to 0.012 ECL units.

Photobacterium frigidiphilum sp. nov., a psychrophilic, lipolytic bacterium isolated from deep-sea sediments of Edison Seamount

A Gram-negative, motile, rod-shaped, psychrophilic and weakly halophilic bacterial strain, SL13T, was isolated from deep-sea sediments (1450 m depth) of Edison Seamount in the western Pacific Ocean. Optimal growth of SL13Trequires the presence of 1·5 % (w/v) NaCl, a pH of 6·0 and a temperature of 14 °C. The whole-cell fatty acid profile of the isolate includes C16 : 1 and C16 : 0 as major fatty acids and contains C20 : 5ω3. This is consistent with corresponding data forPhotobacterium profundum. The DNA G+C content of strain SL13Tis 43·8 mol%. Phylogenetic analyses of 16S rRNA gene sequences place this bacterium in the ‘Gammaproteobacteria’, within the genusPhotobacterium. Sequence similarity analysis indicates that the closest relatives of strain SL13TarePhotobacterium indicum(99·3 %),P. profundum(98·5 %) andPhotobacterium lipolyticum(98·2 %). The DNA–DNA hybridization levels between the isolate and its closest known phylogenetic relatives,P. indicum,P. profundumandP. lipolyticum, are 27·1, 52·4 and 20·2 %, respectively. Thus strain SL13Trepresents a novel species of the genusPhotobacterium, for which the namePhotobacterium frigidiphilumsp. nov. is proposed. The type strain is SL13T(=KCTC 12384T=JCM 12947T).

Two-dimensional fatty acid retention indices

A two-dimensional retention index system for fatty acid methyl esters (2D-FARI) is proposed. The system is based on the application of different temperature and pressure programs on a single capillary column. A calibration sample is analysed and the retention data is calibrated against a set of reference 2D-FARI values. The calibration models are then applied to predict the 2D-FARI values for compounds that are not present in the calibration sample. The two dimensions in the retention index system lead to increased selectivity and a reduced risk of retention index overlap between different compounds. The 2D-FARI system is also more robust towards differences in stationary phase properties than ordinary retention indices and is therefore convenient for comparison of retention data acquired on different columns, or at different times at the same column.

Fatty acid patterns in Chlamydomonas sp. as a marker for nutritional regimes and temperature under extremely acidic conditions

Fatty acid profiles were used to characterize nutritional pathways in Chlamydomonas sp. isolated from an acidic mining lake (pH 2.7). Surprisingly, profiles of Chlamydomonas sp. grown in the lab under photoautotrophic, mixotrophic, and heterotrophic conditions at in situ deep strata lake water temperatures (8 degrees C) were very similar, polyunsaturated fatty acids including alpha-linolenic acid (18:3omega3) and 16:4omega3 along with palmitic acid (16:0) being most abundant. Therefore, heterotrophic growth of Chlamydomonas sp. at low temperatures can result in high concentrations of polyunsaturated fatty acids, as previously only described for some psychrophilic bacteria. By contrast, the cultivation of isolated Chlamydomonas sp. at 20 degrees C, reflecting surface water temperatures, provided fatty acid patterns characteristic of the nutrition strategy applied: the concentration of polyunsaturated fatty acids decreased when the growth pathway changed from photoautotrophic via mixotrophic to heterotrophic. Total fatty acid concentration also diminished in this order. Principal component analysis confirmed the significance of FA profiling to mirror nutritional pathways. Lake-water analysis revealed low concentrations of dissolved organic carbon, mainly consisting of polymeric fulvic acids that are unable to support heterotrophic growth of Chlamydomonas sp. Polymeric fulvic acids present in the deeper strata of the lake turned out to be formed in situ on the basis of organic monomers including reduced sulfur-containing ones, as revealed by thermochemolysis and pyrolysis. Growth of Chlamydomonas sp. in the deep chlorophyll maximum is therefore assumed to mainly result from photosynthesis, despite very low photon densities. Phytol-including metabolites proved to be significant biomarkers to indicate the nutritional pathway of Chlamydomonas sp. alpha, omega-Dicarboxylic acids-light-induced degradation products of unsaturated fatty acids-appeared to be good indicators of photooxidative alterations to the algal species under study.

Complete characterisation of lanolin steryl esters by sub-ambient pressure gas chromatography-mass spectrometry in the electron impact and chemical ionisation modes

Steryl esters occurring in lanolin have been characterised by sub-ambient pressure gas chromatography coupled to mass spectrometry. Electron impact and chemical ionisation modes with different reagent gases have been evaluated in order to carry out unambiguous peak identification. Steryl esters with different sterol (i.e. cholesterol, lanosterol and dihydrolanosterol) and acid moieties either according to carbon number (i.e C10-C23) or isomeric forms (i.e. normal, iso and anteiso) have been identified. Identification of the sterol and acid moieties has been carried out by means of the mass spectral information obtained in the electron impact, chemical ionisation mode either in the positive or negative modes using methane, isobutane and ammonia as reagent gases. Isomeric identification has been achieved by chromatographic retention parameters (i.e. entire-chain length and fractional-chain length) and by the free fatty acid profile also present in lanolin.

Nonsaponifiable lipid components of the pollen of elder (Sambucus nigra L.)

Pollen of the elder (Sambucus nigra L.) was extracted with chloroform-methanol. The extract was separated by column chromatography into the following groups of compounds: hydrocarbons (8.7%). polycyclic aromatic hydrocarbons (0.2%), complex esters (5.2%), triglycerides (18.7%), hydroxy esters (27.9%), free fatty acids and alcohols (16.8%), free sterols (6.8%), and triterpenic alcohols (4.0%). The nonsaponifiable components (hydrocarbons, fatty acids, alcohols, and sterols) were examined in detail using spectroscopic and chromatographic methods (IR spectroscopy, GC, and GC-MS). The identified compounds were characterized by their mass spectra and Kováts retention indices. The double bond positions and their configurations in unsaturated compounds are also reported.

Fatty acid profiles of lipid samples

Most lipids are best characterized by their fatty acids which differ in chain length, the degree of unsaturation, configuration and position of the double bonds, and the presence of other functionalities. The fatty acid profiles are currently most frequently determined by capillary gas chromatography of the methyl esters which are prepared by a variety of methods. These are discussed with an emphasis on more recent developments, along with the stationary phases used for the separations and the methods employed for identification of the fatty acids. HPLC is applied less frequently for ascertaining fatty acid profiles than GC, but a very large number of derivatives for ultraviolet and fluorescence detection have been proposed. This method continues to evoke increasing interest, particularly in conjunction with fluorescence detection. This technique enables attainment of greater sensitivities than with standard GC methods employing flame ionization detection. Extensive applications of it to the analysis of free fatty acids in blood and other biomedical samples are clearly discernible. Other methods, including supercritical fluid chromatography, have found only limited application for fatty acid profiling.