Fatty Acid Composition of the Lipids from Atlantic Salmon-Comparison of Two Extraction Methods without Halogenated Solvents.

The scope of this paper was to apply two recently developed methods for lipid extraction: the methyl tert-butyl ether (MTBE) method and the BUME method. These two methods do not include halogenated solvents, which makes them less hazardous to the environment, less toxic, and needed in less volume compared to the standard methods for lipid extraction. Fatty acid composition of the lipids from Atlantic salmon (Salmo salar Linnæus, 1758) was obtained by both procedures. The methods were effective and thirty-three fatty acids were identified. The amounts of the omega-3 polyunsaturated fatty acids obtained by the MTBE method were found to be similar to the overall mean values observed in farmed salmon. The yield of the total lipids obtained by the BUME method was 13% lower. Although the methods involved different solvents, they showed similar fatty acids profile of the lipids from Atlantic salmon. Both methods were validated and some practical challenges were discussed.

Growth and metabolism of adult polar cod (Boreogadus saida) in response to dietary crude oil.

The increasing human presence in the Arctic shelf seas, with the expansion of oil and gas industries and maritime shipping, poses a risk for Arctic marine organisms such as the key species polar cod (Boreogadus saida). The impact of dietary crude oil on growth and metabolism of polar cod was investigated in the early spring (March-April) when individuals are expected to be in a vulnerable physiological state with poor energy stores. Adult polar cod were exposed dietarily to three doses of Kobbe crude oil during an eight weeks period and followed by two weeks of depuration. Significant dose-responses in exposure biomarkers (hepatic ethoxyresorufine-O-deethylase [EROD] activity and 1-OH phenanthrene metabolites in bile) indicated that polycyclic aromatic hydrocarbons (PAHs) were bioavailable. Condition indices (i.e. Fulton's condition factor, hepatosomatic index), growth, whole body respiration, and total lipid content in the liver were monitored over the course of the experiment. The majority of females were immature, while a few had spawned during the season and showed low hepatic lipid content during the experiment. In contrast, males were all, except for one immature individual, in a post-spawning stage and had larger hepatic energy stores than females. Most specimens, independent of sex, showed a loss in weight, that was exacerbated by exposure to crude oil and low hepatic liver lipids. Furthermore, females exposed to crude oil showed a significant elevation of oxygen consumption compared to controls, although not dose-dependent. This study highlights the importance of the energy status of individuals for their response to a crude oil exposure.

Structure-activity relationship of dihydroxy-4-methylcoumarins as powerful antioxidants: correlation between experimental & theoretical data and synergistic effect.

The chain-breaking antioxidant activities of eight coumarins [7-hydroxy-4-methylcoumarin (1), 5,7-dihydroxy-4-methylcoumarin (2), 6,7-dihydroxy-4-methylcoumarin (3), 6,7-dihydroxycoumarin (4), 7,8-dihydroxy-4-methylcoumarin (5), ethyl 2-(7,8-dihydroxy-4-methylcoumar-3-yl)-acetate (6), 7,8-diacetoxy-4-methylcoumarin (7) and ethyl 2-(7,8-diacetoxy-4-methylcoumar-3-yl)-acetate (8)] during bulk lipid autoxidation at 37 degrees C and 80 degrees C in concentrations of 0.01-1.0 mM and their radical scavenging activities at 25 degrees C using TLC-DPPH test have been studied and compared. It has been found that the o-dihydroxycoumarins 3-6 demonstrated excellent activity as antioxidants and radical scavengers, much better than the m-dihydroxy analogue 2 and the monohydroxycoumarin 1. The substitution at the C-3 position did not have any effect either on the chain-breaking antioxidant activity or on the radical scavenging activity of the 7,8-dihydroxy- and 7,8-diacetoxy-4-methylcoumarins 6 and 8. The comparison with DL-alpha-tocopherol (TOH), caffeic acid (CA) and p-coumaric acid (p-CumA) showed that antioxidant efficiency decreases in the following sequence: TOH>CA>3>4>6>5>2>1=7=8=p-CumA. Theoretical calculations and the "Lipinski's Rule of Five" were used for explaining the structure-activity relationships and pharmacokinetic behavior. A higher TGSO oxidation stability was observed in the presence of equimolar (1:1) binary mixtures of coumarins with TOH (1+TOH, 3+TOH and 5+TOH). However, the synergism (14%) was observed only for the binary mixture of 5 + TOH.

Structure-activity relationships of new 4-hydroxy bis-coumarins as radical scavengers and chain-breaking antioxidants.

The main antioxidant properties of five new 4-hydroxy-bis-coumarins during bulk lipid autoxidation at 80 degrees C and 0.1 mM and 1.0 mM concentrations were studied and compared with 4-hydroxy-2H-chromen-2-one (1). These compounds are: 3,3'-((3,4-dihydroxy-phenyl) methylene) bis (4-hydroxy-2H-chromen-2-one) (2), 3,3'-((3,4-dimethoxyphenyl) methylene) bis (4-hydroxy-2H-chromen-2-one) (3), 3,3'-((4-hydroxy-3,5-dimethoxy-phenyl) methylene) bis(4-hydroxy-2H-chromen-2-one) (4) 3,3'-((3,4,5- trimethoxyphenyl) methylene) bis (4-hydroxy-2H-chromen-2-one) (5) 3,3'-((4-hydroxy-3-methoxy-5-nitrophenyl) methylene) bis (4-hydroxy-2H-chromen-2-one) (6), It was found that compound 2 with a catecholic structure in the aromatic nucleus showed the strongest antioxidant activity. Compound 4 showed a moderate antioxidant activity, and all the other compounds didn't show any capacity as chain-breaking antioxidants. Both 4-hydroxy-bis-coumarins (2 and 4) demonstrated also stronger radical scavenging activity towards DPPH radical by using TLC DPPH rapid test, than compound 1. The other compounds (3, 5, 6) didn't show any capacity as radical scavengers. The structure-activity relationship was discussed on the base of comparable kinetic analysis of studied 4-hydroxy-bis-coumarins with the known and standard antioxidants as alpha-tocopherol (TOH), caffeic acid (CA), sinapic acid (SA), ferulic acid (FA), and p-coumaric acid (p-CumA). In order to study the possible synergism between two phenolic antioxidants, the antioxidant efficiency and reactivity of two equimolar binary mixtures of coumarins and TOH (2+TOH and 4+TOH) and of corresponding cinnamic acid with TOH (CA+TOH and SA+TOH) were also tested and compared. The oxidation stability of the lipid substrate in presence of binary mixtures CA+TOH, SA+TOH and 2+TOH appeared to be higher than that of the individual antioxidants. However, no synergism was obtained for all tested binary mixtures.

Chemical composition of the halophyte plant Stachys maritima Gouan from the Bulgarian Black Sea coast.

Four groups of metabolites from the halophyte plant Stachys maritima Gouan, family Lamiaceae, were investigated: lipids, sterols, volatiles and polar compounds. Most of the metabolites have been previously reported to possess biological activity. Two of the main substances in the volatile fraction--phenidone and naphthalene, unusual for plants--were products of environmental contamination. This is a typical example of how marine pollutants could transfer and threaten terrestrial organisms via the trophic chain. The n-butanol extract possessed a relatively high antibacterial activity against S. aureus and Candida albicans, but was not active against Escherichia coli.

Effect of cobalt ions on the metabolism of some volatile and polar compounds in the marine invertebrates Mytilus galloprovincialis and Actinia equina.

The compositions of the volatile and polar fractions from two coexisting Black Sea invertebrates, the mussel Mytilus galloprovincialis and the beadlet anemone Actinia equina, were established. The main metabolites in the volatile fraction from the investigated animals appeared to be methyl esters of fatty acids and fatty aldehydes. In the polar fraction from both animals low concentrations of free acids and nitrogen-containing compounds were obtained. Free carbohydrates were in much higher concentrations in M. galloprovincialis than in A. equina. Some sterols, probably as polar conjugates, were identified mainly in A. equina. Significant changes among all compounds appeared after treatment of both invertebrates with two different concentrations of cobalt ions. The variety of changes in each invertebrate could be due to their different evolutionary status. The effect of cobalt ions was often stronger at medium cobalt-ion concentrations.

Effect of cobalt ions on lipid and sterol metabolism in the marine invertebrates Mytilus galloprovincialis and Actinia equina.

The lipid and sterol fractions of the mussel Mytilus galloprovincialis and the anemone Actinia equina were analyzed before and after incubation with cobalt ions. There were significant changes in the lipid and sterol composition, strongly depending on the cobalt ions concentrations. The changes in the lipid composition of both invertebrates were different for neutral lipids and phospholipids. These changes concern the length of the fatty acid chains as well as their unsaturation. The cobalt ions inhibited the oxidation of sterols and their alkylation at C-24. Because of these results we can assume that some of the changes caused by cobalt ions might possess adaptive value.

Chemical composition of the sponge Hymeniacidon sanguinea from the Canary Islands.

The fatty acid composition of the lipids from the sponge Hymeniacidon sanguinea was investigated and 73 acids were identified. Three of them were new and their structures, elucidated by gas chromatography/mass spectrometry, were identified as 13-methyl-icosanoic, 15-methyl-docosanoic and 3,13-dimethyl-tetradecanoic. Only 12 sterols were present, with cholestanol predominating in the volatile fraction; 22 compounds were identified, mainly hydrocarbons and fatty acids. In the n-butanol fraction, we found mainly nitrogen-containing compounds. The compositions of sterols and lipids in the sponge collected from two locations with different ecological conditions (Canary Islands and Black Sea) were compared.

Lipophylic compounds from Euphorbia peplis L.--a halophytic plant from the Bulgarian Black Sea coast.

The chemical composition of the lipophylic fraction from the halophytic plant Euphorbia peplis L. was investigated. Compared to other terrestrial higher plants an increase of triacylglycerols and especially of glycolipids was observed. The main phospholipid was phosphatidyl choline, followed by almost equal concentrations of phosphatidyl ethanolamine and phosphatidyl glycerol. A relatively high concentration of phosphatidic acids (6.5% of the total phospholipids) was found. The main sterol appeared to be sitosterol and significant amounts of tetracyclic triterpene alcohols were found. The composition of the volatile compounds is relatively simple and only one chlorinated compound, identified as 2,2-diethoxy-1-chloroethane, was found. There was a strong toxicity of the total lipophylic extract towards Artemia salina.

Composition of lipophylic extracts from two Tinicates, Styela sp. and Phallusia sp. from the Eastern Mediterranean.

Sterols, volatiles and lipids were isolated and identified from lipophylic extracts from two tunicates, Styela sp. and Phallusia sp., occurring in the Eastern Mediterranean. Seventeen sterols were identified. The sterol composition of the two organisms appeared to be similar except for the concentrations of 5alpha-stanols. Both tunicates were characterized by the presence of sterols with a (22Z)-double bond. In the volatiles significant amounts of chlorinated compounds were found (phenols in Styela sp. and hydrocarbons in Phallusia sp.). The fatty acid composition of triacylglycerols and phospholipids of the two tunicates showed significant differences.

Effect of diesel fuel pollution on the lipid composition of some wide-spread Black Sea algae and invertebrates.

Two green algae (Ulva rigida and Cladophora coelothrix), the mussel Mytilus galloprovincialis and the snail Rapana thomasiana from the Bulgarian Black Sea shore have been treated with diesel fuel (100mg l(-1)) in an aquarium with sea-water for three days. The lipids and their fatty acid changes have been examined. Significant changes have been observed mainly in the polar lipids and in the saturation of the fatty acids. These changes appeared to be bigger in the evolutionary less advanced species from both groups of marine organisms--algae and invertebrates (Ulva rigida and Mytilus galloprovincialis respectively). The data obtained could be used for a biomonitoring of the pollution.

Lipids and sterols in Musca domestica L. (Diptera, Muscidae): changes after treatment with sucrose and lead.

Total lipid, fatty acid and sterol composition of larvae and adults of Musca domestica was investigated before and after feeding on sucrose syrup or on the same syrup containing 1% lead nitrate. The effects of sucrose and of lead ions were found to be different. In larvae sucrose diet inhibited the fatty acid elongation and stimulated the first stages of their unsaturation. A significant increase of phytosterol concentrations was obtained. These changes increased the cell membrane permeability. The addition of lead caused a decrease of the fatty acid unsaturation, which decreased the cell membrane permeability. In adults the sucrose diet had no effect on the lipid and sterol composition, while the addition of lead decreased the cholesterol concentration. The composition of lipids and sterols also depends on the diet of larvae before pupation. The data obtained suggested that changes in lipid and sterol composition, which control the permeability of the cell membrane, might be an adaptive response of the organism to the changes of the environment.