New 17-Methyl-13-Octadecenoic and 3,16-Docosadienoic Acids from the Sponge <Emphasis Type="Italic">Polymastia penicillus</Emphasis>

The phospholipid fatty acid composition of the North-East Atlantic sponge Polymastia penicillus (South Brittany, France) was investigated. Sixty fatty acids (FA) were identified as methyl esters (FAME) and N-acyl pyrrolidides (NAP) by gas chromatography–mass spectrometry (GC/MS), including eight Δ5,9 unsaturated FA and three long-chain 2-hydroxylated FA. The major phospholipid FA were palmitic (14.3% of the total FA mixture), vaccenic (12.7%), 15(Z)-docosenoic (13.4%) and 5(Z),9(Z)-hexacosadienoic (13.3%) acids. In addition to the iso- and anteiso-branched saturated FA, several unusual short-chain branched saturated FA were identified. In addition to the known Δ5,9 FA, and interestingly regarding their identification by GC–MS as N-acyl pyrrolidides, was the co-occurrence of unusual FA possessing a Δ3, Δ4 and Δ5 double bond such as iso-4-pentadecenoic, iso-5-heptadecenoic, anteiso-5-heptadecenoic and two new compounds, not hitherto found in nature, namely 17-methyl-13-octadecenoic (0.8%) and 3,16-docosadienoic (1.1%) acids.     

Novel methoxylated FA from the Caribbean sponge Spheciospongia cuspidifera

The Δ⁶ monoenoic methoxylated FA (6Z)-2-methoxy-6-heptadecenoic acid and (6Z)-2-methoxy-6-octadecenoic acid were identified for the first time in nature in the phospholipids from the uncommon Caribbean sponge Spheciospongia cuspidifera. These findings expand the occurrence of Δ⁶ 2-methoxylated FA to C₁₇−C₁₈ chain lengths and establish a new FA biosynthetic possibility for these marine organisms. The novel methoxylated FA also could have originated from the phospholipids of a bacterium in symbiosis with the sponge.     

New 2-Methyl-13-Icosenoic Acid from the Temperate Calcisponge <Emphasis Type="Italic">Leuconia johnstoni</Emphasis>

The fatty acid composition of the temperate calcareous marine sponge Leuconia johnstoni Carter 1871 (Calcaronea, Calcarea) was characterized for the first time in specimens collected off the Brittany coast of France over four years from October 2005 to September 2008. Forty-one fatty acids (FA) with chain lengths ranging from C₁₄ to C₂₂ were identified as fatty methyl esters (FAME) and N-acyl pyrrolidide (NAP) derivatives by gas chromatography–mass spectrometry (GC–MS). Twenty-two saturated fatty acids (SFA) were identified accounting for 52.1–59.0% of the total FA and dimethylacetals (DMA). In addition, among the SFA, we noticed the presence of numerous methyl-branched iso and anteiso FA, suggesting a large number of associated bacteria within L. johnstoni. Thirteen monounsaturated fatty acids (MUFA, 28.0–36.0% of total FA + DMA) were also identified as well as six polyunsaturated fatty acids (PUFA, 4.0–8.2%). A noticeable DMA was detected at a high level, particularly in September 2008 (11.8%), indicating the presence of plasmalogens in this sponge species. This calcareous sponge lacked the non-methylene-interrupted FA (NMI FA) with a Δ5,9 system typical of siliceous Demosponges and Hexactinellids. The occurrence of the unusual 8,13-octadecadienoic acid was reported for the first time as a minor PUFA in a calcareous sponge. The major FA, representing 20–25% of this sponge FA, was identified as the new 2-methyl-13-icosenoic acid from mass spectra of its methyl ester and its corresponding N-acyl pyrrolidide derivatives as well as a dimethyl disulfide adduct.     

Sponge fatty acids. 3. Occurrence of series of n−7 monoenoic andiso-5,9 dienoic long-chain fatty acids in the phospholipids of the marine spongeCinachyrella aff.schulzei keller

The fatty acid composition of phospholipids from the New Caledonian spongeCinachyrella aff.schulzei Keller was studied. More than 60 fatty acids were identified as methyl esters andN-acyl pyrrolidides by gas chromatography and gas chromatography/mass spectrometry. Two isoprenoid fatty acids also were shown to be present, namely 4,8,12-trimethyltridecanoic and 5,9,13-trimethyltetradecanoic acids. The unusual 6-tetradecenoic, 6-pentadecenoic, 12-nonadecenoic and 26-methylheptacosanoic (iso-28∶0) acids were found for the first time in sponge phospholipids. A series of six n−7 monoenoic long-chain fatty acids (C₂₃ to C₂₈) were identified, including the rare 16-tricosenoic, 18-pentacosenoic and 21-octacosenoic acids. Fifteen fatty acids possessing the typical 5,9 dienoic moiety accounted for 30% of the total fatty acid mixture. Two new fatty acids were identified, namely 5(Z)-octacosenoic and 27-methyl-5(Z),9(Z)-octacosadienoic (iso-5,9-29∶2). Based on gas chromatography/Fourier transform infrared experiments, the double bonds were assigned the (Z) configuration. For part 2 of this series, see Reference 1.     

Synthesis and Biological Characterization of (Z)-9-Heptadecenoic and (Z)-6-Methyl-9-Heptadecenoic Acids: Fatty Acids with Antibiotic Activity Produced by Pseudozyma flocculosa

Difficulties in isolating and purifying antibiotic fatty acids from culture filtrates of Pseudozyma flocculosa, a biocontrol agent against powdery mildew, have been limiting factors in studying the properties and understanding the mode of action of the biocontrol agent. We report a new protocol for synthesizing (Z)-9-heptadecenoic and for the first time synthesis of (Z)-6-methyl-9-heptadecenoic acids, two antibiotic fatty acids produced by P. flocculosa. This allowed reproducible and quantifiable means of assaying biological activity of the molecules. In these bioassays, both molecules exhibited antifungal activity corresponding to their expected potency. These new developments should facilitate further studies aimed at deciphering the ecological properties of P. flocculosa.     

A Facile and Efficient Method for the Synthesis of Labeled and Unlabeled Very Long Chain Polyunsaturated Fatty Acids

Several methods are available for elongation of fatty acid acyl chains. The present paper describes adaptation to the fatty acid field of a previously published protocol for manganese-based Wurtz type coupling of alkyl bromides. 22-Bromo-3(Z),6(Z),9(Z),12(Z),15(Z),18(Z)-docosahexaene, easily prepared from 4(Z),7(Z),10(Z),13(Z),16(Z),19(Z)-docosahexaenoic acid, was coupled to homologous ω-bromoesters by stirring for 4 hours at 40°C in the presence of manganese powder, a nickel catalyst and terpyridine. This afforded in yields of 70–75% a series of ω3-hexaenoates of chain lengths of 32–40 carbons. The corresponding fatty acids of >98% purity were obtained following saponification and final purification. By using methyl [2,2,3,3,4,4-²H₆]10-bromodecanoate as coupling partner it was possible to prepare a very long chain fatty acid in isotopically labeled form, i.e., [2,2,3,3,4,4-²H₆]14(Z),17(Z),20(Z),23(Z),26(Z),29(Z)-dotriacontahexaenoic acid. Also prepared were the monounsaturated long chain fatty acids 15(Z)-octadecenoic acid and 15(Z)-tetracosenoic acid. Very long chain fatty acids have been isolated from retina and other tissues and are of biological relevance. The methodology described will assist in further analytical and biological studies in this field.     

Production of hydroxy fatty acids from unsaturated fatty acids byFlavobacterium sp. DS5 hydratase,a C-10 positional- andcis unsaturation-specific enzyme

A new microbial isolate,Flavobacterium sp. DS5, converted oleic and linoleic acids to their corresponding 10-keto-and 10-hydroxy fatty acids. The hydration enzyme seems to be specific to the C-10 position. Conversion products from α- and γ-linolenic acids were identified by gas chromatography/mass spectrometry, Fourier transform infrared, and nuclear magnetic resonance as 10-hydroxy-12(Z),15(Z)-octadecadienoic and 10-hydroxy-6(Z),12(Z)-octadecadienoic acids, respectively. Products from other 9(Z)-unsaturated fatty acids also were identified as their corresponding 10-hydroxy- and 10-keto-fatty acids.Trans unsaturated fatty acid was not converted. From these results, it is concluded that strain DS5 hydratase is indeed a C-10 positional-specific andcis-specific enzyme. DS5 hydratase prefers an 18-carbon monounsaturated fatty acid. Among the C₁₈ unsaturated fatty acids, an additional double bond at either side of the 9,10-position lowers the enzyme hydration activity. Because hydratases from other microbes also convert 9(Z)-unsaturated fatty acids to 10-hydroxy fatty acids, the C-10 positional specificity of microbial hydratases may be universal.     

Efficient Synthesis of the Very-Long-Chain n-3 Fatty Acids,Tetracosahexaenoic Acid (C<Subscript>24</Subscript>:6n-3) and Tricosahexaenoic Acid (C<Subscript>23</Subscript>:6n-3)

Tetracosahexaenoic acid (C₂₄:6n-3, THA, 3) is an essential biosynthetic precursor in mammals of docosahexaenoic acid (C₂₂:6n-3, DHA, 1), the end-product of the metabolism of n-3 fatty acids. THA 3 is present in commercially valuable fishes, such as flathead flounder. Tricosahexaenoic acid (C₂₃:6n-3, TrHA, 2), an odd-numbered-chain fatty acid, has been identified from marine organisms such as the dinoflagellate, Amphidinium carterae. To date, few studies have examined THA 3 and TrHA 2 due to difficulties in detecting and identifying these compounds, so their chemical and biological properties remain poorly characterized. Only one methodology for the chemical synthesis of THA 3 has been presented, and no method for the synthesis of TrHA 2 has been reported. We report here the efficient synthesis of THA 3 in four steps in 56% overall yield, and the synthesis of TrHA 2 in six steps in 48% overall yield. We also present the synthesis of Δ²-THA 4, an intermediate of β-oxidation of THA 3 to DHA 1, in three steps in 73% overall yield.     

Structure-activity relationship of unsaturated fatty acids as mosquito ovipositional repellents

Various straight-chain unsaturated fatty acids from C₁₄ to C₂₄ were evaluated for their ovipositional repellency against gravid females of the southern house mosquitoCulex quinquefasciatus Say, and the relationship between the structures of the fatty acids and their ovipositional repellency was determined. A double bond withZ configuration was prerequisite for an unsaturated fatty acid to be highly repellent;E isomers were less active or even inactive. No relationship was found between the repellency and the number of double bonds in the unsaturated fatty acids. In C₁₈ monounsaturated fatty acids, (Z)-9 acid was more active than (Z)-11 and (Z)-6 acids, indicating that a double bond at the 9 position rendered an acid highly repellent. Among (Z)-9-alkenoic acids of different chain lengths, the most repellent was C₁₈ acid which was also more active than (Z)-11-C₂₀, (Z)-13-C₂₂, and (Z)-15-C₂₄ acids. Oleic[(Z)-9-octadecenoic]acid, which met all these criteria, was the most ovipositionally repellent among the unsaturated fatty acids tested.Diptera: Culicidae.     

Ultrasound-assisted synthesis of santalbic acid and a study of triacylglycerol species inSantalum album (Linn.) seed oil

Methyl ricinoleate (1) was treated with bromine and the dibromo derivative (2) was reacted with ethanolic KOH under ultrasonic irradiation to give 12-hydroxy-octadec-9-ynoic acid upon acidification with dil. HCl. The latter compound was methylated with BF₃/methanol to give methyl 12-hydroxy-octadec-9-ynoate (3). Compound3 was treated with methanesulfonyl chloride in the presence of triethylamine in CH₂Cl₂ to give methyl 12-mesyloxy-octadec-9-ynoate (4). Reaction of methyl 12-mesyloxy-octadec-9-ynoate with aqueous KOH under ultrasonic irradiation (20 kHz) gave (11E)-octadecen-9-ynoic acid (5, santalbic acid, 40%) and (11Z)-octadecen-9-ynoic acid (6, 60%) on acidification with dil. HCl. These isomers were separated by urea fractionation. The¹³C nuclear magnetic resonance (NMR) spectroscopic properties of the methyl ester and the triacylglycerol (TAG) esters of these enynoic fatty acid isomers were studied. The carbon shifts of the unsaturated carbon nuclei of the methyl ester of theE-isomer were unambiguously assigned as 88.547 (C-9), 79.287 (C-10), 109.760 (C-11), and 143.450 (C-12) ppm while the unsaturated carbon shifts of the (Z)-enynoate isomer appeared at 94.277 (C-9), 77.561 (C-10), 109.297 (C-11), and 142.668 (C-12) ppm. In the¹³C NMR spectral analysis of the TAG molecules of type AAA containing either the (Z)-or (E)-enyne fatty acid, the C-1 to C-6 carbon atoms on the α- and β-acyl positions were differentiated. The unsaturated carbon atoms in the α- and β-acyl chains were also resolved into two signals except that of the C-11 olefinic carbon. Sandal (Santalum album) wood seed oil (a source of santalbic acid) was separated by silica chromatography into three fractions. The least polar fraction (7.2 wt%) contained TAG which had a random distribution of saturated and unsaturated fatty acids, of which oleic acid (69%) was the predominant component. The second fraction (3.8 wt%) contained santalbic acid (58%) and oleic acid (28%) together with some other normal fatty acids. Santalbic acid in this fraction was found in both the α- and β-acyl positions of the glycerol “backbone”. The most polar fraction (89 wt%) consisted of TAG containing santalbic acid only. The distribution of the various fatty acids on the glycerol “backbone” was supported by the results from the¹³C NMR spectroscopic analysis.     

A pathway for biosynthesis of divinyl ether fatty acids in green leaves

[1-¹⁴C]α-Linolenic acid was incubated with a particulate fraction of homogenate of leaves of the meadow buttercup (Ranunculus acris L.). The main product was a divinyl ether fatty acid, which was identified as 12-[1′(Z),3′(Z)-hexadienyloxy]-9(Z), 11(E)-dodecadienoic acid. Addition of glutathione peroxidase and reduced glutathione to incubations of α-linolenic acid almost completely suppressed formation of the divinyl ether acid and resulted in the appearance of 13(S)-hydroxy-9(Z), 11(E), 15(Z)-octadecatrienoic acid as the main product. This result, together with the finding that 13(S)-hydroperoxy-9(Z), 11(E), 15(Z)-octadecatrienoic acid served as an efficient precursor of the divinyl ether fatty acid, indicated that divinyl ether biosynthesis in leaves of R. acris occurred by a two-step pathway involving an ω6-lipoxygenase and a divinyl ether synthase. Incubations of isomeric hydroperoxides derived from α-linolenic and linoleic acids with the enzyme preparation from R. acris showed that 13(S)-hydroperoxy-9(Z), 11(E)-octadecadienoic acid was transformed into the divinyl ether 12-[1′(Z)-hexenyloxy]-9(Z), 11(E)-dodecadienoic acid. In contrast, neither the 9(S)-hydroperoxides of linoleic or α-linolenic acids nor the 13(R)-hydroperoxide of α-linolenic acid served as precursors of divinyl ethers.     

Phospholipid studies of marine organisms: New branched fatty acids fromStrongylophora durissima

The phospholipids of the spongeStrongylophora durissima were analyzed. The major phospholipids present were phosphatidylethanolamine (PE), phosphatidylcholine (PC), phosphatidylserine (PS), phosphatidylglycerol (PG) and phosphatidylinositol (PI). The major fatty acid components of the phospholipids consisted of short chain (C₁₄−C₁₉) and very long chain (C₂₅−C₃₀) “Demospongic” acids. Three novel branched Δ⁵ monounsaturated acids,Z-19-methyl-5-pentacosenoic,Z-19-methyl-5-hexacosenoic andZ-19-methyl-5-heptacosenoic acids were encountered in the sponge. The 3-saturated counterparts of these compounds, 19-methylpentacosanoic, 19-methylhexacosanoic and 19-methylheptacosanoic acids, as well as 19-methylpentacosanoic and 20-methyloctacosanoic acids also are hitherto undescribed acids present in the sponge. Trace amounts of 2 very long chain acids also were detected and their structures tentatively assigned as 19,21-dimethylheptacosanoic and 20,22-dimethyloctacosanoic acids. The distribution of these fatty acids according to phospholipid head groups also was described.     

The distribution of brominated long-chain fatty acids in sponge and symbiont cell types from the tropical marine spongeAmphimedon terpenensis

The tropical marine spongeAmphimedon terpenensis (family Niphatidae, order Haplosclerida) has previously been shown to possess unusual lipids, including unusual fatty acids. The biosynthetic origin of these fatty acids is of interest as the sponge supports a significant population of eubacterial and cyanobacterial symbionts. The total fatty acid composition of the sponge was analyzed by gas chromatography/mass spectrometry of the methyl esters. Among the most abundant of the fatty acids in intact tissue were 16∶0, 18∶0 and 3,7,11,15-tetramethylhexadecanoic (phytanic) acid. In addition, three brominated fatty acids, (5E,9Z)-6-bromo-5,9-tetracosadienoic acid (24∶2Br), (5E,9Z)-6-bromo-5,9-pentacosadienoic acid (25∶2Br) and (5E,9Z)-6-bromo-5,9-hexacosadienoic acid (26∶2Br) were also present. The three brominated fatty acids, together with phytanic acid, were isolated from both ectosomoal (superficial) and choanosomal (internal) regions of the sponge. Analysis of extracts prepared from sponge/symbiont cells, partitioned by density gradient centrifugation on Ficoll, indicated that phytanic acid and the three brominated fatty acids were associated with sponge cells only. Further, a fatty acid methyl ester sample from intact tissue ofA. terpenensis was partitioned according to phospholipid class, and the brominated fatty acids were shown to be associated with the phosphatidylserine and phosphatidylethanolamine fractions that are commonly present in marine sponge lipids. The phosphatidylcholine and phosphatidylglycerol fractions were rich in the relatively shorter chain fatty acids (16∶0 and 18∶0). The association of brominated long-chain fatty acids (LCFA) with sponge cells has been confirmed. The findings allow comment on the use of fatty acid profiles in chemotaxonomy and permit further interpretation of LCFA biosynthetic pathways in sponges. The assignment of the sponge studied, which is currently placed asA. terpenensis, is being supported to some extent, but the species is unusual in having C₂₅ fatty acids as the major constituent in this group. Other factors, such as season or microenvironmental conditions, may influence observed fatty acid composition which tends to reduce the usefulness of fatty acid profiles as markers in sponge chemotaxonomy.     

Studies on Mango (<Emphasis Type="Italic">Mangifera indica,</Emphasis> L.) Kernel Fat of Some Kenyan Varieties in Meru

Four varieties (Boribo, Dodo, Kagege, and Kent) of ripe mango (Mangifera indica, L.) fruits were collected directly from the farmers in Meru County (Kenya), peeled, depulped and the stones deshelled. The mango kernels obtained were crushed, sun-dried, and extracted using petroleum ether (b.p. 40–60 °C). The fat content of the mango kernels varied from 8.5 to 10.4 % depending on the variety. The mango seed kernels constituted about (4.76–6.70 %) crude protein (Nx6.25), (1.74–2.26 %) crude ash, (71.90–76.28 %) crude carbohydrate, (1743–1782 kJ) gross energy, (1547–1576 kJ) available energy, and mean protein:energy ratios of (2.63–3.76 mg/kJ) all on a moisture free basis. The moisture content of fresh mango seed kernels varied from 42.1 to 67.6 % depending on the variety. The fat had a melting point of 25–33 °C, an iodine value of 51.08–56.79, an acid value of 4.49–7.48, free fatty acid (as oleic) of 2.26–3.76, a saponification number of 188.8–195.9, unsaponifiable matter of 2.26–2.74 %, a peroxide value of 0.40–0.75, a refractive index(40 °C) of 1.4562–1.4597 and a specific gravity of 0.9017–0.9087. Investigation of the fatty acid composition revealed(GLC) nine fatty acids: tetradecanoic acid (trace-0.05 %), pentadecanoic acid (trace–0.09 %), hexadecanoic acid (4.87–10.57 %), heptadecanoic acid (trace-O.10 %), octadecanoic acid (24.22–32.80 %), 9-(Z)-octadecenoic acid (46.37–58.59 %), 9-(Z), 12-(Z)-octadecadienoic acid (6.73–10.35 %), 9-(Z), 12-(Z), 15-(Z)-octadecatrienoic acid (0.601–1.8 %), and eicosanoic acid (0.62–1.64 %). The fat had the typical characteristics of a vegetable butter.     

Biosynthesis of Unusual Moth Pheromone Components Involves Two Different Pathways in the Navel Orangeworm, <Emphasis Type="Italic">Amyelois transitella</Emphasis>

The sex pheromone of the navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae), consists of two different types of components, one type including (11Z,13Z)-11,13-hexadecadienal (11Z,13Z-16:Ald) with a terminal functional group containing oxygen, similar to the majority of moth pheromones reported, and another type including the unusual long-chain pentaenes, (3Z,6Z,9Z,12Z,15Z)-3,6,9,12,15-tricosapentaene (3Z,6Z,9Z,12Z,15Z-23:H) and (3Z,6Z,9Z,12Z,15Z)- 3,6,9,12,15-pentacosapentaene (3Z,6Z,9Z,12Z,15Z-25:H). After decapitation of females, the titer of 11Z,13Z-16:Ald in the pheromone gland decreased significantly, whereas the titer of the pentaenes remained unchanged. Injection of a pheromone biosynthesis activating peptide (PBAN) into the abdomens of decapitated females restored the titer of 11Z,13Z-16:Ald and even increased it above that in intact females, whereas the titer of the pentaenes in the pheromone gland was not affected by PBAN injection. In addition to common fatty acids, two likely precursors of 11Z,13Z-16:Ald, i.e., (Z)-11-hexadecenoic and (11Z,13Z)-11,13-hexadecadienoic acid, as well as traces of (Z)-6-hexadecenoic acid, were found in gland extracts. In addition, pheromone gland lipids contained (5Z,8Z,11Z,14Z,17Z)-5,8,11,14,17-icosapentaenoic acid, which also was found in extracts of the rest of the abdomen. Deuterium-labeled fatty acids, (16,16,16-D₃)-hexadecanoic acid and (Z)-[13,13,14,14,15,15,16,16,16-D₉]-11-hexadecenoic acid, were incorporated into 11Z,13Z-16:Ald after topical application to the sex pheromone gland coupled with abdominal injection of PBAN. Deuterium label was incorporated into the C₂₃ and C₂₅ pentaenes after injection of (9Z,12Z,15Z)- [17,17,18,18,18-D₅]-9,12,15-octadecatrienoic acid into 1–2 d old female pupae. These labeling results, in conjunction with the composition of fatty acid intermediates found in pheromone gland extracts, support different pathways leading to the two pheromone components. 11Z,13Z-16:Ald is probably produced in the pheromone gland by Δ11 desaturation of palmitic acid to 11Z-16:Acid followed by a second desaturation to form 11Z,13Z-16:Acid and subsequent reduction and oxidation. The production of 3Z,6Z,9Z,12Z,15Z-23:H and 3Z,6Z,9Z,12Z,15Z-25:H may take place outside the pheromone gland, and appears to start from linolenic acid, which is elongated and desaturated to form (5Z,8Z,11Z,14Z,17Z)-5,8,11,14,17-icosapentaenoic acid, followed by two or three further elongation steps and finally reductive decarboxylation.     

Fatty Acid Profile Including <Emphasis Type="Italic">Trans</Emphasis> Fatty Acid Content of Margarines Marketed in Mexico

In this study, the fatty acid profile of 42 margarines marketed in Mexico was identified and quantified including the total trans fatty acids (TFA). The ratio of the sum of cholesterol-lowering fatty acids CLFA (cis-oleic, linoleic and α-linolenic fatty acids) to the sum of cholesterol-raising fatty acids CRFA (C12:0, C14:0, C16:0, TFA) and the ω6/ω3 ratio were calculated to evaluate the nutritional quality of the margarine samples. The results showed that the high content of C12:0, C14:0 and C16:0 fatty acids in some samples indicated the use of coconut and palm oils instead of partially hydrogenated fatty acids in order to decreased TFA content. Of the samples, 33% had less than 1 g/100 g of fat which could be considered as “free from TFA” according to the Danish Legislation. The ω6/ω3 ratio ranged between 5.85:1 and 25.85:1, the ideal relation being 5–10:1. The CLFA/CRFA ranged from 0.46 to 3.10, being the recommended ratio as high as possible. Of the 42 margarines, only five samples had an acceptable fatty acid profile, that is, low TFA and saturated fatty acids, high monounsaturated fatty acids content and adequate ω6/ω3 and CLFA/CRFA ratios.     

Novel Cyclopropane Fatty Acids from the Phospholipids of the Caribbean Sponge <Emphasis Type="Italic">Pseudospongosorites suberitoides</Emphasis>

The cyclopropane fatty acids 17-methyl-trans-4,5-methyleneoctadecanoic acid, 18-methyl-trans-4,5-methylenenonadecanoic acid, and 17-methyl-trans-4,5-methylenenonadecanoic acid were characterized for the first time in nature in the phospholipids (mainly PE, PG and PS) of the hermit-crab sponge Pseudospongosorites suberitoides. Pyrrolidine derivatization was the key in identifying the position of the cyclopropyl and methyl groups in the acyl chains and ¹H NMR was used to determine the trans stereochemistry of the cyclopropane ring. The phospholipids from the sponge also contained an interesting series of iso-anteiso Δ^5,9 fatty acids with chain-lengths between 17 and 21 carbons, with the fatty acids (5Z,9Z)-18-methyl-5,9-nonadecadienoic acid and the (5Z,9Z)-17-methyl-5,9-nonadecadienoic acid being described for the first time in sponges. The anteiso α-methoxylated fatty acid 2-methoxy-12-methyltetradecanoic acid was also identified for the first time in nature in the phospholipids of this interesting marine sponge. The novel cyclopropyl fatty acids could have originated from the phospholipids of a cyanobacterium living in symbiosis with the sponge.     

Identification of Novel α-Methoxylated Phospholipid Fatty Acids in the Caribbean Sponge <Emphasis Type="Italic">Erylus goffrilleri</Emphasis>

The phospholipid fatty acid composition of the Caribbean sponge Erylus goffrilleri is described for the first time. A total of 70 fatty acids with chain lengths between 13 and 29 carbons were identified in the sponge. Methyl-branched fatty acids predominated in E. goffrilleri suggesting the presence of a considerable number of bacterial symbionts. The novel fatty acids (5Z,9Z)-2-methoxy-5,9-hexadecadienoic acid, (5Z,9Z)-2-methoxy-5,9-octadecadienoic acid, (5Z,9Z)-2-methoxy-5,9-nonadecadienoic acid, and (5Z,9Z)-2-methoxy-5,9-eicosadienoic acid are described for the first time in the literature. In addition, the iso-methyl-branched fatty acids (9Z)-2-methoxy-15-methyl-9-hexadecenoic acid and (5Z,9Z)-2-methoxy-15-methyl-5,9-hexadecadienoic acid, also identified in E. goffrilleri, were identified for the first time in nature. Based on the identified metabolites it is proposed that the unprecedented biosynthetic sequence: i-17:1Δ9 → 2-OMe-i-17:1Δ9 → 2-OMe-i-17:2Δ5,9 might be responsible for the biosynthesis of the novel iso-α-methoxylated fatty acids in E. goffrilleri.     

Polyunsaturated Fatty Acid Concentrates of Carp Oil: Chemical Hydrolysis and Urea Complexation

The aims of this study were to compare three treatments in the chemical hydrolysis reaction of bleached oil from carp (Cyprinus carpio) heads and to obtain polyunsaturated fatty acid concentrates by urea complexation. The three treatments were carried out with different oil:ethanol molar ratios. In the treatment with a 1:39 molar ratio, a higher yield of free fatty acids was found. These fatty acids were submitted to urea complexation (−10 °C for 20 h, and urea–fatty acid ratio of 4.5–1). There was a 31.4% increase in monounsaturated and polyunsaturated fatty acids (MUFA and PUFA) content and a 75% decrease in saturated fatty acids (SAF) content. An increase of 85.4% in the EPA + DHA content was found. The non-urea complexing fraction can be considered a rich source of MUFA and PUFA with a total amount of 88.9%.     

Trans,n-3, and n-6 fatty acids in canadian human milk

The presence oftrans fatty acids in human milk may be a concern because of their possible adverse nutritional and physiological effects on the recipient infant. The mother's diet is the source of human milktrans fatty acids, and since these fatty acids are prevalent in many common foods of the Canadian diet, thetrans fatty acid content and the fatty acid composition of Canadian human milk were measured by gas-liquid chromatography coupled with silver nitrate-thin layer chromatography. In samples obtained from 198 lactating mothers across Canada, the average percentage of totaltrans (sum oft18∶1,t18∶2, andt18∶3) was 7.2% of breast milk fatty acids with a range of 0.1–17.2%. Analysis oft18∶1 isomer distribution indicated that partially hydrogenated vegetable oils are the major source of thesetrans fatty acids in human milk, whereas contribution from dairy products appeared to be relatively minor. Linoleci and α-linolenic acid levels were inversely related to the totaltrans fatty acids, indicating that the elevation oftrans fatty acids in Canadian human milk is at the expense of n-3 and n-6 essential fatty acids. Levels of arachidonic and docosahexaenoic acids did not correlate with their parent fatty acids, indicating that it might be difficult to elevate the levels of n-6 and n-3 C_20–22 polyunsaturated fatty acids in breast milk by increasing levels of linoleic and α-linolenic acids in the mother's diet.