Nonmethylene-interrupted Acids Research Articles

Non-methylene-interrupted fatty acids with Δ5 unsaturation in Sargassum species.

Detailed fatty acid compositions of five species of the brown algae Sargassum (S. fulvellum, S. horneri, S. boreale, S. thunbergii, and S. yezoense) were determined using silver ion solid phase extraction, gas chromatography (GC), and GC-mass spectrometry (GC-MS) techniques. In addition to a high number of typical saturated and unsaturated fatty acids, the GC-MS spectra of the 4,4-dimethyloxazoline derivatives of fatty acids revealed the occurrence of small amounts of unusual non-methylene-interrupted (NMI) fatty acids with Δ5 unsaturation, namely, 5,9-eicosadienoic (5,9-20:2), 5,11,14-eicosatrienoic (5,11,14-20:3), and 5,11,14,17-eicosatetraenoic (5,11,14,17-20:4) acids. Of these three NMI acids, the 5,9-20:2 acid was found to be the most abundant (0.4%-2.3% of the total fatty acids) and was detected for the first time in algae.

Fatty acid composition of seven Sargassum species

Fatty acid compositions of seven Sargassum species from different parts of the world were determined. C18 and C20 polyunsaturated fatty acids were major components. Arachidonic acid predominated among polyenoic acids in all the algal species examined, except for S. miyabei which had high concentrations of eicosapentaenoic acid also. Small amounts of a 20:2 nonmethylene-interrupted acid were found in all species examined. The fatty acid composition of Sargassum is species-specific; palmitic and C20 polyunsaturated fatty acid contents varied in algae collected from different sites.

Cis-5-Olefinic Nonmethylene-Interrupted Fatty Acids in Lipids of Seeds, Arils and Leaves of Japanese Yew

Fatty acids from the lipids of the Japanese yew Taxus cuspidata seeds collected at various districts all contained rich amounts of cis-5, cis-9-octadecadienoic acid (5, 9-18 : 2) (16.118.9%) with small amounts of 5, 9, 12-18 : 3 (1.83.4%) and 5, 11, 14-20 : 3 (1.02.8%) as cis-5-olefinic nonmethyleneinterrupted (NMI) acids. On the other hand, fatty acids from the neutral lipids of the arils and leaves contained appreciable amounts of 5, 11, 14-20 : 3 (leaves 8.1%and arils 1.2%) and 5, 11, 14, 17-20 : 4 (leaves 6.2% and arils 1.5%), but 5, 9-18 : 2was not detected or detected only in a trace amount in them. Fatty acids from the galactolipids of the leaves also contained small amounts of the NMI acids (5, 9, 12, 15-18 : 4 0.3%, 5, 11, 14-20 : 3 0.4%, 5, 11, 14, 17-20 : 4 1.8%), in addition to a large amount of linolenic acid (72.8%). The 5-olefinic NMI acids were generally more rich in neutral lipids than in polar lipids. The yew seeds showed nearly the same fatty acid composition during maturation.

Seasonal changes in lipid and fatty acid composition of the freshwater mollusk,Diplodom patagonicus

AbstractDiplodom patagonicus is a freshwater bivalve mollusk living in lakes of the patagonian Andes mountains in Argentina. Lipid composition and seasonal changes in the mollusk were studied in the natural habitat. In addition to common nonpolar and polar lipids, small amounts of alk‐1‐enyldiacylglycerol ethers and significant quantities of ceramide aminoethyl phosphonate were present. Total lipid content changed during the year, primarily because of decreased triacylglycerols in winter. The fatty acid composition of the lipids, remarkably different from that of marine bivalves, and even from other fresh water animals, was especially rich in the ω6 fatty acids, linoleic and arachidonic (ca. 25%), and poor in the ω3 acids, 20∶5 and 22∶6. The ω6/ω3 acid ratio was ca. 2, which is very high compared to marine bivalves. The fatty acid composition and the ω6/ω3 acid ratio were constant during the whole year, suggesting a very stable diet, rich in vegetal detritus and poor in diatoms. The influence of environmental temperature fluctuation with season on fatty acid composition also was negible. Modest proportions of 22∶2 nonmethylene‐interrupted (NMI) acids were detected and confirmed by mass spectrometry. It was shown that 20∶2 NMI acids were absent.

Fatty acid composition of ten marine algae from australian waters

Detailed fatty acid analyses are reported for ten benthic algae from Australian waters of which the data for Cladophora fascicularis (Chlorophyta); Polysiphonia pungens, Porphyra sp., Centroceras clavatum (Rhodophyta); Hormosira banksii, Ralfsia sp., and Dictyota dichomota (Phaeophyta) are presented for the first time. The analyses report the exact molecular structure of component acids which is essential for taxonomic and food chain studies. The acid 16:4ω3 could be taxonomically distinguishing for species of the Chlorophyta. The occurrence of cis-vaccenic acid (18:1ω7) in the algae reported here suggests a distribution in marine benthic algae which is wider than hitherto realised, with particular taxonomic importance for Chlorophyta species in which it occurs in high levels. Corallina officinalis was found to contain the non-methylene interrupted acids 20:2 and 22:2.