Chemical composition of some tissues of the Antarctic fish Notothenia rossii marmorata,fischer 1885

Muscle, liver, stomach, intestinal tract and pyloric caeca of the Antarctic fish Notothenia rossii marmorata, Fischer 1885, were analysed for dry matter, crude protein, carbohydrate, total lipids, ash, chloride, phosphorus and fluoride. It was found that the levels of these classes of substance varied considerably within ten fishes of a pre-spawning community.The highest level of protein was found in the stomach (80·8% mean value on a dry weight basis) and the lowest in the liver (39·6%); for total lipids in the liver and stomach the situation was reversed with the relevant figures being 40·8% and 11·27%, respectively. The pyloric caeca showed a maximum of ash content (6·34%), whilst only 3·92% was found in the liver. The liver was extremely rich in carbohydrates (8·22%) whilst, at 1·64%, the muscle contained least. Although N. rossii marmorata mainly feeds on the fluoride-containing krill (Euphausia superba Dana), the tissues investigated showed only a low level of fluoride (10–40 ppm).     

Zinc and copper content in marine fish samples collected from the eastern Mediterranean Sea

Zinc and copper contents in the edible parts (muscle, fillet) of 49 commercially used fish species from the eastern Mediterranean Sea (Izmir Outer Bay, Homa Lagoon/Izmir and Mersin Bay) were determined by differential pulse stripping anodic voltammetry. In the sample preparation step, all frozen fish samples were lyophilized, milled in a ball mill and finally decomposed in an oxygen plasma ashing chamber. Among the three sampling locations, the highest zinc concentration was found in Mediterranean shad (Alosa fallax nilotica) from Izmir Outer Bay with 9.73 mg/kg wet weight and the highest copper content was found in derbio (Trachinotus ovatus) from Homa Lagoon with 1.14 mg/kg wet weight. The accuracy of the concentrations determined in this study was checked by the measurements of certified reference material no. 422 cod muscle from the Commission of the European Communities, Community Bureau of Reference. All zinc and copper concentrations observed in species of the eastern Mediterranean Sea showed that fish from this area are good sources of these essential elements.     

Lipid,sterol and fatty acid composition of antarctic krill (Euphausia superba Dana)

The lipid classes, fatty acids of total and individual lipids and sterols of Antarctic krill (Euphausia superba Dana) from two areas of the Antarctic Ocean were analyzed by thin layer chromatography (TLC), gas liquid chromatography (GLC) and gas liquid chromatography/mass spectrometry (GLC/MS). Basic differences in the lipid composition of krill from the Scotia Sea (caught in Dec. 1977) and krill from the Gerlache Strait (caught in Mar. 1981) were not observed. The main lipid classes found were: phosphatidylcholine (PC) (33–36%), phosphatidylethanolamine (PE) (5–6%), triacylglycerol (TG) (33–40%), free fatty acids (FFA) (8–16%) and sterols (1.4–1.7%). Wax esters and sterol esters were present only in traces. More than 50 fatty acids could be identified using GLC/MS, the major ones being 14∶0, 16∶0, 16∶1(n−7), 18∶1(n−9), 18∶1(n−7), 20∶5(n−3) and 22∶6(n−3). Phytanic acid was found in a concentration of 3% of total fatty acids. Short, medium-chain and hydroxy fatty acids (C≤10) were not detectable. The sterol fraction consisted of cholesterol, desmosterol and 22-dehydrocholesterol.     

Synthesis and mass spectrometry of 1-acyl and 3-acyl-sn-glycerol carbonates

sn-Glycerol-1,2-carbonate was prepared fromD-serine,sn-glycerol-2,3-carbonate fromL-serine, via 1-0- or 3-0-benzyl-sn-glycerol, respectively.sn-Glycerol-2,3-carbonate was also prepared fromD-mannitol orD-serine following thesn-glycerol-3-β,β,β-trichloroethylcarbonate route.sn-Glycerol-1,2-carbonate andsn-glycerol-2,3-carbonate were acylated with saturated and unsaturated fatty acid chlorides to form 3-acyl-sn-glycerol-1,2-carbonates and 1-acyl-sn-glycerol-2,3-carbonates, respectively. The mass spectra of the enantiomeric monoacyl-sn-glycerol carbonates showed molecular ions and acyl cations (RCO⁺) of high intensity. The heterocyclic dioxolan-2-one ring was remarkably stable during electron impact.