The composition of conjugated lipids obtained from the viscera of sea squirts (Pyura michaelseni) was investigated. The sea squirts that belong to Prochordata on animal classification, are very unique marine animal in either evolutional or biological aspects. The conjugated lipids were extracted with chloroform-methanol (2 : 1, vol/vol) after simple lipids were extracted with acetone, and phosphatidyl ethanolamine (PE), phosphatidyl choline (PC), and sphingomyelin (SM) found as main phospholipids were separated and purified by silicic acid column chromatography, Iatrobeads column chromatography, DEAE-cellulose column chromatography, and preparative TLC. The purified phospholipids were identified by TLC, IR, analysis of their degradation products, and quantitative analysis of phosphorus and fatty acid ester. The fatty acids composition of PE and PC were mainly composed of unsaturated acids (90%), in which polyunsaturated acids (C20 : 5, C22 : 6) were predominant. On the other hand, the fatty acids in SM contained hydroxy acids (h-FA) in addition to non-hydroxy acids (n-FA) (n-FA/h-FA, about 5/1) and both acids mainly composed of saturated acids, and main component of long chain bases was C18-sphingadienine. The facts that SM occurrs in a considerable amount and phosphonolipid is not found in sea squirts suggest the close relation between sea squirts and vertebrate.
High resolution gas chromatography of fatty acid methyl esters derived from marine organism lipids was carried out on wall-coated open-tubular (WCOT) glass columns of different polarity. The times required for the analysis were shortened with increasing polarity of the liquid phases, but the column efficiency decreased apparently. Effective separations of positional isomers of monounsaturated and methylene-interrupted polyunsaturated fatty acids were obtained on SILAR-5CP column. The use of the column also made possible the separation of some non-methylene interrupted fatty acids. The equivalent chain lengths of 86 fatty acid methyl esters on SILAR-5CP have been presented. Plots of carbon number vs. log relative retention time for methyl esters of normal saturated C8C22 fatty acids showed slightly positive or negative deviations from straight lines. Peak area percentage of C22 : 6 methyl ester reduced with increasing retention time, but selection of appropriate conditions permitted fair agreement with weight percentage. Fatty acid compositions of sardine, pollack, copepod, seaweed and sea urchin have been presented as examples of the analysis.
The well known property of surfactants to denature proteins was systematically reexamined to elucidate the molecular aspects of denaturation associated with the chemical structure of surfactants. Bovine Serum Albumin (abbreviated as BSA) was used for specimen. The degree of denaturation of protein was estimated as the change of molar ellipticity of BSA as obtained from CD spectra at 220nm in 50mM sodium phosphate buffer at pH 7.0. The denaturation power of the commercially available surfactants were found to be in the order LAS>SDS>DTMAC>AOS>AES>>Noionics≅Ampholytic The ampholytic and nonionic surfactants hardly denatured BSA compared with those ionic surfactants. The effect of intramolecular electrical shielding is expected for ampholytic surfactant. The longer the oxyethylene chain of AES was, the less the BSA denaturation was. The AES with more than 6 oxyethylene chains does not cause any change in the CD spectrum of BSA. A remarkable effects was observed in inhibiting denaturation of BSA caused by anionic surfactants with the addition of cationic surfactant or amine oxide.
4-Nonanolide (γ-nonalactone) and 4-undecanolide (γ-undecalactone), famous perfumes known as so-called Aldehyde C-18 and C-14, have been synthesized via lactonization of 4-hydroxy acid derived from 1-nitroalkane through the Michael addition to ethyl acrylate followed by the Nef reaction and reduction. Each step of the reaction sequence was found to proceed in fairly good yield, and thus this sequence prescribes a facile general synthetic method of γ-alkyl-γ-butyrolactone.