C18 Unsaturated Fatty Acid Research Articles

Measurement of diffusion coefficients of C18 unsaturated fatty acid methyl esters, naphthalene, and benzene in supercritical carbon dioxide by a tracer response technique

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMeasurement of diffusion coefficients of C18 unsaturated fatty acid methyl esters, naphthalene, and benzene in supercritical carbon dioxide by a tracer response techniqueToshitaka. Funazukuri, Sumito. Hachisu, and Noriaki. WakaoCite this: Anal. Chem. 1989, 61, 2, 118–122Publication Date (Print):January 15, 1989Publication History Published online1 May 2002Published inissue 15 January 1989https://doi.org/10.1021/ac00177a008RIGHTS & PERMISSIONSArticle Views205Altmetric-Citations43LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (566 KB) Get e-Alerts Get e-Alerts

Effect of overload of capillary gas-liquid chromatographic columns on the equivalent chain lengths of C18 unsaturated fatty acid methyl esters

Effect of overload of capillary gas-liquid chromatographic columns on the equivalent chain lengths of C18 unsaturated fatty acid methyl esters

60Co-gamma-radiolysis of C18 unsaturated fatty acid methyl esters in an oxygen free state

60Co-gamma-radiolysis of C18 unsaturated fatty acid methyl esters in an oxygen free state

Further characterization of the enzyme system producing C6-aldehydes from C18-unsaturated fatty acid in tea chloroplasts.

When C6-aldehydes (cis-3-hexenal, trans-2-hexenal and n-hexanal) were produced from C18-unsaturated fatty acids by the chloroplast lamellae as an enzyme source, oxygen which may act in singlet state is required. Light illumination, CCCP and DCMU gave no effect on the enzyme activity, though the enzyme system was localized in chloroplasts. It was likely that galactolipids and/or phospholipids played an important role in exhibiting a stable and maximal enzyme activity because of the significant decrease in the activity after the treatment of tea chloroplasts with potato lipolytic acyl hydrolase. The activity of the enzyme system was also inhibited by DCIP, MB, PMS, NTB, SKF 525-A and cytochrome c. These results suggest that the enzyme system in chloroplasts is different from the lipoxygenase–hydroperoxide lyase system in etiolated seedlings and fruits.

THE PAPER CHROMATOGRAPHIC FRACTIONATION OF PLANT STERYL ESTERS

The even-numbered C2–C22saturated and the C18-unsaturated fatty acid esters of beta- and gamma-sitosterol, stiginasterol, ergosterol, stigmastanol, and gamma-sitostanol were used separately and in model mixtures for the evaluation of existing and the development of new paper chromatographic methods for the separation and identification of these compounds. Satisfactory separations of the esters were obtained by the ascending reversed phase chromatography on cellulose or glass fiber paper using one of the following systems depending upon the number of carbon atoms in the fatty acid moiety of the ester: C2–C12, aqueous acetic acid/chloroform/paraffin oil; C8–C18, aqueous propionic acid/paraffin oil; C8–C22, acidified aqueous methanol/chloroform/paraffin oil or aqueous butyric acid/paraffin oil. The rate of migration of the esters was inversely proportional to the molecular weight and was increased by the introduction of unsaturation.The increased movement due to unsaturation has been correlated with the number of ethylenic hydrogens, and the possibility that polarity of these atoms might account for this phenomenon is discussed. The reversed phase paper partition chromatography of sterols as their esters is suggested as a potential tool for evaluation of polarity of the various attributes of the sterol nucleus in terms of the chain length of the ester fatty acid. The rule of independent contributions of the constituents of a molecule to its distribution isotherm was observed not to hold in this fatty ester series.

THE PAPER CHROMATOGRAPHIC FRACTIONATION OF PLANT STERYL ESTERS

The even-numbered C2–C22saturated and the C18-unsaturated fatty acid esters of beta- and gamma-sitosterol, stiginasterol, ergosterol, stigmastanol, and gamma-sitostanol were used separately and in model mixtures for the evaluation of existing and the development of new paper chromatographic methods for the separation and identification of these compounds. Satisfactory separations of the esters were obtained by the ascending reversed phase chromatography on cellulose or glass fiber paper using one of the following systems depending upon the number of carbon atoms in the fatty acid moiety of the ester: C2–C12, aqueous acetic acid/chloroform/paraffin oil; C8–C18, aqueous propionic acid/paraffin oil; C8–C22, acidified aqueous methanol/chloroform/paraffin oil or aqueous butyric acid/paraffin oil. The rate of migration of the esters was inversely proportional to the molecular weight and was increased by the introduction of unsaturation.The increased movement due to unsaturation has been correlated with the number of ethylenic hydrogens, and the possibility that polarity of these atoms might account for this phenomenon is discussed. The reversed phase paper partition chromatography of sterols as their esters is suggested as a potential tool for evaluation of polarity of the various attributes of the sterol nucleus in terms of the chain length of the ester fatty acid. The rule of independent contributions of the constituents of a molecule to its distribution isotherm was observed not to hold in this fatty ester series.

Octadecadienoic acids of lamb caul fat.

IN the course of investigations on the fat of rumen contents1, it was observed that the iodine values of C18 unsaturated fatty acid fractions were substantially higher than could be accounted for by the content of diene and triene acids determined by alkali isomerization2. However, the amounts of material isolated were small, and in order to investigate further the acids responsible for this anomaly, the methyl esters of the C18 unsaturated acids from the caul fat of lambs two to three weeks old, earlier described3, were used.