Abstract Fifteen groups of rats were maintained on diets free of fat or supplemented with different levels of linoleate, arachidonate or linolenate. After 100 days on the diets the rats were sacrificed and liver slices were incubated with acetate‐1‐ 14 C. The individual fatty acids were separated by gas chromatography and their radioactivity was determined by liquid scintillation counting. The C 20 esters were separated by GLC, collected, and the structures of the components were determined by ozonolysis. The acetate incorporation into the various polyunsaturated fatty acids was influenced by the previous dietary conditioning. The distributions of radioactivity indicated that metabolic reactions taking place in the rat liver are modified by dietary supply of essential fatty acids.
Abstract Beef and pork testes, graafian follicles and the residual ovaries were extracted and the lipids from each were separated into lipid classes by thin‐layer chromatography. The fatty acids from each class were analyzed as their methyl esters by gas‐liquid chromatography. The lipids from the reproductive tissues were found to be relatively rich in polyunsaturated acids, many of which did not correspond to the more commonly encountered unsaturated acids. These less familiar acids were identified by comparing their chromatographic characteristics with standards of established composition. The polyunsaturated acids of lipids of the reproductive tissues examined are predominantly of the linoleate family. Only in the phospholipids of ovarian tissues did the linolenate family of acids reach high proportions of the total polyunsaturates. Nine members of the linoleate family were identified in the lipids of reproductive tissues. Five higher metabolites of oleate were identified as normal components of these tissues. Diglycerides were found as a significant lipid class only in testis tissue. The diglycerides and cholesteryl esters of beef testis contain tetracosatetraenoic acid as major fatty acids. The triglycerides of reproductive tissues are notably rich in polyunsaturated acids. In the study, 16 polyunsaturated acids were identified by ozonolysis‐reduction and several others were tentatively identified by retention time data. Two acids, previously unreported, are 10,13,16‐docosatrienoic acid and 9,12,15,18‐tetracosatetraenoic acid.
A new method for the detection and estimation of long-chain epoxy acids in seed oils is described. It depends on the measurement of increased absorption at 2.795 μ in the near infrared spectrum caused by chlorohydrins produced from epoxides by treatment with anhydrous ethereal hydrogen chloride. The method is sensitive to approximately 0.2% of epoxy acid in an oil and is specific for epoxides. Hydroxy components of a sample do not interfere since the strongly associated hydroxyl band of chlorohydrins is normally clearly resolved from other OH absorption. The presence of large amounts of vicinally unsaturated hydroxy acids, however, results in large changes in absorption intensity in the 2.8 μ region on HCl treatment and in these cases epoxide concentration cannot be accurately measured but must be estimated. These reactive hydroxy acids, which lead to spurious epoxide values by the conventional methods, lose hydroxyl during the acid treatment, and measurement of the decrease in their absorption at 2.762 μ means that their concentration may be estimated concurrently with that of epoxy components. Other reactive acids, such as cyclopropenoid acids, which result in high epoxide values by the usual methods, do not interfere. Results obtained by this spectrophotometric method are compared, for some oils, with those obtained by the usual chemical methods of epoxide determination.
Abstract The potential of the rectal route for administration of essential fatty acids (EFA) as monoglyceride (MG) was investigated. EFA‐deficient rats were supplemented with 14 mg linoleic acid/day for 3 days. Supplementation was either by oral administration as corn oil, orally as corn oil‐derived MG or rectally as MG. The patterns of polyunsaturated fatty acids (PUFA) in liver and serum lipids, characteristic of EFA deficiency, were altered in the direction of normalcy in similar magnitude by all modes of supplementation, indicating that the rectal route may be useful for administration of EFA. The amounts of phospholipids (PL) and free fatty acids (FFA) in liver changed by all modes of administration. The magnitude of change of total PL and of FFA in liver depended upon the chemical form in which linoleic acid was administered and the route of administration, indicating that these factors affect lipid metabolism.
Abstract The mechanisms of mass spectrometric fragmentation and their applications to the elucidation of structure of lipids related to fatty acids are reviewed. The mechanism of fragmentation of saturated fatty acids and the mass spectrometric determination of the position of the double bond in unsaturated esters are emphasized. The use of pyrolysis‐mass spectrometry for locating double bonds is introduced. Patterns of fragmentation of wax esters and glycerides are also given.
Supplements of purified fatty acid methyl or ethyl esters were fed at levels of 0.8% of dietary calories to each of seven groups of weanling rats for a period of 60 days. The esters were 9,12-octadecadienoate (18:2) ; 9,12,15-octadecatrienoate (18:3); 10,13-nonadecadienoate (19:2); 5,8,11,14-eicosatetraenoate (20:4); 5,8,11,14,17 - eicosapentaenoate (20:5); 4,7,10,13,16,19-docosahexaenoate (22:6); and 12:13-epoxyoctadeca-9-enoate (epoxyoleate). Rats fed a fat-free diet served as control animals. The effects of these dietary supplements on the fatty acid compositions of the nonphospholipids and phospholipids from liver microsomal and mitochondrial particles, and of unfractionated lipids from liver, testes, epididymal, and heart tissues were determined by gas–liquid chromatography. Epoxyoleate and 19:2, which are structurally related to linoleic acid, did not function as essential fatty acids as judged by the chemical and biological symptoms of fat deficiency. Dietary 20:5 and 22:6, both related to linolenate, were less active than linoleate in preventing the biological symptoms of fat deficiency, but more active in depressing the content of eicosatrienoate. Docosapentaenoic acid of the linoleate family was identified by reductive ozonolysis and shown to increase with an increase in dietary 18:2 or 20:4.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMass spectrometric location of triple bonds in fatty acids and fragmentation mechanisms of N-acylpyrrolidinesAnthony J. Valicenti, Wayne H. Heimermann, and Ralph T. HolmanCite this: J. Org. Chem. 1979, 44, 7, 1068–1073Publication Date (Print):March 1, 1979Publication History Published online1 May 2002Published inissue 1 March 1979https://pubs.acs.org/doi/10.1021/jo01321a009https://doi.org/10.1021/jo01321a009research-articleACS PublicationsRequest reuse permissionsArticle Views85Altmetric-Citations16LEARN 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 InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDisplacement Analysis of Lipids. VII. Carrier Separation of Unsaturated Fatty Acids1aRalph T. HolmanCite this: J. Am. Chem. Soc. 1951, 73, 11, 5289–5292Publication Date (Print):November 1, 1951Publication History Published online1 May 2002Published inissue 1 November 1951https://pubs.acs.org/doi/10.1021/ja01155a082https://doi.org/10.1021/ja01155a082research-articleACS PublicationsRequest reuse permissionsArticle Views43Altmetric-Citations11LEARN 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 InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
