Summary The ability of a series of 18 carbon acetylenic fatty acids to fulfill the unsaturated fatty acid requirements of Escherichia coli and Saccharomyces cereuisiae was investigated. Despite their high melting points (>4O”C), several isomers of the acetylenic fatty acids were as efficient or more efficient in supporting growth than the analogous fatty acid having a cis-double bond. The efficiencies of the different positional isomers in supporting cell proliferation varied from essentially 0 cells per fmol for the 2-5 and 13-17 isomers to high values when the acetylenic bond was near the center of the chain: e.g. 45 E. coli and 5.5 S. cereuisiae cells/fmol for the 10 isomer. A striking ineffectiveness of the 9 isomer was observed with E. coli. The 7, 8 and 10 isomers were at least lo-fold more efficient than any of the other positional isomers in supporting the growth of E. colt In contrast, the 9 isomer was among the most effective acetylenic fatty acids tested with the yeast mutant. Chromatographic analysis of the extracted lipids indicated that each of the acetylenic isomers tested (except A2 and A3) could be esterified by the prokaryotic and eukaryotic microorganisms. The content of unsaturated plus cyclopropane acids observed when growth ceased in E. coli cultures supplemented with gro~h-limiting concentrations of the acetylenic fatty acids ranged from approx. 15 mol% for the 8 isomer to approx. 35 mol% for the 14 and 17 isomers. The 8-11 isomers were observed to be esterified predominantly at the two position in phosphatidylethanolamine of E. coli and in phosphatidylcholine of S. cereuisiae.

The ability of a series of 18 carbon acetylenic fatty acids to fulfill the unsaturated fatty acid requirements of Escherichia coli and Saccharomyces cerevisiae was investigated. Despite their high melting points (>40°C), several isomers of the acetylenic fatty acids were as efficient or more efficient in supporting growth than the analogous fatty acid having a cis-double bond.

A series of isomeric methyl octadecynoates was analyzed by mass spectrometry; each isomer gave a unique spectrum. The characteristic ions were those resulting from a McLafferty rearrangement of the allenic sites or of the already-rearranged allenic sites. The acetylenic esters were also subjected to oxymercuration whereupon a carbonyl group was formed at either of the original actylenic carbon atoms providing two oxostearates. Further reaction with NaBH4 formed hydroxy esters which, after silylation, gave diagnostic mass spectra indicative of the triple bond location. Applied to esters with both double and triple bonds, this procedure permitted differentiation between the two types of unsaturation. Methoxyl groups marked the original double bond locations and hydroxyls did so for triple bonds.

The polymorphism of 25 glycerol trioctadecenoates with double bonds ranging from Δ4-Δ17 was investigated by differential scanning calorimetry. Triglycerides withcis bonds in odd positions Δ7-Δ13 exhibited three intermediate melting (β′-) forms, but those withcis bonds in even positions, exceptcis Δ4, lacked β′-forms. Among thetrans compounds, only Δ11, 13, and 14 showed β′-forms. Thecis andtrans Δ5 triglycerides were unusual, because they readily assumed low melting (α-) forms that were not easily converted to high melting (β-) forms. β-Form mp of compounds in each series (cis ortrans) alternated depending upon double bond position; an even position correlated with high mp. Heats of fusion (ΔHf) for β-forms, likewise, fluctuated with double bond position but nonuniformly;trans Δ6 had the highest ΔHf (43 cal/g),cis Δ12 the lowest (21 cal/g).

Although acetylenic acids are not normally found in mammalian tissues, octadecynoyl-CoA esters can serve as substrates for rat liver microsomal acyl-CoA: phospholipid acyltransferases. The relatively high rate of transfer to the 2-hydroxyl of 1-acylglycerol-3-phosphorylcholine by the 5-, 9-, and 12-positional cis, trans and yne isomers of acids supports the concept that π-bonds at these positions facilitate esterification irrespective of configuration. The preferred positional isomers for transfer to the 1-hydroxyl, however, are different for the cis and yne derivatives, indicating a sensitivity of the enzyme(s) to configuration. In the latter transfer, an alternating selectivity occurred with the acetylenic isomers between 8 to 13 that was opposite to the pattern for the cis-octadecenoyl transfers.

The chromatographic behaviour of the methyl octadecynoates on thin layers of silica impregnated with silver nitrate is reported.

The conversion of linoleic acid to its hydroperoxide by soybean lipoxygenase and the conversion of arachidonic acid to prostaglandin E2 by a preparation of sheep seminal vesicles, both previously shown to be irreversibly inhibited by eicosa-5,8,11, 14-tetraynoic acid, are similarly inhibited by octadeca-9,12-diynoic acid. No other member of a series of ten diynoic fatty acids, nor any of fifteen positional isomers of octadecynoic acid, showed detectable inhibition. Of a group of four isomeric octadecenynoic acids, having one acetylenic and either a cis- or trans-ethylenic bond in the 9 or 12 positions, none significantly inhibited soybean lipoxygenase, whereas only one, octadec-cis-9-en-12-ynoic acid failed to strongly inhibit prostaglandin synthesis.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSelective transfers of trans-ethylenic acids by acyl coenzyme A. Phospholipid acyltransferasesHarumi Okuyama, William E. M. Lands, Frank D. Gunstone, and J. A. BarveCite this: Biochemistry 1972, 11, 23, 4392–4398Publication Date (Print):November 1, 1972Publication History Published online1 May 2002Published inissue 1 November 1972https://pubs.acs.org/doi/10.1021/bi00773a028https://doi.org/10.1021/bi00773a028research-articleACS PublicationsRequest reuse permissionsArticle Views26Altmetric-Citations71LEARN 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

Chemischer InformationsdienstVolume 3, Issue 48 Organic Dyes ChemInform Abstract: IR- UND RAMAN-UNTERSUCHUNGEN MONOUNGESAETTIGTER OLEFINISCHER UND ACETYLENISCHER FETTSAEUREN UND DEREN DERIVATE J. E. D. DAVIES, J. E. D. DAVIESSearch for more papers by this authorP. HODGE, P. HODGESearch for more papers by this authorJ. A. BARVE, J. A. BARVESearch for more papers by this authorF. D. GUNSTONE, F. D. GUNSTONESearch for more papers by this authorI. A. ISMAIL, I. A. ISMAILSearch for more papers by this author J. E. D. DAVIES, J. E. D. DAVIESSearch for more papers by this authorP. HODGE, P. HODGESearch for more papers by this authorJ. A. BARVE, J. A. BARVESearch for more papers by this authorF. D. GUNSTONE, F. D. GUNSTONESearch for more papers by this authorI. A. ISMAIL, I. A. ISMAILSearch for more papers by this author First published: November 28, 1972 https://doi.org/10.1002/chin.197248066Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume3, Issue48November 28, 1972 RelatedInformation

The Raman spectra of CCl4 solutions of the 6,12; 7,12; 8,12; 9,12; and 10,12 isomers of octadecadiynoic acid and of the octadecadienoic acid methyl esters of both the cis,cis and trans,trans series are reported. Provided that there are two or more methylene groups between the unsaturated groups, the double and triple bond vibrational wavenumber values are close to those found in monounsaturated derivatives. An attempt has been made to obtain a correlation between the relative intensities of the nu(CequalsC) and delta(CH2) bands and the ratio of the number of double bonds to methylene groups in the molecule.

The sixteen octadecynoic acids and the fifteen octadec-trans-enoic acids have been synthesised.