16 Fatty Acids and Related Compounds By N. POLGAR The Dyson Perrins Laboratory Oxford 1 Reviews THE first volume' of 'Topics in Lipid Chemistry' published this year contains comprehensive reviews on cyclopropane and cyclopropene fatty acids,'" milk lipids,Ib structure determination of fatty esters by gas-liquid chromatography," hydrogenation with homogeneous and heterogeneous cata1ysts,Id optically active long-chain compounds and their absolute configurations," and mass spectro- metry of fatty acid derivatives.1s Topics reviewed elsewhere include the odd- numbered polyunsaturated fatty acids,2 the Cecropia juvenile hormones and their analog~es,~.~ and the my cob act in^.^ The occurrence structure and meta- bolism of the nonisoprenoid aliphatic hydrocarbons of bacteria have been re- viewed,6 with emphasis on recent work on the chemistry and biosynthesis of the hydrocarbons of Sarcina lutea.An issue' of Chern. and Phys. Lipids is devoted to the chemistry and metabolism of sphingolipids. 2 Isolation and Structure of Natural Acids Normal-chain natural products reported include 13~-hydroxy-cis-9,trans-1 1 -octadecadienoic acid* (the enantiomer of coreolic acid) and its lactone,' isolated from the seed oil of Monnina emarginata(Polygalaceae),a plant native to Uruguay ; this seed oil also contains small amounts of 13-0x0-trans-9-octadecenoic and 13-0x0-trans-9,trans-11-0ctadecadienoic acids.' A rich new source and useful material for the laboratory preparation of cis-15-tetracosenoic and cis-17-hexacosenoic acids is the fat of the commercially available Tropeolum speciosum seeds.'Topics in Lipid Chemistry,' ed. F. D. Gunstone Logos Press London vol. 1 1968; (a) W. W. Christie p. 1 ; (h) W. R. Morrison p. 51 ; (c) G. R. Jamieson p. 107; (d) E. N. Frankel and J. H. Dutton p. 161 ;(e)C. R. Smith jun. p. 277 v) J. A. McCloskey p. 369. H. Schlenk Progr. Chem. Fats and Lipids 1970 9 587. B. M. Trost Accounts Chem. Res. 1970 3 120. Yu. S. Tsizin and A. A. Drabkina Russ. Chem. Rev. 1970 39 498. G. A. Snow Bacreriol. Rev. 1970 34 99. ' P. W. Albro and J. C. Dittmer Lipids 1970 5 320. ' A collection of papers dedicated to H. E. Carter ed. C. C. Sweeley Chem. and Phys. Lipids 1970 5 (No. I) pp. 1-300. B. E. Phillips C.R. Smith jun. and L. W. Tjarks Biochim. Biophys. Acfa 1970 210 353. B. E. Phillips C. R. Smith jun. and L. W. Tjarks J. Urg. Chern. 1970,35 1916. lo C. Litchfield Lipids 1970 5 144. 524 N. Polgar There has been continued interest in various groups of branched-chain acids. From Mycobacterium phlei series of iso- anteiso- and (n-8)-methyl-substituted fatty acids," as well as monoenoic acids12 containing 20 to 27 carbon atoms including a series of 5-enoic acids have been isolated. A study on the structural relationship between the latter and the mycolic acids synthesised by the same organism led to the suggestion that the 5-enoic acids may serve as precursors for the mycolic acids." The mycolic acids from Corynebacterium hofmanii include a dienic C36 acid having the structure [l ; R' = Me.(CH,),CH:CH.(CH,),.; R2 = Me-(CH,),.CH :CH.(CH,),.] with ethylenic linkages in each alkyl chain. The lower my- colic acids (up to about C,,) previously thought to be characteristic of Cory- nebacteria have now been found also to occur as major components of the acylglucoses of Mycobacterium srnegmatis grown in the presence of gl~cose,'~ and also as dimycolate of trehalose ('cord factor') in Nocardia asteroides.' R .CH( OH)*CH R2C02 H (1) Other mycolic acids studied include those of Mycobacterium paratuberculosis.' Among the mycolic acids occurring in this organism are a series of dicarboxylic acids which are found to be present as esters derived from eicosan-2-01; such esters would represent according to a hypothetical biogenetic scheme presented earlier,' 'intermediates in the formation of dicarboxylic mycolic acids from higher ketomycolic acids.Comparative studies' of the molecular rotations shown by de- rivatives of various mycolic acids from Nocardia and Mycobacteria indicate that the previous assignment of 2R,3R configurations is valid for all the acids studied. 3 Synthesis Normal-chain Acids.-1 1 -Oxo[ 1,ll-' 4Cz]eicosanoic and 13-oxo[ 1,l 3-14C,]- docosanoic acids" have been synthesised by the acylation of cyclic enamines ; the 0x0-acids can be reduced to the corresponding saturated fatty acids. thus providing a method for the synthesis of long-chain fatty acids containing 14C in two positions. Methyl esters of polyunsaturated fatty acids labelled with tritium have been prepared by partial stereoselective reduction of the corresponding acetylenic esters with tritiated disiamylborane (bis-3-methyl-2-butylborane) followed by protonolysis with tritiated acetic acid.20 I.M. Campbell and J. Naworal J. Lipid Res. 1969 10 593. l2 C. P. Asselineau C. S. Lacave H. L. Montrozier and J.-C. Prome European J. Biorhem. 1970 14 406. I' M. Welby-Gieusse M. A. Laneelle and J. Asselineau European J. Biochem. 1970 13 164. 'P. J. Brennan D. P. Lehane and D. W. Thomas European J. Biochem. 1970,13 1 17. Is T. loneda E. Lederer and J. Rozanis Chem. and Phys. Lipids 1970 4 375. l6 M. A. Laneelle and G. Laneelle European J. Biochem. 1970 12,296. '' A. H. Etemadi and J. Gasche Bull. SOC.Chim. biol.1965 47,2095. C. Asselineau G. Tocanne and J.-F. Tocanne Bull. SOC.chim. France 1970 1455. l9 J. S. W. Hunter and R. J. Light Biochemistry 1970,9 4283. 2o D. S. Sgoutas H. Sanders and E. M. Yang J. Lipid Res. 1969,10,642. Fatty Acids and Related Compounds 525 Ten octadecadiynoic acids and the related cis,cis-and trans,trans-octadeca- dienoic acids,21 as well as some new C1 m-alicyclic and acyclic acids,22 including 9-pentadecenoic and 6,12-pentadecadienoic acids have been prepared. A synthesis of trans-3,cis-5-tetradecadienoic(megatomoic) acid the sex attractant of the black carpet beetle (Attagenus megatoma) starting from 1-decyne has been reported.23 The preparations and properties of conjugated oxo-octadecenoic24 and dioxo-octadecenoic acids' have been described.The 8- 9- and 10-pentadecynoic acids have been synthesised by refinements26 of the five-step Ahmad-Strong method. Racemic helenynolic acid (4) has been prepared2' from crepenynic acid (2) by epoxidation followed by base-catalysed rearrangement of the cis-epoxy-acid (3);the latter has been found to be present among the epoxy-acids of HeEichrysum bracteaturn seed oil and the synthesis described might represent the pathway by which helenynolic acid is produced by this seed oil from the crepenynic acid also present. Me.(CH,),C~CCH,.CHfCH.(CH,),CO,H (2) /*\ Me.(CH2)4CrCCH2CHC He( CH ,),-CO ,H Me.(C H J4-C fCCH f CH.CH(0H),(CH,),.CO H (4) Cycloalkane and Cycloalkene Acids-The first total syntheses of the prosta- glandins F2 (6 ; R = H) and E2 (7) as their naturally occurring optically active forms have been published;28 these syntheses represent an adaptation of the earlier described2' stereocontrolled syntheses of the racemic forms of these prostaglandins and involve resolution of the intermediate hydroxy-acid (5).The common intermediate the (+)-11,15-bistetrahydropyranyIether (6; R = tetrahydropyranyl) of prostaglandin F2, has now also been employed3' for total syntheses of the natural forms of the prostaglandins F, (8) and El (9) (the first total synthesis of the latter had been published in 19693'). 21 F. D. Gunstone and M. Lie Ken Jie Chem. and Phys. Lipids 1970,4 1. 22 A. K. Sen Gupta and H. Peters Chem. and Phys. Lipids 1969,3 371. 23 J. 0.Rodin M.A. Leaffer and R. M. Silverstein J. Org. Chem. 1970 35 3152. 24 A. Tubul J. Arnoux E. Ucciani and M. Naudet Chem. and Phys. Lipids 1970,4,208. 25 M. Naudet J. Arnoux and A. Tubul Chem. and Phys. Lipids 1970,4 217. 26 D. R. Howton and R. A. Stein J. Lipid Res. 1969 10 631. 27 H. B. S. Conacher and F. D. Gunstone Lipids 1970,5 137. 28 E. J. Corey T. K. Schaaf W. Huber U. Koelliker and N. M. Weinshenker J. Amer. Chem. Soc. 1970,92 397. 29 E. J. Corey N. M. Weinshenker T. K. Schaaf and W. Huber J. Amer. Chem. SOC. 1969,91 5675. 30 E. J. Corey R. Noyori and T. K. Schaaf J. Amer. Chem. SOC.,1970,92,2586. 31 E. J. Corey I. Vlatias and K. Harding J. Amer. Chem. Soc. 1969 91 535. 526 N. Polgar HC Other syntheses published in this field include total syntheses of the (-t)-prostaglandins E2 and F2=via tricarbocyclic intermediate^,,^ and of the methyl ester of (*)-prostaglandin E (distinguished from prostaglandin E2 by an addi- tional cis-double bond between C-17 and C- 18) through endo-bicyclohexane intermediate^.^^ A total synthesis34 of prostaglandin El incorporating stereo- chemical control at the nuclear chiral centres involves construction of a cis-hydrindanone system in which a thermodynamically predominant exo-side- chain orientation prevails.Details are available35 of the synthesis36 of methyl sterculate (10; n = 7) from methyl stearolate and diazoacetic ester. Another synthesis37 involves photolysis of diazomethane in the presence of methyl stearolate. Its lower homologue methyl malvalate (10; n = 6) has been synthesised by several procedures3* including a route via the intermediate (1 1); the latter was obtained by reaction of 1-chlorohexadec-7-yne with ethyl diazoacetate.Syntheses adaptable for 32 E. J. Corey 2.Arnold and J. Hutton Tetrahedron Letters 1970 307. 33 U. Axen J. L. Thompson and J. E. Pike Chem. Comm. 1970,602. 34 D. Taub R. D. Hoffsommer C. H. Kuo H. L. Slates Z. S. Zelawski and N. L. Wendler Chem. Comm. 1970 1258. 35 W. J. Gensler M. B. Floyd R. Yanase and K. M. Pober J. Amer. Chem. SOC.,1970 92 2472. 36 Cf. Ann. Reports (B) 1969 66 546. 37 E. R. Altenburger J. W. Berry and A. J. Deutschman J. Amer. Oil.Chemists' SOC. 1970 47 77. 38 W. J. Gensler K. W. Pober D. M. Solomon and M. B. Floyd J. Org. Chem.1970,35 2301. Fatty Acids and Related Compounds 527 preparing methyl malvalate labelled with 14C in various positions including the cyclopropene methylene group are also described.39 FFt2 Me-(CH,),-C=C.(CH,),.CO,Me (10) CH.CO2 H /\ Me.(CH,),.C=C.(CH,),Cl (1 1) Branched-chain Acids.-~~,4~,6~,8~-Tetramethyloctacosanoic acid (13) a major component of the branched-chain acids of tubercle bacilli has been synthesised4' via methyl 2~,4~,6~-trimethyldodec-ll-enoate (12; n = 2)41 and 2~,4~,6D,8~- tetramethyltetradec-13-enoate(12 ;n = 3) followed by chain-lengthening of the latter. D CH :CH-(CH,),.(CHMeCH,),,CHMe.CO,Me-CO,Me (12) D D Me.(CHz),,-(CHMeCH,)3CHMe.C0,H (13) A stereochemically controlled synthesis42 of methyl natural bixin (15) involves 5-methoxycarbonyl-3-methylpenta-cis-(Z)-2-~runs~~)~-dien-l -a1 (14) as the key intermediate.This synthesis confirms the cis-(Z)-4-structure previously assigned on the basis of n.m.r. studies ;it also represents the first stereochemically controlled direct total synthesis of a carotenoid containing a methylated cis-double bond. MeOZC MeOzC (15) A new stereospecific route43 to the Cecropia juvenile hormones (16) and (17) utilises a single intermediate for both compounds. Other recent syntheses include 39 W. J. Gender K. W. Pober D. W. Solomon R. Yanase. and M. B. Floyd Chem. Comm. 1970,287. 40 G. Odham E. Stenhagen and K. Waern Arkiv Kemi 1970,31 533. 41 Cf. Ann. Reports (B) 1969,66 547. 4z G. Pattenden J.E. Way and B. C. L. Weedon J. Chem. SOC.(0,1970,235. 43 E. J. Corey and H. Yamamoto J. Amer. Chem. SOC., 1970,92,6636. 528 N. Polgar some highly stereoselective to the hormone (16) and a stereospecific route47 to a biologically active isomer of the C17 hormone (17). A short non- stereospecific synthesis recently reported48 provides a synthetic approach to the pure hormones as well as their stereoisomers. C r r Et.CMeCH.(CH,),CR :CH+(CH,),CMe:CHC0,Me \/ 0 (16) R = Et (17) R = Me The preparation of a series of tritium-labelled long-chain iso-acids by anodic syntheses has also been described.49 4 Reactions A soluble enzyme preparation from a pseudomonad has been shown to catalyse the stereospecific hydration of cis-double bonds between C-9 and C-10 in oleic5' as well as in linoleic acid5' to yield the corresponding 10D-hydroxy-acids.The same enzyme system has also been found5' to catalyse the stereospecific con- version of cis- and trans-9,lO-epoxystearic acids to threo-and erythro-9,lO- dihydroxystearic acids respectively. The Diels-Alder addition products of ethylene and trans,trans-9,11 -octa- decadienoic acid have been subjected to oxidation with per acid^^^ and ozone,54 and the resulting products investigated. The effect of solvents upon the cyclisa- tion of methyl ricinelaidate by solvolysis of its tosylate has been studied and the mechanism disc~ssed.~ The formation of 1,4-epoxides from methyl linoleate and related esters by reaction with toluene-p-sulphonic acid and an appropriate solvent has been de~cribed.~~ The oxymercuration4emercuration of long-chain unsaturated esters has been utilised for preparative procedures ;57 the presence of a substituent (OH OMe OAc) has been found to affect the proportion of the resulting isomeric products and in some cases give rise to novel products.44 R. J. Anderson C. A. Henrick and J. B. Siddall J. Amer. Chem. SOC.,1970,92 735. 45 E. E. van Tamelen and J. P. McCormick J. Amer. Chem. Soc. 1970,92,737. 46 W. S. Johnson T. J. Brocksom P. Loew D. H. Rich L. Werthemann R. A. Arnold Tsung-tee Li and D. J. Faulkner J. Amer. Chem. SOC.,1970,92 4463. 47 E. J. Corey and H. Yamamoto J. Amer. Chem. SOC.,1970,92,6637. 48 J. A. Findlay W. D. MacKay and W. S.Bowers J. Chem. SOC.(C),1970 2631. 49 I. Bjorkhem and H. Danielsson European J. Biochem. 1970 14,473. W. G. Niehaus jun. A. Kisic D. J. Bednarczyk and G. J. Schroepfer jun. J. Biol. Chem. 1970,245 3790. '' G. J. Schroepfer jun. and W. G. Niehaus jun. J. Biol. Chem. 1970,245 3798. 52 W. G. Niehaus jun. A. Kisic A. Torkelson D. J. Bednarczyk and G. Schroepfer jun. J. Biol. Chem. 1970 245 3802. 53 E. J. Dufek L. E. Gast and J. P. Friedrich J.Amer. Oil Chemists' Soc. 1970,47 47. 54 E. J. Dufek J. C. Cowan and J. P. Friedrich J. Amer. Oil Chemists' SOC.,1970,47 51. 55 E. Ucciani A. Vantillard and M. Naudet Chem. and Phys. Lipids 1970 4 225. 56 G. G. Abbot F. D. Gunstone and (in part) S. D. Hoyes Chem. and Phys. Lipids 1970 4 351. 57 F. D. Gunstone and R.P. Inglis Chem. Comm. 1970 877. Fatty Acids and Related Compounds 529 Methods used for the preparation of epiminostearates have been compared ;5 it is found that the addition of NN-dichlorourethane to olefins results in mixtures of cis- and trans-aziridines whereas the iodine isocyanate method is stereo- specific cis-olefins giving rise to cis- and trans-olefins forming trans-aziridines. Reaction of thallium(II1) acetate with an excess of aliphatic carboxylic acids results in the formation of the corresponding a-acyloxy-acids.5 Undec-lO-enoic acid in the presence of polyphosphoric acid has been shown6' to yield a mixture of 2-n-hexylcyclopent-2-enone and 2-n-pentylcyclohex-2-enone. 5 Glycerol and Diol Lipids The structures (18; X = Me R = 11,12-methyleneoctadecanoyl)and (18; X = H R = 10-methyloctadecanoyl) derived from diol esters of ornithine have been proposed61 for lipids isolated from BruceIla melitensis and Mycobac-terium bouis respectively.Me.(CH2)1,-CH(OH).CH,CONHCHCO,CHX.CH,OR I (CH213NH2 (18) Stereospecific syntheses of optically active unsaturated 1,2-diglycerides ilia 1,2-isopropylidene-sn-glycero1-3-~~~-trichloroethylcarbonate have been repor- ted.62 Dihydroxyacetone has been to be a convenient starting material for the synthesis of 1,3-diglycerides since it is readily acylated with fatty acyl chlorides and the central keto-group is rapidly reduced by borohydride in tetrahydrofuran solution. The mass spectra of deuteriated glycerol 1,3-distearates have been The diesters of 2,3-dihydroxy-octadecane,isolated from the preen gland of the green pheasant have been Neutral diol plasmalogens have been synthesised.66 The positional distribution of fatty acids in the phospholipids and triglycerides of M.smegmatis and M. bo~is,~' as well as the structure of the phospholipids of Arthrobacter simplex68 containing 2-hydroxy-acids have been investigated. A procedure has been described for the separation of phosphatidylcholines (lecithins) according to the number of ethylenic bonds in their fatty acid residues;69 the 58 T. A. Foglia G. Maerker and G. R. Smith J. Amer. Oil Chemists' Soc. 1970,47 384. E. C. Taylor H. W. Altland and G. McGillivray Tetrahedron Letters 1970 5285. 6o M. F. Ansell and T. M. Kafka Tetrahedron 1969 25 6025." J.-C. Prome C. Lacave and M. A. Laneelle Compt. rend. 1969 269C. 1664. 62 F. R. Pfeiffer C. K. Miao and J. A. Weisbach J. Org. Chem. 1970,35,221. 63 P. H. Bentley and W. McCrae J. Org. Chem. 1970 35 2082. " A. Morrison M. D. Barratt and R. Aneja Chem. and Phys. Lipids 1970 4 47. h5 K. Saito and M. Gamo J. Biochem. (Tokyo) 1970,67,841. " J. G. Kramer and H. K. Mangold Chem. and Phys. Lipids 1970 4 332. " R. W. Walker H. Barakat and J. G. C. Hung Lipids 1970,5 684. 68 I. Yano Y.Furukawa and M. Kusunose Biochim. Biophys. Acta 1970,210 105. 69 R. J. King and J. A. Clements J. Lipid Res. 1970 11 381. 530 N. Polgar procedure involves chromatography ofthe mercuric acetate adducts on a column of partially methylated dextran (Sephadex LH-20).A general synthesis7'v7 of glycerophospholipids involves the direct phosphory- lation of the appropriate alcohols with phosphatidic acids using tri-isopropyl- benzenesulphonyl chloride as a condensing agent. 2-Acylphosphoglycerides have been prepared7 by a procedure involving phosphorylation of 1-alkenyl-2-acylglycerols.Syntheses of 2-monoacylphos-phoglycerides with a 14C-labelled unsaturated acyl group from their 1,2-diacyl- derivatives by hydrolysis of the 1-acyl group with purified lipase preparations are also described. A 3-acyl-sn-glycero-l-phosphorylcholine, representing an antipode of the naturally occurring lysophosphatidylcholines has been s~nthesised~~ from 3,4-isopropylidene-~-mannitol. Other syntheses of model compounds include those of various analogues of deoxylysophosphatidyIcholines,75phosphogly-cerides derived from acetylenic and cyclopropane fatty and a synthesis of threonine phosph~glycerides.~ A procedure78 for the preparation of 1-alkyl-2-acylphosphoglycerides labelled with [l-14C]oleic acid is based upon the acyla- tion of the cadmium chloride complex of 1-alkylglycero-3-phosphorylcholine.In the course of studies of the phosphonolipids a procedure for the synthesis of phosphonic acid analogues of the racemic as well as both enantiomeric forms of phosphatidyl(N-methy1)ethanolamineshas been developed ;79 phosphonic acid analogues with a P-C bond of phosphatidic acids have also been synthesised.80 6 Sphingolipids A stereospecific synthesis of sphinganine (19)(previously named dihydrosphingo- sine) from the readily available 3-amino-3-deoxy-l,2 :5,6-di-O-isopropylidene-a-D-allofuranose has been described,8 and the occurrence of sphinga-4,8-dienine in oyster sphingoglycolipid reported.82 D D Me.(CH,) ,.CH(OH).CH(N H,).CH ,OH (19) 'O R.Aneja J. S. Chadha and A. P. Davies Biochim. Biophys. Acta 1970,218 102. 71 R. Aneja and A. P. Davies Chem. and Phys. Lipids 1970 4 60. 72 H. Eibl and W. E. M. Lands Biochemistry 1970,9 423. 73 A. J. Slotboom G. H. de Haas G. J. Burbach-Westerhuis and L. L. M. van Deenen Chem. and Phys. Lipids 1970,4 30. 74 H. Eibl and 0. Westphal Annalen 1970 738 161. '' H. Eibl and 0. Westphal Annalen 1970 738 170. 76 D. L. Turner M. J. Silver E. Baczynski R. R. Holburn S.F. Herb and F. E. Luddy Lipids 1970 5 650. 77 J. W. Moore and M. Szelke Tetrahedron Letters 1970 4423. 78 A. Poulos J. Lipid Res. 1970 11,496. '' E. Baer and S. K. Pavanaram Canad. J. Biochem. 1970,48,979. *O E. Baer and H. Basu Canad. J. Biochem. 1970,48 1010. " E. J. Reist and P. H. Christie J. Org. Chem. 1970 35 3521. 82 A. Hayashi and T. Matsubara Biochim. Biophys. Acta 1970 202 228. Fatty Acids and Related Compounds 531 A sphingolipid of the anaerobic bacterium Bacteroides mefaninogenicus has been foundB3 to be a ceramide phosphorylglycerol phosphate. Studies of various synthetic ceramides by g1.c.-mass spectrometry of their trimethylsilyl ether derivatives have been de~cribed.~~’~ A sensitive estimations6 of sphing-4-enine (previously named sphingosine) involves fluorescence measure- ments of a complex formed with 1-naphthylamino-4-sulphonicacid.7 Glycolipids The structures of acylglucoses isolated from Corynebacteria and M ycobacteria grown in the presence of glu~ose,’~ as well as those of the diesters of trehalose (‘cord factors’) produced by Nocardia asteroides and N. rhodochrous’ have been investigated and further studies reported on the complex glycolipids from Myco bacteria8 7-’ and N ~cardia.~~.~ A synthesis of phosphatidylcholine analogues derived from sugar alcohols has been de~cribed.’~ 8 Other Natural Compounds Related to Fatty Acids Further studies of the methyl-branched hydrocarbons occurring in blue-green algae have been reported.”-’ The presence of homologous series of mono- di- and trimethyl-substituted hydrocarbons in the egg of the tobacco hornworm Manduca sexta has been demonstrated,’* the branching points of the di- and tri-methylalkanes are near the centre of the alkyl chain and separated by three carbon atoms.Homologous series of long-chain 3,7,11-and 4,8,12-trimethyl- alkanes are the major constituents of the cuticular alkanes of the ant Attu colombicu.” In studies of the stereochemistry of the homologous phthiocerols A (20; n = 20 and 22 X = OH Y = OMe R = Et) and B (20;n = 20 and 22 X = OH Y = OMe R = Me) constituents of tubercle bacilli conversion of the phthiocerols A into the optically active hydrocarbons (20; n = 20 and 22 X = H Y = H R = Et) resulted in the assignment”’ of S-configuration to the asymmetric ” D.C. White and A. N. Tucker Lipids 1970,5 56. 84 S. Hammarstrom B. Samuelsson and K. Samuelsson J. Lipid Res. 1970 11 150. a5 S. Hammarstrom J. Lipid Res. 1970 11 175. a6 L. Coles and G. M.Gray J. Lipid Res. 1970 11 164. ” J. Markovits and E. Vilkas Biochim. Biophys. Acta 1969 192,49. I. Azuma Y. Yamamura and A. Misaki J. Bacteriol. 1969 98 331. 89 C1. Amar-Nacash and E. Vilkas Bull. SOC.Chim. biol. 1970,52 145. 90 F. Kanetsuma and G. S. Blas Biochim. Biophys. Acta 1970 208 434. 91 P. V. Narasimh Acharya and D. S. Goldman J. Bacteriol. 1970 102 733. q2 M. Guinand M. J. Vacheron and G. Michel F.E.B.S. Letters 1970 6 37. 93 M. A. Laneelle and J. Asselineau F.E.B.S. Letters 1970 7 64. y4 H. Eibl and 0.Westphal Annafen 1970 738 174. 95 J. Han and M. Calvin Chem. Comm. 1970 1490. 96 E. Gelpi H. Schneider J. Mann and J. Oro Phytochemistry 1970 9,603. 97 S. W. G. Fehler and R. J. Light Biochemistry 1970,9,418. ” D. R.Nelson and D. R. Sukkestad Biochemistry 1970,9,4601. ” M. M. Martin and J. G. MacConnell Tetrahedron 1970 26 307. loo K. Maskens and N. Polgar Chem. Comm. 1970 340. 532 N. Polgar centre bearing the methyl branch (C-4of the phthiocerols A). Moreover conver- sion of the phthiocerols A and B into the methoxyphthiocerans (20; n = 20and 22 X = H Y = OMe R = Et) and (20;n = 20 and 22 X = H,Y = OMe R = Me) respectively and comparison of these methoxy-derivatives with synthetic compounds showed that the centres bearing the methoxy-group have R-configuration.' The opposite configurations have been deduced' O2 by the method of molecular-rotation differences with calculations of rotatory powers based upon Brewster's rules; the asymmetric centres of the P-diol group (C-9 and C-11 ofthe phthiocerols A) were assigned R,R-configurati~ns.'~~ Me.(CH,);CHCH,CH.(CH,),.CHCHR 'x It I X Me Y Terrestrol (3,7,1l-trimethyldodeca-6,lO-dienol),isolated from male bumble- bees has been shown to have L-configuration'04 by a study of the cyclic acetals prepared from the corresponding aldehyde and D-( -)-propane- 1,2-diol.In studies of the chlorosulpholipids a novel class of lipids discovered in Ochromonas danica the most abundant sulpholipid of this organism has been shown to be a disulphate of 2,2,11,13,15,16-hexachloro-n-docosane-1,14-dio1.105 Cyanolipids consisting of long-chain fatty acids esterified with an unsaturated isoprenoid hydroxy- or dihydroxy-nitrile have been isolated from the seed oils of various plants.'06,107 9 Miscellaneous A methodlo8for establishing the position of double bonds in mono- and poly- enoic long-chain esters involves reduction of their methoxymercuration products with sodium borohydride followed by combined g.1.c.-mass spectrometry of the resulting methoxylated esters.The mercuric acetate adducts of unsaturated fatty acids have been shown'0g to be suitable for determination of the cis:trans ratio by n.m.r. spectroscopy. A mass spectrometric method" for discriminating between methyl esters of isomeric monoenoic and cyclopropanoid fatty acids as well as between those derived from normal iso- and anteiso-acids involves measurements of the ratio of the intensity of the parent molecular ion P to that of the P-32 ion.lo' K. Maskens and N. Polgar Chem. Comm. 1970 673. lo' M. Welby-Gieusse and J. F. Tocanne Tetrahedron 1970 26,2875. *03 J. F. Tocanne Bull. SOC.chim. France 1970 750. Io4 S. Stallberg-Stenhagen Acta Chem. Scand. 1970,24 358. Io5 J. Elovson and P. R. Vagelos Biochemistry 1970 9 31 10. lo6 K. L. Mikolajczak C. R. Smith jun. and L. W. Tjarks Lipids 1970 5,672. lo' K. L. Mikolajczak C. R. Smith jun. and L. W. Tjarks Lipids 1970,5 812. lo* P. Abley F. J. McQuillin D. E. Minnikin K. Kusamran K. Maskens and N. Polgar Chem. Comm. 1970 348. lo' K.Schaumburg Lipids 1970 5 505. I. M. Campbell and J. Naworal J. Lipid Res. 1969 10 589. Fatty Acids and Related Compounds The g.1.c. and mass spectral properties of perdeuteriated fatty-acid methyl esters (including esters of various methyl-branched and unsaturated long-chain acids) from Scenedesrnus obliquus which had been grown in D,O have been stu- died."' The g.1.c. equivalent chain lengths have been deterrnined'l2 for a number of isomeric methyl octadecenoates and octadecynoates. The t.1.c. and g.1.c. properties of some di-unsaturated C esters,' l3 as well as of the octadecenyl compounds' ' (alcohols acetates trifluoroacetates aldehydes and hydrocarbons) derived from the methyl cis-octadec-2- to -17-enoates have been investigated.The n.m.r. spectra of a number of octadecadiynoic acids and of the derived methyl cis,cis-and trans,trans-octadecadienoates,' ' as well as of some conjugated fatty-acid methyl esters' have been studied. Gel permeation chromatography on Sephadex LH-20 has been shown"' to be useful for the separation of various hydroxy-lipids e.g. 1,2- and 1,3-diglycerides from long-chain alcohols or alkyl ethanediol mono-ethers from cholesterol. 'I1 G. Wendt and J. A. McCloskey Biochemistry 1970,9,4854. l2 C. R. Scholfield and H. J. Dutton J. Amer. Oil Chemists' SOC. 1970,47 1. F. D. Gunstone and M. Lie Ken Jie Chem. and Phys. Lipids 1970,4 131. I l4 F. D. Gunstone and M. Lie Ken Jie Chem. and Phys. Lipids 1970,4 139. F. D. Gunstone M. Lie Ken Jie and R. T. Wall Chem.and Phys. Lipids 1969,3,297. 0.Suzuki T. Hashirnoto K. Hayarnizu and 0.Yamamoto Lipids 1970,5 457. 'I7 M. Calderon and W. J. Baumann J. Lipid Res. 1970 11 167.