A convenient laboratory method for preparingtrans,trans-9, 11-octadecadienoic acid

A convenient laboratory method to preparetrans,trans- 9,11-octadecadienoic acid (TTA) via a polyester intermediate is described. Ricinelaidic acid was heated at 235C under vacuum for 3-4 hr to form a polyester having a mol wt of 1,500-1,600. Pyrolysis of this polyester and simultane-ous distillation of the products gave crude dehy-drated acids. TTA was crystallized from a 95% ethanol solution of these acids, in a yield of 35%. Of the variables affecting pyrolysis, the mol wt of polyester had the greatest effect on yield of TTA. Paper II in the series on “Reactions of Conjugated Fatty Acids,” presented at AOCS meeting in Atlanta, 1963. A laboratory of the No. Utiliz. Res. & Dev. Div., ARS, USDA.     

Lipoxygenase fromZea mays: 9-d-hydroperoxy-trans-10,cis-12-octadecadienoic acid from linoleic acid

Lipoxygenase from the germ of corn,Zea mays, oxidized linoleic acid to primarily 9-d-hydroperoxy-trans-10,cis-12-octadecadienoic acid. No. Utiliz. Res. Dev. Div., ARS, USDA.     

Dimorphotheca sinuata lipoxygenase: Formation of 13-L-hydroperoxy-cis-9,trans-11-octadecadienoic acid from linoleic acid

Lipoxygenase (EC 1.13.1.13) from the seed ofDimorphotheca sinuata oxidized linoleic acid to predominantly 13-L-hydroperoxy-cis-9,trans-11-octadecadienoic acid. When the reaction proceeded at pH 6.9, the 13-hydroperoxide was the only isomer detected; but at pH 5.1, the 13-isomer was 92% of the total, the remaining 8% being the 9-hydroperoxide. At both pH's small amounts of hydroxyoctadecadienoic acid accumulated during the reaction. This acid from the pH 6.9 reaction was analyzed as 13-hydroxy-cis,trans-octadecadienoic. The postulate advanced by many workers that dimorphecolic acid, 9-D-hydroxy-trans-10,trans-12-octadecadienoic acid, is biosynthesized via a lipoxygenase product was not proved. Although the product specificity ofD. sinuata lipoxygenase is like that of lipoxygenase type 1 from soybeans, its inactivity at pH 9 demonstrated that it is a novel enzyme. ARS, USDA.     

Taxus baccata seed oil: A new source ofcis-5,cis-9-octadecadienoic acid

Methyl esters prepared from the seed oil of the coniferTaxus baccata L. were found by gas liquid chromatography to contain 12% of a component which, when isolated by preparative thin layer chromatography and characterized by mass spectrometry, ozonolysis and nuclear magnetic resonance, was identified ascis-5,cis-9-octadecadienoic acid.     

Preparation ofcis,cis,cis-5,8,11-eicosatrienoic acid from arachidonic acid

Arachidonic acid was reduced by hydrazine to yield isomeric eicosatrienoic acids with other products. Methylcis,cis,cis-5,8,11-eicosatrienoate was isolated from the products by silver ion chromatography and preparative gas liquid chromatography in 8% yield. The structure was confirmed by spectral studies and oxidative degradation.     

Metabolism in humans ofcis-12,rans-15-octadecadienoic acid relative to palmitic,stearic, oleic and linoleic acids

Mixtures of triglycerides containing deuterium-labeled hexadecanoic acid (16∶0), octadecanoic acid (18∶0),cis-9-octadecenoic acid (9c–18∶1),cis-9,cis-12-octadecadienoic acid (9c, 12c–18∶2) andcis-12,trans-15-octadecadienoic acid (12c,15t–18∶2) were fed to two young-adult males. Plasma lipid classes were isolated from samples collected periodically over 48 hr. Incorporation and turnover of the deuterium-labeled fats in plasma lipids were followed by gas chromatography-mass spectrometry (GC-MS) analysis of the methyl ester derivatives. Absorption of the deuterated fats was followed by GC-MS analysis of chylomicron triglycerides isolated by ultracentrifugation. Results were the following: (i) endogenous fat contributed about 40% of the total fat incorporated into chylomicron triglycerides; (ii) elongation, desaturation and chain-shortened products from the deuterated fats were not detected; (iii) the polyunsaturated isomer 12c,15t–18∶2 was metabolically more similar to saturated and 9c–18∶1 fatty acids than to 9c,12c–18∶2 (iv) relative incorporation of 9c,12c–18∶2 into phospholipids did not increase proportionally with an increase of 9c,12c–18∶2 in the mixture of deuterated fats fed; (v) absorption of 16∶0, 18∶0, 9c–18∶1, 9c,12c–18∶2 and 12c,15t–18∶2 were similar; and (vi) data for the 1- and 2-acyl positions of phosphatidylcholine and for cholesteryl ester fractions reflected the known high specificity of phosphatidylcholine acyltransferase and lecithin:cholesteryl acyltransferase for 9c,12c–18∶2. These results illustrate that incorporation of dietary fatty acids into human plasma lipid classes is selectively controlled and that incorporation of dietary 9c,12c–18∶2 is limited. These results suggest that nutritional benefits of diets high in 9c,12c–18∶2 may be of little value to normal subjects and that the 12c,15t–18∶2 isomer in hydrogenated fat is not a nutritional liability at the present dietary level.     

A soy extract catalyzes formation of 9-oxo-trans-12,13-epoxy-trans-10-octadecenoic acid from 13-hydroperoxy-cis-9,trans-11-octadecadienoic acid

In the presence of oxygen, a crude soy extract converted 13-hydroperoxy-cis-9,trans-11-octadecadienoic acid into numerous products, from which 9-oxo-trans-12,13-epoxy-trans-10-octadecenoic acid was isolated. Additionally, the soy extract oxidized linoleic acid to the oxo-epoxyoctadecenoic acid, presumably via a sequential reaction involving lipoxygenase oxidation of linoleic acid followed by degradation of the resultant linoleic acid hydroperoxide. However, the linoleic acid substrate yielded two isomeric linoleic acid hydroperoxides and because of this, two isomeric oxoepoxyoctadecenoic acids. Presented in part at the 13th Congress, International Society for Fat Research, Marseilles, France, August 30–September 4, 1976.     

氯化(8S,9R)-(-)-N-苄基辛可尼定的合成

等摩尔的苄氯与辛可尼定在无水乙醇中回流2－4h,即可得到氯化（8S,9R）－（－）－N－苄基辛可尼定,产率为60％,e,e．值为＞99％。     

Synthesis of 9,12-Dioxo-10(Z)-dodecenoic acid, a new fatty acid metabolite derived from 9-hydroperoxy-10,12-octadecadienoic acid in lentil seed (Lens culinaris medik.)

The previously unknown linoleic acid peroxidation product 9,12-dioxo-10(Z)-decenoic acid (Z5) was detected in lentil seed fluor (Lens culinaris Medik.) by electron impact mass spectrometry (El-MS) after derivatization with pentafluorobenzyl-hydroxylamine-hydrochloride, methylation of acidic groups with diazomethane, and protection of hydroxylic groups with N-methyl-N-trimethylsilyl-trifluoroacetamide. The structure of the natural product was confirmed by synthesis of Z5, 9,12-dioxo-10(E)-decenoic acid, and derivatives. EI-MS, nuclear magnetic resonance and gas chromatographic data of these compounds and synthetic intermediates are discussed.     

Volatile compounds from the triacylglycerol ofcis,cis 9,15-linoleic acid

cis,cis 9,15-Linoleic acid, one of the isomers produced by partial hydrogenation of linolenic acid, may be a precursor of the hydrogenation odor observed during heating of partially hydrogenated soybean oil in air. Odors of hydrogenation, for example the melon odor, are associated with foods cooked in partially hydrogenated soybean oil that has undergone oxidative deterioration during heating. To better understand this oxidation mechanism, the volatiles from decomposition of the oxidation products of a synthesized model compound, tricis,cis 9,15-linoleoylglycerol, heated in air at 192°C were collected, separated, quantitated by gas chromatography with flame ionization detection and identified by mass spectrometry. Major volatiles observed indicated that each of the isolated double bonds at carbons 9,10 and 15,16 isomerized to form an allylic radical. The allylic radical derived from the isolated double bond at carbons 9,10 reacted with oxygen to form the 8,9,10 and 11 monohydroperoxides. The allylic radical derived from the isolated double bond at carbons 15,16 produced the 14,15,16 and 17 monohydroperoxides. The 8,9,10 and 11 monohydroperoxides are the expected precursors of the following volatiles identified by mass spectrometry: 2,8-undecadienal (5.9%), 2,7-decadienal (7.8%), 6-nonenal (8.4%) and 5-octenal (1.5% of total volatiles), respectively. These four aldehydes are analogous to major volatiles obtained from thermal decomposition of autoxidized trioleoylglycerol. The 14,15,16 and 17 monohydroperoxides are the expected precursors of 2-pentenal (9.0%), 2-butenal (8.0%), propanal (12.1%) and ethanal (2.0% of total volatiles), respectively. Among the above volatiles, 6-nonenal (cucumber-melon) is reported to have the most intense odor associated with deteriorated partially hydrogenated soybean oil.     

8-硫-1,6-二氮双环[4.3.0]壬烷-7,9-二酮的合成及单晶结构

以二硫化碳、甲醇、氢氧化钾为起始原料,经3步反应生成5-甲氧基-1,3,4-噻二唑-2(3H)-酮,再与1,4-二溴丁烷进行取代,然后脱甲基,最后发生亲核取代反应得到8-硫-1,6-二氮双环[4.3.0]壬烷-7,9-二酮。通过熔点、1HNMR、13CNMR、元素分析及X射线衍射分析等方法对产物的结构进行了表征,目标化合物属于三斜晶系,P1空间群,晶胞参数a=0.784 00(16)nm,b=1.046 4(2)nm,c=1.051 4(2)nm,α=63.84(3)°,β=79.62(3)°,γ=89.42(3)°,V=0.759 2(3)nm3,Z=4,wR(F2)=0.125,μ=0.37 mm-1。     

Formation oftrans-12,13-epoxy-9-hydroperoxy-trans-10-octadecenoic acid from 13-L-hydroperoxy-cis-9,trans-11-octadecadienoic acid catalyzed by either a soybean extract or cysteine-FeC13

A soybean extract or an ethanolic solution of cysteine and ferric chloride catalyzed the conversion of 13-L-hydroperoxy-cis-9,trans-11-octadecadienoic acid to numerous products among which wastrans-12,13-epoxy-9-hydroperoxy-trans-10-octadecenoic acid. When this fatty acid was treated further with the cysteine-ferric chloride solution, 9-hydroxy-12,13-epoxy-10-octadecenoic and 9-oxo-12,13-epoxy-10-octadecenoic acids were formed. Thus,trans-12,13-epoxy-9-hydroperoxy-trans-10-octadecenoic acid probably is an intermediate in the formation of the latter two compounds. Additionally, theerythro andthreo isomers oftrans-12,13-epoxy-11-hydroperoxy-cis-9-octadecenoic acid tenatatively were identified as products. Presented in part at the 13th World Congress, International Society for Fat Research, Marseilles, France, August 30-September 4, 1976, and the AOCS Meeting, Chicago, September 1976.     

Production of 15-, 16- and 17-hydroxy-9-octadecenoic acids by bioconversion of oleic acid withBacillus pumilus

SeveralBacillus strains were tested for their ability to hydroxylate oleic acid. Two strains—BD-174 and BD-226—converted oleic acid into a trio of hydroxy-octadecenoic acids. Bioconversion in 72–120 hr produced 5–11% of hydroxy acids relative to oleic acid as measured by gas chromatography. These acids were identified as the 15-, 16- and 17-hydroxy-9-octadecenoic acids by gas chromatography-mass spectrometry of trimethyl silyl derivatives of the product acids and their hydrogenated counterparts.     

8-R-9苄基-9H-嘌呤衍生物的合成研究

采用 (Ph3 P) 2 PdCl2 为催化剂 ,DMF为溶剂 ,对 8 碘 9 苄基 9H 嘌呤与有机锡试剂RSnBu3 (R=乙烯基、2 噻吩基、2 呋喃基、苯乙炔基和苯基等 )之间的Stille偶合反应进行了研究 ,合成出了5种 8位取代的嘌呤衍生物。在反应温度为 80℃ ,n(8 碘 9 苄基 9H 嘌呤 )∶n (RSnBu3 )∶n〔(Ph3 P) 2 PdCl2 〕 =1 0∶1 2∶0 0 5的较佳工艺条件下 ,产品收率 4 1%～ 91%。用1H NMR、13 C NMR和MS对产物进行了表征     

8-碘-9-苄基-9H-嘌呤的合成

以9 苄基 9H 嘌呤和碘代丁二酰亚胺(NIS)等为主要原料,以THF为溶剂,对8 碘 9 苄基 9H 嘌呤的合成反应进行了研究。对主要反应条件的影响结果进行了考察,在反应温度70℃,n(9 苄基 9H 嘌呤)∶n(碘代丁二酰亚胺)=1 0∶2 5,反应时间48h的较佳条件下,产物收率>87%。用1HNMR、13CNMR、MS、碳氢相关谱(HETCOR)和远程碳氢相关谱(LongRangeHETCOR)等技术对产物结构进行了表征。     

Identification of 11,15-octadecadienoic acid from beef and mutton tallow

By means of gas liquid chromatography and thin layer chromatography on Silica gel G/AgNO₃ we isolated some isolinoleic acids from beef and mutton tallow, which by their chromatographical behavior, IR analysis and by double bond determination by ozonolysis are mainly stereo-isomeric 11,15-octadecadienoic acids and in a smaller amount stereo-isomers of 10,15-octadecadienoic acids. 4-Cis- and 4-trans-heptenals, 2-trans,6-cis- and 2-trans,6-trans-nonadienals have been isolated from the DNPH mixture obtained from the volatile decomposition products of an oxidized synthetic mixture of stereo-isomeric 11,15-octadecadienoic acids. Presented in part by G. Hoffmann at the 7th ISF Congress, Hamburg, October 1964.     

The effect of copper,managanese and cobalt acetates on the autoxidation oftrans-9,trans-11-octadecadienoic acid in 90% v/v aqueous acetic acid

The autoxidation oftrans-9,trans-11-octadecadienoic acid in 90% v/v aqueous acetic acid has been studied, at 80 C, with and without copper, manganese and cobalt acetate. The initial 9,11-octadecadienoic acid concentration was 0.05 M in most of the experiments. The metallic acetate concentrations were 10⁻⁵ to 10⁻² M. Copper and manganese acetates retard the autoxidation. With copper acetate, this retardation involves both the induction period and the rapid autocatalytic stage. Manganese acetate prolongs the induction period. A slightly lowered rate is observed at low cobalt acetate concentrations (∼10⁻⁵ M), but higher cobalt acetate concentrations clearly accelerate the autoxidation.     

Cutin acids: Synthesis and mass spectrometry of methyl 16-hydroxy-7-oxo-, 16-hydroxy-8-oxo-, 16-hydroxy-9-oxo-, 16-hydroxy-10-oxo- and 7,16-, 8,16-, 9,16- and 10,16-dihydroxyhexadecanoates

Methyl esters of 8 16-carbon acids which occur in cutin of plants have been synthesized from methyl 16,17-dihydroxy-7-oxo- and 16,17-dihydroxy-9-oxoheptadecanoates. 16-Hydroxy-7-oxo- and 16-hydroxy-9-oxohexadecanoates were prepared by lead tetraacetate cleavage followed by sodium triacetoxyborohydride reduction; 16-hydroxy-8-oxo- and 16-hydroxy-10-oxohexadecanoates were prepared by successive ketalization, ester reduction, diol cleavage, acylation, oxidation and methanolysis. Dihydroxy esters were prepared by reduction of oxo esters with sodium borohydride. Mass spectra of TMS ethers of the esters, of pyrrolides and of TMS esters of pyrrolidides have been compared. Mass spectra of mixtures of hydroxyoxo derivatives and of dihydroxy derivatives show that correction factors are required for quantitative analysis, particularly when 7-substituted isomers are present. Presented at the AOCS meeting, San Francisco, May, 1979. NRCC No. 18651.