Volatile compounds produced by copper-catalyzed oxidation of butterfat

Anhydrous butterfat treated with copper and stored under vacuum at 38C in the dark for 9 weeks yielded the C_5–8 n-alkanes, acetic acid and the C_4,5,7,9 alkan-2-ones. The same butterfat stored under oxygen for 1 week yielded the C_1,2,3,5-7 n-alkanes, the C_2,4–6,8 alk-l-enes, the C_7,8 alk-l-ynes, the C_2–6 n-alkanoic acids, ethanol, the C_2–7 n-alkanals, 3-methylbutanal and 4-methylpentanal, the C_1–4 n-alkyl formates, ethyl acetate and propionate,n-propyl acetate and propionate, and butanone. Both treatments yielded carbon dioxide. All samples including those not treated with copper yielded butane-2,3-dione. Visiting Scientist from Division of Dairy Research, C.S.I.R.O., Highett, Victoria, Australia.     

The effect of a fat free diet on esterified monoenoic fatty acid isomers in rat tissues

Rats were maintained 120–140 days on a normal diet (group 1) or one deficient in fatty acids (group 2). Isomer composition was determined of monoenoic fatty acids (16∶1, 18∶1) isolated from total lipids of heart, kidney, lung, brain and lumbar fat, and from separated neutral lipids and phospholipids of heart and kidney. Group 1: The number of major isomers of C_16∶1 and C_18∶1 was similar in all tissues but their proportions varied in different tissues and types of lipid. Group 2: The proportions of 16∶1(n−7) increased and of other 16∶1 isomers decreased in all tissues; 18∶1(n−9) was increased at the expense of (n−7) in heart, to a lesser extent in kidney, and was little changed in lung, lumbar fat, or brain. The decrease in proportion of 18∶1(n−7) was greatest in heart-muscle phospholipids. C_20∶3 comprised 95% (n−9) and 5% (n−7) in heart and kidney lipids. The changes in group 2 probably represent the body’s attempts to maintain lipids with the physical and chemical properties necessary to normal biological function. Nomenclature of fatty acids as in IUPAC-IUB Commission on Biochemical Nomenclature, “The nomenclature of lipids,” J. Biol. Chem. 242:4845–49 (1967).     

Restructing butterfat through blending and chemical interesterification. 1. Melting behavior and triacylglycerol modifications

Chemical interesterification of butterfat-canola oil blends, ranging from 100% butterfat to 100% canola oil in 10% increments, decreased solid fat content (SFC) of all blends in a nonlinear fashion in the temperature range of 5 to 40°C except for butterfat and the 90∶10 butterfat/canola oil blend, whose SFC increased between 20 and 40°C. The sharp melting associated with butterfat at 15–20°C disappeared upon interesterification. Heats of fusion for butterfat to the 60∶40 butterfat/canola oil blend decreased from 75 to 60 J/g. Blends with >50% canola oil displayed a much sharper drop in enthalpy. Heats of fusion were 30–50% lower on average for interesterified blends than for their noninteresterified counterparts. Both noninteresterified and interesterified blends deviated substantially from ideal solubility, with greater deviation as the proportion of canola oil increased. The change in the entropy of melting was consistently higher for noninteresterified blends than for interesterified blends. Chemical interesterification generated statistically significant differences for all triacylglycerol carbon species (C) from C₃₀ to C_56′ except for C_42′ and in SFC at most temperatures for all blends.     

Low erucic acid canola oil does not induce heart triglyceride accumulation in neonatal pigs fed formula

Canola oil is not approved for use in infant formula largely because of concerns over possible accumulation of triglyceride in heart as a result of the small amounts of erucic acid (22∶1n−9) in the oil. Therefore, the concentration and composition of heart triglyceride were determined in piglets fed from birth for 10 (n=4–6) or 18 (n=6) d with formula containing about 50% energy fat as 100% canola oil (0.5% 22∶1n−9) or 100% soybean oil, or 26% canola oil or soy oil (blend) with palm, high-oleic sunflower and coconut oil, providing amounts of 16∶0 and 18∶1 closer to milk, or a mix of soy, high-oleic sunflower and flaxseed oils with C₁₆ and C₁₈ fatty acids similar to canola oil but without 22∶1. Biochemical analysis found no differences in heart triglyceride concentrations among the groups at 10 or 18 d. Assessment of heart triglycerides using Oil Red O staining in select treatments confirmed no differences between 10-d-old piglets fed formula with 100% canola oil (n=4), 100% soy oil (n=4), or the soy oil blend (n=2). Levels of 22∶1n−9 in heart triglyceride and phospholipid, however, were higher (P<0.01) in piglets fed 100% canola oil or the canola oil blend, with higher levels found in triglycerides compared with phospholipids. The modest accumulation of 22∶1n−9 associated with feeding canola oil was not associated with biochemical evidence of heart triglyceride accumulation at 10 and 18 d.     

Gas-chromatographic analysis of the aliphatic fractions of brown coal wax

The individual composition of the fractions of wax isolated from brown coal from the Sergeevskoe deposit was studied using gas chromatography. It was found that the aliphatic constituents of wax are C₁₄–C₄₂ n-alkanes with high coefficients of oddness, C₁₄–C₃₀ saturated alcohols, C₁₄–C₃₆ higher fatty acids, and esters. The contribution of unsaturated compounds was found. The structure and formation conditions of coal are considered.     

Interesterification of butterfat by commercial microbial lipases in a cosurfactant-free microemulsion system

Lipase-catalyzed interesterification of butterfat was carried out in a cosurfactant-free microemulsion system containing mixtures of Span 60 and Tween 60 (ICI Specialty Chemicals Altemix Inc., Brantford, Ontario, Canada) as surfactants. Four commercial lipases were used—Lipozyme 10,000L (Novo Nordisk, Copenhagen, Denmark) and N, D and MPA (Amano Pharmaceutical Co. Ltd., Nagoya, Japan). Stereospecific analyses of fractionated selected high-molecular weight triacylglycerols were performed by enzymatic deacylation with commercial pancreatic lipase, random generation ofrac-1,2-diacylglycerols by Grignard degradation, synthesis ofrac-phosphatidylcholines and a stereospecific release ofsn-1,2 diacylglycerols by phospholipase A₂. The results showed that the hydrolytic affinity of commercial lipases demonstrated an acyl-group specificity toward lower-molecular weight fatty acids C4–C14∶0. Stereospecific analyses of fatty acids of interesterified selected triacylglycerols of butterfat catalyzed by lipase N demonstrated a 46% increase in the proportion of C18∶1cis Δ⁹ at thesn-2 position, whereas those catalyzed by lipases MAP, D and Lipozyme 10,000L were enriched with C16∶0 at the same position by 21, 35 and 41%, respectively.     

Induction time of hydrate formation in a flow loop

A set of experiments were developed to study the effect of the supersaturation on the induction time of the hydrate formation in a flow loop. Propane, carbon dioxide and a mixture of methane and propane were used to form hydrate in the loop. Induction time was measured with varying temperature and pressure which gave rise to change in the supersaturation. It was found that induction time was indirectly dependent on the supersaturation in all experiments. Measured values of induction time were in the range of 9–12 minutes for carbon dioxide, 82–103 minutes for propane and 7–22 minutes for 0.73C₁+0.27C₃ at the given operating conditions. Hydrate nucleation were carried out at 5°C and 3–5 MPa for carbon dioxide, 2–5°C and 1MPa for propane and 4°C and 2–4 MPa for 0.73C₁+ 0.27C₃. In order to calculate the induction time, a semiempirical correlation as a function of supersaturation was used. The equation parameters I were determined based on the experimental data via nonlinear regression.     

Δ5-Olefinic acids in the seed lipids from four Ephedra species and their distribution between the α and β positions of triacylglycerols. Characteristics common to coniferophytes and cycadophytes

The fatty acid compositions of the seed lipids from four Ephedra species, E. nevadensis, E. viridis, E. przewalskii, and E. gerardiana (four gymnosperm species belonging to the Cycadophytes), have been established with an emphasis on Δ5-unsaturated polymethylene-interrupted fatty acids (Δ5-UPIFA). Mass spectrometry of the picolinyl ester derivatives allowed characterization of 5,9- and 5,11–18∶2; 5,9,12–18∶3; 5,9,12,15–18∶4; 5,11–20∶2; 5,11,14–20∶3; and 5,11,14,17–20∶4 acids. Δ5-UPIFA with a Δ11-ethylenic bond (mostly C₂₀ acids) were in higher proportions than δ5-UPIFA with a δ9 double bond (exclusively C₁₈ acids) in all species. The total δ5-UPIFA content was 17–31% of the total fatty acids, with 5, 11, 14–20∶3 and 5, 11, 14, 17–20∶4 acids being the principal δ5-UPFIA isomers. The relatively high level of cis-vaccenic (11–18∶1) acid found in Ephedra spp. seeds, the presence of its δ5-desaturation product, 5, 11–18∶2 acid (proposed trivial name: ephedrenic acid), and of its elongation product, 13–20∶1 acid, were previously shown to occur in a single other species, Ginkgo biloba, among the approximately 170 gymnosperm species analyzed so far. Consequently, Ephedraceae and Coniferophytes (including Ginkgoatae), which have evolved separately since the Devonian period (≈300 million yr ago), have kept in common the ability to synthesize C₁₈ and C₂₀ δ5-UPIFA. We postulate the existence of two δ5-desaturases in gymnosperm seeds, one possibly specific for unsaturated acids with a δ9-ethylenic bond, and the other possibly specific for unsaturated acids with a δ11-ethylenic bond. Alternatively, the δ5-desaturases might be specific for the chain length with C₁₈ unsaturated acids on the one hand and C₂₀ unsaturated acids on the other hand. The resulting hypothetical pathways for the biosynthesis of δ5-UPIFA in gymnosperm seeds are only distinguished by the position of 11–18∶1 acid. Moreover, ¹³C nuclear magnetic resonance spectroscopy of the seed oil from two Ephedra species has shown that δ5-UPIFA are essentially excluded from the internal position of triacylglycerols, a characteristic common to all of the Coniferophytes analyzed so far (more than 30 species), with the possibility of an exclusive esterification at the sn-3 position. This structural feature would also date back to the Devonian period, but might have been lost in those rare angiosperm species containing δ5-UPIFA.     

Comparative studies on the fatty acid composition of moderately and extremely thermophilic bacteria

The fatty acids of three strains of extremely thermophilic bacteria and three strains of moderately thermophilic bacteria were examined by gas liquid chromatography. All the thermophiles contained straight, iso, and ante-iso branched fatty acids. Iso C_17∶0 acid was abundant in both the moderately thermophilic strains (10–33%) and the extremely thermophilic strains (50–61%). The pair of fatty acids iso C_15∶0 and iso C_17∶0 was the predominant pair in both the moderately (34–64%) and extremely (76–87%) thermophilic strains. The pair of fatty acids ante-iso C_15∶0 and ante-iso C_17∶0 was present in larger amount in moderately (25–34%) than in extremely (8.5–15%) thermophilic strains. No hydroxy cyclopropane, or unsaturated fatty acids were found. One extreme thermophile,Flavobacterium thermophilum HB-8 was grown at 6 different culture temperatures from 49–82 C, and the changes of its fatty acid composition were studied. The ratios of iso C_17∶0/iso C_15∶0 and ante-iso C_17∶0/ante-iso C_15∶0 were much greater at higher culture temperatures, indicating chain elongation.     

Arachidonic, eicosapentaenoic, and biosynthetically related fatty acids in the seed lipids from a primitive gymnosperm, Agathis robusta

The fatty acid composition of the seeds from Agathis robusta, an Australian gymnosperm (Araucariaceae), was determined by a combination of chromatographic and spectrometric techniques. These enabled the identification of small amounts of arachidonic (5,8,11,14–20∶4) and eicosapentaenoic (5,8,11,14,17–20∶5) acid for the first time in the seed oil of a higher plant. They were apparently derived from γ-linolenic (6,9,12–18∶3) and stearidonic (6,9,12,15–18∶4) acids, which were also present, via chain elongation and desaturation, together with other expected biosynthetic intermediates [bis-homo-γ-linolenic (8,11,14–20∶3) and bishomo-stearidonic (8,11,14,17–20∶4) acids]. Also present were a number of C₂₀ fatty acids, known to occur in most gymnosperm families, i.e., 5,11–20∶2, 11,14–20∶2 (bishomo-linoleic), 5,11,14–20∶3 (sciadonic), 11,14,17–20∶3 (bishomo-α-linolenic), and 5,11,14,17–20∶4 (juniperonic) acids. In contrast to most other gymnosperm seed lipids analyzed so far, A. robusta seed lipids did not contain C₁₈ Δ5-desaturated acids [i.e., 5,9–18∶2 (taxoleic), 5,9,12–18∶3 (pinolenic), or 5,9,12,15–18∶4 (coniferonic)]. These structures support the simultaneous existence of Δ6- and Δ5-desaturase activities in A. robusta seeds. The Δ6-ethylenic bond is apparently introduced into C₁₈ polyunsaturated acids, whereas the Δ5-ethylenic bond is introduced into C₂₀ polyunsaturated acids. A general metabolic pathway for the biosynthesis of unsaturated fatty acids in gymnosperm seeds is proposed. When compared to Bryophytes, Pteridophytes (known to contain arachidonic and eicosapentaenoic acids), and species from other gymnosperm families (without such acids), A. robusta appears as an “intermediate,” with the C₁₈ Δ6-desaturase/C₁₈→C₂₀ elongase/C₂₀ Δ5-desaturase system in common with the former subphyla, and the unsaturated C₁₈→C₂₀ elongase/C₂₀ Δ5-desaturase system specific to gymnosperms. The following hypothetical evolutionary sequence for the C₁₈ Δ6/Δ5-desaturase class in gymnosperm seeds is suggested: Δ6 (initial)→Δ6/Δ5 (intermediate)→Δ5 (final).     

SAPO-11/HBeta composites for catalytic cracking of 2-butylene: effects of defect structure

SAPO-11/HBeta composite was synthesized by using hydrothermal method (SB-H) and applied as catalyst for cracking of 2-butylene to C₂–C₃ olefins. SB-H sample exhibited comparatively high selectivity and high yield of C₂–C₃ olefins. XRD, IR, ²⁷Al and ³¹P MAS NMR, Py-IR characterizations indicate that defect structure P(AlO₄) _n (n < 4) really existed in SB-H sample. SAPO-11 and HBeta chemically bonded and the defect P(AlO₄) _n (n < 4) formed during the hydrothermal synthesis of SB-H sample. P(AlO₄) _n (n < 4) unit caused new B acidic sites, which increased B acidic amount and B acidic distribution on SB-H sample. The improvement of B acidity decreased apparent active energy of cracking of 2-butylene to C₂–C₃ olefins on SB-H sample. Therefore, the high selectivity and high yield of C₂–C₃ olefins were obtained on SB-H sample in catalytic cracking of 2-butylene.     

Relationships between chemical structure and inhibitory activity of C6 through C9 volatiles emitted by plant residues

Leaf, stem, flower, fruit, and root residues of a wide variety of plants have been reported to emit bioactiven-alkanes, 2-alkanols,n-alkanals, 2-alkenals, 2-alkanones, andn-alkanoic acids containing from six to nine carbon atoms. During a 72-hr exposure to the vapor phase of these compounds (6.9, 20.8 or 34.4 M/liter), germination of onion, carrot, and tomato seeds was inhibited to varying degrees. The extent of inhibition caused by these plant residue volatiles depended upon the compound type and concentration, carbon-chain length, and the seed species tested. Tomato seeds recovered more fully from exposure to these volatile inhibitors than did those of carrot and onion. Degree of recovery in all three species depended on the type and concentration of volatile present. The C₇ and C₈ compounds were the most inhibitory among these 24 volatiles. Of the six classes of chemicals examined, the 2-alkenals were the most inhibitory, followed by the 2-alkanols,n-alkanals, and 2-alkanones, which were equally effective as seed germination inhibitors. The straight-chain alkanes and alkanoic acids were relatively noninhibitory. Tests of a C₇ and C₉ alkadienal indicated that the C₇ compound was the more inhibitory.Mention of a commercial or proprietary product does not constitute an endorsement by the U.S. Department of Agriculture.     

α-sulfonated fatty acid esters: II. Solution behavior of α-sulfonated fatty acid polyethylene glycol esters

Sodium α-sulfonated, fatty acid polyethylene glycol monoesters [C _m H_2m+1CH(SO₃Na)COO(C₂H₄O) _n H] and diesters [C _m H_2m+1CH(SO₃Na)COO(C₂H₄O) _n COCH(SO₃Na)C _m H_2m+1], wherem=10–16 andn=1–35, were prepared by esterification of α-sulfonated, fatty acids with polyethylene glycols, followed by neutralization with NaOH. Crude products were purified by reversed-phase column chromatography on an octadecyl-modified silica gel. Characteristic solution behavior of these α-sulfonated fatty acid esters was, examined, and the following features were observed. All monoesters prepared in this work had Krafft points below 0°C and also possessed good calcium stabilities. Critical micelle concentrations of the monoesters increased monotonously, as a rule, with an increase in the number of oxyethylene units. These results suggest that the polyethylene glycol residue of the monoester behaves as a hydrophile. On the other hand, diesters possessed high water solubility, low foamability, and critical micelle concentrations that were lower by a factor of ten compared to those of the monoesters.     

Characterization of chilean hazelnut (Gevuina avellana mol) seed oil

The fatty acid composition, tocopherol and tocotrienol content, and oxidative stability of petroleum benzene-extracted Gevuina avellana Mol (Proteaceae) seed oil were determined. Positional isomers of monounsaturated fatty acids were elucidated by gas chromatography-electron impact mass spectrometry after 2-alkenyl-4,4-dimethyloxazoline derivatization. This stable oil (Rancimat induction period at 110°C: 20 h) is composed of more than 85% monounsaturated fatty acids and about equal amounts (6%) of saturated and polyunsaturated (principally linoleic) fatty acids. Unusual positional isomers of monounsaturated fatty acids, i.e., C_16:1 Δ¹¹, C_18:1 Δ¹², C_20:1 Δ¹¹, C_20:1 Δ¹⁵, C_22:1 Δ¹⁷, and presumably C_22:1 Δ¹⁹ were identified. The C_18:1 Δ¹² and C_22:1 Δ¹⁹ fatty acids are described for the first time in G. avellana seed oil. While only minute quantities of α-, γ-tocopherols and β-, γ- and δ-tocotrienols were found, the oil contained a substantial amount of α-tocotrienol (130 mg/kg). The potential nutritional value of G. avellana seed oil is discussed on the basis of its composition.     

Essential fatty acid-deficient rats: II. On the fatty acid composition of partially hydrogenated arachis,soybean and herring oils and of normal,refined arachis oil

The fatty acid composition of partially hydrogenated arachis (HAO), partially hydrogenated soybean (HSO) and partially hydrogenated herring (HHO) oils and of a normal, refined arachis oil (AO) was studied in detail by means of direct gas liquid chromatography, ultraviolet and infrared spectrophotometry and by thin layer chromatography fractionation on silver nitrate-silica gel plates followed by gas liquid chromatography. It was shown that the partially hydrogenated oils all contained fatty acids withtrans double bonds. In the plant oils, thetrans acids were present mainly as elaidic acid. The HHO showed an almost equal distribution betweentrans 18∶1 ω9,trans 20∶1 ω>9 andtrans 22∶1 ω>9. Sometrans configuration was also found in the C₂₀-and C₂₂-dienes and trienes of the HHO. In all the oils, conjugated fatty acids were present in minor amounts only (<0.5%). Special attention was given to the ω-acids known to be of specific nutritional value. The HSO contained about 32% linoleic acid, whereas the content ofcis, trans+trans, cis andtrans, trans octadecadienoic isomers was 1.7% and 0.5%, respectively. The amount of linoleic acid in the HSO was even higher than that of AO (29%). The HAO contained only 0.8% 18∶2 ω6 (linoleic acid). Further, two 18∶2 fatty acids with ω>6, acis, cis and atrans, trans isomer, were present in small amounts. The HHO contained 0.5% 18∶2 ω6 (linoleic acid). Isomers of 18∶2 ω>6 were also found in the HHO. They may be hydrogenation products of higher unsaturated C₁₈-acids orginally present. All the C₂₀- and C₂₂-dienes and trienes were shown to have an ω-chain greater than 6. Fatty acids with ω6-structure were not formed during partial hydrogenation of the oils studied.     

Preparation and physical properties of some C18 unsaturated fatty esters containingL-amino acid residues and methyl esters ofN-stearoylamino acids

A series of five C₁₈ unsaturated fatty esters (1–5) containing anL-amino acid residue (glycine, alanine, valine, leucine, phenylalanine) was prepared from methyl 12-amino-9-cis-octadecenoate and five methylN-stearoyl-amino acid ester derivatives (6–10) from stearoyl chloride and the sameL-amino acids. The infrared analysis of compounds 1–5 showed characteristic absorption bands at 3300 and 1665 cm⁻¹ for the amino and amido functions, while the amido function in compounds 6–10 gave absorption bands at 3300 and 1680 cm⁻¹. The position of the amido group (peptide linkage) in compounds 1–5 was readily determined by mass spectral analysis.¹H nuclear magnetic resonance (NMR) analysis showed a doublet at 7.15 ppm for the amide proton (NHCO) in compounds 1–5, while in compounds 6–10 the amide proton signal appeared at 6.0 ppm. In¹³C NMR, the amido carbonyl resonance appeared at 171–175 ppm. In compounds 1–5 the effect of the amide function on the ethylene carbon (C-9) gave a signal at 124.1–125.3 ppm, while the remaining ethylenic carbon appeared at 131.9–132.5 ppm. The methine carbon (C-12) of the alkenyl chain was shifted to 48.4–49.8 ppm, and the assignment of the various carbon nuclei in the amino acid residue was readily achieved. In the methylN-stearoylamino acid ester derivatives (6–10), the methine carbon adjacent to the amido system and alpha to the carbomethoxy group appeared between 41.2–57.0 ppm depending on the type of alkyl group present in the amino acid moiety. The phenyl system in compounds 5 and 10 was confirmed by the¹³C signals in the 127–136 ppm range and by the proton signals in the 7.0–7.27 ppm region.     

Comparative characterization of the distribution of biomarker hydrocarbons in the chemical transformation products of oxygen-containing precursors of petroleum

The distribution of biomarker hydrocarbons in the thermolysis and thermocatalysis products of oxygen-containing compounds (possible petroleum hydrocarbon precursors) was studied by gas chromatography-mass spectrometry. It was found that n-alkylcyclohexanes and steranes were generated in the course of thermolysis along with expected hydrocarbons—n-alkanes and isoprenes, which resulted from the loss of a functional group. In this case, the molecular-weight distributions of n-alkanes and n-alkylcyclohexanes correlated well with each other. In the course of thermocatalysis, the homologous series of n-alkanes and n-alkylcyclohexanes were also generated; however, an n-alkylcyclohexane distribution maximum had an even number of carbon atoms in the molecule (C₁₈). It was experimentally found that the sterane fragments of oxygen-containing compounds formed upon thermolysis were thermodynamically unstable; this was supported by the formation of biological C₂₇–C₂₉ 5α, 14α, 17α, 20S, and 20R and 5β, 14α, 17α, and 20R (coprostane) steranes as a result of thermolysis. Unlike thermolysis, all of the four epimers of regular C₂₇–C₂₉ (5α, 14α, 17α, 20S, and 20R and 5α, 14β, 17β, 20S, and 20R) steranes were formed as a result of thermocatalysis. It was found that the relative distribution of biomarker hydrocarbons in the thermolysis products of various oxygen-containing compounds largely reflected the structure of the parent organic substance, as compared with that upon thermocatalysis in the presence of active aluminosilicate.     

Prevention of cholesterol cholelithiasis by dietary unsaturated fats in hormone-treated female hamsters

We examined the effect of diet on gallstone incidence and the composition of biliary phosphatidylcholines in methyltestosterone-treated female hamsters. These hamsters were fed a nutritionally adequate purified lithogenic diet containing 2% corn oil, 4% butterfat, 0.3% cholesterol, and 0.05% methyltestosterone, resulting in a cholesterol gallstone incidence of 86%. This incidence was lowered when mono-and polyunsaturated fats or fatty acids were added to the diet: 2.5% oleic acid resulted in total prevention of cholesterol cholelithiasis, 2.5% linoleic acid, and 4% safflower oil (78% linoleic acid content) reduced gallstone incidence to 26 and 8%, respectively. An additional 4% butterfat (29% oleic acid content) produced gallstones in 50% of the animals. At the end of the 6-wk feeding period, the bile of all hamsters was supersaturated with cholesterol. The major biliary phosphatidylcholine species in all groups were (sn-1-sn-2): 16:0–18:2, 16:0–18:1, 18:0–18:2, 16:0–20:4, and 18:2–18:2. The safflower oil-and linoleic acidfed hamsters exhibited an enrichment of 16:0–18:2 (16–18%); added butterfat or oleic acid increased the proportion of 16:0–18:1 (9 and 25%, respectively). We conclude that the phosphatidylcholine molecular species in female hamster bile can be altered by dietary fats/fatty acids and that mono-and polyunsaturated fatty acids play a role in suppressing the induced cholelithiasis.     

Incorporation of 1-chlorooctadecane into FA and β-hydroxy acids of <Emphasis Type="Italic">Marinobacter hydrocarbonoclasticus</Emphasis>

The lipids of the gram-negative marine bacterium Marinobacter hydrocarbonoclasticus, cultivated in synthetic seawater supplemented with 1-chlorooctadecane as sole source of carbon, were isolated, purified, and their structures determined. Three pools of lipids were isolated according to the sequential procedure used: unbound lipids extracted by organic solvents, ester-bound lipids released under alkaline conditions, and amide-bound lipids released by acid hydrolysis. FA isolated from the unbound lipids included ω-chlorinated (21%, w/w, of this fraction; C₁₆ predominant) and nonchlorinated compounds (22%; w/w, C₁₈ predominant). These acids were accompanied by a high proportion of ω-chloro-C₁₈ alcohols (43%, w/w) and a lower amount of ω-chloro-β-hydroxy-C₁₈,-C₁₆, and-C₁₄ acids (5%, w/w). These data, together with the isolation from the culture medium of γ-butyrolactone, suggested a metabolism of 1-chlorooctadecane through oxidation into ω-chloro acid and then the classic β-oxidation pathway. The analysis of the ester-bound and amide-bound lipids revealed that significant amounts of ω-chloro-β-hydroxy C₁₀–C₁₂ acids were incorporated into the lipopolysaccharides of the bacterium. Incorporation of these ω-chloro-β-hydroxy acids into the lipopolysaccharides represents a novel route for chloroalkane assimilation in hydrocarbonoclastic gram-negative bacteria. The formation of chlorinated hydroxy acids, like the ω-chloro FA in the cellular lipids, could account for an incomplete mineralization of chloroparaffins in the environment.     

Leaf Epicuticular Wax Chemicals of the Japanese Knotweed Fallopia japonica as Oviposition Stimulants for Ostrinia latipennis

Extraction, fractionation, and gas chromatography−mass spectrometry analyses guided by bioassays have shown that n-alkanes and free fatty acids in leaf epicuticular wax of the Japanese knotweed Fallopia (Reynoutria) japonica stimulate oviposition in the Far-Eastern knotweed borer, Ostrinia latipennis (Lepidoptera: Crambidae). n-Alkanes made up 48.1% of the total amount of epicuticular wax, and their carbon chain length was in the C₁₆−C₃₃ range, with n-nonacosane (n-C₂₉) most abundant, followed by n-C₂₇, n-C₂₅, and n-C₃₁. Free fatty acids with C₉−C₂₂ accounted for 22.3%, and hexadecanoic acid was predominant. A mixture of authentic n-alkanes and fatty acids of the composition found in the epicuticular wax, a mixture of n-alkanes, and a mixture of fatty acids significantly enhanced oviposition. Thus, it was demonstrated that both n-alkanes and free fatty acids in leaf epicuticular wax of F. japonica are naturally occurring oviposition stimulants for O. latipennis.