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1.
Yoko Watanabe Masaharu Nakajima Tsutomu Hoshino Koda Jayasimhulu Elwood E. Brooks Edna S. Kaneshiro 《Lipids》2001,36(5):513-519
Members of the bacterial genus Bdellovibrio include strains that are free-living whereas others are known to invade and parasitize larger Gram-negative bacteria. The
bacterium can synthesize several sphingophospholipid compounds including those with phosphoryl bonds as well as phosphonyl
bonds. In the present study, the dominant sphingophosphonolipid component was isolated by column chromatography, and the long-chain
bases, fatty acids, and polar head groups were identified by thin-layer and gas-liquid chromatographic procedures. The definitive
structural identity of the sphingolipid was established by nuclear magnetic resonance and mass spectrometry of hydrolysis
products and the intact compound. The compound was identified as N-2′-hydroxypentadecanoyl-2-amino-3,4-dihydroxyheptadecan-1-phosphono-(1-hydroxy-2-aminoethane). 相似文献
2.
The parasitic mite Varroa destructor Anderson & Trueman reproduces on the immature stage of the honeybee, Apis mellifera L. Mites are found more often on drone brood than worker brood and only infrequently on queen brood. We investigated the chemical basis for the low incidence of mites on queen brood. V. destructor mites were deterred by a crude extract of royal jelly, a glandular secretion produced by nurse bees and fed to queen larvae. Bioassay-driven fractionation of the crude extract via column chromatography resulted in one active fraction that was as active as the crude extract. Compounds in the active fraction were identified using gas chromatography (GC) and coupled gas chromatography/mass spectrometry (GC-MS). Before injection, compounds were esterified with MeOH/sulfuric acid, followed by silylation of any hydroxyl groups present. The active fraction contained at least 22 compounds, all fatty acids, several of which contained an additional hydroxyl group on the alkyl chain. Synthesis of some of these compounds that are not commercially available is described. A synthetic mixture containing most of the compounds in the active fraction was as active as the active fraction in the bioassay. 相似文献
3.
The lipids ofNeurospora crassa, isolated in pure form from freeze-dried mycelium, were found to contain squalene, sterol esters, triglycerides, free fatty
acids, geranylgeraniol, free sterols, carotenoids, cardiolipin, phosphatidyl ethanolamine, phosphatidyl choline, phosphatidyl
serine, and phosphatidic acid. The above compounds were isolated in pure form by column and thin layer chromatography and
were characterized by infrared spectroscopy and chromatographic mobilities. Fatty acid moieties were characterized by gas
liquid chromatographic retention times of their methyl esters relative to those of authentic standards. The fatty acid composition
of the triglycerides was found to be similar to that of phosphatidic acid, cardiolipin, and lecithin. 相似文献
4.
A. Robles Medina A. Giménez Giménez F. García Camacho J. A. Sánchez Pérez E. Molina Grima A. Contreras Gómez 《Journal of the American Oil Chemists' Society》1995,72(5):575-583
n-3 Polyunsaturated fatty acids (n-3 PUFA) from the marine microalgaIsochrysis galbana were concentrated and purified by a two-step process—formation of urea inclusion compounds followed by preparative high-performance
liquid chromatography. These methods had been developed previously with fatty acids from cod liver oil. By the urea inclusion
compounds method, a mixture that contained 94% (w/w) stearidonic (SA), eicosapentaenoic (EPA), plus docosahexaenoic (DHA)
acids (4:1 urea/fatty acid ratio and 4°C crystallization final temperature) was obtained from cod liver oil fatty acids. Further
purification of SA, EPA, and DHA was achieved with reverse-phase C18 columns. These isolations were scaled up to a semi-preparative column. A PUFA concentrate was isolated fromI. galbana with methanol/water (80:20, w/w) or ethanol/water (70:30, w/w). With methanol/water, a 96% EPA fraction with 100% yield was
obtained, as well as a 94% pure DHA fraction with a 94% yield. With ethanol/water as the mobile phase, EPA and DHA fractions
obtained were 92% pure with yields of 84 and 88%, respectively. 相似文献
5.
A wild-type strain ofDictyostelium discoideum was grown uponAerobacter aerogenes. Fatty acid compositions of lipid fractions and of total lipids obtained from vegetative amoebae and mature sorocarps were
compared. Fatty acids isolated from vegetative cells were found to include large quantities of 17- and 19-carbon cyclopropane
fatty acids while straight-chain, saturated fatty acids represented only 10% (w/w) of total fatty acids. These cyclopropane
fatty acids appear to be derived from ingested bacteria and are preferentially incorporated into neutral lipids of the slime
mold. Development of amoebae to mature sorocarps is accompanied by a substantial decrease in cyclopropane fatty acid content
and a concomitant increase in unsaturated fatty acids, mostly as octadeca-5,11-dienoic acid. The †-22 stigmastenyl ester fraction
is the richest source of this acid. Fully 65% of the fatty acids in this fraction are the octadecadienoate. 相似文献
6.
David B. S. Min Sherman S. Lin Stephen S. Chang 《Journal of the American Oil Chemists' Society》1975,52(2):28-33
Minor constituents in high quality tall oil fatty acids have been isolated successfully by liquid column chromatography, using silicic acid as the adsorbent. The minor constituents contained two types of compounds: those which were noneffective and those which were effective in causing the darkening of tall oil fatty acids during heating. The former consisted oftrans-3,5-dimethoxystilbene and rosin acids. The latter was separated into numerous fractions by the combination of chemical methods, silicic acid column chromatography, and low temperature fractional crystallization. The fractions were characterized by functional group analyses, chemical reactions, and UV and IR spectrometric methods. Most of the fractions contained two-three times as much oxygen in the molecule as the original sample and were highly oxidized fatty acids. They had mol wt ranging 300–551 and contained double bonds, carbonyl, ester, peroxide, and hydroxyl groups. The effect of these minor constituents upon the color stability of tall oil fatty acids during heating was postulated as being due to the hydroxyl groups located in the α-position to the double bond in the molecule. 相似文献
7.
trans-3,5-Dimethoxystilbene has been isolated from high quality tall oil fatty acids (unsaponifiables 1.5% maximum, rosin acids
1.5% maximum), using liquid column chromatography and low temperature solvent fractional crystallization. The structure of
this compound was determined with the aid of IR, mass and NMR spectrometry. Thetrans-3,5-dimethyoxystilbene was found to be responsible for the development of a red color during the epoxidation of the tall
oil fatty acids.
Paper of the Journal Series, New Jersey Agricultural Experiment Station, Rutgers, The State University. 相似文献
8.
Lachlan Dow Dr. Frederike Stock Alexandra Peltekis Dávid Szamosvári Dr. Michaela Prothiwa Adrien Lapointe Dr. Thomas Böttcher Dr. Benjamin Bailleul Prof. Wim Vyverman Prof. Peter G. Kroth Dr. Bernard Lepetit 《Chembiochem : a European journal of chemical biology》2020,21(8):1206-1216
The mechanisms underlying interactions between diatoms and bacteria are crucial to understand diatom behaviour and proliferation, and can result in far-reaching ecological consequences. Recently, 2-alkyl-4-quinolones have been isolated from marine bacteria, both of which (the bacterium and isolated chemical) inhibited growth of microalgae, suggesting these compounds could mediate diatom–bacteria interactions. The effects of several quinolones on three diatom species have been investigated. The growth of all three was inhibited, with half-maximal inhibitory concentrations reaching the sub-micromolar range. By using multiple techniques, dual inhibition mechanisms were uncovered for 2-heptyl-4-quinolone (HHQ) in Phaeodactylum tricornutum. Firstly, photosynthetic electron transport was obstructed, primarily through inhibition of the cytochrome b6f complex. Secondly, respiration was inhibited, leading to repression of ATP supply to plastids from mitochondria through organelle energy coupling. These data clearly show how HHQ could modulate diatom proliferation in marine environments. 相似文献
9.
Porcine omental lipid extracts were fractionated and the major lipid components characterized. Approximately 97% of the chloroform/methanol
extract consisted of triglycerides containing primarily 16∶0, 18∶0, 18∶1, and 18∶2 fatty acids. Small quantities of free fatty
acids, cholesterol, di- and monoglycerides were also detected. The phospholipid fraction, obtained by solvent partition and
Unisil column chromatography and characterized by high performance liquid chromatography (HPLC) and HPLC-mass spectrometry,
was found to consist primarily of phosphatidylcholine, sphingomyelin, phosphatidylethanolamine, phosphatidylserine, and phosphatidylinositol.
The neutral glycolipids, isolated by solvent partition and Unisil column chromatography and identified by HPTLC and HPLC,
were found to consist primarily of di-, tri-and tetraosylceramides. The complex glycolipid fraction, obtained from Folch upper
phase solvent partition and characterized by HPTLC and immunoblotting, was found to consist primarily of ganglio-, globo-,
and neolacto- neutral glycolipids and ganglio-, globo-, neolacto- and fucosylated gangliosides. 相似文献
10.
Robert H. McCluer James E. Evans Marcia Williams Ann L. Griffith Nicholas Catsimpoolas 《Lipids》1987,22(4):229-235
Feline omental lipid extracts, previously reported to be angiogenic in the cornea of rabbits, were fractionated and the major
lipid components characterized. Approximately 97% of the chloroform/methanol extract consisted of triglycerides containing
primarily 16∶0, 18∶0, 18∶1 and 18∶2 fatty acids. Trace quantities of free fatty acids, cholesterol, di- and monoglycerides
were also detected. The phospholipid fraction, obtained by solvent partition and Unisil column chromatography and characterized
by high performance liquid chromatography (HPLC)-mass spectrometry, was found to consist of phosphatidylcholine, sphingomyelin,
phosphatidylethanolamine and phosphatidylserine. The neutral glycolipids, isolated by solvent partition and Unisil column
chromatography and identified by high performance thin layer chromatography and HPLC of their perbenzoylated derivatives,
were found to consist of glucosyl- and galactosylceramides, galabiosylceramide, lactosylceramide, globotriaosylceramide and
globotetraosylceramide. The complex glycolipid fraction, obtained from Folch upper phase solvent partition, was found to consist
primarily of Forssman glycolipid and gangliosides GM3 and GD3. Smaller amounts of GM1 and other unidentified gangliosides were also present.
The ganglioside nomenclature is according to the system of Svennerholm (J. Neurochem. 10, 613–623, 1963) 相似文献
11.
Kazuo Watanabe Chikako Ishikawa Itsuko Ohtsuka Masazumi Kamata Miho Tomita Kazunaga Yazawa Hiroshi Muramatsu 《Lipids》1997,32(9):975-978
An unidentified bacterial strain, SCRC-21406, isolated from the intestine of a marine fish, Glossanodon semifasciatus, produced docosahexaenoic acid at 23% (mol/mol) [=28% (w/w)] of total fatty acids in a medium containing 0.5% (wt/vol) peptone
and 0.1% (wt/vol) yeast extract at 12°C under atmospheric pressure. The cell yield was 0.43 g/L. The major lipids of the strain
were phosphatidylethanolamine and phophatidylglycerol. Docosahexaenoic acid was localized at the sn-2 positions of both phospholipids. The amounts of polyunsaturated fatty acids other than docosahexaenoic acid were extremely
small [<3% (mol/mol)]. Monousaturated fatty acids of the cis-7, cis-9 and cis-11 types were detected. 相似文献
12.
Determination of the free fatty acids in small quantities of vegetable oil is accomplished by gas liquid chromatography. The
free fatty acids are isolated from a hexane solution of the vegetable oil into an aqueous solution of trimethylphenylammonium
hydroxide (TMPH). Due to the alkalinity of TMPH, the free fatty acids readily partition into this aqueous phase. Injection
of the free fatty acid-TMPH salts into a gas chromatograph results in pyrolytic methylation of the free fatty acid salts—yielding
the methyl esters. Excellent results were obtained when this new procedure was used on neutral lipid oils containing known
amounts of free fatty acids and compared with the results obtained by a modified BF3/MeOH esterification procedure. When compared to the AOCS titration procedure, this new procedure gave comparable results.
This new procedure has advantages over the AOCS procedure: it is more sensitive and gives quantitative results for individual
free fatty acids. This new procedure also has several advantages over the modified BF3/MeOH esterification procedure: it is easily and more rapidly performed, there is no deposition of glyceride on the column
when the sample is injected, and because there is quantitative recovery, the new procedure is more sensitive and can be used
on oils with a low weight percentage of free fatty acids. 相似文献
13.
Human cerumen was separated by column chromatography into the following groups of compounds: hydrocarbons, squalene, wax esters
and cholesterol esters, triacylglycerols, free fatty acids, free fatty alcohols, monoacylglycerols, free cholesterol, free
sterols, and free hydroxy acids. The groups of compounds obtained were examined in detail by gas chromatography and gas chromatography–mass
spectrometry. In total, about one thousand compounds have been identified. 相似文献
14.
Mohamed Fawzy Ramadan S. G. Kinni M. Seshagiri Jörg-Thomas Mörsel 《Journal of the American Oil Chemists' Society》2010,87(8):885-894
Semecarpus anacardium (family Anacardiaceae) has many applications in the Ayurvedic and Siddha systems of medicine in India. Detailed knowledge on the composition of S. anacardium oil, in consideration of potential utilization, is of major importance. In this investigation, column chromatography, gas
chromatography, thin layer chromatography and liquid chromatography techniques were performed to analyze lipid classes, fatty
acids and fat-soluble bioactives of S. anacardium crude seed oil. The amount of neutral lipids in the crude seed oil was the highest, followed by glycolipids and phospholipids,
respectively. Linoleic followed by palmitic and oleic were the major fatty acids. The ratio of unsaturated fatty acids to
saturated fatty acids was higher in neutral lipid classes than in the polar lipids. The main sterol compounds were β-sitosterol,
campesterol and stigmasterol. δ-Tocopherol followed by β-tocopherol were the main tocopherols. When S. anacardium seed oil and extra virgin olive oil were compared for their radical scavenging activity toward 1,1-diphenyl-2-picrylhydrazyl
radical and galvinoxyl radical (by electron spin resonance spectrometry), S. anacardium seed oil exhibited a stronger RSA. 相似文献
15.
Mary J. Garson Mary P. Zimmermann Max Hoberg Rundi M. Larsen Christopher N. Battershill Peter T. Murphy 《Lipids》1993,28(11):1011-1014
Preliminary investigation of the phospholipid fatty acid composition of the tropical marine spongeAmphimedon terpenensis by gas chromatography/mass spectrometry revealed the presence of some novel brominated fatty acids. Two new brominated fatty
acids, (5E, 9Z)-6-bromo-5,9-tetracosadienoic acid (2a) and (5E, 9Z)-6-bromo-5,9-pentacosadienoic acid (3a) were subsequently isolated from a chloroform/methanol (3∶1, vol/vol) extract of the
sponge and characterized as their methyl esters 2b and 3b. The known brominated fatty acid (5E, 9Z)-6-bromo-5,9-hexacosadienoic acid (4a) was also isolated. The new fatty acid methyl esters were confirmed as brominated δ5,9
acid derivatives by chemical ionization mass spectrometry. The position of the bromine substituent was determined to be C-6
by nuclear magnetic resonance techniques while the stereochemistry of the two double bonds was deduced by nuclear Overhauser
enhancement difference spectroscopy. The biosynthetic implications of the co-occurrence of the three brominated acids are
discussed. 相似文献
16.
Dubis Eligiusz Poplawski Janusz Wróbel Jerzy T. Kúsmierz Józef Maliński Edmund Szafranek Janusz 《Lipids》1986,21(7):434-439
The exoskeleton triglyceride fraction isolated from the Colorado beetle,Leptinotarsa decemlineata Say, was studied. Analysis of the hydrolysis products and direct capillary column gas chromatography showed that, apart from
triglycerides, the fraction contained no diol lipids. The composition of the natural triacylglccerol mixture was assessed
by gas chromatography and by field desorption and electron impact mass spectrometry. Triglycerides isolated from the Colorado
beetle are typical glycerol triesters, with long chain (mainly oleic or palmitic) fatty acids. The structures of two major
components (91%), i.e., trioleoyl glycerol and 1,2-dioleoyl-3-palmitoyl glycerol, were determined. 相似文献
17.
A. Riaublanc R. Ratomahenina P. Galzy M. Nicolas 《Journal of the American Oil Chemists' Society》1993,70(5):497-500
A newCandida parapsilosis lipase was isolated and studied. This enzyme was purified by hydrophobic chromatography on a phenyl-sepharose CL4B column
followed by gel permeation on a Sephacryl S300 HR column. It was a 160 kg·mol−1 molecular-weight oligomeric enzyme. Optimal activity was obtained at 45°C and pH 6.5. The lipase activity toward various
acylglycerols and esters was studied. The hydrolysis rate was greater for secondary acylesters than for primary acylesters.
This lipase showed a high specificity for long-chain fatty acids and particularly for polyunsaturated fatty acids. This enzyme
was able to catalyze the synthesis of various oleoylesters in aqueous medium. 相似文献
18.
Characterization of Aroma-Active Compounds in Iranian cv. Mari Olive Oil by Aroma Extract Dilution Analysis and GC–MS-Olfactometry
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Asghar Amanpour Hasim Kelebek Songul Kesen Serkan Selli 《Journal of the American Oil Chemists' Society》2016,93(12):1595-1603
Aroma, aroma‐active compounds and fatty acid profiles of Iranian olive oil obtained from the cv. Mari were investigated for the first time in the current study. Aroma extracts were isolated from the oil by using a purge and trap extraction system and their compositions were analyzed by gas chromatography‐mass spectrometry‐olfactometry (GC–MS‐O). A total of 35 aroma compounds comprising alcohols, aldehydes, acids, esters, ketones, terpenes and volatile phenols were identified and quantified in the assayed samples. Aldehydes were present at the highest levels, followed by ketones and alcohols. (E)‐2‐Hexenal was quantitatively (1589 µg kg?1) the main aroma compound in the analyzed oils, followed by hexanal and (E)‐2‐heptenal. The aroma‐active volatiles were elucidated in the aromatic extract by applying aroma extract dilution analysis (AEDA). The results of AEDA revealed 17 aroma‐active compounds. Under these condition it was possible to completely identify 16 of these compounds. Regarding to the flavor dilution (FD) factor, the most potent odorants with the highest FD factor were (E)‐2‐hexenal (512), followed by hexanal, 6‐methyl‐5‐hepten‐2‐one, (E)‐2‐decenal and one unknown compound (LRI = 1871). The fatty acid profile of the tested oils was composed of thirteen compounds. Oleic acid was the main fatty acid (76.01 %) followed by palmitic acid. 相似文献
19.
E. L. Schneider Sook P. Loke D. T. Hopkins 《Journal of the American Oil Chemists' Society》1968,45(9):585-590
A method is described for the analysis of cyclopropenoid fatty acids in oils. The method consists of reacting the methyl esters
of the cyclopropenoid fatty acids with silver nitrate in methanol to form ether and ketone derivatives. The derivatives formed
from the cyclopropenoid fatty acids are separated from the methyl esters of the normal fatty acids by gas-liquid chromatography
on a 15% diethylene glycol succinate column. The method is applicable to oils containing from 0.01% to 100% of cyclopropenoid
fatty acids. The derivatives of oils containing lew levels of cyclopropenoids are separated from the normal methyl esters
by alumina chromatography prior to gas-liquid chromatography. Studies on the quantitative aspects of the derivative formation,
alumina chromatography, and gas-liquid chromatography are reported. Analyses for total cyclopropenoid fatty acid content of
cottonseed oil andSterculia foetida oil by the gas-liquid chromatographic and hydrobromic acid titration procedures showed good agreement. Replicate analyses
of a sample ofSterculia foetida oil for malvalic and sterculic acid gave coefficients of variation of 6.04% and 1.17%, respectively. 相似文献
20.
D. A. Wolfe P. Venkata Rao D. G. Cornwell 《Journal of the American Oil Chemists' Society》1965,42(7):633-637
The fatty acid composition of carcass and exoskeleton lipids was determined for the freshwater crayfishOrconectes rusticus. Lipid fractions were isolated by column and thin-layer chromatography. Fatty acid methyl esters and alcohol acetates were
then prepared and analyzed by gas-liquid chromatography. Peak identities were established from retention time data for methyl
esters, hydrogenated methyl esters, and saturated, monoene, diene, and polyene methyl esters separated as acetoxy-mercuri-methoxy
derivatives. Minor component acids were estimated from their relative compositions in these fractions.
Presented at the symposium honoring J. B. Brown, AOCS meeting in Chicago, 1964. 相似文献