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1.
Isomeric methyl esters of fatty acids in three groups (C15, C17, C19) have been isolated from ruminant fats. Basic structural analysis by physiochemical techniques indicated that these odd-numbered fatty acids were even chain with a single methyl branch on the chain. High resolution open-tubular gas liquid chromatographic studies indicate that, with the exception of iso acid impurities in these fractions, only even-numbered carbons of the fatty acid chains bear the methyl branch.  相似文献   

2.
Codling moth females (Cydia pomonella, Lepidoptera: Tortricidae) (CM) usually lay single eggs and have a tendency to disperse. In a first experiment we observed that single females exposed to 20 apples distribute their eggs regularly among apples, suggesting a dispersive oviposition behavior. In a dual-choice situation, isolated females avoided oviposition on areas of cardboard treated with a methylene dichloride egg extract at the dose of ca. 1.0 egg equivalent/cm2. A strong avoidance was obtained in response to a 20-fold dose, which was accompanied by a significant reduction of total oviposition. Seven major compounds found by GC analyses in the methylene dichloride extract of 2 to 3-day-old eggs were saturated or unsaturated C14-C18 straight-chain fatty acids: myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, and linolenic acid. This was confirmed by GC-MS analysis of an extract made by ethyl ether. Smaller amounts of three methyl esters were also identified as methyl myristate, methyl palmitate, and methyl stearate. A blend of the seven fatty acids (FA) mimicked rather well the avoidance provoked by the extract, and this avoidance was confirmed by choice between treated and untreated fruits by single females. The treatment of apples with the 7FA mixture induced an aggregative distribution of the eggs among apples. We also found that the amounts of fatty acids harvested in the extract depend on the egg age. Amounts of fatty acids increased until eggs were 4 days old and then decreased before hatching. In this paper we discuss the possible role of simple molecules, such as fatty acids and their esters, as semiochemicals indicative of juvenile tissues.  相似文献   

3.
A total of fifteen saturated fatty acid esters were newly identified from the secretions of an unidentified Anaulaciulus sp. (Julida: Julidae). The fatty acid components of the esters were composed of normal chain acids (from C10 to C14) and of branched chain acids (from iso-C12 to iso-C15 and anteiso-C15). The alcohol moieties were all composed of normal chain alcohols varying from n-butanol to n-octanol. The most abundant component found in the total esters was n-hexyl laurate (64.7%). Novel compounds identified from the millipede secretion extracts include six branched iso- and anteiso-fatty esters, an odd-numbered C11-fatty acid ester, a C13-fatty acid ester, and a C7-alcohol ester, all of which were previously undescribed natural products. In addition, a characteristic mixture of benzoquinones, such as 2-methyl-1,4-benzoquinone, 2-methoxy-3-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, 2-methoxy-6-methyl-1,4-benzoquinone, and 2,3-dimethoxy-5-methyl-1,4-benzoquinone were identified from the secretions, together with trace amounts of 1,4-benzoquinone.  相似文献   

4.
H. Singh  K. K. Carroll 《Lipids》1970,5(1):121-127
The lipid composition of beef and human pituitary was determined by chromatographic and spectrophotometric methods. Beef pituitary lipid contained about 25% nonpolar lipids and 75% phospholipids whereas nonpolar lipids made up approximately 60% of the total in human pituitaries. The main nonpolar (i.e., low polarity) lipids in human pituitary were triglycerides, cholesterol, free fatty acids and an unidentified component in the triglyceride fraction. Cholesterol was the major nonpolar lipid component in freshly collected beef anterior and posterior pituitary, but the amount of free fatty acids appeared to increase during storage. Preliminary investigation of the unknown nonpolar lipid in human pituitaries suggested that it was an unsaturated hydroxy compound with no carbonyl functions. Thin layer chromatography indicated that it was also present in smaller amounts in freshly collected beef pituitaries. The main phospholipids of beef anterior, posterior and human pituitary were phosphatidyl ethanolamine, phosphatidyl choline, phosphatidyl inositol, phosphatidyl serine and sphingomyelin. The fatty acid composition of total nonpolar lipids, free fatty acids, total phospholipids, phosphatidyl ethanolamine and phosphatidyl choline of beef anterior and posterior pituitary was determined by gas liquid chromatography. Mixtures of saturated and unsaturated fatty acids ranging from C12 to C22 were present; the main fatty acids were palmitic, stearic, oleic, linoleic and arachidonic.  相似文献   

5.
The proximate, physicochemical, and fatty acid compositions of seed oil extracted from khat (Catha edulis) were determined. The oil, moisture, crude protein, crude fiber, crude carbohydrate, and ash content in seeds were 35.54, 6.63, 24, 1.01, 30.4 %, and 1.32 g/100 g DW respectively. The free fatty acids, peroxide value, saponification value, and iodine value were 2.98 %, 12.65 meq O2/kg, 190.60 mg KOH/g, and 145 g/100 g oil, respectively. Linolenic acid (C18:3, 50.80 %) and oleic (C18:1, 16.96 %) along with palmitic acid (C16:0, 14.60 %) were the dominant fatty acids. The seed oil of khat can be used in industry for the preparation of liquid soaps and shampoos. Furthermore, high levels of unsaturated fatty acids make it an important source of nutrition especially as an animal product substitute for omega‐3 fatty acids owing to the high content of linolenic acid.  相似文献   

6.
N. Nicolaides 《Lipids》1971,6(12):901-905
By combined gas liquid chromatography-mass spectrometry a series of monomethyl branched fatty acids was found in the fatty acid moiety of the wax esters of vernix caseosa. The methyl branch occurred on the even C-atoms of chains ranging from C11 to C17 (some 43 compounds in all). Except for the iso acids and possibly some of the anteiso acids, these could be formed by replacement of malonyl CoA with a molecule of methyl malonyl CoA at the point of the branch. Smaller amounts of fatty acids also were found with two methyl branches occurring on the even C-atoms of chains ranging from C9 to C15.  相似文献   

7.
Capillary gas chromatography-mass spectrometry (GC-MS) analysis of the sterol ester fatty acid methyl esters of the crayfish hepatopancreas revealed the presence of at least 30 kinds of unusual furan fatty acids (F acids), which accounted for 28.49% of the total sterol ester fatty acids. On the other hand, only small amounts were found in triacylglycerols (0.5%) and phospholipids (0.7%). Among the F acids, 17 acids were the hitherto unknown ones, the major component being 12,15-epoxy-13,14-dimethyleicosa-12,14-dienoic acid (F6) (41.83% of the total F acids). These novel acids possessed chain lengths of C12 to C22, with the largest concentration at C20 (45.38%), C18 (41.97%) and C16 (10.35%). Odd-numbered F acids also were found, though in a very small amount (0.4%). In the living things other than the crayfish, the longest chain F acid (C24) was detected in the sterol ester of the carp hepatopancreas. The bullfrog, an amphibian, and the turtle, a reptilian, were found to have F acids as well in their livers. Olefinic furan fatty acids, which were detected by GC-MS, were found to have resulted during the analytical process from cyclodehydration of the diketo-ene formed by autoxidation of the F acids.  相似文献   

8.
Skin-surface lipids from the monkeyMacaca fascicularis are composed of sterol esters (38%), cholesterol (4%) and two types of wax diesters, identified as Type II (IIa and IIb, 17% and 40%, respectively). Type IIa contained diesters of 1,2-alkanediols esterified with two molecules of long-chain (C14−C34) fatty acids having straight and branched chains. In the diesters IIa, fatty acids shorter than C19 predominated in position 1, and fatty acids longer than C20 predominated in position 2. Type IIb contained diesters of 1,2-alkanediols esterified with C4 and C5 branched-chain fatty acids (predominantly isovaleric acid) at position 1 and long-chain (C14−C27) acids, having straight and branched chains, at position 2. The shortchain acids were converted to 2-nitrophenylhydrazides and analyzed by high-performance liquid chromatography (HPLC). Ammonia chemical ionization (CI)-gas chromatography (GC)-mass spectrometry (MS) resolved the intact diesters IIb into 12 peaks corresponding to molecular weights ranging from 597 to 748, and showed that the molecular species, such as C21−C16−C5 (diol, fatty acid in position 2, fatty acid in position 1), C22−C16−C5 and C23−C16−C5, were prevalent. The fatty acids from both diesters were mostly (>98%) saturated. The 1,2-alkanediols from both diesters consisted of C16−C26 saturated straight- and branched-chain components. The acyl groups of sterol esters contained 86% C14−C34 branched-chain acids. The unsaturated fatty acids (5.4%) belonged to a straight-chain monoenoic series having extremely long chains (C18−C34). The branched-chain structures in the fatty acids and diols were iso and anteiso. These results show the species-specific profile for the skin-surface lipid synthesis.  相似文献   

9.
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 C17∶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 C15∶0 and iso C17∶0 was the predominant pair in both the moderately (34–64%) and extremely (76–87%) thermophilic strains. The pair of fatty acids ante-iso C15∶0 and ante-iso C17∶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 C17∶0/iso C15∶0 and ante-iso C17∶0/ante-iso C15∶0 were much greater at higher culture temperatures, indicating chain elongation.  相似文献   

10.
The free sterols and phospholipids of the demospongeAplysina fistularis were isolated and analyzed. The free sterols consisted mainly of the unusual 26-methylated sterols aplysterol (53%) and 24(28)-dehydroaplysterol (7%) together with 7 commonly occurring sterods. The major phospholipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol, phosphatidylethanolamine, phosphatidylserine and diphosphatidylglycerol. The major fatty acyl components of the phospholipids consisted of 85% C14−C20 acids, including the unprecedented 2,6,10-trimethyl-5-tetradecenoic acid and 11-methyloctadecanoic acid. The remaining 15% were C27−C30 demospongic acids, including 2 novel acids tentatively assigned the structures 5,9,23-octacosatrienoic acid and 5,9,23-nonacosatrienoic acid, and 3 novel acids proven to be 5,9,21-octacosatrienoic acid, Z,Z-20-methyl-5,9-hexacosadienoic acid and Z,Z-22-methyl-5,9-octacosadienoic acid. The biosyntheses of the novel demospongic acids are proposed to occur by chain elongation of monoenoic or branched precursors followed by desaturation. The large quantities of typically bacterial phospholipids and fatty acids found implied the presence of bacteria in the sponge, in agreement with microscopic studies. Analysis of the phospholipid-bound fatty acids in a sponge cell-enriched fraction indicated that the demospongic acids, including the 2 branched structures, were the major acids of the sponge cells. The presence inA. fistularis of demospongic acids containing membrane disordering groups—methyl branches or double bonds—on the ω7 carbon is proposed to be due to the need by the sponge for membranes possessing fluidity near the middle of the phospholipid bilayer. It is also proposed that the C26 methyl group of aplysterol causes disordering of the phospholipid bilayer in the same region, and thus also evolved in response to this need. For part 1, see ref. 1. Phylum porifera, class demospongia, subclass ceractinomorpha, order verongida, family aplysinidae (2). Formerly known asVerongia thiona de Laubenfels. Major diagnostic fragments from peak 23:M+ 471 (2.9%); m/z 442 (C26, 0.2%); m/z 428 (C25, 0.2%); m/z 414 (C24, 0.1%); m/z 400 (C23, 0.3%); (absence of C22 peak); m/z 374 (C21, 0.2%); m/z 360 (C20, 0.2%); m/z 234 (C11, 1.0%); m/z 220 (C10, 0.7%); m/z 206 (C9, 0.5%); m/z 194 (C8, 0.4%); m/z 180 (C7, 24.9%); m/z 166 (C6, 1.2%); m/z 152 (C5, 0.8%); m/z 140 (C4, 1.3%); m/z 126 (C3, 18.7%). Major diagnostic fragments from peak 25:M+ 485 (0.9%); m/z 456 (C27, 0.1%); (absence of C26, C25 peaks); m/z 414 (C24, 0.3%); m/z 400 (C23, 0.1%); m/z 402 (C23, 0.1%); (absence of C22 peak); m/z 374 (C21, 0.1%); m/z 360 (C20, 0.1%); m/z 234 (C11, 0.5%); m/z 220 (C10, 0.3%); m/z 206 (C9, 0.1%); m/z 194 (C8, 0.2%); m/z 180 (C7, 18.0%); m/z 166 (C6); m/z 152 (C5), m/z 140 (C4); m/z 126 (C3, 15.0%).  相似文献   

11.
Methyl esters of a Canadian Atlantic herring oil containing 62% monoethylenic fatty acids were subjected to batch fractional distillation under vacuum on a pilot plant scale, to study the feasibility of fractionating fatty acid esters of marine oils of low iodine value into monounsaturated fractions with increased commercial value for industrial chemical uses. A total of 64 methyl ester fractions were collected and analyzed by gas liquid chromatography. Recoveries of the major saturated and monounsaturated acids were close to 100%, and some fractions contained over 90% of the desired 22:1 long chain monounsaturated acids. The short chain polyunsaturated acids were recovered in good yields, but the long chain highly unsaturated acids were recovered in yields of 60% or less due to oxidative and thermal decomposition in the particular apparatus employed. If small amounts of unsaturated acids are acceptable, fractional distillation of low iodine value marine oils could inexpensively supply fractions with high concentrations of methyl esters of longer chain (C20 and C22) monounsaturated and shorter chain (C14) saturated acid or (C16) saturated-monounsaturated acid mixture.  相似文献   

12.
The adsorption equilibria are discussed for fatty acids 16∶1n?7, 16∶2n?4, and 20∶5n?3 (eicosapentaenoic acid, EPA). These fatty acids are major components of a polyunsaturated fatty acid concentrate from the microalga Phaeodactylum tricornutum. The solvents used were methanol/water (1% acetic acid) mixtures of different compositions, and the adsorbents used were chromatographic reversed-phases octylsilyl C8, octadecylsilyl C18, and dodecylsilyl C22 of different particle and pore sizes. The kinetic studies showed that equilibrium was attained instantaneously, suggesting an absence of mass transfer limitations. The equilibrium data were fitted by the Freundlich isotherm. The separation efficiency of EPA from 16∶1n?7 and 16∶2n?4 in all the adsorbent-solvent systems was compared in terms of the separation factors αEPA/16:2n-4=K EPA/K 16:2n-4 and α16:1n-7/EPA=K 16:1n-7/K EPA, where K i is the fatty acid distribution ratio between the stationary and the liquid phases. The EPA separation from 16∶1n?7 and 16∶2n?4 by liquid chromatography could be predicted using the Craig model for the various solvent-adsorbent combinations. The best adsorbents for purifying EPA were: C18, PEP, 8 μm, 100 Å, and C22, 10 μm, 100 Å, and the best solvent was methanol/water (1% acetic acid) 75∶25, w/w.  相似文献   

13.
Crambe abyssinica andLunaria annua, members of the Cruciferae family, have seed oil glycerides containing ca. 55–65% of C22 and C24 unsaturated fatty acids. Fatty acids were prepared by saponification; fatty alcohols, by sodium reduction of glycerides; liquid wax esters, byp-toluenesulfonic acid-catalyzed reaction of fatty acids with fatty alcohols; and methyl esters, by reaction of fatty acids with diazomethane. Solid hydrogenated glyceride oils and wax esters were compared with several commercial waxes. Chemical and physical constants were determined for the seed oils and their derivatives. Position of unsaturation in theCrambe fatty acids was determined by gas chromatographic analysis of the permanganate-periodate degradation products. The major dicarboxylic acid was brassylic (C13), proving the docosenoic acid to be erucic. Presented in part at the AOCS meeting in New Orleans, La., 1962. A laboratory of the No. Utiliz. Res. & Dev. Div., ARS, U.S.D.A.  相似文献   

14.
B. F. Szuhaj  R. L. McCarl 《Lipids》1973,8(5):241-245
Fatty acid composition of neutral and polar lipid fractions from rat hearts was determined in rats of different ages as their diet source changed. Piebald rats were weaned at 21 days and were fed standard lab chow. Lipids from rat hearts, mothers milk and lab chow were purified on a Sephadex G-25 fine column and separated into neutral and polar lipid fractions by silicic acid column chromatography. These lipid fractions were then hydrolyzed and methylated with BF3 in methanol, prior to gas liquid chromatographic separation on a 1/8 in. × 10 ft aluminum column of 15% EGS on 80–100 mesh acid-washed Chromosorb W. Three major fatty acids in the neutral lipid fraction comprised 72% of total neutral lipid fatty acids from young hearts. At sexual maturity (at least 74 days old) C18∶1 was the major fatty acid, followed by C16∶0 and C18∶0. The same three fatty acids comprised 83% of total polar lipid fatty acids, but C18∶0 was the major fatty acid, followed by C16∶0 and C18∶1. The fatty acid composition of dietary lipids influenced the total neutral lipid fatty acid composition of the rat heart, but had little influence on the fatty acid composition of the polar lipid fraction. Presented in part at the AOCS Meeting, New Orleans, April 1970.  相似文献   

15.
The lipid class compositions of adult Pacific oysters [Crassostrea gigas (Thunberg)] were examined using latroscan thin-layer chromatography/flame-ionization detection (TLC/FID), and fatty acid compositions determined by capillary gas chromatography and gas chromatography/mass spectrometry (GC/MS). The fatty acid methyl esters were separated using argentation TLC and also analyzed as their 4,4-dimethyloxazoline derivatives using GC/MS. Major esterified fatty acids inC. gigas were 16∶0, 20∶5n−3, and 22∶6n−3. C20 and C22 nonmethylene interrupted (NMI) fatty acids comprised 4.5 to 5.9% of the total fatty acids. The NMI trienoic fatty acid 22∶3(7,13,16) was also identified. Very little difference was found in the proportions of the various lipid classes, fatty acids or sterols between samples of adult oysters of two different sizes. However, significant differences in some of the lipid components were evident according to the method of sample preparation used prior to lipid extraction with solvents. Lyophilization (freeze drying) of samples led to a significant reduction in the amounts of triacylglycerols (TG) extracted by solvents in two separate experiments (7.0 and 52.5% extracted). Extracts from lyophilized samples had less 16∶0, C18 unsaturated fatty acids, and 24-ethylcholest-5-en-3β-ol, while C20 and C22 unsaturated fatty acids comprised a higher proportion of the total fatty acids. There was no significant change in the amounts of polar lipids, total sterols, free fatty acids or hydrocarbons observed in extracts from lyophilized samples relative to extracts from nonlyophilized samples. Addition of water to the freezedried samples prior to lipid extraction greatly improved lipid yields and resulted in most of the TG being extracted.  相似文献   

16.
The hepatopancreatic fatty acid extract of the snow crab contains a high percentage (26%) of odd-carbon-numbered fatty acids and a substantial quantity (29%) of methyl-branched fatty acids, as indicated by gas chromatography/mass spectrometry (GC/MS) and gas liquid chromatography (GLC). A wide distribution in chain length of the fatty acids (C10 to C26) and in positional isomers of the linear monoenes are also indicated by GC/MS.  相似文献   

17.
Extracts of whole booklice (Liposcelis bostrychophila)—sequentially extracted in hexane and aqueous 80% methanol (80%MeOH)—repel conspecifics. A methanol-soluble fraction (MFr) of the 80% methanol extract was more repellent than either its corresponding water fraction (WFr) or the hexane extract. The repellent effect of the MFr was repeatable across extracts prepared on different occasions over a 1 month period. Gas chromatography, mass-spectrometry (GC-MS) analyses showed that saturated (C16; C18) monoenoic (C16:1; C18:1) and a dienoic fatty acid (C18:2) and the corresponding methyl esters of all but C16:1 and C18 constituted approximately 95% and 30%, of the detected compounds in the methanol fractions and the hexane extract, respectively. Qualitative thin layer chromatography showed that cholesterol was present in methanol fractions and the hexane extract, and also enabled tentative identification of triacylglycerols and phospholipids in the methanol fractions. Extracts of wheatgerm, dried skimmed milk powder, active yeast, and wholemeal flour—L. bostrychophila dietary components—were analyzed by GC-MS, and C16, C18:1 and C18:2 were detected, indicating that C18 and the methyl esters were not directly extractable and/or that they were products of booklice metabolism. A fatty acid amide (stearamide) previously identified in cuticular extracts of L. bostrychophila was not detected, and therefore was not responsible for the observed biological activity. Pure fatty acids and fatty acid methyl esters repelled settling of L. bostrychophila at 10 mM, with the exception of palmitic and stearic acids, indicating, among other things, a difference between the efficacy of saturated and unsaturated fatty acids. The effect of concentrations <10 mM was less significant, although palmiteoleic acid appeared to be attractive to L. bostrychophila at 0.1 mM. Fatty acids and fatty acid methyl esters were at a much lower concentration than 10 mM in the repellent methanol fractions, indicating that an interaction between known and as yet unidentified compounds is likely. The significance of fatty acids in relation to the biology and behavior of L. bostrychophila and their potential for use in traps and monitoring are discussed.  相似文献   

18.
Jasminum auriculatum (Vahl) (family: Malvaceae) widely grown in India was analysed for its fatty acids and waxy constituents. Straight-chain hydrocarbons (C20-C34), fatty acids (C14-C23) and fatty alcohols (C21-C32) were found in the 95% aqueous ethanol extract of the leaves of the plant. Malvalic acid was the only cyclic acid identified. Hydrocarbons (C29 and C31), fatty acids (C16, C18, C18:1, C18:2, C18:3 and C22) and fatty alcohols (iso-C26, C28 and C30) were the major components. Four polyalcohols, namely D-mannitol, xylitol, inositol and sorbitol, have also been found in the alcoholic extract of the leaves.  相似文献   

19.
HCl-catalyzed ethanolysis followed by saponification readily surmounts the resistance of long chain wax esters to direct hydrolysis by alkali. Additionally, choosing ethyl instead of methyl esters allows baseline separations between long-chain alcohols and corresponding esters in gas liquid chromatographic (GLC) analysis of total alcohol and acid components before saponification. Liquid wax esters were analyzed on a temperature-programmed 3% OV-1 silicone column. Geographical and genetic effects on the variability of jojoba oil composition were investigated with five different seed samples. Major constituents in jojoba seed oil from shrubs in the Arizona deserts, as indicated by GLC analyses of oil, ethanolysis product, isolated fatty alcohols and methyl esters of isolated fatty acids, were C40 wax ester 30%, C42 wax ester 50% and C44 wax ester 10%; octadecenoic acid 6%; eicosenoic acid 35%, docosenoic acid 7%, eicosenol 22%, docosenol 21% and tetracosenol 4%. Oil from smaller leaved prostrate plants growing along California’s oceanside showed a slight tendency toward higher molecular size than oils from the California desert and Arizona specimens. The wax esters are made up of a dispro-portionately large amount of docosenyl eicosenoate and are not a random combination of constituent acids and alcohols.Lunaria annua synthetic wax ester oil was used as a model for evaluating the analytical procedures. Presented at the AOCS Meeting, Chicago, September 1970 No. Utiliz, Res. Dev. Div., ARS, USDA.  相似文献   

20.
The physicochemical and fatty acid compositions of seed oil extracted from Thunbergia fragrans were determined. The oil content, free fatty acids, peroxide value, saponification value and iodine value were 21.70 %, 2.25 % (as oleic acid), 9.6 (mequiv. O2/kg), 191.71 (mg KOH/g) and 127.84 (g/100 g oil) respectively. The fatty acid profiles of the methyl esters showed the presence of 90.16 % unsaturated fatty acids and 9.84 % saturated fatty acids. Palmitoleic acid, which is usually found in marine foods and is unique in seed oils of botanical origin, was the major component (79.24 %). The oil can also be used in industries for the preparation of liquid soaps, shampoos and alkyd resin.  相似文献   

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