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1.
J. Jacob 《European Journal of Lipid Science and Technology》1974,76(6):241-244
Diester Waxes and Unusual Fatty Acids in Lipids of Sebaceous Gland Systematic investigations of lipids of sebaceous gland of birds have shown close relationship between the structure of these lipids and the individual species in the natural system of birds. In almost all the species studied so far the lipids of sebaceous gland consist of wax esters which are made up of unusual fatty acids and alcohols. Thus in the group of passeriformes (sparrows) 3-methyl substituted fatty acids, in the group of strigiformes (owls) 2-propyl and 2-butyl substituted fatty acids, and in the group of columbiformes (pigeons) 3-hydroxy fatty acids are found as constituents of the wax esters. Diester waxes are found in galliformes (hens), columbiformes, limicolae (snipes) and in some members of passeriformes. Unusual constituents of these waxes are alkanediols, 3-hydroxy fatty acids, and alkylhydroxymalonic acids. The structures were elucidated by a combination of GLC and mass spectrometry. Some of the mass spectra are discussed. 相似文献
2.
Wax composition of sunflower seed oils 总被引:1,自引:3,他引:1
Amalia A. Carelli Lorna M. Frizzera Pedro R. Forbito Guillermo H. Crapiste 《Journal of the American Oil Chemists' Society》2002,79(8):763-768
Waxes are natural components of sunflower oils, consisting mainly of esters of FA with fatty alcohols, that are partially
removed in the winterization process during oil refining. The wax composition of sunflower seed as well as the influence of
processing on the oil wax concentration was studied using capillary GLC. Sunflower oils obtained by solvent extraction from
whole seed, dehulled seed, and seed hulls were analyzed and compared with commercial crude and refined oils. The main components
of crude sunflower oil waxes were esters having carbon atom numbers between 36 and 48, with a high concentration in the C40−C42 fraction. Extracted oils showed higher concentrations of waxes than those obtained by pressing, especially in the higher
M.W. fraction, but the wax content was not affected significantly by water degumming. The hull contribution to the sunflower
oil wax content was higher than 40 wt%, resulting in 75 wt % in the crystallized fraction. The oil wax content could be reduced
appreciably by hexane washing or partial dehulling of the seed. Waxes in dewaxed and refined sunflower oils were mainly constituted
by esters containing fewer than 42 carbon atoms, indicating that these were mostly soluble and remained in the oil after processing. 相似文献
3.
Constituents of Montan Wax II: Hydroxy Acids The group of hydroxy acids which occur in a large number of natural waxes as condensing component of the ester wax part were found in Montan wax as well and were studied closely. The methyl esters of the total acids were treated with succinic anhydride and the resulting hydrogen succinates of the methyl esters of hydroxy acids separated by means of an anion exchanger. 相似文献
4.
The composition of beeswax and other waxes secreted by insects 总被引:1,自引:0,他引:1
A. P. Tulloch 《Lipids》1970,5(2):247-258
This review deals, with waxes of members of two quite different groups of insects, the bees and the scale insects, which secrete
large amounts of wax. The former use was as a structural material and the latter as a protective material. The compositions
of waxes from some of these insects are described and particular attention is paid to the compositions of the unhydrolyzed
waxes and to the presence of hydroxy acids. New analyses of beeswax and of wax of a species of bumble bee are reported. The
structures of the diesters, hydroxyesters and diols of beeswax are elucidated. The bumble bee wax contains major proportions
of saturated and unsaturated hydrocarbons, and of long chain saturated, mono- and diunsaturated esters. The relationship between
structure and function of the waxes is discussed.
Issued as National Research Council of Canada No. 11260.
One of six papers to be published from the Symposium on Natural Waxes, presented at the AOCS Meeting, San Francisco, April
1969. 相似文献
5.
Environmental Behaviour and Toxicology of Waxes Plant and animal waxes are chemically relatively stable nontoxic substances and are used by humans since ages. In the nature waxes have protective function against environmental influences. This protective action is possible due to great resistance of the waxes towards environment, which also means low biological degradability. Obviously, waxes are undigestible and non-toxic in human and animal organism. Partially synthesized waxes based on montana wax, a plant fossil wax, have a structure similar to natural waxes, and therefore they resemble natural waxes with regard to environmental behaviour and are fully harmless from toxicological viewpoint. Also fully synthetic waxes, such as polyethylene waxes and polyethylene oxide waxes have, according to results obtained so far, no undesirable effects on environment. Waxes have been approved in foods worldwide, obviously due to their favorable toxicological properties. 相似文献
6.
K. Blaettner J. Kaupp G. Nowy K. Petz W. Straßberger 《European Journal of Lipid Science and Technology》1970,72(11):964-967
Epichlorohydrine in the Synthesis of Waxes Waxes that are soluble in usual wax solvents are of interest in special fields of application. It is not possible to prepare clear solutions of appreciable concentration using natural waxes, such as carnauba wax or derivatives of montana wax. Although these waxes are well soluble when hot, however, on cooling they separate out as crystalline or pasty masses. For preparing easily soluble waxes a new path of synthesis was found. Thus, waxes having ether or ester groups which were also easily soluble in the cold were prepared by reacting epichlorohydrine with such compounds, which, apart from having a long hydrocarbon chain also possessed a functional group with one active hydrogen atom. 相似文献
7.
Waxes Having High Dispersibility and Special Consideration of Their Suitability in the Manufacture of Colouring Masses for Carbon Paper Increasing amounts of waxes having fundamentally different chemical composition are being used as dispersion aids. In the manufacture of colouring masses for carbon papers, the materials used as vehicle of the colour and as dispersing agent for carbon black are hydrocarbons, wax acids and their natural esters. Whereas low-priced paraffins are mainly used for cheap carbon papers meant for a single use, carnauba wax is used for better quality carbon papers which can be used several times. The latter wax is especially suited because of its carbon black-dispersing and oil-binding properties. Since crude montana wax does not have these properties to such an extent as the carnauba wax, it was attempted to improve the carbon black-dispersing and oil-binding of montana wax by chemical synthesis. This was achieved by reacting crude montana wax with maleic anhydride and subsequent esterification of the reaction products with glycols. The results were successfully applied to the solution of problems involving dispersion of pigments and plastic additives. 相似文献
8.
Determination of Functional Groups in Oxidized Paraffin Waxes Methods are described for the quantitative determination of alcohols, esters, carbonyl compounds, acids and peroxides in oxidized paraffin waxes. When analysing for alcohols, the hydroperoxide content of the wax must be taken into account in the final calculation whereas the peroxides must be reduced before determining the ester and carbonyl compounds. Without these measures values are found which are too high. 相似文献
9.
Plant waxes 总被引:5,自引:0,他引:5
P. E. Kolattukudy 《Lipids》1970,5(2):259-275
The surface of plants is covered with a complex mixture of lipids, often in crystalline form, called plant waxes. The chemistry,
biosynthesis, catabolism and function of plant waxes are reviewed. The most common components are hydrocarbons, wax esters,
free fatty alcohols and acids. Ketones, secondary alcohols, diols, aldehydes, terpenes and flavones are also found. The major
function of the wax appears to be protection of the organism from water loss and other hazards of the environment. The alkanes
are formed from fatty acids either by elongation followed by decarboxylation or by head-to-head condensation between two biochemically
dissimilar fatty acids followed by specific decarboxylation of one of them. Fatty acyl-CoA is reduced to the aldehyde which
in turn is reduced to the alcohol. The alcohol is then esterified with acyl moieties from acyl-CoA or phospholipids. Plant
waxes undergo very little catabolism in plants but animals can degrade them to a limited extent and microorganisms readily
degrade them.
One of six papers to be published from the Symposium on Natural Waxes, presented at the AOCS Meeting, San Francisco, April
1969. 相似文献
10.
W. Straßberger 《European Journal of Lipid Science and Technology》1969,71(3):215-218
Synthesis of Waxes by Guerbet Reaction Branched chain waxes possess better liquifying properties and superior solubility in organic solvents than straight chain waxes. Branched chain waxes having both of the above properties were therefore synthesized by a new principle, namely the Guerbet reaction. Guerbet alcohols, based on technical octadecyl alcohol were esterified with various mono- and dicarboxylic acids. Strongly branched and relatively low melting waxes were thus obtained which, inspite of their greater solubility in organic solvents, exhibit insignificant liquifying effect in wax pastes. As against these, when the Guerbet alcohols from stearyl alcohol are oxidized, branched chain wax alcohols are obtained which in native as well as saponified state show liquifying action on wax pastes. The Guerbet reaction is explained taking the example of a mixture of two primary alcohols. 相似文献
11.
Lutz Matthies 《European Journal of Lipid Science and Technology》2001,103(4):239-248
Natural waxes have been used by mankind since prehistoric times. Many uses of wax are based on the imitation of its natural functions. Waxes in nature primarily serve to provide protective barriers on the surfaces of living organisms. Their functions are also determined by wax characteristics such as adhesion and cohesion, as well as slip and deformation effects. In ancient times, for example, wax seals were used to help preserve food and beverages. Beeswax has remained an important material for manufacturing candles up to the present day. Recent vegetable waxes have been used in industry since the mid‐nineteenth century, for example in care products. Refined and chemically processed montan‐based waxes are quite similar to naturally occurring vegetable ester waxes in their structure and application characteristics. They are similar in their environmental characteristics and are also nontoxic. Crude montan wax itself belongs to the naturally occurring waxes of vegetable origin such as candelilla wax and carnauba wax. 相似文献
12.
Summary Methods for the determination of acid, ester, hydroxyl, and ketone (or aldehyde) groups and of mean molecular weights of small
samples of natural waxes are reported. Complete analyses can be made on 0.5 g. of sample. A simplified procedure for quantitative
separation of acid and unsaponifiable fractions of a wax is also reported.
Molecular distillations of beeswax, caranda wax, crude and refined candelilla wax, and ouricury wax, have fractionated these
complex mixtures into simpler ones. Hydrocarbons and free unsubstituted alcohols and acids, if present, distil readily at
150°C. A pot still suitable for convenient molecular distillation of up to 100-g. charges of waxes or other high melting materials
is described.
A method for the calculation of composition of unhydrolyzed waxes based upon function group analysis of molecular distillation
fractions is described. Results of application of this method to the waxes distilled are reported and show the ubiquitousness
of hydroxy acids. All of the above waxes and carnauba wax contain major proportions of esters of the hydroxy acids, and none
contains as much as one-half simple esters of unsubstituted acids and alcohols.
A portion of a dissertation submitted by Thomas Wagner Findley to the Graduate School of the Ohio State University in partial
fulfilment of the requirements for the Ph.D. degree.
S. C. Johnson and Son Inc. Fellow in Physiological Chemistry, 1946-50. 相似文献
13.
Kfm. F. Reutner 《European Journal of Lipid Science and Technology》1968,70(3):162-167
Analysis of Waxes and Mixtures of Waxes by Thin-Layer Chromatography A few commercial waxes were investigated by thin-layer chromatography. The following mobile phases and temperatures were employed: benzene, benzene + 0.5% acetic acid and benzene + 2% methyl acetate at 45°C; tetrachloroethylene at 80°C and tetrachloroethylene + 0.5% acetic acid at 70°C. A few examples showing the possibility of analyzing wax mixtures with the help of the methods described here, are given. 相似文献
14.
Thomas K. Miwa 《Journal of the American Oil Chemists' Society》1971,48(6):259-264
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
15.
R. G. Binder T. H. Applewhite G. O. Kohler L. A. Goldblatt 《Journal of the American Oil Chemists' Society》1962,39(12):513-517
The fatty acid composition of a number of domestic and foreign castor oils was determined by consecutive column and gas-liquid
Chromatographic analysis. After saponification of the oils and removal of the unsaponifiables, the nonhydroxy, monohydroxy,
and dihydroxy acids were fractionated by partition chromatography on silicic acid. The amount of acid in each fraction was
determined by titration or weighing. Gravimetric data were in good agreement with the titrimetric data. The acids obtained
by saponification were converted to methyl esters with diazomethane and similarly subjected to partition chromatography. The
methyl esters from various fractions were analyzed by gas-liquid chromatography. Components were tentatively identified by
their comparative retention times and confirmed
Presented at the AOCS meeting in Chicago, 1961.
A laboratory of the Western. Utilization Research and Development Division, Agricultural Research Service, U.S.D.A. 相似文献
16.
Limanathes douglasii seed oil glycerides contain fatty acids which predominantly (97%) have 20 or more carbon atoms. Fatty acids were prepared
by saponification; fatty alcohols, by sodium reduction of the glycerides; and liquid wax esters, byp-toluenesulfonic acid-catalyzed reaction of the fatty acids with the fatty alcohols. Solid waxes were prepared by hydrogenation
of the glyceride oil and of the wax esters. Chemical and physical constants were determined forLimnanthes douglasii seed oil and its derivatives. The liquid wax esters had properties very similar to those of jojoba (Simmondsia chinensis) seed oil. The solid hydrogenated wax ester was identical in physical appearance and melting point to hydrogenated jojoba
seed oil.
A laboratory of the Northern Utilization Research and Development Division, Agricultural Research Service, USDA. 相似文献
17.
Quantitative Determination of Unpolar Dimeric Fatty Acids in Fats and Oils Fatty acids obtained by saponification of fats followed by removal of unsaponifiables and petroleum ether insoluble oxidized fatty acids, were treated to give urea-adducts. The mixture of fatty acids which did not form adducts was esterified and separated by thin-layer chromatography. It was shown by mass-spectrometry that the methyl esters of unpolar dimeric fatty acids occupied a definite zone in the chromatogram. The methyl esters of unpolar dimeric fatty acids can be quantitatively estimated by charring the chromatogram under standardized conditions and densitometry of the above zone, whereby a test substance is co-chromatographed for comparison. The relative standard deviation in the chromatography and densitometric determination was approximately 10%. The lower limit of detection was at 0.005% of the methyl ester of unpolar dimeric fatty acid. Using dimeric fatty acids lebelled with radioactive carbon, it was proved that approximately up to 90% of the unpolar dimeric fatty acids can be detected by this method. 相似文献
18.
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
19.
Systematic Quantitative Analysis of Natural Waxes with the Help of Ion-Exchange, Column and Thin-Layer Chromatography A method was developed for the quantitative separation of natural waxes into substance classes. The hydrocarbons were separated by the adsorption chromatography on silica gel/CS2 column and the separation of acids from alcohols was achieved on a two-phase ion-exchange column after saponification. The isolation of the individual homologues (C16? C32) from the alcohol and acid mixtures was carried out with the help of reversed phase column chromatography by stepwise increase in temperature and acetic acid concentration. 相似文献
20.
Waxes are important as building material and for the chemical communication of the honeybee Apis mellifera carnica. In this study chemometric tools were established for classifying the different waxes inside the hive. By using gas chromatography in combination with mass spectrometry, components of different types of waxes were analyzed. By considering different substance classes of waxes, discriminant function analyses revealed distinct subtypes of comb waxes and of cuticular waxes. It is shown that the aging of comb wax is in part a spontaneous physicochemical process due to differential volatilities of compound classes with different chain length ranges. On the other hand it is directly influenced by the bees by adding lipolytic enzymes to the comb wax. The data suggest that the varying cuticular wax and comb wax compositions could serve as cues for bees to recognize castes, sexes, or comb age. 相似文献