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991.
Naguib-Mostafa A. Smith A. K. deMan J. M. 《Journal of the American Oil Chemists' Society》1985,62(4):760-762
Journal of the American Oil Chemists' Society - Scanning electron microscopy was used to study the crystal structure of hydrogenated Canola oil. Fixation of the samples was carried out at 10 C... 相似文献
992.
993.
Characterization of branched chain fatty acids from subcutaneous triacyglycerols of barley-fed lambs 总被引:1,自引:0,他引:1
The fatty acids of subcutaneous triacylglycerols (containing ca. 11% of branched chain components) from lambs fed on barley-rich diets were fractionated by treatment with mercuric acetate and by urea adduct formation to yield concentrates rich in the branched chain components, all of which were saturated. The concentrates were subjected to analysis by high resolution gas liquid chromatography in conjunction with mass spectrometry. The branched chain fatty acids consisted of a complex mixture of mono-, di-, and trimethyl substituted components. The greater part of the mixture comprised monomethyl substituted acids of chain length 10–17 carbon atoms. Within each of these molecular species, a number of positional isomers was identified, notably in respect of methyltetradecanoic acid (methyl substituent on carbon 2, 4, 6, 8, 10, and 12) and methylhexadecanoic acid (methyl substituent on carbon 2, 4, 6, 8, 12, and 14). Homologous series also could be recognized of one of which all eight members from 4-methyldecanoic acid to 4-methylheptadecanoic acid were identified; together they accounted for ca. 39% of the branched chain fatty acids which were sampled for mass spectrometry. The dibranched acids identified consisted of five members of a homologous series, ranging in chain length from 11–15 carbon atoms and with substituent methyl groups at positions 4 and 8. Though the identity of only one tribranched acid (2,6,10-trimethyltetradecanoic acid) was established, others also apparently were present in the mixture. The probable involvement of methylmalonate in the biosynthesis of these branched chain acids is discussed briefly, with particular reference to the availability of vitamin B12 in relation to the activity of methylmalonyl coenzyme A mutase. 相似文献
994.
995.
J. K. Weil F. D. Smith A. J. Stirton R. G. Bistline 《Journal of the American Oil Chemists' Society》1963,40(10):538-541
Even chain sodium alkanesulfonates from the Strecker reaction, odd chain sodium alkanesulfonates from the alkaline decarboxylation
of α-sulfo acids, and sodium 1-hydroxy-2-alkanesulfonates from the reduction of esters of α-sulfo acids were compared with
respect to Krafft point, critical micelle concentration, detergency and foam height. Sodium alkanesulfonates and crude fusion
products from the α-sulfo acids (mixtures of alkanesulfonates of one less carbon atom with a lesser amount of a soap of two
less carbon atoms) are more soluble and have better detergent and foaming properties. Sodium 1-hydroxy-2-alkanesulfonates
resemble monosodium salts of α-sulfo acids.
Alkanesulfonic acids and 1-hydroxy-2-alkane-sulfonic acids obtained from the sodium salts by ion exchange have lower Krafft
points and are more readily soluble. The critical micelle concentrations of 1-hydroxy-2-alkanesulfonic acids and α-sulfo acids
are nearly the same and about equal to those of alkanesulfonic acids of one less carbon atom.
Presented at the AOCS meeting in Toronto, Canada, 1962.
A laboratory of the E. Utiliz. Res. & Dev. Div., ARS, U.S.D.A. 相似文献
996.
O. Motl K. Strnský L. Novotný K. Ubik 《European Journal of Lipid Science and Technology》1977,79(1):28-32
Composition of the Seed Oil of Clustered Elder (Sambucus racemosa L.) The seeds of clustered elder (Sambucus racemosa L.) contain 28% of an oil. Its separation to groups of components was carried out by adsorption chromatography. Single groups of substances were further analysed by TLC and GLC in combination with physico-chemical methods (IR and MS). Thus the following substances were found and identified: n-alkanes (C17–C33), 2-methyl- and 3-methylalkanes, squalene, a mixture of esters, triglycerides, β-sitosterol, campesterol and a mixture of diglycerides. The conditions for the separation of esters by silica gel column chromatography were also found. The mixture of esters was thus separated into a group of aliphatic wax esters (C34–C44) and four groups of esters of steroidal alcohols (mainly β-sitosterol and campesterol) with aliphatic unsaturated acids (predominantly C18:1, C18:2 and C18:3). In the triglycerides representing the main fraction of the oil (93%), the acids C16:0, C18:1, C18:2 and C18:3 are present. The same acids were also found in diglycerides. 相似文献
997.
998.
K. K. Carroll 《Journal of the American Oil Chemists' Society》1967,44(11):607-614
Effects of diet on acetate incorporation into cholesterol and fatty acids in liver slices, and on the level of plasma cholesterol,
were studied in rats and rabbits. Feeding fats and oils in a com-mercial diet stimulated acetate incorporation into rat-liver
cholesterol much more than feeding them in a semisynthetic diet. This effect seemed to be specific for cholesterol since incorporation
into fatty acids was not similarly affected. High levels of dietary casein inhibited acetate incorporation into both cholesterol
and fatty acids. Rat-liver slices generally incorporated more acetate into cholesterol than rabbit-liver slices, but incorpora-tion
into fatty acids was often higher in the latter. Rabbit plasma cholesterols were higher on butter diets than on corn oil diets.
Further eleva-tion of plasma cholesterol was observed when casein was added to the butter diet but not when it was added to
the corn oil diet. Plasma cho-lesterols were elevated, and acetate incorporation into liver cholesterol and fatty acids was
inhibited in suckling rats and rabbits whereas recently weaned animals gave results similar to those of adults. The inverse
relationship between plasma cholesterol level and acetate incorporation into cholesterol may be attributable to feedback con-trol
of liver cholesterol biosynthesis. Other mechanisms which may account for the observed effects of dietary fats and protein
on cholesterol metabolism, and the possible relevance of the findings to atherosclerosis, are discussed. 相似文献
999.
Robert K. Jenkins 《应用聚合物科学杂志》1967,11(2):171-177
Arbitrary cure times and glass transition temperatures are reported for an epoxy resin cocrosslinked by various weight fractions of hexamethylenediamine (HMDA) and m-phenylenediamine (m-PLDA). The glass transition temperatures of the epoxy resin systems studied yielded an excellent fit to an empirical equation developed by Dyvik for copolymers. The cure time parameters were found to be a linear function of the weight fractions of each crosslinking agent present. The mechanical properties of the epoxy resins were measured by an in situ dynamic modulus technique which employed the use of a resin-coated metallic substrate. 相似文献
1000.
Poly(1,3,4-oxadiazole-2,5-diylvinylene) and poly(1,4-phenylene-1,3,4-oxadiazole-2,5-diylvinylene) were prepared by polymerizing different quantities of terephthalic acid (T), maleic acid (M), and hydrazine sulfate (HS) in the presence of fuming sulfuric acid. Homopolymers of M and T and various copolymers of M:T were prepared. The polymers were characterized by viscosity, IR, UV, and elemental analysis. Their solubility in different solvents was investigated. The relative thermal stability of the polymers was evaluated by TGA and DTA. 相似文献