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1.
Synthesis of polyunsaturated fatty acid-enriched triglycerides by lipase-catalyzed esterification 总被引:2,自引:0,他引:2
L. Esteban Cerdán A. Robles Medina A. Giménez Giménez M. J. Ibáñez González E. Molina Grima 《Journal of the American Oil Chemists' Society》1998,75(10):1329-1337
This paper reports on the synthesis of triglycerides by enzymatic esterification of polyunsaturated fatty acids (PUFA) with
glycerol. A PUFA concentrate obtained from cod liver oil was used to optimize the reaction to favor triglyceride synthesis
with lipases. The type and amount of lipase and organic solvent, glycerol content, temperature, water content, and amount
and time of addition of molecular sieves were studied. The optimal reaction mixture and conditions were: 9 mL hexane, 60°C,
0.5% (vol/vol) water, 1 g molecular sieves added after 24 h of reaction, glycerol/fatty acid molar ratio 1:3 and 100 mg of
Novozym 435 (Novo Nordisk A/S) lipase. Under these conditions, an enriched triglyceride yiedl of 84.7% containing 27.4% eicosapentaenoic
acid and 45.1% docosahexaenoic acid was obtained from a cod liver oil PUFA concentrate. 相似文献
2.
Eberhard Fehling 《Journal of the American Oil Chemists' Society》1995,72(3):355-359
Gel permeation chromatography of hydroxylated fatty acids (HOFA), prepared from various plant oils by a novel technical process,
showed the presence of considerable amounts of estolides formed by intermolecular esterification of the HOFA. Thin-layer chromatographic
fractionation followed by gas chromatography of the fractions revealed that the nonpolar estolides contain predominantly saturated
fatty acids esterified tothero-9, 10-dihydroxy octadecanoic acid or dihydroxy tetrahydrofuran octadecanoic acids, e.g., 9,12-dihydroxy-10, 13-epoxy octadecanoic
acid and 10,13-dihydroxy-9, 12-epoxy octadecanoic acid. The fractions of polar estolides consist mainly of intermolecular
esters of the above dihydroxy fatty acids. 相似文献
3.
Ching T. Hou Harold Gardner Wanda Brown 《Journal of the American Oil Chemists' Society》1998,75(11):1483-1487
Hydroxy fatty acids are important industrial materials. We isolated a microbial culture, Clavibacter sp. ALA2, which converts linoleic acid to many polyhydroxy fatty acids. Structures of the products were determined as: 12,13,17-trihydroxy-9(Z)-octadecenoic
(THOA, main product), 12-[5-ethyl-2-tetrahydrofuranyl]-7,12-dihydroxy-9(Z)-dodecenoic (ETDDA), and 12-[5-ethyl-2-tetrahydrofuranyl]-12-hydroxy-9(Z)-dodecenoic
(ETHDA) acid. The yield of THOA was 25% and the relative amount of the products were THOA/ETDDA/ETHDA =9:1.3:1. The structures
of the hydroxy unsaturated fatty acids resemble those of plant self-defense substances. 相似文献
4.
The conversion of oleic acid to 10-hydroxystearic acid with resting cells ofNocardia cholesterolicum (NRRL 5767) has been previously reported. These same microorganisms also convert linoleic and linolenic acids to 10-hydroxy-12c-octadecenoic and 10-hydroxy-12c,15c-octadecadienoic acids, respectively. The reaction occurs best at 35°C and a pH of 6.5. Under optimum conditions, 75–80% of
the unsaturated fatty acid substrate is converted to the corresponding hydroxy acid. The hydroxy products were characterized
by gas chromatography, gas chromatographymass spectrometry, nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy.
Other microorganisms that successfully converted these substrates include another strain ofNocardia cholesterolicum (NRRL 5768) andNocardia sp. (NRRL 5636).
Presented at the 82nd Annual meeting of the American Oil Chemists’ Society, Chicago, IL, May 12–15, 1991. 相似文献
5.
6.
Ching T. Hou 《Journal of the American Oil Chemists' Society》1995,72(11):1265-1270
A new microbial isolate,Flavobacterium sp. DS5, converted oleic and linoleic acids to their corresponding 10-keto-and 10-hydroxy fatty acids. The hydration enzyme
seems to be specific to the C-10 position. Conversion products from α- and γ-linolenic acids were identified by gas chromatography/mass
spectrometry, Fourier transform infrared, and nuclear magnetic resonance as 10-hydroxy-12(Z),15(Z)-octadecadienoic and 10-hydroxy-6(Z),12(Z)-octadecadienoic acids, respectively. Products from other 9(Z)-unsaturated fatty acids also were identified as their corresponding 10-hydroxy- and 10-keto-fatty acids.Trans unsaturated fatty acid was not converted. From these results, it is concluded that strain DS5 hydratase is indeed a C-10
positional-specific andcis-specific enzyme. DS5 hydratase prefers an 18-carbon monounsaturated fatty acid. Among the C18 unsaturated fatty acids, an additional double bond at either side of the 9,10-position lowers the enzyme hydration activity.
Because hydratases from other microbes also convert 9(Z)-unsaturated fatty acids to 10-hydroxy fatty acids, the C-10 positional specificity of microbial hydratases may be universal. 相似文献
7.
Volker Spitzer 《Journal of the American Oil Chemists' Society》1996,73(4):489-492
The mass spectra of the 4,4-dimethyloxazoline derivatives from various fatty acids with a hydroxy group in conjugation with
conjugated double-triple bonds (7-hydroxy-trans-10-heptadecene-8-ynoic acid; 7-hydroxy-trans-10, 16-heptadecadiene-8-ynoic acid; 8-hydroxy-rans-11-octadecene-9-ynoic acid; 8-hydroxy-trans-11, 17-octadecadiene-9-ynoic acid) have been examined and compared with their analogous nonhydroxy derivatives. The position
of the hydroxy group was unequivocally proven by characteristic odd-numbered fragment peaks, explainable by α-cleavage at
the hydroxy group at the oxazoline end of the molecule. The weak ions produced by α-cleavage at the other side of the hydroxy
group indicated that the hydroxy group must be in conjugation with the ene-yne system. Fragments that allow one to distinguish
between ene-yne or yne-ene systems were absent. In conjunction, the weak molecular ion and the more intense M-18 ion could
confirm the molecular weight of each fatty acid.
This work was presented in parts at the Second International Symposium of Natural Products and Their Applications in Concepción/Chile
(30.11.-2.12.94). (Title of the symposium in Spanish is II Simposio internacional de productos naturales y sus applicaciones.) 相似文献
8.
Nikolaus Weber Klaus Vosmann Eberhard Fehling Kumar D. Mukherjee Dieter Bergenthal 《Journal of the American Oil Chemists' Society》1995,72(3):361-368
A novel process has been described recently for the preparation of hydroxylated fatty acids (HOFA) and HOFA methyl esters
from plant oils. HOFA methyl esters prepared from conventional and alternative plant oils were characterized by various chromatographic
methods (thin-layer chromatography, high-performance liquid chromatography, and gas chromatography) and gas chromatography-mass
spectrometry as well as1H and13C nuclear magnetic resonance spectroscopy. HOFA methyl esters obtained fromEuphorbia lathyris seed oil, low-erucic acid rapeseed oil, and sunflower oil contain as major constituents methylthreo-9,10-dihydroxy octadecanoate (derived from oleic acid) and methyl dihydroxy tetrahydrofuran octadecanoates, e.g., methyl
9,12-dihydroxy-10,13-epoxy octadecanoates and methyl 10,13-dihydroxy-9,12-epoxy octadecanoates (derived from linoleic acid).
Other constituents detected in the products include methyl esters of saturated fatty acids (not epoxidized/derivatized) and
traces of methyl esters of epoxy fatty acids (not hydrolyzed). The products that contain high levels of monomeric HOFA may
find wide application in a variety of technical products. 相似文献
9.
Gerhard Knothe 《Journal of the American Oil Chemists' Society》2001,78(5):537-540
Esters of some common fatty acids and diacids with Guerbet alcohols were prepared by p-toluenesulfonic acid-catalyzed esterification. Such materials are of interest in applications such as additives in various
industrial products. Gas chromatography-mass spectrometry with chemical ionization using methane as ionization gas is an efficient
characterization method for these Guerbet esters and diesters. Under these conditions, structural features such as molecular
weight and site of branching are easily determined. The spectra of the present compounds were compared to those of di-Guerbet
esters reported earlier and differences noted. The compounds were also characterized by 13C nuclear magnetic resonance spectroscopy. 相似文献
10.
11.
Ben‐Li Zhang Sbastien Pionnier Stephan Buddrus 《European Journal of Lipid Science and Technology》2006,108(2):125-133
The origin of hydrogen in fatty acids produced in vivo by chicken was studied by using isotope tracing monitored by 2H NMR. Chickens were fed with deuterium‐labeled water, deuterium‐labeled glucose/fructose and trideuterated acetate. The site‐specific isotope distribution of the fatty acids produced in vivo by the chickens was analyzed after transformation into methyl esters. A connection was observed between the hydrogen atoms of the feeds and water and those of the different molecular positions of the fatty acids produced by chicken. Water hydrogen makes an important contribution to the formation of the lipids. The hydrogen of the enzyme‐bound acetyl or malonyl moiety in acyl‐CoA may be transferred from the C‐1, C‐2 or C‐6 of glucose or fructose and indirectly from water. The hydrogen introduced by the cofactor NADPH may be abstracted from C‐1 and C‐3 of glucose, through its regeneration in the pentose phosphate metabolism pathway, and contains hydrogen atoms of water. The exogenous acetate enters into the in vivo fatty acid biosynthesis pathway in an efficient way and can make an important contribution to the biosynthesis of the lipids. 相似文献
12.
Jonathan A. Zerkowski Daniel K. Y. Solaiman 《Journal of the American Oil Chemists' Society》2006,83(7):621-628
A series of mono- and diamines and one triamine have been prepared using methyl 17-hydroxy oleate as the common starting material.
The 17-hydroxy oleate is an abundant bioderived material obtained from acid alcoholysis of sophorolipids, which in turn are
produced by fermentation of agricultural by-products. Incorporation of the amino unit(s) can be selectively performed at either
end of the chain or at its middle. The chief synthetic reactions used are allylic bromination, Curtius rearrangement, and
the Mitsunobu reaction. These fatty amines also possess functionality such as hydroxy groups, carboxylic acids, and C−C double
bonds. The amines are isolated in protected form using a variety of protecting groups, the identities of which can be selected
on the basis of the intended use of the amine. These novel compounds will be of interest in the preparation of highly functionalized
polymers and surfactants, among other areas. 相似文献
13.
介绍了直链不饱和脂肪酸制备支链脂肪酸的研究现状,综述了脂肪酸异构机理,异构催化剂如白土催化剂、沸石催化剂,催化剂的筛选原则,着重讨论了各种常用沸石对于脂肪酸异构反应不同的影响以及现有的合成工艺。分析了脂肪酸的分离技术,包括精馏分离法、溶剂结晶法、尿素包结法、超临界流体萃取法的优缺点,指出沸石催化生产支链饱和脂肪酸的关键问题是需要解决混合脂肪酸作为原料反应的选择性问题,其相关的基础性工作,如更明确的反应机理和催化剂结构参数对反应的影响,仍是将来的研究方向。 相似文献
14.
N. V. Gaiday A. B. Lmbs D. V. Kuklev N. A. Latyshev 《Journal of the American Oil Chemists' Society》1991,68(4):230-233
Conditions of the iodolactonization reaction (ILreaction) were optimized as a method for separation of natural polyunsaturated
fatty acids. The effects of the solvent, temperature and the ratio of components of the iodizing complex KI/I2 upon the rate of the synthesis of several iodolactones (ILs) in the IL-reaction are described. It was shown that the rate
of formation of γ-ILs was significantly higher than that for δ-ILs. This offers opportunity for obtaining pure docosahexaenoic
acid (DHA) from fatty acid (FA) concentrates. The possibility for selective reduction of δ-ILs in the presence of γ-ILs to
yield pure arachidonic acid (AA) or eicosapentaenoic acid (EPA) or fatty acid concentrates has been demonstrated. Preparation
of pure AA from a mixture of AA, DHA and other FAs by the IL-reaction without Chromatographie procedures is described. 相似文献
15.
Chloroform extracts from a culture broth of the biocontrol fungusSporothrix flocculosa were separated by thin-layer chromatography (TLC). Compounds with antifungal activity were revealed with theCladosporium cucumerinum bioassay on TLC plates and were isolated by using silica gel column, preparative TLC, and reverse-phase high-performance liquid chromatography (RP-HPLC). They were identified by standard methods of nuclear magnetic resonance (NMR), gas chromatography (GC), mass spectrometry (MS), and infrared spectrum (IR). In addition to an active molecule previously described, two new fatty acids with antibiotic activity were characterized, 9-heptadecenoic acid and 6-methyl-9-heptadecenoic acid, the latter displaying the strongest activity among all three active molecules. This high number of active metabolites produced byS. flocculosa would explain its rapid and strong activity as a biocontrol agent of powdery mildews. In this context, screening ofS. flocculosa isolates for increased production of these molecules should help in selection of candidates with superior biocontrol properties.Contribution no. 150 du Centre de recherche en horticulture. 相似文献
16.
F. Servat D. Montet M. Pina P. Galzy A. Arnaud H. Ledon L. Marcou J. Graille 《Journal of the American Oil Chemists' Society》1990,67(10):646-649
Biotechnological synthesis of a new class of amphiphilic molecules—fatty hydroxamic acids—was carried out using the lipase
ofMucor miehei by reacting hydroxyl amine with the fatty acids in their free or methyl ester form. Concurrently with enzymatic synthesis,
chemical synthesis of hydroxamic fatty acids has also been developed by adapting methods that already existed for water-soluble
acids. Different parameters were studied to determine the optimum operating conditions: temperature, molar ratio of reagents,
quantity of biocatalyst and length of reaction. A general method, whatever the type of fatty acids used, is described. 相似文献
17.
酰胺键的合成是有机化学中非常重要和有意义的反应之一。国内外学者已对酰胺键的形成进行了长期研究,目前合成酰胺的底物和方法多种多样,然而,这些合成方法存在各种各样的资源浪费和环境污染问题。羧酸和胺之间的催化脱水缩合反应是合成相应酰胺的最理想方法,利用羧酸和胺在催化剂作用下直接缩合形成酰胺,避免了使用活化试剂带来的诸多问题。近年来以硼类和过渡金属为主体的催化剂得到广泛研究,并取得了一系列成果。本文主要介绍了以羧酸和胺为底物,同时符合绿色化学理念的催化合成方法,通过对这些催化剂催化性能的总结与分析,阐述了各种催化剂的优缺点。其中硼化合物催化的直接酰胺化反应是研究较多、前景最为诱人的方法,因此基于硼类化合物的特殊结构,设计更具活性的此类催化剂将是今后研究发展的方向。 相似文献
18.
Lipase catalyzed formation of fatty amides 总被引:2,自引:0,他引:2
Raymond G. Bistline Alexander Bilyk Stephen H. Feairheller 《Journal of the American Oil Chemists' Society》1991,68(2):95-98
Certain lipase preparations were found to facilitate the preparation of fatty amides at 20°C in hexane. Lipase preparations
investigated were from the fungiCandida rugosa, Rhizomucor miehei and porcine pancreas. Reactants were various primary alkylamines and fatty acid methyl esters or triglycerides. Moderate
yields of fatty amides were obtained using aR. miehei lipase preparation which is immobilized on a solid support as catalyst, although all three lipase preparations showed some
catalytic activity under these conditions and, in addition, showed different kinds of selectivity for fatty acid and alkylamine
chain lengths. No reaction was observed in similar experiments using one fatty acid as the substrate or one secondary amine. 相似文献
19.
Régine Gruiec Nicolas Noiret Henri Patin 《Journal of the American Oil Chemists' Society》1995,72(9):1083-1085
Tetrahydro-2-pyranyl ethers from fatty primary alcohols can be converted in a one-step procedure into the corresponding carboxylic
acids in high yields. This process avoids the synthesis of symmetrical esters, particularly for long-chain compounds. This
reaction proved to be useful, for instance, to produce polyunsaturated fatty acids immediately before their biological testing. 相似文献
20.
Anette Bysted Aase Ærendahl Mikkelsen Torben Leth 《European Journal of Lipid Science and Technology》2009,111(6):574-583
Three surveys of the content of trans fatty acids (TFA) in foods on the Danish market were carried out before and after the Danish regulation was introduced in January 2004 restricting the use of industrially produced (IP)‐TFA to a maximum of 2 g per 100 g fat in any food product. For this purpose, food samples were collected in 2002–3, 2004–5, and 2006–7. Of these, 60 paired samples (defined as samples included in two of the three investigations and with higher levels of IP‐TFA in the first determination than in the second) were identified. Comparisons of the fatty acid profiles showed that, in 68% of the products (e.g. sweets, cakes and cookies as well as fast food such as pie and tortilla), IP‐TFA were mainly substituted with saturated fatty acids (SFA). In some cases, the SFA source was coconut fat, whereas in other products, palm oil was added instead of partially hydrogenated oils. However, in important cases like frying fats, healthier fat substitutes with monounsaturated fatty acids were used. The surveys showed that the IP‐TFA content has been reduced or removed from most products with originally high IP‐TFA content, like French fries, microwave oven popcorn and various bakery products, so that IP‐TFA are now insignificant for the intake of TFA in Denmark. 相似文献