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1.
Microbial lipase-catalyzed hydrolysis, esterification, and alcoholysis reactions were carried out on acid oils of commerce
such as coconut, soybean, mustard, sunflower, and rice bran for the purpose of making fatty acids and various monohydric alcohol
esters of fatty acids of the acid oils. Neutral glycerides of the acid oils were hydrolyzed byCanadida cylindracea lipase almost completely within 48 h. Acid oils were converted into fatty acid esters of short- and long-chain alcohols like
C4, C8, C10, C12, C16, and C18 in high yields by simultaneous esterification and alcoholysis reactions withMucor miehei lipase as catalyst. Acid oils of commerce can be utilized as raw materials in making fatty acids and fatty acid esters using
lipase-catalyzed methodologies. 相似文献
2.
Lipase-catalyzed alcoholysis of soy phospholipids was investigated to simultaneously make lysophospholipids and fatty acid
esters of individual alcohols. Alcoholysis was carried out by stirring a mixture of soy phospholipids and individual alcohols
in equimolar proportions with 10% (by weight of reactants) Mucor miehei lipase at 55°C for 24 h. The products were isolated by column chromatography after removal of the lipase. Lysophospholipids
(in 69–78% molar yield) were obtained from soy phospholipids, and the yield of esters of various alcohols also conformed nearly
with theoretical yields. 相似文献
3.
Medium-chain fatty acid-rich glycerides by chemical and lipase-catalyzed polyester-monoester interchange reaction 总被引:4,自引:0,他引:4
Medium-chain triglycerides (MCT) that contain caprylic acid (C8:0) and capric acid (C10:0) have immense medicinal and nutritional importance. Coconut oil can be used as a starting raw material for the production
of MCT. The process, based on the interchange reaction between triglycerides and methyl esters of medium-chain fatty acids
by chemical catalyst (sodium methoxide) or lipase (Mucor miehei) catalyst, appears to be technically feasible. Coconut oils with 25–28.3% (w/w) and 22.1–25% (w/w) medium-chain fatty acids
have been obtained by chemical and lipase-catalyzed interchange reactions. Coconut olein has also been modified with C8:0 and C10:0 fatty acids, individually as well as with their mixtures, by chemical and lipase-catalyzed interchange reactions. Coconut
olein is a better raw material than coconut oil for production of mediumchain fatty acid-rich triglyceride products by both
chemical and lipase-catalyzed processes. 相似文献
4.
Gary J. Blomquist Charles L. Soliday Barbara A. Byers Joyce W. Brakke Larry L. Jackson 《Lipids》1972,7(5):356-362
Wax esters of secondary alcohols constitute 18–20% of the cuticular lipid extract ofMelanoplus packardii and 26–31% of the cuticular lipids ofMelanoplus sanguinipes. The total number of carbons in the wax esters range from 37–54 with 41 predominating in both species. The fatty acids ofM. packardii wax esters are 16∶0, 18∶0, 14∶0, 20∶0 and 12∶0 in decreasing quantity. The fatty acids ofM. sanguinipes wax esters are 18∶0, 20∶0, 16∶0 22∶0, 14∶0, 19∶0 and 17∶0 in decreasing quantity. The secondary alcohols from the wax esters
ofM. packardii are C25, C23 and C27 in decreasing quantity, and the secondary alcohols of theM. sanguinipes are C23, C25, C21, C27, C24, C22 and C26 in decreasing quantity. Each secondary alcohol consists of two to four isomers with the hydroxyl group located near the center
of the chain.
Montana Agriculture Experiment Station, Journal Series No. 332. 相似文献
5.
Keum T. Hwang Susan L. Cuppett Curtis L. Weller Milford A. Hanna 《Journal of the American Oil Chemists' Society》2002,79(6):521-527
Grain sorghum wax has been judged to be a potential source of natural wax with properties similar to carnauba wax. Approximately
0.16–0.3% (w/w) wax can be extracted from grain sorghum depending on the efficiency of the organic solvents. Although the
melting points of carnauba wax and sorghum wax are similar, i.e., 78–86 and 77–85°C, respectively, they differ in acid values,
i.e., 2–10 and 10–16, respectively, and saponification numbers, i.e., 77–95 and 16–49, respectively. Improved knowledge of
the properties, composition, and analysis of grain sorghum wax would assist in efforts for industrial application of this
product. Major components of sorghum wax are hydrocarbons, wax esters, aldehydes, free fatty alcohols, and FFA. The hydrocarbons
consist mainly of C27 and C29, and the aldehydes, alcohols, and acids are mainly C28 and C30. The wax esters are mostly esters of C28 and C30 alcohols and acids. 相似文献
6.
The total lipids of eleven species of Myctophids caught at depths between 20 and 700 m in the northern Pacific Ocean were
analyzed using silicic acid column chromatography (lipid classes) and capillary gas chromatography (fatty acid and fatty alcohol
composition). The major components in the lipid classes were triacylglycerols or wax esters; triacylglycerols were the dominant
acyl neutral lipids (68.1–96.1%) in eight species, and wax esters were found as the dominant lipid (85.5–87.9%) in three species.
The major fatty acids and alcohols contained in the was esters of the three fishes were 18:1n–9, 20:1n–9, 20:1n–11, and 22:1n–11
for fatty acids, and 16:0, 18:1, 20:1, and 22:1 for fatty alcohols. Fatty acids in the triacylglycerols ranging from C14 to C22 were predominantly of even chain length. The major components were 16:0, 16:1n–7, 18:1n–9, 20:1n–11, 22:1n–11, 20:5n–3 (icosapentaenoic
acid), and 22:6n–3 (docosahexaenoic acid). In both the triacylglycerols and the wax esters, the major fatty components were
monoenoic acids and alcohols. It is suggested from the lipid chemistry of the Myctophids that they may prey on the same organisms
as the certain pelagic fishes such as saury and herring, because the large quantities of monoenoic fatty acids are similar
to those of saury, herring, and sprats whose lipids originate from their prey organisms such as zooplanktons which are rich
in monoenoic wax esters. 相似文献
7.
E. Fehling S. Schönwiese E. Klein K. D. Mukherjee N. Weber 《Journal of the American Oil Chemists' Society》1998,75(12):1757-1760
A method has been developed for the preparation of highly pure malvalic (cis-8,9-methyleneheptadec-8-enoic) and sterculic (cis-9,10-methyleneoctadec-9-enoic) acid methyl esters starting from Bombax munguba and Sterculia foetida seed oils. The methyl esters of these oils were prepared by sodium methylate-catalyzed transmethylation followed by cooling
(6°C) the hexane solution of crude methyl esters and separation of insoluble fatty acid methyl esters by centrifugation in
the case of B. munguba and by column chromatography in the case of S. foetida. Subsequently, the saturated straight-chain fatty acid methyl esters were almost quantitatively removed by urea adduct formation.
Finally, methyl malvalate and methyl sterculate were separated from the remaining unsaturated fatty acid methyl esters, in
particular methyl oleate and methyl linoleate, by preparative high-performance liquid chromatography on C18 reversed-phase using acetonitrile isocratically. Methyl malvalate and methyl sterculate were obtained with purities of 95–97
and 95–98%, respectively. 相似文献
8.
Wax esters were isolated from commercial orange roughy (Hoplostethus atlanticus) oil by column chromatography and fractionated by argentation thin layer chromatography. Following transesterification, the
resultant fatty acid methyl esters and fatty alcohols were analyzed by gas chromatography. both acyl- and alkyl-moieties were
mainly of the monoene structure within the 16∶1–22∶1 range. After derivatization, the positions of the double bonds of even
numbered fatty acid and fatty alcohol isomers were located by chromatography-mass spectrometry and compared.
Results of these positional analyses indicate that the primary desaturation reactions takes place in the Δ9 position of pre-existing
(C14 to C24) acyl chains. It is proposed that acyl components from 18∶1 are subjected to chain elongation to form a mixture of 24∶1 isomers
as the final product. Apart from the 24∶1 acyl moiety of the wax esters, in which the double bond was almost exclusively in
the Δ15 position, de novo biosynthetic reactions on acids and alcohols appear to yield related acyl- and alkyl-moieties of
resynthesized wax esters. 相似文献
9.
A process for the preparation of food-grade rice bran wax and the determination of its composition 总被引:2,自引:2,他引:2
A two-step method was developed for the preparation of food-grade wax. The first step involved the solventdefatting of crude
wax, which gave a dark brown, dry, powdered wax with a m.p. of 75–79°C. The major impurity in the defatted wax was the dark
brown resinous matter. In the second step, the resinous matter was removed by bleaching with sodium borohydride in isopropanol.
This step yielded a pale yellow, odorless wax with purity higher than 99% and with a m.p. of 80–83°C. The resinous matter
was a mixture of aliphatic aldehydes, fatty alcohols, and FA. High-temperature GC analysis of the purified rice bran wax indicated
that it contained 11 major and 9 minor types of saturated wax esters. The major and minor peaks contained C44–C64 and C45–C59 wax esters, respectively. Rice bran wax was mainly a mixture of saturated esters of C22 and C24 FA and C24 to C40 aliphatic alcohols, with C24 and C30 being the predominant FA and fatty alcohol, respectively. The alcohol portion of the wax esters also contained small amounts
of branched and odd carbon number fatty alcohols. 相似文献
10.
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
11.
Douglas G. Hayes Kenneth D. Carlson Robert Kleiman 《Journal of the American Oil Chemists' Society》1996,73(9):1113-1119
The lipolysate from immobilizedRhizomucor miehei lipase (Lipozyme
tm
)-catalyzed hydrolysis of lesquerella oil contains typically 35% free fatty acid (FFA), 2% monoglyceride, 25% diglyceride
(DG), and 38% triglyceride (TG). Of the FFA, 75–80% are hydroxy acids (HFA). Various methods for isolating HFA from the lipolysate
were examined, and a novel saponification/extraction method was developed. Lipolysate was mixed with 4 vol equivalents each
of KOH/phosphate buffer and polar organic solvent. Hexane was then added to enhance phase separation. Three phases formed:
a lower aqueous phase containing nothing of interest, a polar organic solvent middle phase that contained mostly fatty acid
soaps, and a hexane-rich upper phase that contained mostly DG and TG, which can be recycled to a relipolysis step. The middle
phase, when treated with concentrated hydrochloric acid, NaCl-saturated water, and hexane, released the FFA into the hexane.
This fraction, referred to as the “Product” contained >99% of the FFA released in the lipolysis. “Product” consisted of 85–90%
FFA, of which 75–80% was HFA. The other 10–15% of the “Product” consisted of partial glycerides and TG. The most critical
parameters for the extraction are the pH of the aqueous solution and the polarity of the organic solvent (acetone was found
to be the best choice). Additional purification steps for the “Product” are discussed. 相似文献
12.
The esterification of five medium- and long-chain acetylenic alcohols (2-nonyn-1-ol, 10-undecyn-1-ol, 6-octadecyn-1-ol, 9-octadecyn-1-ol,
and 13-docosyn-1-ol), seven olefinic alcohols (cis-3-nonen-1-ol, 10-undecen-1-ol, cis-6-octadecen-1-ol, cis-9-octadecen-1-ol, trans-9-octadecen-1-ol, trans-9, trans-11-octadecadien-1-ol, cis-9, cis-12-octadecadien-1-ol), and four short-chain unsaturated alcohols (allyl alcohol, 3-butyn-1-ol, 3-pentyn-1-ol, and cis-2-penten-1-ol) with pentanoic or stearic acid in the presence of various lipase preparations was studied. With the exception
of 2-nonyn-1-ol, where Lipase AY-30 (Candida rugosa) was used as the biocatalyst, the esterification of C11, C18, and C22 acetylenic alcohols with pentanoic acid appeared to be generally unaffected by the presence of an acetylenic bond in the
alcohol as relatively high yields of the corresponding esters (78–97%) were obtained. However, medium- and long-chain olefinic
alcohols were discriminated by Lipase AY-30, Lipolase 100T (Rhizomucor miehei), and especially by porcine pancreatic lipase (PPL), when esterification was conducted with pentanoic acid. Esterification
of medium-and long-chain acetylenic or olefinic alcohols with a long-chain fatty acid, stearic acid, was very efficient except
when Lipase AY-30 and Lipolase 100T were used. Short-chain unsaturated alcohols were much more readily discriminated. 3-Pentyn-1-ol
and 3-butyn-1-ol were difficult (<5% yield) to esterify with pentanoic or stearic acid in the presence of Lipase AY-30 and
PPL, respectively. Very low yields (<26%) of esters were produced when 3-butyn-1-ol and 3-pentyn-1-ol were reacted with pentanoic
or stearic acid, when catalyzed by lipase from Candida cylindracea, No reaction took place between 3-butyn-1-ol and stearic acid in the presence of Lipase AY-30. Esterification of short-chain
acetylenic and olefinic alcohols was most efficiently achieved with Lipolase 100T (Rhizomucor miehei), Lipozyme IM20 (Rh. miehei), or Novozyme 435 (Candida antarctica) as the biocatalyst. 相似文献
13.
Roxana Irimescu Kiyomi Furihata Kazuhiko Hata Yugo Iwasaki Tsuneo Yamane 《Journal of the American Oil Chemists' Society》2001,78(7):743-748
Symmetrically structured triacylglycerols (TG) rich in docosahexaenoic acid (DHA) with caprylic acid (CA) at the outer positions
were synthesized enzymatically form bonito oil in a two-step process: (i) ethanolysis of bonito oil TG to 2-monoacylglycerols
(2-MG) and fatty acid ethyl esters, and (ii) reesterification of 2-MG with ethyl caprylate. Ethanolysis catalyzed by immobilized
Candida antarctica lipase (Novozym 435) yielded 92.5% 2-MG with 43.5% DHA content in 2 h. The 2-MG formed were reesterified with ethyl caprylate
by immobilized Rhizomucor miehei lipase (Lipozyme IM) to give structured TG with 44.9% DHA content [based on fatty acid composition with caprylic acid (CA)
excluded] in 1 h. The final structured lipids comprised 85.3% TG with two CA residues and one original fatty acid residue,
13% TG with one CA residue and two original fatty acid residues, and 1.7% tricaprylolglycerol (weight percent). The amount
of TG with two CA residues and one C22 residue (22∶6=DHA, 22∶5, and 22∶4) was 51 wt%. The 1,3-dicapryloyl-2-docosahexaenoylglycerol to 1,2(2,3)-dicapryloyl-3 (1)-docosahexaenoylglycerol
ratio (based on high-performance liquid chromatography peak area percentages) was greater than 50∶1. The recovery of TG as
structured lipids after silica gel column purification was approximately 71%. Ethyl esters and 2-MG formed at 2 h of ethanolysis
could be used to determine the positional distribution of fatty acids in the intial TG owing to the high 1,3-regiospecificity
of Novozym 435 and the reduced acyl migration in the system. 相似文献
14.
The lower jaw fat of the Amazon River dolphinInia geoffrensis contains 52.8% wax ester, 44.7% triglyceride and 2.5% diacyl glyceryl ether, while its dorsal blubber fat is >98% triglyceride.
Examination of the intact lipids, the derived fatty acids and the derived fatty alcohols by gas chromatography reveals that
the blubber triglycerides show characteristics of freshwater fish fats, but the jaw fat lipids have several distinctive features.
Jaw fat wax esters, triglycerides and diacyl glyceryl ethers are all rich in C10, C12 and C14 fatty acids and contain no polyunsaturated acids. The fatty alcohols in the wax esters are over 90% saturated. The major
carbon numbers in the jaw fat triglycerides (C38–C46) are considerably lower than those of the blubber triglycerides (C48–C54). The possible adaptation of the jaw lipids for use in the underwater echolocation process of this dolphin is discussed. 相似文献
15.
Two unusual lipid classes were detected by thin-layer chromatography in the neutral lipids derived from goat cauda-epididymal
sperm plasma membrane. The lipids were identified as wax esters and 1-O-alkyl-2,3-diacylglycerols based on chromatographic properties, identity of their hydrolysis products, and infrared/1H nuclear magnetic resonance spectral evidence. The membrane containedca. 3 and 5 μg/mg protein of wax esters and alkyldiacylglycerols, respectively. The relative proportions of wax esters and alkyldiacylglycerols
in the total neutral lipids were 1.5% and 2.4%, respectively. The lipids contained fatty acids with chain lengths of C14 to C22. The major fatty acids of the wax esters were 14∶0, 16∶0, 16∶1ω7, 18∶0 and 18∶1ω9. The fatty acids in alkyldiacylglycerol
were 16∶0, 18∶0, 22∶5ω3 and 22∶6ω3. Alkyldiacylglycerol was particularly rich in docosahexaenoic acid 22∶6ω3) representing
30% of the total fatty acids. The alcohols of wax ester were all saturated with C20–C29 carbon chains. The deacylated products derived from alkyldiacylglycerols were identified as hexadecyl, octadecyl and octadec-9′-enyl
glycerol ethers. 相似文献
16.
Lipids were extracted from the mandibular fat body (jaw), the fatty forehead (melon), and the dorsal blubber of a Pacific
beaked whale (Berardius bairdi) and separated into lipid classes by preparative thin layer chromatography. The head fats were mixtures of wax esters and
triglycerides with a very small amount of diacyl glyceryl ether. The blubber fat contained 97% was ester and 3% triglyceride.
Gas liquid chromatography (GLC) of the intact lipid classes indicated an unusually low C26–C30 range for most of the jaw and melon wax esters compared to the more normal C32–C40 molecules found in the blubber. Distinctive lower molecular weight C24–C40 triglycerides occurred in the head fats vs. the usual C44–C58 range in the blubber. Most diacyl glyceryl ethers were in the C35–C46 range, below the molecular weight of hexadecyldipalmitoyl glyceryl ether (C48). GLC of the derived fatty acid methyl esters showed that the lower molecular weight neutral lipids in the head fats were
due to high levels of iso-10∶0, n−10∶0, iso-11∶0, iso-12∶0, n−12∶0, and iso-13∶0 acids. The wax ester fatty alcohols and the
alkoxy chains of the glyceryl ethers were mostly the C14–C20 chain lengths commonly observed in marine organisms. The distinctive medium chain neutral lipids in the jaw and melon fats
of this whale may be related to the postulated acoustical role of these tissues in echolocation. 相似文献
17.
Substrate preferences for lipase-mediated acyl-exchange reactions with butteroil are concentration-dependent 总被引:1,自引:0,他引:1
Substrate preferences for pancreatic lipase-mediated acyl-exchange reactions with butteroil were concentration-dependent for
the series of acyl donors and alcohol acceptors evaluated. For acidolysis reactions, the initial reaction rates and percent
reaction yields after 18 h at 50 μmol acyl donor per gram substrate mixture were similar forn-fatty acids and their methyl and glycerol esters. At 400–500 μmol g−1 (and greater), order of initial reaction rates and percent reaction yield was fatty acid glycerol esters > fatty acid methyl
esters > fatty acids. At concentrations above 300–500 μmol g−1, reaction inhibition was observed for fatty acid substrates, and inhibition took place at lower concentrations for the shorter-chainlength
fatty acids of those evaluated (5–17 carbons). Inhibition was primarily attributed to acidification of the microaqueous environment
of the lipase. Desorption of water by the fatty acid substrate may be a secondary mode of inhibition. The concentration dependence
of initial reaction rates and percent reaction yield was similar for then-alcohol substrates evaluated (2–15 carbons) for alcoholysis reactions with butteroil. Optimum alcohol concentration was 375–500
μmol g−1 (except for butanol, which was 1 mmol g−1, above which reaction inhibition was observed. Inhibition was attributed to desorption of water from the enzyme by the alcohol
substrate. Relative reactivity of classes of alcohols for this reaction system was primary alcohols > secondary alcohols >
tertiary alcohols. Generally, alcoholysis reactions were faster than acidolysis reactions, and triacylglycerols were the best
substrates for acidolysis reactions with butteroil at high levels (up to 2 mmol g−1) of acyl donor substrate. 相似文献
18.
Douglas G. Hayes Robert Kleiman 《Journal of the American Oil Chemists' Society》1995,72(11):1309-1316
Eight lipases were screened for their ability to synthesize estolides from a mixture that contained lesquerolic (14-hydroxy-11-eicosenoic)
acid and octadecenoic acid. With the exception ofAspergillus niger lipase, all 1,3-specific enzymes (fromRhizopus arrhizus andRhizomucor miehei lipases) were unable to synthesize estolides.Candida rugosa andGeotrichum lipases catalyzed estolide formation at >40% yield, with >80% of the estolide formed being monoestolide from one lesquerolic
and one octadecenoic acyl group:Pseudomonas sp. lipase synthesized estolides at 62% yield, but the product mixture contained significant amounts of monoestolide with
two lesquerolic acyl groups as well as diestolide. ImmobilizedR. miehei lipase was chosen to catalyze the esterification of mono-and polyestolide, derived synthetically from oleic acid, with fatty
alcohols or α,ω-diols. Yields were >95% for fatty alcohol reactions and >60% for diol reactions. In addition, the estolide
linkage remained intact through the course of the esterification process. Esterification of estolides improved the estolide’s
properties—for example, lower viscosity and higher viscosity index—but slightly raised the melting point. Estolides and, particularly,
estolide esters may be suitable as lubricants or lubricant additives. 相似文献
19.
Ghanwa Afach Yasuhiro Kawanami Nopparat Cheetangdee Kazuhiro Fukada Ken Izumori 《Journal of the American Oil Chemists' Society》2008,85(8):755-760
The diesterification of d-psicose (the C-3 epimer of d-fructose) with fatty acid vinyl esters of selected acyl chain lengths (C8, C10, and C12) was successfully carried out using Candida antarctica lipase (Novozym 435) at 45 °C for 24 h to give the 1,6-diacyl-d-psicofuranoses with a high regioselectivity in good yields (83–90%). These diesters of d-psicose have hydrophilic-lipophilic balance (HLB) values (6.5–8.2) similar to HLB values of monoglyceride compounds which
constitute the largest single type of emulsifiers employed by the food industry. Ability of the d-psicose diesters to stabilize oil-in-water emulsions and the weight-averaged oil-droplet diameter in the emulsions was evaluated
in this study. Emulsion stability of oil droplets stabilized by d-psicose dicaprylate (0.3%, w/v in oil phase) was comparable to d-fructose dicaprylate (0.2%, w/v). It was further confirmed that the d-psicose diesters exhibited an emulsification activity depending on the chain length of fatty acid; d-psicose dicaprate showed better emulsion stability than the other diesters. 相似文献
20.
Enzymatic synthesis of esters of lactic acid and straight-chain alcohols with different chain lengths (C6–C18) were investigated in batch reactions with hexadecanol (C16) as the model alcohol. Cyclohexane was the best solvent for higher ester yields, and the best biocatalyst was the immobilized Candida antarctica lipase B (Novozym 435) as well as the textile-immobilized Candida sp. lipase. A method was established to obtain ester yields in the range of 71 to 82% for the different alcohols, and the most favorable conditions for the esterification reaction using Novozym 435 were an equimolar ratio of lactic acid to alcohol, each at a concentration of 120 mM each; a 50°C reaction temperature; 190 rpm shaking speed; and the addition of 100 mg molecular sieves (4 Å) for drying. The ester yield increased with increasing lipase load, and a yield of 79.2% could be obtained after 24 h of reaction at 20 wt% of Novozym 435. The immobilized Candida sp. lipase prepared in the laboratory also could be used to produce esters of lactic acid and straight-chain alcohols, but it had a much lower activity than Novozym 435 with a temperature optimum of 40°C. 相似文献