Thirty percent of the fatty acids fromHeliophila amplexicaulis seed oil are hydroxy acids, primarily lesquerolic acid (14-hydroxy-cis-11-eicosenoic acid) with a trace of a new fatty acid, 16-hydroxy-cis-13-docosenoic acid. The hydroxy acids in the oil are found exclusively in the 1 and/or 3 positions of the triglycerides and
are completely acylated with C20 or C22 saturated or monoenoic acids.
The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of
Agriculture over other firms or similar products not mentioned. 相似文献
Carboxylic acid reductases (CARs) catalyze the reduction of a broad range of carboxylic acids into aldehydes, which can serve as common biosynthetic precursors to many industrial chemicals. This work presents the systematic biochemical characterization of five carboxylic acid reductases from different microorganisms, including two known and three new ones, by using a panel of short‐chain dicarboxylic acids and hydroxy acids, which are common cellular metabolites. All enzymes displayed broad substrate specificities. Higher catalytic efficiencies were observed when the carbon chain length, either of the dicarboxylates or of the terminal hydroxy acids, was increased from C2 to C6. In addition, when substrates of the same carbon chain length are compared, carboxylic acid reductases favor hydroxy acids over dicarboxylates as their substrates. Whole‐cell bioconversions of eleven carboxylic acid substrates into the corresponding alcohols were investigated by coupling the CAR activity with that of an aldehyde reductase in Escherichia coli hosts. Alcohol products were obtained in yields ranging from 0.5 % to 71 %. The de novo stereospecific biosynthesis of propane‐1,2‐diol enantiomer was successfully demonstrated with use of CARs as the key pathway enzymes. E. coli strains accumulated 7.0 mm (R)‐1,2‐PDO (1.0 % yield) or 9.6 mm (S)‐1,2‐PDO (1.4 % yield) from glucose. This study consolidates carboxylic acid reductases as promising enzymes for sustainable synthesis of industrial chemicals. 相似文献
Lesquerolic and auricolic acids were obtained from hydrolyzed lesquerella oil by a low-temperature crystallization procedure.
The lesquerolic and auricolic fatty acid fraction was enriched from 55–59% to 85–99% with high yields (94%). Washing the free
fatty acids with pH 6.0 buffer provided reproducible crystallizations of those hydroxy fatty acids. In contrast, when hydrolyzed
oil from Lesquerella fendleri was not buffer-washed, there was, in most cases, no separation of hydroxy fatty acids by crystallization. This crystallization
procedure is suitable for a large-scale separation process of the hydroxy fatty acids from nonhydroxy fatty acids obtained
from hydrolyzed lesquerella oil. 相似文献
The self-metathesis reaction of soy, rapeseed, tall, and linseed oil fatty acids was investigated for the synthesis of symmetrical
long-chain unsaturated-α,ω-dicarboxylic acids. The metathesis reactions were carried out in the presence of a Grubbs catalyst
under solvent-free condition at a catalyst loading of 0.01 mol% to fatty acid substrate at 50 °C. Under these conditions,
the conversions of starting unsaturated acids to metathesis products were >80% and the isolated yields of unsaturated dicarboxylic
acid products were >70% of theoretical. This approach represents an effective and efficient route for the synthesis of these
potentially useful dicarboxylic acids since they can serve as important intermediates in the production of several materials
such as biodegradable polymers.
Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information
and does not imply recommendation or endorsement by the US Department of Agriculture. 相似文献
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
Oleic acid was hydroxylated in the allylic positions with the selenium dioxide/tert.-butylhydroperoxide system to give 8-hydroxy-9(E)-octadecenoic acid, 11-hydroxy-9(E)-octadecenoic acid and the novel 8,11-dihydroxy-9(E)-octadecenoic acid. This is a viable method for obtaining hydroxy fatty acids. The unsaturated hydroxy acids were hydrogenated
with the hydrazine/air system to give the cor-responding saturated products. 8,11-Dihydroxyoctadecanoic acid thus obtained
is also a novel compound. The saturated and unsaturated dihydroxy products were obtained aserythro/threo isomers as determined by nuclear magnetic resonance.
Presented in part at the 83rd AOCS Annual Meeting, Toronto, Ontario, Canada, 1992. 相似文献
Clavibacter sp. ALA2 transformed linoleic acid into a variety of oxylipins. In previous work, three novel fatty acids were identified,
(9Z)-12,13,17-trihydroxy-9-octadecenoic acid and two tetrahydrofuran-(di)hydroxy fatty acids. In this report, we confirm the
structures of the tetrahydrofuran-(di)hydroxy fatty acids by nuclear magnetic resonance as (9Z)-12-hydroxy-13,16-epoxy-9-octadecenoic acid and (9Z)-7,12-dihydroxy-13,16-epoxy-9-octadecenoic acid. Three other products of the biotransformation were identified as novel heterobicyclic
fatty acids, (9Z)-12,17;13,17-diepoxy-9-octadecenoic acid, (9Z)-7-hydroxy-12,17;13,17-diepoxy-9-octadecenoic acid, and (9Z)-12,17;13,17-diepoxy-16-hydroxy-9-octadecenoic acid. Thus, Clavibacter ALA2 effectively oxidized linoleic acid at C-7,-12,-13,-16, and/or-17. 相似文献
Fatty acids are versatile precursors for fuels, fine chemicals, polymers, perfumes, etc. The properties and applications of fatty acid derivatives depend on chain length and on functional groups and their positions. To tailor fatty acids for desired properties, an engineered P450 monooxygenase has been employed here for enhanced selective hydroxylation of fatty acids. After oxidation of the hydroxy groups to the corresponding ketones, Baeyer–Villiger oxidation could be applied to introduce an oxygen atom into the hydrocarbon chains to form esters, which were finally hydrolyzed to afford either hydroxylated fatty acids or dicarboxylic fatty acids. Using this strategy, we have demonstrated that the high-value-added flavors exaltolide and silvanone supra can be synthesized from stearic acid through a hydroxylation/carbonylation/esterification/hydrolysis/lactonization reaction sequence with isolated yields of about 36 % (for ω−1 hydroxylated stearic acid; 100, 60, 80, 75 % yields for the individual reactions, respectively) or 24 % (for ω−2 hydroxylated stearic acid). Ultimately, we obtained 7.91 mg of exaltolide and 13.71 mg of silvanone supra from 284.48 mg stearic acid. 相似文献
Using ester-forming reactions such as carbodiimide coupling and a modified Yamaguchi symmetrical anhydride method, a variety
of estolides based on 17-hydroxy oleic and 17-hydroxy stearic acid have been prepared. These hydroxy fatty acids are produced
in good yields from hydrolysis of sophorolipids, which are in turn derived from fermentation of fats and oils. Since the estolides
are formed one unit, or ester bond, at a time, their length and sequence can be precisely controlled. The key to this control
is the use of protecting groups at either the carboxylic or hydroxy end of the starting hydroxy fatty acids. Two mono-protected
dimers, for example, when combined in a fragment-condensation approach, give a tetramer with no “contamination” from estolides
of other lengths. This methodology opens the way to functionalized estolides, and several variants were prepared: hybrid estolides,
containing non-fatty acid moieties such as amino acids; polymerizable estolides, containing a norbornene unit; and non-linear
estolides that extend from a branched core such as glycerol or pentaerythritol. With the benzoyl chloride-mediated symmetrical
anhydride method, yields for individual coupling steps ranged from 75 to 93%.
Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information
and does not imply recommendation or endorsement by the US Department of Agriculture. 相似文献
Two hydroxy acids, lesquerolic (53 wt%) and auricolic (4%), are present at significant quantities inLesquerella fendleri seed oil. Results reported here indicate the selective release of hydroxy fatty acids during hydrolysis of this oil catalyzed
byRhizopus arrhizus lipase. For example, hydroxy acids composed 85–90 wt% of the free fatty acids released during lipolysis, as compared to 54%
present overall in the oil. In addition, over 80% of the lesquerolic acid is released from the triglycerides. The reason for
this lipase’s success was determined to be its 1,3-positional specificity. The vast majority of lesquerella oil’s hydroxy
acids is at the 1- and 3-positions of its triglycerides, as confirmed by the compositional analysis of partial glycerides
formed during lipolysis. 相似文献
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
A liquid-partition chromatographic procedure was used to separate hydroxy fatty acids, their methyl esters, and reduced fatty
ester hydroperoxides. Mixtures of methyl stearate, mono- and dihydroxystearate, and mixtures of the corresponding free fatty
acids were easily separated. Chromatographic determinations for ricinoleate in castor oils compared favorably with the chemical
and infrared analyses.
The chromatographic procedure was used to separate hydroxy fatty acids inDimorphotheca andStrophanthus seed oils. The methyl ester of dimorphecolic acid, the principal hydroxy fatty ester ofDimorphotheca oil, behaved like reduced methyl linoleate hydroperoxide and showed a polarity intermediate between methyl 12-hydroxystearate
and methyl 9,10-dihydroxystearate. The 9-hydroxy-12-octadecenoic ester ofStrophanthus oil had a larger retention volume than methyl ous hydroxy fatty esters isolated chromatographically. The diene content of
the reduced hydroperoxides agrees well with values reported in the literature (1,5,16). The diene content of the chromatographed
methyl dimorphecolate is higher than reported by Smithet al. (20) for their preparations but agrees well with the value reported by Chipault and Hawkins (6) for puretrans-trans conjugated methyl linoleate. The extinction coefficient of methyl 12-hydroxystearate at 2.8 μ is higher than that reported
for ricinoleate and the absorption band is much sharper. Because of these two conditions no association of the hydroxyl groups
is indicated. These results also confirm the purity of the hydroxy fatty esters obtained by LPC. This method has been a valuable
adjunct to the study of various oxygen-containing fatty acid and esters and was used to characterize the hydroxy esters obtained
from the hydrogenation of methyl linolenate hydroperoxides (9). This work offers a basis for the development of analytical
methods to determine the hydroxy and other polar acid content of fatty glycerides and their derivatives. 相似文献
There is a widely held belief that exercise leads to lipid peroxidation. Plasma hydroxy fatty acids originate from the diet and possibly from lipid peroxidation in vivo. We examined whether acute exercise (1 h at ∼76% of predicted maximal aerobic capacity) leads to an increase in plasma hydroxy fatty acids without the confounding influence of the diet in 7 male athletes. In addition, using a random‐sequence cross‐over design, we examined whether vitamin C supplementation of 1 g per day for 10 days prior to exercise could prevent exercise‐induced lipid peroxidation. Supplementation doubled the plasma vitamin C from 56.9 ? 3.4 to 112.7 ? 14.6 μM (P< 0.001) and lowered pre‐exercise plasma hydroxy fatty acids from 1.30 ? 0.18 to 1.03 ? 0.14 μM (P< 0.05). Plasma hydroxy fatty acid levels rose up to 3‐fold during exercise in some athletes on placebo and peak levels were reached after 20 min. The rise in plasma hydroxy fatty acid levels was delayed and remained lower after supplementation with vitamin C compared to placebo: 0.01 ? 0.07 vs. 0.63 ? 0.16 μM (P< 0.05). Vitamin C supplementation reduced pre‐exercise creatine kinase levels (193 ? 52 vs. 277 ? 68 U/L; P< 0.05) but its effect on exercise‐induced changes in creatine kinase did not reach statistical significance. In conclusion, large supplements of vitamin C reduced exercise‐induced lipid peroxidation in athletes. This small, but carefully controlled study illustrates the usefulness of plasma hydroxy fatty acid levels to monitor lipid peroxidation in vivo in acute studies. 相似文献
Fatty acid distillates (FADs) produced during physical refining of vegetable oil contains large amount of free fatty acid. A mutant of Candida tropicalis (M20) obtained after several stages of UV mutation are utilized to produce dicarboxylic acids (DCAs) from the fatty acid distillates of rice bran, soybean, coconut, palm kernel and palm oil. Initially, fermentation study was carried out in shake flasks for 144 h. Products were isolated and identified by GLC analysis. Finally, fermentation was carried out in a 2 L jar fermenter, which yielded 62 g/L and 48 g/L of total dibasic acids from rice bran oil fatty acid distillate and coconut oil fatty acid distillate respectively. FADs can be effectively utilized to produce DCAs of various chain lengths by biooxidation process. 相似文献
Hydroxy unsaturated glycerides were sought from safflower and linseed oils by partial sulfation with sulfuric acid, followed
by hydrolysis of sulfate to hydroxy groups. Sulfation of oleicrich oils or their fatty acids and subsequent hydrolysis (effected
conveniently with acidified barium chloride) yielded hydroxy products corresponding to 50–70% of the monoene content. Sulfation
of a mixture of methyl oleate and linoleate with 78% w/w of sulfuric acid was directed mainly at the oleate component. Safflower
oil was partially sulfated without side reactions using 78% or 79% w/w of sulfuric acid, the hydrolyzed products showing hydroxyl
value (HV) of about 35 for a loss of 13 units of iodine value (IV). Use of more concentrated sulfuric acid, and subsequent
hydrolysis, led to sulfur-containing products which include sultones. Treatment of atrans,trans, but not of acis,trans conjugated diene with sulfuric acid led to sultone formation. It is postulated that when linoleate is sulfated with strong
acids, acidisomerization to atrans,trans conjugated diene occurs, probably followed by 1,4-addition of -OH and -SO3H and quick dehydration of these moieties to give a 1,4-sultone. Linseed oil was apparently sulfated without side reactions
using 80% w/w sulfuric acid at 0–5 C and then hydrolyzed to a product of HV 77 and IV 159. 相似文献
In addition to some usual fatty acids, the seed oil ofJodina rhombifolia (Santalaceae) contains nine acetylenic fatty acids [9-octadecynoic acid (stearolic acid) (1.1%),trans-10-heptadecen-8-ynoic acid (pyrulic acid) (20.1%), 7-hydroxy-trans-10-heptadecen-8-ynoic acid (2.3%),trans-10,16-heptadecadien-8-ynoic acid (0.7%), 7-hydroxy-trans-10,16-heptadecadien-8-ynoic acid (0.1%),trans-11-octadecen-9-ynoic acid (ximenynic acid) (20.3%), 8-hydroxy-trans-11-octadecen-9-ynoic acid (12.2%),trans-11,17-octadecadien-9-ynoic acid (1.5%), 8-hydroxy-trans-11,17-octadecadien-9-ynoic acid (1.3%), 9-hydroxystearic acid (<0.1%) and 9,10-epoxystearic acid (0.7%)]. The fatty acids
have been analyzed by gas chromatography/mass spectrometry of their methyl ester and 4,4-dimethyloxazoline derivatives. The
hydroxy fatty acid methyl esters have been examined also as trimethyl-silyl ethers. Furthermore, the fatty acid methyl esters
(FAME) have been fractionated according to their polarity (FAME-A: nonhydroxy; FAME-B: hydroxy fatty acids) and to their degree
of unsaturation (FAME-A1/A2; FAME-B1/B2) by preparative thin-layer chromatography and argentation chromatography, respectively.
All of these fractions have been analyzed by ultraviolet and infrared spectroscopy, and the fractions FAME-A and FAME-B have
been analyzed further by nuclear magnetic resonance (1H,13C, 2D H/C, attached proton test) spectroscopy and gas chromatography/mass spectrometry.
This work is dedicated to the 65th birthday of Prof. Dr. K. Pfeilsticker, Institut of Food Science, University Bonn (Germany). 相似文献
Fatty acid hydratases (FAHs) catalyze regio- and stereo-selective hydration of unsaturated fatty acids to produce hydroxy fatty acids. Fatty acid hydratase-1 (FA-HY1) from Lactobacillus Acidophilus is the most promiscuous and regiodiverse FAH identified so far. Here, we engineered binding site residues of FA-HY1 (S393, S395, S218 and P380) by semi-rational protein engineering to alter regioselectivity. Although it was not possible to obtain a completely new type of regioselectivity with our mutant libraries, a significant shift of regioselectivity was observed towards cis-5, cis-8, cis-11, cis-14, cis-17-eicosapentaenoic acid (EPA). We identified mutants (S393/S395 mutants) with excellent regioselectivity, generating a single hydroxy fatty acid product from EPA (15-OH product), which is advantageous from application perspective. This result is impressive given that wild-type FA-HY1 produces a mixture of 12-OH and 15-OH products at 63 : 37 ratio (12-OH : 15-OH). Moreover, our results indicate that native FA-HY1 is at its limit in terms of promiscuity and regiospecificity, thus it may not be possible to diversify its product portfolio with active site engineering. This behavior of FA-HY1 is unlike its orthologue, fatty acid hydratase-2 (FA-HY2; 58 % sequence identity to FA-HY1), which has been shown earlier to exhibit significant promiscuity and regioselectivity changes by a few active site mutations. Our reverse engineering from FA-HY1 to FA-HY2 further demonstrates this conclusion. 相似文献
Biotransformation of long‐chain fatty acids into medium‐chain α,ω‐dicarboxylic acids or ω‐aminocarboxylic acids could be achieved with biocatalysts. This study presents the production of α,ω‐dicarboxylic acids (e.g., C9, C11, C12, C13) and ω‐aminocarboxylic acids (e.g., C11, C12, C13) directly from fatty acids (e.g., oleic acid, ricinoleic acid, lesquerolic acid) using recombinant Escherichia coli‐based biocatalysts. ω‐Hydroxycarboxylic acids, which were produced from oxidative cleavage of fatty acids via enzymatic reactions involving a fatty acid double bond hydratase, an alcohol dehydrogenase, a Baeyer–Villiger monooxygenase and an esterase, were then oxidized to α,ω‐dicarboxylic acids by alcohol dehydrogenase (ADH, AlkJ) from Pseudomonas putida GPo1 or converted into ω‐aminocarboxylic acids by a serial combination of ADH from P. putida GPo1 and an ω‐transaminase of Silicibacter pomeroyi. The double bonds present in the fatty acids such as ricinoleic acid and lesquerolic acid were reduced by E. coli‐native enzymes during the biotransformations. This study demonstrates that the industrially relevant building blocks (C9 to C13 saturated α,ω‐dicarboxylic acids and ω‐aminocarboxylic acids) can be produced from renewable fatty acids using biocatalysis.
Royal jelly (RJ) is a beehive product that has gained a significant scientific and commercial interest due to its healthy properties. In the present study, lipid content, fatty acid profile and phytosterol amount were determined in eight local and four commercial pure RJ samples. A mixture of diethyl ether/isopropanol 50/1 (v/v) was chosen to extract fat matter from RJ. Lipid amounts ranged from 2.3 and 7.2 % and from 2.0 to 3.2 % of the fresh product in local and commercial RJ, respectively. Fourteen fatty acids and three phytosterols were identified. About 70 % of the total fatty acids consisted of (E)‐10‐hydroxy‐2‐decenoic and 10‐hydroxydecanoic acid. No significant difference was observed between local and commercial samples in regards to the relative amount of individual fatty acids. Sterols were in the range 179–701 and 329–1,097 mg kg?1 of fat in local and commercial RJ, respectively. A significant difference (p ≤ 0.05) was observed within RJ types in regards to the 24‐methylenecholesterol fraction, amounting to 77 and 67 % of identified sterols in local and commercial products, respectively. 相似文献
Polyunsaturated fatty acids can be oxygenated by cytochrome P450 to hydroxy and epoxy fatty acids. Two major classes of hydroxy
fatty acids are formed by hydroxylation of the ω-side chain and by hydroxylation of bisallylic methylene carbons. Bisallylic
cytochrome P450-hydroxylases transform linoleic acid to 11-hydroxylinoleic acid, arachidonic acid to 13-hydroxyeicosa-5Z,8Z,11Z,14Z-tetraenoic
acid, 10-hydroxyeicosa-5Z,8Z,11Z,14Z-tetraenoic acid and 7-hydroxyeicosa-5Z,8Z,11Z,14Z-tetraenoic acid and eicosapentaenoic
acid to 16-hydroxyeicosa-5Z,8Z,11Z,14Z,17Z-pentaenoic acid, 13-hydroxyeicosa-5Z,8Z,11Z,14Z,17Z-pentaenoic acid and 10-hydroxyeicosa-5Z,8Z,11Z,14Z,17Z-pentaenoic
acid as major metabolites. The bisallylic hydroxy fatty acids are chemically unstable and decompose rapidly tocis-trans conjugated hydroxy fatty acids during acidic extractive isolation. Bisallylic hydroxylase activity appears to be augmented
in microsomes induced by the synthetic glucocorticoid dexamethasone and by some other agents, but the P450 gene families of
these hydroxylases have yet to be determined. The fatty acid epoxides, which are formed by cytochrome P450, are chemically
stable, but are hydrolyzed to diols by soluble epoxide hydrolases. Epoxidation of polyunsaturated fatty acids is a prominent
pathway of metabolism int he liver and the renal cortex and epoxygenase activity appears to be under homeostatic control in
the kidney. Many arachidonate epoxygenases have been identified belonging to the CYP2C gene subfamily. Epoxygenases have also
been found in the central nervous system, endocrine organs, the heart and endothelial cells. Epoxides of arachidonic acid
have been found to exert pharmacological effects on many cells. 相似文献