bluuebunny/crossref_metadata_2025_split huggingface dataset:
Production of polyhydroxy fatty acids from linoleic acid by Clavibacter sp. ALA2
Authors: Hou Ching T. , Gardner Harold , Brown Wanda 
Published: May 2007

AbstractHydroxy 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.
Application of potato lipid acyl hydrolase for the synthesis of monoacylglycerols
Authors: Macrae Alasdair R. , Visicchio Jean E. , Lanot Alexandra 
Published: May 2007

AbstractProtein extracts from potato tubers contain a lipid acyl hydrolase (LAH) with an unusual selectivity. The component responsible for the enzyme activity is a group of closely related glycoproteins, known as patatin. Potato LAH catalyzes the rapid hydrolysis of monoacylglycerols (MAG), but in contrast expresses only low activity with di‐ and triacylglycerols. The selectivity of the LAH can be exploited for the synthesis of MAG from fatty acids and glycerol in microaqueous reaction systems. Oleic, linoleic, linolenic, capric, lauric, and myristic acids can be used as reactants, and in each case the reaction products contain >95 mol% MAG and <5 mol% diacylglycerol. By removing water from the reaction mixture by distillation under vacuum, excellent conversions of fatty acids into MAG are possible. Low conversions are observed with palmitic and stearic acids, because of the necessity to use a high temperature (70°C) to maintain a liquid reaction mixture. Potato LAH is rapidly inactivated at 70°C in the microaqueous reaction systems. Potato LAH also catalyzes the selective synthesis of monoesters from oleic acid and simple diols. With oleic acid and diglycerol, monoesters are again the main reaction products, but 17 mol% diesters are also formed.
Production of 8,11,14,17‐cis‐eicosatetraenoic acid (20:4ω‐3) by a Δ5 and Δ12 desaturase‐defective mutant of an arachidonic acid‐producing fungus Mortierella alpina 1S‐4
Authors: Kawashima Hiroshi , Sakuradani Eiji , Kamada Nozomu , Akimoto Kengo , Konishi Kyoko , Ogawa Jun , Shimizu Sakayu 
Published: May 2007

AbstractA Δ5 and Δ12 desaturase‐defective mutant of an arachidonic acid‐producing fungus, Mortierella alpina 1S‐4, produced 8,11,14,17‐cis‐eicosatetraenoic acid (20:4ω3) intracellularly when grown with linseed oil. Dihomo‐γ‐linolenic acid was the only C20 polyunsaturated fatty acid (4.9 wt% of total mycelial fatty acids) other than 20:4ω3. AA and 5,8,11,14,17‐cis‐eicosapentaenoic acid were not detected. The mycelial lipids consisted of 82.2% (by mol) triacylglycerol (TG), 7.1% diacylglycerol, 8.9% phospholipids (PL), and 1.9% free fatty acids. The percentage of 20:4ω3 was higher in PL (30.1%) than in TG (11.6%), and highest in phosphatidylcholine (38.9%). Under the optimal conditions with a 5‐L jar fermenter, 20:4ω3 production amounted to 97.4 mg/g dry mycelia with a mycelial yield of 23 g/L on the twelfth day (corresponding to 2.24 g/L medium and 37.1% of total mycelial fatty acids).
Enhancement of arachidonic acid production by Mortierella alpina 1S‐4
Authors: Higashiyama Kenichi , Yaguchi Toshiaki , Akimoto Kengo , Fujikawa Shigeaki , Shimizu Sakayu 
Published: May 2007

AbstractThe effect of mineral addition on arachidonic acid (AA) production by Mortierella alpina 1S‐4 was evaluated. At first, the addition of minerals such as sodium, potassium, calcium, and magnesium was examined in flask cultures, and then the addition of phosphorus with the optimal amounts of the minerals was investigated in a 10‐L jar‐fermenter. As a result, 1.5% soy flour medium with the addition of 0.3% KH2PO4, 0.1% Na2SO4, 0.05% CaCl2·2H2O, and 0.05% MgCl2·6H2O was found to enhance the AA yield 1.7‐fold over that without mineral addition. When 1% yeast extract with the above mineral mixture was used, the AA yield was enhanced 1.35‐fold over that without minerals. We also verified that an increase in the polar lipid content occurred in the case of only KH2PO4 addition, and that the above‐mentioned increase in the AA yield was due to the minerals themselves, not a pH buffer effect.
Lipase‐catalyzed synthesis of kojic acid esters in organic solvents
Authors: Liu Kuan‐Ju , Shaw Jei‐Fu 
Published: May 2007

AbstractKojic acid is an inhibitor of bacteria, viruses, and fungi. It is used for inhibiting the browning effect of tyrosinase in the food and cosmetic industries. To improve its lipophilic properties, Pseudomonas cepacia lipase and Penicillium camembertii lipase were used for catalyzing the esterification of kojic acid to synthesize kojic acid monolaurate and kojic acid monooleate. These products showed a 69.5% inhibitory effect on tyrosinase in hydrophobic organic solvent. The yields of kojic acid esters were affected by enzymes, substrates, organic solvent, and temperature. Lauric and oleic acids were the best substrates for esterification among various fatty acids tested. CaCl2 and MnCl2 stimulate Pseudomonas cepacia lipasecatalyzed esterification by 7.0%. On the contrary, MgCl2, SrCl2, and ZnCl2 inhibited the reaction. The best pH of buffer for lipase pretreatment was pH 6.0. Pseudomonas and Penicillium lipases can be reused for the synthesis of kojic acid esters. After reaction at 40°C for 10 d, the Penicillium and Pseudomonas lipases still retained 57.0% and 92.0% of their initial activities, respectively.
Lipase‐catalyzed synthesis of chiral triglycerides
Authors: Chandler Ian C. , Quinlan Paul T. , McNeill Gerald P. 
Published: May 2007

AbstractUnder certain reaction conditions, the acidolysis of tripalmitin with oleic acid using immobilized lipase from Rhizomucor miehei resulted in a higher level of monosubstituted oleoyldipalmitoyl (OPP) triglycerides than had been predicted according to kinetic modeling. The reaction products were subjected to chiral analysis by high‐performance liquid chromatography (HPLC), which indicated that the enzyme was more active at the sn‐1 position of the triglyceride than at the sn‐3 position, resulting in synthesis of the chiral triglyceride 1‐oleoyl‐2,3‐dipalmitoyl‐sn‐glycerol. A kinetic model was developed and was correlated with the HPLC method to provide a simple means to predict the stereoselectivity of lipase‐catalyzed reactions. By using the model, the stereoselectivity of immobilized Rhizomucor miehei lipase was found to depend strongly on the initial water activity (aw) of the reaction mixture, with greater selectivity occurring at lower aw. The sn‐1 selectivity was essentially maintained using various solvents, or without solvent, when aw was kept constantly low. Variation in the fatty acid composition of the triglyceride indicated that shorter‐chain fatty acids result in greater stereoselectivity, while variation of the chainlength of the free fatty acid indicated an enhancement by the longest chainlength. The stereoselectivity of this lipase was confirmed using a new 13C nuclear magnetic resonance method. By using immobilized R. miehei lipase at low aw approximately 80% of the chiral triglyceride found in the reaction mixture was the sn‐1 enantiomer, at high reaction conversion.
Evaluation of immobilized modified lipase: Aqueous preparation and reaction studies in n‐hexane
Authors: Green Kenneth D. , Nakajima Mitsutoshi 
Published: May 2007

AbstractLipase Saiken 100 (Rhizopus japonicus) and its immobilized form displayed very poor activity (hydrolysis and interesterification) in microaqueous n‐hexane solutions. Enzyme modification by the addition of stearic acid or sorbitan monostearate significantly improved activity. A ceramic carrier (SM‐10) was used to immobilize modified lipase Saiken (stearic acid, sorbitan monostearate, and lecithin) and was found to further enhance hydrolysis and interesterification rates in n‐hexane. In addition, the biocatalysts were re‐used for four consecutive batch reactions with no significant shortfall in activity. Reaction rates were also greatly affected by the total reaction water content. Careful control of the biocatalyst water content prior to use and additional reaction water were required to optimize activity and minimize hydrolytic diglyceride byproducts. Hydrolysis and interesterification reaction rates were favored with immobilized biocatalyst water contents of 6.25 and 0.43 wt% with additional reaction water contents of 600 and 20 mg/L, respectively.
Optimization of the reaction conditions in the lipase‐catalyzed synthesis of structured triglycerides
Authors: Schmid U. , Bornscheuer U. T. , Soumanou M. M. , McNeill G. P. , Schmid R. D. 
Published: May 2007

AbstractStructured triglycerides of the ABA‐type, containing one type of fatty acid (A) in the sn‐1 and sn‐3 positions and a second type of fatty acid (B) in the sn‐2 position of the glycerol, were synthesized using lipases. The highest yields and purities were achieved in a two‐step process, where a triglyceride of the B‐type was subjected to an alcoholysis reaction in an organic solvent catalyzed by sn‐1,3‐regiospecific lipases yielding the corresponding 2‐monoglyceride (2‐MG). Using this strategy, e.g., 2‐monopalmitin (2‐MP) was obtained in up to 88% yield at >95% purity by crystallization. Esterification of 2‐MP with oleic acid resulted in the formation of 1,3‐oleyl‐2‐palmitoyl‐glycerol in up to 72% yield containing 94% palmitic acid in the sn‐2 position. The best lipases were from Rhizomucor miehei, Rhizopus delemar, and Rhizopus javanicus. Water activity, solvent, and carrier for lipase immobilization strongly influenced the yield and purity of the products in both steps. Furthermore, 2‐MG from fish oil were produced by alcoholysis in up to 84% yield at >95% purity.
Solvent‐free enzymatic synthesis of structured lipids from peanut oil and caprylic acid in a stirred tank batch reactor
Authors: Lee Ki‐Teak , Akoh Casimir C. 
Published: May 2007

AbstractStructured lipids were synthesized by transesterification of peanut oil and caprylic acid in a stirred‐batch reactor. Different substrate molar ratios (1:1 to 1:4, peanut oil/caprylic acid) were used. The reaction was performed for 72 h at 50°C catalyzed by IM60 lipase from Rhizomucor miehei (10 g, 2% w/w substrate) in the absence of organic solvent. The highest incorporation of caprylic acid was obtained with a 1:2 molar ratio (peanut oil/caprylic acid) after 72 h reaction. With a 1:2 molar ratio, the incorporation increased by 28% from 1:1. On the other hand, a 1:4 molar ratio gave the lowest incorporation during the reaction. The effect of different mixing speeds (200, 640, or 750 rpm) on reaction was studied with a 1:2 substrate molar ratio for 24 h. A high incorporation of caprylic acid (14.3 mol%) was obtained at 640 rpm, while 200 rpm gave the lowest incorporation (2.2 mol%), suggesting that good mixing is essential in a stirred‐batch reactor. After 24 h of reaction at different rpm, IM60 lipase was recovered, washed with hexane, and reacted with substrates to study its stability after reaction at different mixing speeds. The results showed that caprylic acid incorporation was similar (24.9, 24.3, 24.2 mol%) at 200, 640, and 750 rpm, respectively. When 20 g of IM60 lipase (4% w/w substrate) instead of 10 g was used in a 1:1 substrate molar ratio reaction, the incorporation of caprylic acid increased by 26% after 72 h. To study enzyme reuse, 10 g of IM60 lipase was used in a 1:1 substrate molar ratio for 24 h at 640 rpm. The incorporation of caprylic acid gradually decreased with increased number of reuses. During five times of reuse, 15, 13.9, 9.6, 6.7, and 9.7 mol% of caprylic acid were incorporated into peanut oil, respectively.
Large‐scale purification of γ‐linolenic acid by selective esterification using Rhizopus delemar lipase
Authors: Shimada Yuji , Sakai Norihito , Sugihara Akio , Fujita Hiroyuki , Honda Yo , Tominaga Yoshio 
Published: May 2007

Abstractγ‐Linolenic acid (GLA) is a physiologically valuable fatty acid, and is desired as a medicine, but a useful method available for industrial purification has not been established. Thus, large‐scale purification was attempted by a combination of enzymatic reactions and distillation. An oil containing 45% GLA (GLA45 oil) produced by selective hydrolysis of borage oil was used as a starting material. GLA45 oil was hydrolyzed at 35°C in a mixture containing 33% water and 250 U/g‐reaction mixture of Pseudomonas sp. lipase; 91.5% hydrolysis was attained after 24 h. Film distillation of the dehydrated reaction mixture separated free fatty acids (FFA; acid value 199) with a recovery of 94.5%. The FFA were selectively esterified at 30°C for 16 h with two molar equivalents of lauryl alcohol and 50 U/g of Rhizopus delemar lipase in a mixture containing 20% water. The esterification extent was 52%, and the GLA content in the FFA fraction was raised to 89.5%. FFA and lauryl esters were not separated by film distillation, but the FFA‐rich fraction contaminated with 18% lauryl esters was recovered by simple distillation. To further increase the GLA content, the FFA‐rich fraction was selectively esterified again under similar conditions. As a result, the GLA content in the FFA fraction was raised to 97.3% at 15.2% esterification. After simple distillation of the reaction mixture, lauryl esters contaminating the FFA‐rich fraction were completely eliminated by urea adduct fractionation. When 10 kg of GLA45 oil was used as a starting material, 2.07 kg of FFA with 98.6% GLA was obtained with a recovery of 49.4% of the initial content.
Separation of eicosapentaenoic acid and docosahexaenoic acid in fish oil by kinetic resolution using lipase
Authors: Haraldsson Gudmundur G. , Kristinsson Björn 
Published: May 2007

AbstractThe objective of this study was to investigate the use of lipases as catalysts for separating eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in fish oil by kinetic resolution. Transesterification of various fish oil triglycerides with a stoichiometric amount of ethanol by immobilized Rhizomucor miehei lipase under anhydrous solvent‐free conditions resulted in a good separation. When free fatty acids from the various fish oils were directly esterified with ethanol under similar conditions, greatly improved results were obtained. By this modification, complications related to regioselectivity of the lipase and nonhomogeneous distribution of EPA and DHA into the various positions of the triglycerides were avoided. As an example, when tuna oil comprising 6% EPA and 23% DHA was transesterified with ethanol, 65% conversion into ethyl esters was obtained after 24 h. The residual glyceride mixture contained 49% DHA and 6% EPA (8:1), with 90% DHA recovery into the glyceride mixture and 60% EPA recovery into the ethyl ester product. When the corresponding tuna oil free fatty acids were directly esterified with ethanol, 68% conversion was obtained after only 8h. The residual free fatty acids comprised 74% DHA and only 3% EPA (25:1). The recovery of both DHA into the residual free fatty acid fraction and EPA into the ethyl ester product remained very high, 83 and 87%, respectively.
Transesterification of trimethylolpropane and rapeseed oil methyl ester to environmentally acceptable lubricants
Authors: Uosukainen Esa , Linko Yu‐Yen , Lämsä Merja , Tervakangas Tommi , Linko Pekka 
Published: May 2007

AbstractBiodegradable trimethylolpropane [2‐ethyl‐2‐(hydroxymethyl)‐1,3‐propanediol] esters of rapeseed oil fatty acids were synthesized by transesterification with rapeseed oil methyl ester both by enzymatic and chemical means, both in bench and pilot scales. Nearly complete conversions were obtained with both techniques. A reduced pressure of about 2 to 5 kPa, to remove the methanol formed during transesterification, was critical for a high product yield. The quantity of added water was also critical in the biocatalysis. Candida rugosa lipase was used as biocatalyst and an alkaline catalyst in chemical transesterifications. In biocatalysis the maximum total conversion to trimethylolpropane esters of up to 98% was obtained at 42°C, 5.3 kPa, and 15% added water. The maximum conversion of about 70% to the tri‐ester was obtained at the slightly higher temperature of 47°C. The reaction time was longer in the biocatalysis, but considerably higher temperatures were required in chemical synthesis. In the chemical synthesis tri‐ester yields increased when the temperature was first held at 85 to 110°C for 2.5 h and subsequently increased to up to 120°C for 8 h. The trimethylolpropane esters obtained were tested as biodegradable hydraulic fluids and compared to commercially available hydraulic oils. The hydraulic fluids based on trimethylolpropane esters of rapeseed oil had good cold stability, friction and wear characteristics, and resistance against oxidation at elevated temperatures.
Purification of ethyl docosahexaenoate by selective alcoholysis of fatty acid ethyl esters with immobilized Rhizomucor miehei lipase
Authors: Shimada Yuji , Maruyama Kazuaki , Sugihara Akio , Baba Takashi , Komemushi Sadao , Moriyama Shigeru , Tominaga Yoshio 
Published: May 2007

AbstractEthyl docosahexaenoate (E‐DHA) is efficiently enriched by the selective alcoholysis of ethyl esters originating from tuna oil with lauryl alcohol using immobilized lipase. Alcoholysis of ethyl esters by immobilized Rhizopus delemar lipase raised the E‐DHA content in the unreacted ethyl ester fraction from 23 to 49 mol% in 90% yield. However, the content of ethyl eicosapentaenoate (E‐EPA) was higher than the initial content. Hence we attempted to screen for a suitable lipase to decrease the E‐EPA content, and chose Rhizomucor miehei lipase. Several factors affecting the alcoholysis of ethyl esters were investigated, and the reaction conditions were determined. When alcoholysis was performed at 30°C with shaking in a mixture containing ethyl esters/lauryl alcohol (1:3, mol/mol) and 4 wt% of the immobilized R. miehei lipase, the E‐DHA content in the ethyl ester fraction was increased and the E‐EPA content was decreased. By alcoholyzing ethyl esters in which the E‐DHA content was 45 mol% (E‐tuna‐45) for 26 h, the E‐DHA content was increased to 74 mol% in 71% yield and the E‐EPA content was decreased from 12 to 6.2 mol%. To investigate the stability of the immobilized lipase, batch reactions were carried out continually by replacing the reaction mixture with fresh E‐tuna‐45/lauryl alcohol (1:3, mol/mol) every 24 h. The decrease in the alcoholysis extent was only 17% even after 100 cycles of reaction. It was found that increasing the proportion of lauryl alcohol increased the conversion of E‐EPA to lauryl‐EPA. When an ethyl ester mixture in which the E‐DHA content was 60 mol% (E‐tuna‐60) was alcoholyzed for 24 h with 7 molar equivalents of lauryl alcohol, the E‐DHA content was raised to 93 mol% with 74% yield and the E‐EPA content was reduced from 8.6 to 2.9 mol%.
Selective hydrolysis of borage oil with Candida rugosa lipase: Two factors affecting the reaction
Authors: Shimada Yuji , Fukushima Nobuhiro , Fujita Hiroyuki , Honda Yo , Sugihara Akio , Tominaga Yoshio 
Published: May 2007

AbstractA 46% γ‐linolenic acid (GLA)‐containing oil was produced by selective hydrolysis of borage oil (GLA content, 22%) at 35°C for 15 h in a mixture containing 50% water and 20 units (U)/g reaction mixture of Candida rugosa lipase. The GLA content was not raised over 46%, even though the hydrolysis extent was increased by extending the reaction time and by using a larger amount of the lipase. However, 49% GLA‐containing oil was produced by hydrolysis in a reaction mixture with 90% water. This result suggested that free fatty acids (FFA) that accumulated in the mixture affected the apparent fatty acid specificity of the lipase in the selective hydrolysis and interfered with the increase of the GLA content. To investigate the kinetics of the selective hydrolysis in a mixture without FFA, glycerides containing 22, 35, and 46% GLA were hydrolyzed with Candida lipase. The result showed that the hydrolysis rate decreased with increasing GLA content of glycerides, but that the release rate of GLA did not change. Thus, it was found that the apparent fatty acid specificity of the lipase in the selective hydrolysis was also affected by glyceride structure. When 46% GLA‐containing oil was hydrolyzed at 35°C for 15 h in a mixture containing 50% water and 20 U/g of the lipase, GLA content in glycerides was raised to 54% at 20% hydrolysis. Furthermore, GLA content in glycerides was raised to 59% when the hydrolysis extent reached 60% using 200 U/g of the lipase. These results showed that repeated hydrolysis was effective to produce the higher concentration of GLA oil. Because film distillation was found to be extremely effective for separating FFA and glycerides, large‐scale hydrolysis of borage oil was attempted. As a result, 1.5 kg of 56% GLA‐containing oil was obtained from 7 kg borage oil by repeated reaction.
Trans fatty acids in Canadian margarines: Recent trends
Authors: Ratnayake W. M. N. , Pelletier G. , Hollywood R. , Bacler S. , Leyte D. 
Published: May 2007

AbstractThe fatty acid composition and the trans fatty acid content of the top‐selling 109 Canadian margarines were determined by a combined capillary gas‐liquid chromatography/infrared spectroscopy method. The 109 brands accounted for 68% of the margarine brands sold in Canada and represented 74% of the market share. The mean level of total trans content in tub margarines (n=79) was 18.8% (g/100 g fatty acids) and ranged from 0.9 to 46.4%. The most frequent occurrence of trans in tub margarines was in the 15–20% range; 48 of the 79 tub brands were in this range but seven brands contained more than 40% trans. The trans content of hard margarines (n=30) ranged from 16.3 to 43.7% and the mean value was 34.3%. In 20 of the 109 brands, the levels of trans,trans isomers of linoleic acid exceeded the maximum level of 1% recommended for Canadian margarines. The levels of cis,trans/trans,cis isomers of linoleic acid were also high; 78 brands contained more than 1% and in 16 brands, the levels were in the 6–7% range. Linoleic acid content in the 109 brands ranged from 1.0 to 45.2% and averaged 18.3%. In 33 samples, linoleic acid was below the level of 5% recommended by an ad hoc committee of Health Canada. Moreover, in these, the total trans content exceeded 30%, and trans polyunsaturated fatty acid level was greater than 5%. There were eight margarines prepared from nonhydrogenated fat and their total trans content was below 2.5%. From the trans content and market share of each of the margarine brands, the average intake of trans fatty acids from margarine was estimated as 0.96 g/person/d. The intake of trans fatty acids in Canada from various sources was previously estimated by us as 8.4 g/person/d. Thus it is suggested that only 11% of the dietary trans fatty acids are supplied by margarines and the majority of trans fatty acids in the Canadian diet is derived from hidden fats in fast foods and bakery products.