bluuebunny/crossref_metadata_2025_split huggingface dataset:
Activity and stability ofPenicillium cyclopium lipase in surfactant and detergent solutions
Authors: Xia J. , Chen X. , Nnanna I. A. 
Published: November 2006

AbstractActivity and stability of an alkaline lipase fromPenicillium cyclopium var.album (PG 37) were studied in surfactant and detergent solutions. Three anionic surfactants [Na salts of C12SO4− (sodium dodecyl sulfate), C12ØSO3/− (linear alkyl benzene sulfonate), and C11COO− (laurate)] and four homologous series of nonionic surfactants of C12–15 polyoxethylenated fatty alcohols (AEO3, AEO5, AEO7, and AEO9) were evaluated. At a concentration range of 3.2–40 μM, sodium dodecyl sulfate and laurate stimulated the activity of PG 37 lipase. At concentrations greater than 5.6 μM, linear alkylbenzene sulfonate inhibited PG 37 lipase activity. Nonionic surfactants, AEO5 and AEO7, in the concentration range of 0.25–20 mM, enhanced and stabilized the activity of PG 37 lipase. The presence of PG 37 lipase in detergent formulaton improved detergency ∼20%. The mechanism of inhibition of the lipolytic activity of PG 37 lipase is proposed to be partly due to the formation of inactive (BR)n‐E complex between the hydrophobic moiety of the surfactants and the surface of the lipase. Conversely, formation of a soluble (RB)n‐E complex between the hydrophilic group of the surfactant and lipase may account for the increased lipolytic activity of PG 37 lipase.
Foaming properties of surfactin, a lipopeptide biosurfactant fromBacillus subtilis
Authors: Razafindralambo Hary , Paquot Michel , Baniel Alain , Popineau Yves , Hbid Choukri , Jacques Philippe , Thonart Philippe 
Published: November 2006

AbstractFoaming properties of surfactin were investigated and compared to those of sodium dodecyl sulfate (SDS) and bovine serum albumin (BSA). Foams were formed by a bubbling technique. Evolution of the foam volume and the liquid in the foam was monitored with optical and conductimetric methods to characterize foam formation and stability. Excellent foaming properties of surfactin were shown by its higher ability to form and stabilize the foam at a concentration as low as 0.05 mg/mL, in comparison with SDS and BSA. Surfactin produced a foam with intermediate maximum density and stabilized the liquid in foam, as well as BSA.
Malaysian red palm oil in a surfactant association structure
Authors: Zaizi D. , Hamdan S. , Dzulkefly K. , Anuar K. , Faujan B. H. A. , Laili C. R. 
Published: November 2006

AbstractThe interlayer spacings of a lamellar liquid‐crystalline structure, before and after incorporation of red palm oil, were determined by means of small‐angle X‐ray diffraction. The results agreed with earlier investigations on refined, bleached, and deodorized palm olein for the anionic host. The cationic host, after addition of red palm oil, showed two features of interest. First, the results showed a drastic decrease of its extrapolated interlayer spacing, and, second, the slope exhibited a value twice that of the host value.
A novel compound, 12,13,17‐trihydroxy‐9(Z)‐Octadecenoic acid, from linoleic acid by a new microbial isolateClavibacter sp. ALA2
Authors: Hou Ching T. 
Published: November 2006

AbstractA novel compound, 12,13,17‐trihydroxy‐9(Z)‐octadecenoic acid (THOA), was produced from linoleic acid by microbial transformation at 25% yield. The newly isolated microbial strain that catalyzed this transformation was identified asClavibacter sp. ALA2. The product was purified by high‐pressure liquid chromatography, and its structure was determined by1H and13C nuclear magnetic resonance, Fourier transform infrared, and mass spectroscopy. Maximum production of THOA was reached after 85 h of reaction. THOA was not further metabolized by strain ALA2. This is the first report on 12,13,17‐trihydroxy unsaturated fatty acid and its production by microbial transformation.
Enzymatic synthesis of geranyl acetate by transesterification with acetic anhydride as acyl donor
Authors: Yee Lisa N. , Akoh Casimir C. 
Published: November 2006

AbstractPseudomonas sp. lipase (PS) was immobilized by adsorption technique onto glass beads and tested for its ability to synthesize geranyl acetate by transesterification with acetic anhydride as the acyl donor. Reactions were carried out inn‐hexane containing 0.1 M geraniol, 0.1 M acetic anhydride, and 200 units of lipase PS. Enzyme load, effect of substrate concentration, added water, temperature, time course, organic solvent, pH memory, and enzyme reuse were studied. Yields of up to 96% were obtained with 200 units (approximately 11% w/w of reactants) of enzyme. Increasing amounts of geraniol inhibited lipase activity, while excess acyl donor concentration enhanced ester production. Yields as high as 97% were obtained at 50°C, 24 h incubation, with no added water. Solvents with logP values ≥3.0 showed the highest conversion yields. Solvent‐free samples also performed well. The pH range of 4–9 gave good yields (92–98.4%). Enzyme reuse studies showed the lipase remained active after 15 runs.
Combined nonenzymatic‐enzymatic method for the synthesis of simple alkyl fatty acid esters from soapstock
Authors: Haas Michael J. , Scott Karen M. 
Published: November 2006

AbstractSoapstock (SS) is a by‐product of the extraction of oilseeds to produce edible oils. Annual U.S. production exceeds one‐half million tons. A representative sample of SS consists of 45.1% water, 10.0% free fatty acids, 10.1% triglycerides, 1.8% diglycerides, 3.6% phosphatidylethanolamine, 2.2% phosphatidylinositol, 2.7% phosphatidylcholine, 14.0% solvent‐insolubles and 10.5% other material, which was not characterized. A process has been developed that sequentially employs a nonenzymatic and an enzymatic step to convert the lipid‐linked and the free fatty acids of SS to the esters of monohydric alcohols. The first step of the process employed alcohol and potassium hydroxide to transesterify the glyceride‐and phosphoglyceride‐linked fatty acids of the substrate. Because water inhibited the reaction, it was necessary that the SS be dried before use. Nonetheless, even with some batches of SS with water contents below 1% (weight basis), ester hydrolysis accompanied esterification. Each of five examined simple primary alcohols participated effectively in the transesterification reaction, which proceeded rapidly at room temperature and was essentially complete within 1 h. The average ratio of transesterification to hydrolysis in four examined small primary alcohols was 4:1. However, in methanol this value was 99:1 due to the virtual absence of hydrolysis. Significant transesterification by a secondary alcohol (isopropanol) did not occur at room temperature. The minimum effective molar ratio of alcohol to lipid‐linked fatty acids was 20:1. The minimum effective concentration of KOH was between 0.10 and 0.15N. The efficiency of the transesterification reaction exceeded 90% of theoretical maximum. The second step of the process involves lipase‐mediated esterification of the free fatty acids in the preparation that are not esterified by the alkaline transesterfication. Of four lipase preparations examined (Novo Lipozyme IM 20 and SP435, and Amano PS30 and CE), only SP‐435 catalyzed significant esterification of the free fatty acids. The reaction was not catalyzed by heat‐denatured enzyme. In the pH range between 6 and 13.5, the enzyme reaction proceeded best at pH 6, although also well at pH 7. The optimal water concentration was 0.70% (vol/vol). At an enzyme dosage of 1.1% (weight basis, relative to the dry weight of SS present) under optimal conditions and at 42°C, 63% of the free fatty acids in a post‐alcoholysis mixture were enzymatically esterified. The addition of molecular sieves did not increase esterification, which was probably retarded by the high viscosities of the reactions. Under the optimal conditions identified here, the degree of conversion of the fatty acids in SS to simple alkyl esters by the combined reaction scheme was 81%. Opportunities exist for further optimization of these reactions.
Production of docosahexaenoic and docosapentaenoic acids bySchizochytrium sp. isolated from Yap Islands
Authors: Nakahara T. , Yokochi T. , Higashihara T. , Tanaka S. , Yaguchi T. , Honda D. 
Published: November 2006

AbstractA marine microbe (strain SR21) from the coral reef area of the Yap Islands was isolated by a screening test for polyunsaturated fatty acids and was found to accumulate lipid that contained 22:5n‐6 docosapentaenoic acid (DPA) as well as 22:6n‐3 docosahexaenoic acid (DHA). Strain SR21 was identified as genusSchizochytrium in Labyrinthulomycota, owing to its ultrastructural character and life cycle, which is composed of vegetative cell, zoosporangium, and zoospore stages. After cultural optimization, both in flask and fermenter, the highest DHA and DPA productivities of 2.0 and 0.44 g/L per day, respectively, were obtained in a medium of 60 g/L glucose and corn steep liquor/ammonium sulfate in a half salt concentration of seawater in fermenter culture at 28°C and pH 4. This productivity was almost twice that obtained with flask culture, indicating its high resistance to mechanical stirring. The lipid extracted from the cell was about 50% of the dry cell weight and was composed of 93% triacylglycerol (TG). DHA content of the lipid was 34% of total fatty acids. The TG profile was simple, and the content of the most dominant TG, 1,3‐dipalmitoyl‐2‐DHA‐TG, was 27%. TG that contained DHA and n‐6‐DPA amounted to 57 and 17%, respectively, of total TG molecules. Strain SR21 was revealed to be an excellent source of microbial DHA and n‐6 DPA.
Design and action of steroidal aromatase inhibitors
Authors: Li Shengrong , Parish Edward J. 
Published: November 2006

AbstractThe biosynthesis of estrogens involves three sequential hydroxylations, progressing from cholesterol, that are mediated by an enzyme complex referred to as aromatase. The last steps in this sequence involve aromatization of the A ring of the steroid nucleus. Compounds that inhibit aromatase have potential applications in the treatment of advanced estrogen‐dependent mammary carcinoma and prostatic hyperplasia. The enzyme aromatase is currently a priority target for the development of active‐site directed inhibitors. A number of steroid inhibitors may inactivate aromatase by diverse interactions with the enzyme and include competitive inhibitors, affinity labelling agents, and mechanism‐based inhibitors (“suicide substrates”). By designing steroidal analogs with substituents at various positions on the steroid nucleus, information has been obtained on the structural requirements needed for favorable interactions with the enzymatic sites.
Sugar ester‐modified lipase for the esterification of fatty acids and long‐chain alcohols
Authors: Basheer Sobhi , Nakajima Mitsutoshi , Cogan Uri 
Published: November 2006

AbstractThe esterification reaction of a long‐chain fatty acid and a fatty alcohol with a surfactant‐modified lipase in a microaqueousn‐hexane system was studied. Various lipases from different sources were first modified with a surfactant of the sugar ester type to improve their dispersibility in apolar organic solvents. This enzyme modification technique converted inactive crude lipases to highly active biocatalysts for the esterification of long‐chain fatty acids and fatty alcohols in a microaqueous n‐hexane system. The hydrophilic‐lipophilic balance value and chainlength of the fatty acid residue of the fatty acid sugar ester, used for modifying the lipases, significantly influenced the amount of precipitated lipase that was dissolved in the aqueous solution, the protein content of the lipase‐surfactant complex and its esterification activity.
Application of lipases to the regioselective synthesis of sucrose fatty acid monoesters
Authors: Sarney Douglas B. , Barnard Mark J. , MacManus David A. , Vulfson Evgeny N. 
Published: November 2006

AbstractA regioselective synthesis of 6′‐O‐acyl sucrose monoesters has been developed through the lipase‐catalyzed esterification of sucrose acetals with fatty acids in both organic solvents and under solvent‐free conditions. The products were obtained in overall yields of 20–27% after hydrolysis of the isopropylidene groups with aqueous acids. The strict selectivity of the enzymes used also enabled the preparation of a monoester fraction that was highly enriched in 6‐O‐acyl sucrose. This was accomplished by lipase‐catalyzed transesterification of sucrose monoesters, prepared by conventional chemical methods, in propan‐2‐ol. After removal of the transesterification products (sucrose and fatty acid isopropyl esters) and column chromatography on silica gel, the obtained monoester product contained 80% of the single regioisomer, 6‐O‐acyl sucrose.
Synthesis of medium‐chain glycerides by lipase in organic solvent
Authors: Kwon Dae Young , Song Hyo Nam , Yoon Suk Hoo 
Published: November 2006

AbstractUsing commercial lipases from various microbial origins, medium‐chain glycerides, such as mono‐, di‐, and tricaprin, were synthesized in isooctane from glycerol and capric acid. The enzyme reaction was performed with 0.35 M capric acid, 0.025 M glycerol, and 0.46 g silica gel to remove water in 5 mL of isooctane with 30 mg lyophilized lipase. Of the 21 kinds of lipases, 11 showed good synthetic activities. Lipases fromPseudomonas aeruginosa (Lipase PS),Rhizomucor miehei lipase andChromobacterium viscosum lipase (Lipase CV) showed high activities for the production of tricaprin, while lipase OF‐360 (fromCandida rugosa) and lipase D (Rhizopus delemar) were good for dicaprin production. Lipases CC and MY fromC. rugosa (C. cylindracea) and lipase D (Rhizopus delemar) were good for dicaprin production. Lipases CC and MY fromC. rugosa (C. cylindracea) also showed high activities for dicaprin and tricaprin. Some lipases, especially lipase PS, had high thermal stability over 60°C. The optimal lyophilization pH to dehydrate the lipase coincides with the optimal buffer solution pH for hydrolysis.
Esterification and interesterification reactions catalyzed by acetone powder from germinating rapeseed
Authors: Jachmanián I. , Mukherjee K. D. 
Published: November 2006

AbstractAcetone powder from germinating rape (Brassica napus L.) seedlings exhibits essentially similar activity in lipolysis of triacylglycerols as the corresponding seedling homogenates. Acetone powder from rape seedlings catalyzes the esterification of a fatty acid, such as oleic acid, withn‐butanol or a long‐chain alcohol, such as oleyl alcohol. Furthermore, the acetone powder catalyzes alcoholysis of a methyl ester, such as methyl oleate withn‐butanol or oleyl alcohol, and acidolysis of methyl oleate with a fatty acid, such as erucic acid. However, triacylglycerols are not accepted as substrates fro interesterification reactions. In esterification of fatty acids withn‐butanol, catalyzed by the acetone powder from rape seedlings, fatty acids having an olefinic bond next to the carboxyl group as acis‐6 double bond, e.g., γ‐linolenic, gorlic and petroselinic acids, or those having acis‐4 double bond, e.g., docosahexaenoic acid, are strongly discriminated against as substrates. Such substrate selectivities can be utilized for the enrichment of definite fatty acids from mixtures, derived from naturally occurring oils,via kinetic resolution.
Distribution of Δ5‐olefinic acids in the triacylglycerols fromPinus koraiensis andPinus pinaster seed oils
Authors: Gresti Joseph , Mignerot Corinne , Bézard Jean , Wolff Robert L. 
Published: November 2006

AbstractPurified triacylglycerols (TAG) fromPinus koraiensis andP. pinaster seed oils, which are interesting and commercially available sources of Δ5‐olefinic acids (i.e.,cis‐5,cis‐9,cis‐12 18:3 andcis‐5,cis‐11,cis‐14 20:3 acids) were fractionated by reversed‐phase high‐performance liquid chromatography, and each fraction was examined by capillary gas‐liquid chromatography for its fatty acid composition. A structure could be assigned to more than 92% of TAG from both oils. In both instances, ca. 48% of the TAG were shown to contain at least one δ5‐olefinic acid. In the great majority of TAG, our data showed that there is only one molecule of δ5‐olefinic acid per molecule of TAG. This is compatible with theoretical calculations based on the proportion of total δ5‐olefinic in the oils. Thecis‐5,cis‐9,cis‐12 18:3 acid (14.2 and 8.6% of total fatty acids in the seed oils ofP. koraiensis andP. pinaster, respectively) and thecis‐5,cis‐11,cis‐14 20:3 acid (1.1 and 8.1% of total fatty acids in the seed oils ofP. koraiensis andP. pinaster, respectively) are preferentially associated with two molecules of linoleic acid, and to a lesser extent, to one molecule of linoleic acid and one molecule of oleic acid, or two oleic acid molecules. However, several other combinations occur, each in low amounts. The distribution of δ5‐olefinic acids in TAG is evidently not random. Combining these results with the known preferential esterification of δ5‐olefinic acids to the 1,3‐positions of TAG would suggest that most of these acids are present at only one of these positions at a time.
Fuel properties and emissions of soybean oil esters as diesel fuel
Authors: Chang David Y. Z. , Van Gerpen Jon H. , Lee Inmok , Johnson Lawrence A. , Hammond Earl G. , Marley Stephen J. 
Published: November 2006

AbstractThe effects of using blends of methyl and isopropyl esters of soybean oil with No. 2 diesel fuel were studied at several steady‐state operating conditions in a four‐cylinder turbocharged diesel engine. Fuel blends that contained 20, 50, and 70% methyl soyate and 20 and 50% isopropyl soyate were tested. Fuel properties, such as cetane number, also were investigated. Both methyl and isopropyl esters provided significant reductions in particulate emissions compared with No. 2 diesel fuel. A blend of 50% methyl ester and 50% No. 2 diesel fuel provided a reduction of 37% in the carbon portion of the particulates and 25% in the total particulates. The 50% blend of isopropyl ester and 50% No. 2 diesel fuel gave a 55% reduction in carbon and a 28% reduction in total particulate emissions. Emissions of carbon monoxide and unburned hydrocarbons also were reduced significantly. Oxides of nitrogen increased by 12%.
Turbidimetric measurement of haze in canola oil by acetone precipitation
Authors: Liu Hua , Przybylski Roman , Michael Eskin N. A. 
Published: November 2006

AbstractFormation of turbidity in canola oil was facilitated with addition of acetone, and a method to measure the sediment content based on the oil turbidity has been developed. Canola oil was mixed with acetone at the ratio of 60:40, and the turbid solution developed in an ice bath for 20 min. The turbidity of the oil solution was determined by a turbidimeter. The relation between turbidity of the oil solution and sediment content was nonlinear and could be correlated by a second‐order polynomial. There was no difficulty in the development of turbidity in canola oil solutions in the presence of added lecithin (2%, w/w). However, with added lecithin, turbidity was 23% higher at the same sediment content.
Uses of biotechnology in modifying plant lipids
Authors: Budziszewski Greg J. , Croft Kevan P. C. , Hildebrand David F. 
Published: November 2006

AbstractThis review discusses fatty acid modification of oilseeds with additional emphasis on production of oxygenated derivatives. In a relatively short period, less than a decade, our understanding of the enzymes involved in plant fatty acid synthesis has increased to the point where we understand how they might be used in oilseed modification. Further, through modern molecular biological techniques, the actual genes for many of these important enzymes have been cloned. Use of genetic transformation systems has allowed us to fundamentally alter the normal biosynthetic pathways in highly specific ways, in manners that would be either difficult or impossible using traditional breeding techniques. Alteration of plant lipid biosynthesis is not restricted to using genes from the plants themselves, but interspecies transfer is possible, either from completely unrelated plant species (often of no commercial value but possessing unusual biochemical properties) or from animals, fungi, and prokaryotic organisms. In this way “designer” plants possessing altered metabolism, tailored to the interests or needs of certain industries, nutritionists, and the consumer can be created.
Eicosapentaenoic acid, but not docosahexaenoic acid, increases mitochondrial fatty acid oxidation and upregulates 2,4‐dienoyl‐CoA reductase gene expression in rats
Authors: Willumsen Nina , Vaagenes Hege , Lie Øyvind , Rustan Arild C. , Berge Rolf K. 
Published: November 2006

AbstractThe aim of the present study was to investigate whether eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) was responsible for the triglyceride‐lowering effect of fish oil. In rats fed a single dose of EPA as ethyl ester (EPA‐EE), the plasma concentration of triglycerides was decreased at 8 h after acute administration. This was accompanied by an increased hepatic fatty acid oxidation and mitochondrial 2,4‐dienoyl‐CoA reductase activity. The steady‐state level of 2,4‐dienoyl‐CoA reductase mRNA increased in parallel with the enzyme activity. An increased hepatic long‐chain acyl‐CoA content, but a reduced amount of hepatic malonyl‐CoA, was obtained at 8 h after acute EPA‐EE treatment. On EPA‐EE supplementation, both EPA (20:5n‐3) and docosapentaenoic acid (DPA, 22:5n‐3) increased in the liver, whereas the hepatic DHA (22:6n‐3) concentration was unchanged. On DHA‐EE supplementation retroconversion to EPA occurred. No statistically significant differences were found, however, for mitochondrial enzyme activities, malonyl‐CoA, long‐chain acyl‐CoA, plasma lipid levels, and the amount of cellular fatty acids between DHA‐EE treated rats and their controls at any time point studied. In cultured rat hepatocytes, the oxidation of [1‐14C]palmitic acid was reduced by DHA, whereas it was stimulated by EPA. In thein vivo studies, the activities of phosphatidate phosphohydrolase and acetyl‐CoA carboxylase were unaffected after acute EPA‐EE and DHA‐EE administration, but the fatty acyl‐CoA oxidase, the rate‐limiting enzyme in peroxisomal fatty acid oxidation, was increased after feeding these n‐3 fatty acids. The hypocholesterolemic properties of EPA‐EE may be due to decreased 3‐hydroxy‐3‐methylglutaryl‐CoA reductase activity. Furthermore, replacement of the ordinary fatty acids, i.e., the monoenes (16:1n‐7, 18:1n‐7, and 18:1n‐9) with EPA and some conversion to DPA concomitant with increased fatty acid oxidation is probably the mechanism leading to changed fatty acid composition. In contrast, DHA does not stimulate fatty acid oxidation and, consequently, no such displacement mechanism operates. In conclusion, we have obtained evidence that EPA, and not DHA, is the fatty acid primarily responsible for the triglyceride‐lowering effect of fish oil in rats.