bluuebunny/crossref_metadata_2025_split huggingface dataset:
A review of tobacco BY‐2 cells as an excellent system to study the synthesis and function of sterols and other isoprenoids
Authors: Hemmerlin Andréa , Gerber Esther , Feldtrauer Jean‐François , Wentzinger Laurent , Hartmann Marie‐Andrée , Tritsch Denis , Hoeffler Jean‐François , Rohmer Michel , Bach Thomas J. 
Published: January 2018

AbstractIn plants, two pathways are utilized for the synthesis of isopentenyl diphosphate (IPP), the universal precursor for isoprenoid biosynthesis. In this paper we review findings and observations made primarily with tobacco BY‐2 cells (TBY‐2), which have proven to be an excellent system in which to study the two biosynthetic pathways. A major advantage of these cells as an experimental system is their ability to readily take up specific inhibitors and stably‐ and/or radiolabeled precursors. This permits the functional elucidation of the role of isoprenoid end products and intermediates. Because TBY‐2 cells undergo rapid cell division and can be synchronized within the cell cycle, they constitute a highly suitable test system for determination of those isoprenoids and intermediates that act as cell cycle inhibitors, thus giving an indication of which branches of the isoprenoid pathway are essential. Through chemical complementation, and use of precursors, intracellular compartmentation can be elucidated, as well as the extent to which the plastidial and cytoslic pathways contribute to the syntheses of specific groups of isoprenoids (e.g., sterols) via exchange of intermediates across membranes. These topics are discussed in the context of the pertinent literature.
Sterol metabolism in the opportunistic pathogen Pneumocystis: Advances and new insights
Authors: Kaneshiro Edna S. 
Published: January 2018

AbstractPneumocystis can transiently colonize healthy individuals without causing adverse symptoms, and most people test positive for exposure to this organism early in life. However, it can cause Pneumocystis pneumonia (PcP) in people with impaired immune systems and is a major cause of death in HIV/AIDS. Although it has close affinities to the Ascomycetes, Pneumocystis has features unlike those of any single group of fungi. For example, Pneumocystis does not synthesize ergosterol, which is consistent with the inefficacy of amphotericin B and some triazoles in clearing PcP. Pneumocystis sterols include distinct Δ7 24‐alkylsterols. Metabolic radiolabeling experiments demonstrated that P. carinii synthesizes sterols de novo. Cholesterol is the most abundant sterol in Pneumocystis; most, if not all, is scavenged from the mammalian host lung by the pathogen. The P. carinii erg7, erg6, and erg11 genes have been cloned, sequenced, and expressed in heterologous systems. The recombinant P. carinii S‐adenosyl‐l‐methionine:C‐24 sterol methyl transferase (SAM:SMT) has a preference for lanosterol over zymosterol as substrate, and the enzyme can catalyze the transfer of either one or two methyl groups to the C‐24 position of the sterol side chain. Two different sterol compositions were detected among human‐derived P. jirovecii; one was dominated by C28 and C29 sterols, and the other had high proportions of higher molecular mass components, notably the C32 sterol pneumocysterol. The latter phenotype apparently represents organisms blocked at 14α‐demethylation of the sterol nucleus. These studies suggest that SAM:SMT is an attractive drug target for developing new chemotherapy for PcP.
Detailed sterol compositions of two pathogenic rust fungi
Authors: Giner José‐Luis , Zhao Hui 
Published: January 2018

AbstractTeliospores of cedar‐apple rust Gymnosporangium juniperi‐virginianae were collected from the eastern red cedar Juniperus virginiana, and aeciospores of quince rust G. clavipes were collected from the fruit of English hawthorn Crataegus laevigata. The sterol fractions were separated by HPLC, and their identities were determined by 600 MHz 1H NMR. Twenty‐six sterols were isolated from G. juniperi‐virginianae and 18 sterols were isolated from G. clavipes. The principal sterol of both fungi was (Z)‐stigmasta‐7,24(28)‐dien‐3β‐ol. Other major sterols were (24S)‐ergost‐7‐en‐3β‐ol, (24S)‐stigmast‐7‐en‐3β‐ol, and (24S)‐stigmasta‐5,7‐dien‐3β‐ol. The sterols of the hosts were found to be very different from those of the fungi. The 24‐alkyl sterols of the fungi had the 24α‐configuration, whereas those of the hosts had the 24β‐configuration. Similarities to the sterol composition of the AIDS pneumonia fungus Pneumocystis carinii are discussed.
Phospholipase D‐catalyzed synthesis of novel phospholipid‐phytosterol conjugates
Authors: Hossen Monjur , Hernandez Ernesto 
Published: January 2018

AbstractIn the present study, plant sterols were modified to form amphiphiles by synthesizing phospholipid derivatives from them so they could be formulated in different functional foods and possibly improve their effects as therapeutic agents. The new phosphatidyl derivatives, phosphatidyl‐sitosterols, were synthesized by the transfer reaction of a phosphatidyl residue from PC to β‐sitosterol by phospholipase D (PLD EC 3.1.4.4) from Streptomyces sp. in a biphasic medium.
Review of chemical syntheses of 7‐keto‐Δ5‐sterols
Authors: Parish Edward J. , Kizito Stephen A. , Qiu Zhihai 
Published: January 2018

AbstractSteroids bearing ketone functionality at carbon‐7 are found commonly in nature, and the most prevalent of these are the 7‐keto‐Δ5‐sterols. These substances have diverse biological properties and are present in biological samples and food products. For the purpose of studying this class of oxysterols, many chemical methods, involving the chemical oxidation of Δ5‐sterols to the corresponding 7‐keto‐Δ5‐sterols derivatives have been developed to produce these compounds. We have undertaken a review and evaluation of chemical methods for the synthesis of these compounds and have endeavored to enhance one of these procedures to yield products for chemical and biological investigations.
Chemical and physical characteristics of cocoa butter substitutes, milk fat and malaysian cocoa butter blends
Authors: Sabariah S. , Md. Ali A. R. , Chong C. L. 
Published: January 2018

AbstractTwo ternary systems of confectionery fats were studied. In the first system, lauric cocoa butter substitutes (CBS), anhydrous milk fat (AMF), and Malaysian cocoa butter (MCB) were blended. In the second system, high‐melting fraction of milk fat (HMF42) was used to replace AMF and also was blended with CBS and MCB. CBS contained high concentrations of lauric (C12:0) and myristic (C14:0) acids, whereas palmitic (C16:0), stearic (C18:0), and oleic (C18:1) acid concentrations were higher in MCB. In addition, AMF and HMF42 contained appreciable amounts of short‐chain fatty acids. CBS showed the highest melting enthalpy (143.1 J/g), followed by MCB (138.8 J/g), HMF42 (97.1 J/g), and AMF (72.9 J/g). The partial melting enthalpies at 20 and 30°C demonstrated formation of a eutectic along the binary blends of CBS/MCB, AMF/MCB, and HMF42/MCB. However, no eutectic effect was observed along the binary lines of AMF/CBS and HMF42/CBS. Characteristics of CBS included two strong spacings at 4.20 and 3.8 Å. MCB showed a strong spacing at 4.60 Å and a weak short‐spacing at 4.20 Å. On the other hand, AMF exhibited a very weak short‐spacing at 4.60 Å and two strong spacings at 4.20 and 3.8 Å, while HMF42 showed an intermediate short‐spacing at 4.60 Å and also two strong short‐spacings at 4.20 and 3.8 Å. Solid fat content (SFC) analyses at 20°C showed that CBS possessed the highest solid fat (91%), followed by MCB (82.4%), HMF42 (41.4%), and AMF (15.6%). However, at 30°C, MCB showed the highest SFC compared to the other fats. Results showed that a higher SFC in blends that contain HMF does not necessarily correlate with a stronger tendency to form the β polymorph.
13C nuclear magnetic resonance characterization of the reaction products of lamb pregastric lipase‐catalyzed hydrolysis of tributyrylglycerol
Authors: Barton Richard H. , O’Connor Charmian J. 
Published: January 2018

AbstractLamb pregastric lipase (LPGL), extracted from the tongue root and epiglottis of suckling lamb, has been used to catalyze the hydrolysis of emulsified tributyrylglycerol. Reactions were generally carried out at 35°C and initial pH 7.0. The speciation of the products of the reaction has been examined by 13C nuclear magnetic resonance spectroscopy. Varying rates of reaction were produced by increasing the amount of enzyme added relative to the amount of lipid. A system rate parameter, ΔpH/Δt, which is the change in pH (ΔpH) from time zero to the time when the sample was removed (Δt), has been developed. 1,2(2,3)‐Dibutyrylglycerol and 2‐monobutyrylglycerol have been identified as products of LPGL‐catalyzed hydrolysis, while 1,3‐dibutyrylglycerol and 1(3)‐monobutyrylglycerol are products of uncatalyzed acyl transfer reactions.
A comparison of mid‐infrared and raman spectroscopies for the authentication of edible oils
Authors: Marigheto N. A. , Kemsley E. K. , Defernez M. , Wilson R. H. 
Published: January 2018

AbstractRobust, routine, and rapid instrumental methods for the determination of the authenticity of edible oils, and the detection of adulteration, are continually being sought. In this paper, we compare mid‐infrared and Raman spectroscopies for their ability to discriminate between oils of differing botanical origin and for their ability to detect added adulterants. Furthermore, we used sufficient numbers of samples to permit a comparison of some of the chemometric methods (linear discriminant analysis, artificial neural networks) available and looked at the results obtained when the two spectroscopic datasets were combined. We show that mid‐infrared spectroscopy, in combination with linear discriminant analysis, gave the best classification rates and adulteration detection levels compared to Raman or combined data.
Precombustion of fatty acids and esters of biodiesel. A possible explanation for differing cetane numbers
Authors: Knothe Gerhard , Bagby Marvin O. , Ryan Thomas W. 
Published: January 2018

AbstractFatty acids of C18 chainlength as well as their methyl, ethyl, n‐propyl, and n‐butyl esters were injected into a constant‐volume combustion apparatus suitable for collecting material from the fuel spray prior to the onset of ignition. The collected material from this precombustion phase of the injection event was analyzed by gas chromatography‐mass spectrometry. Compounds identified as forming during the precombustion phase were straight‐chain and branched alkanes, alkenes, and cyclic hydrocarbons, as well as aldehydes, ketones, esters, substituted benzenes, and other species, such as furans. Some of the compounds formed during precombustion have low cetane numbers (CN). Low‐cetane aromatic compounds were found more prominently for more unsaturated fatty compounds. Thus, the low CN of the intermediary precombustion species may constitute a possible partial explanation why some compounds, for example the more unsaturated fatty compounds, have relatively low CN.
Fat content and fatty acid composition of oils extracted from selected wild‐gathered tropical plant seeds from Nigeria
Authors: Ezeagu Ikechukwu E. , Petzke Klaus J. , Lange Erika , Metges Cornelia C. 
Published: January 2018

AbstractAs the search for alternative sources of food to alleviate hunger continues, this study was undertaken to determine the fat content and the fatty acid composition of 15 lesser‐known wild tropical seeds gathered in Nigeria. Results were contrasted with five tropical soybean varieties (Glycine max). The fat content varies from less than 1% (Pterocarpus santalinoides, Daniellia ogea) to 59% (Entandrophragma angolense). The fatty acid composition of most of the wild and mostly leguminous seeds differed considerably, compared to the composition of tropical soybeans. The oil of Adansonia digitata, Prosopis africana, Afzelia lebbeck, Enterolobium cyclocarpium, and Sesbania pachycarpa contained high proportions of linoleic and oleic acid as well as palmitic and linolenic acid. Seeds of Milletia thonningii, Lonchocarpus sericeus, and S. pachycarpa were much higher in linolenic acid and relatively poor in linoleic acid, compared to soybeans. The content of saturated fatty acids was higher than that of soybeans, resulting in lower polyunsaturated/saturated (P/S) ratios (0.83–2.12) than observed in soybeans (P/S=3.4), with the exception of the composition of S. pachycarpa (P/S=3.15). Some of these less familiar wild seeds could be used as sources for industrial or edible oils, provided that possible toxic constituents could be removed.
Characterization of chilean hazelnut (Gevuina avellana mol) seed oil
Authors: Bertoli C. , Fay L. B. , Stancanelli M. , Gumy D. , Lambelet P. 
Published: January 2018

AbstractThe fatty acid composition, tocopherol and tocotrienol content, and oxidative stability of petroleum benzene‐extracted Gevuina avellana Mol (Proteaceae) seed oil were determined. Positional isomers of monounsaturated fatty acids were elucidated by gas chromatography‐electron impact mass spectrometry after 2‐alkenyl‐4,4‐dimethyloxazoline derivatization. This stable oil (Rancimat induction period at 110°C: 20 h) is composed of more than 85% monounsaturated fatty acids and about equal amounts (6%) of saturated and polyunsaturated (principally linoleic) fatty acids. Unusual positional isomers of monounsaturated fatty acids, i.e., C16:1 Δ11, C18:1 Δ12, C20:1 Δ11, C20:1 Δ15, C22:1 Δ17, and presumably C22:1 Δ19 were identified. The C18:1 Δ12 and C22:1 Δ19 fatty acids are described for the first time in G. avellana seed oil. While only minute quantities of α‐, γ‐tocopherols and β‐, γ‐ and δ‐tocotrienols were found, the oil contained a substantial amount of α‐tocotrienol (130 mg/kg). The potential nutritional value of G. avellana seed oil is discussed on the basis of its composition.
Effect of mustard meal on the production of arachidonic acid by Mortierella elongata SC‐208
Authors: Chaudhuri S. , Ghosh S. , Bhattacharyya D. K. , Bandyopadhyay S. 
Published: January 2018

AbstractA strain of Mortierella elongata SC‐208 that was isolated from soil of a mustardseed extraction plant can produce arachidonic acid in significant amounts, and it was grown in three different media, one of which contained 0.5% deoiled mustard meal. The arachidonic acid content in the lipid part of dry mycelium (23.2 g/L) was as high as 33% w/w from the medium that contained mustard meal, and the overall yield of arachidonic acid was 0.49 g/L. The arachidonic acid contents in the phospholipid fraction and the triglyceride fraction were 39.5 and 30.2%, respectively.
Lipolytic synthesis of optically active 1,2‐dibutyryl‐sn‐glycerol. Identification of diglyceride by solvent‐dependent specific rotation
Authors: O’Connor Charmian J. , Lai Douglas T. , Barton Richard H. 
Published: January 2018

AbstractThe objective was to determine whether the initial pregastric lipase catalyzed hydrolysis of a triacylglycerol to 1,2(2,3)‐diacylglycerol was a consequence of sn‐specific hydrolysis. The identity of the reaction products for the enzyme‐assisted hydrolysis and uncatalyzed acyl‐transfer reaction sequence of tributyrylglycerol was assigned by 13C nuclear magnetic resonance. The optical activity of the product 1,2‐dibutyryl‐sn‐glycerol (yield >50%, pH 6.5, 35°C, 13 min) was solvent dependent, being −2.92° (c ∼1.3, CHCl3) and +3.32° (c ∼1.2, pyridine), and confirmation of sn‐3 specificity by pregastric lipase was obtained.
Enzymatic incorporation of docosahexaenoic acid into borage oil
Authors: Namal Senanayake S. P. J. , Shahidi Fereidoon 
Published: January 2018

AbstractLipase‐catalyzed acidolysis of acylglycerols of borage (Borago officinalis L.) oil with a docosahexaenoic acid (DHA) concentrate, prepared from algal oil, in organic solvents was studied. Seven lipases were used as biocatalysts for the acidolysis reaction. Novozyme 435 from Candida antarctica, as compared to lipases from Mucor miehei and Pseudomonas sp., showed the highest degree of DHA incorporation into borage oil. Other lipases tested, such as those from Aspergillus niger, C. rugosa, Thermomyces lanuginousus and Achromobacter lunatus, were rather ineffective in the incorporation of DHA into borage oil. Effects of variation of reaction parameters, namely, enzyme load, temperature, time course, and type of solvent, were monitored for C. antarctica as the biocatalyst of choice. Incorporation of DHA increased with increasing amount of enzyme, reaching 27.4% at an enzyme concentration of 150 lipase activity units. As incubation time progressed, DHA incorporation also increased. After a reaction time of 24 h, the contents of total n‐6 and n‐3 polyunsaturated fatty acids in acylglycerols were 44.0 and 27.6%, respectively. The highest degree of DHA incorporation was achieved when hexane was used as the reaction medium. The positional distribution of DHA in modified borage oil was determined using pancreatic lipase hydrolysis. Results showed that DHA was randomly distributed over the sn‐1, sn‐2, and sn‐3 positions of the triacylglycerol. Thus, preparation of modified borage oil acylglycerols containing both DHA (22:6n‐3; 27.4%) and γ‐linolenic acid (18:3n‐6; 17.0%) was successfully achieved and products so obtained may have beneficial effects beyond simple physical mixtures of the two oils. The final oil had a ratio of n‐3 to n‐6 of 0.42–0.62 which is nutritionally more suitable than the original unaltered borage oil.
Bioconversion of oleic acid by Bacillus strain NRRL BD‐447: Identification of 7‐hydroxy‐17‐oxo‐9‐cis‐octadecenoic acid
Authors: Lanser A. C. , Manthey L. K. 
Published: January 2018

AbstractContinuing efforts to isolate and assign structures to the products from the bioconversion of oleic acid with Bacillus strain NRRL‐447 have resulted in identification of a positional isomer of the hydroxy‐keto fatty acid previously reported. After high‐performance liquid chromatographic isolation, the new compound was identified by gas chromatography‐mass spectrometry and nuclear magnetic resonance analyses to be 7‐hydroxy‐17‐oxo‐9‐cis‐octadecenoic acid.
Quantitative differential scanning calorimetric analysis for determining total polar compounds in heated oils
Authors: Tan C. P. , Che Man Y. B. 
Published: January 2018

AbstractA new differential scanning calorimetry (DSC) method was developed for the determination of total polar compounds (TPC) in heated oils. Three different types of edible oils, refined, bleached, and deodorized corn oil (CO), palm olein (RBDPO), and soybean oil (SO), were used in this study, Each type of edible oil was heated at 180°C in a deep fryer to obtain a range of TPC concentrations. In this study, the cooling thermograms of oil samples at a scanning rate of 1°C/min from −30 to −85°C showed a well‐defined single crystallization peak. The study found that six DSC parameters, namely, peak temperature (PT), enthalpy (EN), onset (ON) and offset (OF) temperatures, peak height (HT), and the range of temperatures (RT) (the difference between onset and offset temperature) of this single crystallization peak could predict well the TPC of heated oils by using stepwise multiple linear regression analysis. These six parameters were used as independent variables while values from standard method were used as dependent variables. The coefficient of determination (R2) of calibration models for CO, RBDPO, and SO were 0.9996, 0.9709, and 0.9980, respectively. Calibration models were validated with an independent set of samples. The R2 of validation models were 0.9995, 0.9559, and 0.9961, respectively. Based on the results obtained, DSC appears to be useful instrumental method in determining the TPC of edible oils, and it may have the potential to replace the time‐ and chemical‐consuming standard method.
Microwave roasting and molecular species of triacylglycerols in soybean embryonic axes
Authors: Yoshida Hiromi , Takagi Sachiko 
Published: January 2018

AbstractEmbryonic axes were separated from soybeans roasted in a microwave oven. Molecular species and fatty acid distributions of triacylglycerols (TAG) isolated from total lipids in the embryonic axis were analyzed by a combination of argentation thin‐layer chromatography (TLC) and gas‐liquid chromatography. A modified argentation‐TLC procedure, developed to optimize the separation of the complex mixture of total TAG, provided 15 different groups of TAG, based on both the degree of unsaturation and the total length of fatty acid groups. Fatty acid methyl ester analysis was performed to determine the composition of each band. Fifteen molecular species of TAG were still found in the embryonic axes following roasting treatment. Microwave roasting for 6 min did not change the molecular species of the embryonic axis TAG (with a few exceptions), nor cause a loss of unsaturated fatty acids. However, microwave roasting for 12 min caused a significant decrease (P<0.05) not only in molecular species containing more than four double bonds but also in the amount of diene and triene species present in TAG. These results suggest that no significant changes in molecular species or fatty acid distribution of TAG would occur within 6 min of microwave roasting, ensuring that a good quality product would be attained.
A twin‐screw extruder for oil extraction: II. Alcohol extraction of oleic sunflower seeds
Authors: Dufaure Corinne , Mouloungui Zéphirin , Rigal Luc 
Published: January 2018

AbstractOur work is about the extraction of sunflower seed oil in a twin‐screw extruder with or without the injection of 2‐ethylhexanol and acidified 2‐ethylhexanol. 2‐Ethylhexanol is mixed with phosphoric acid. The oil recovery is increased to 90% by the co‐injection of acidified alcohol. Mixing phosphoric acid with the alcohol enhances the lability of the oily spherosomes. Its addition increases the destruction of the membranes enveloping the lipid‐containing organelles to release the oil more easily. Phosphoric acid exhibits an extracting and a degumming role. The best oil quality was obtained at a low extraction temperature (80°C), when 88% of the oil was removed. After alcoholic distillation, the oil exhibited a total acid value (mineral acidity plus organic acidity) of 4 mg KOH/g of oil and an organic phosphorus content below 30 ppm.
Mechanical and physical properties of protein‐starch based plastics produced by extrusion and injection molding
Authors: Huang H. C. , Chang T. C. , Jane J. 
Published: January 2018

AbstractProcessing conditions, ingredient ratio, and moisture content were optimized for making soy protein/starch based plastics using a twin‐screw extruder and an injection molding machine. A metering pump and a high speed mixer were used for ingredient mixing. The optimal processing temperature for injection molding was 130°C, and the moisture content of extruded pellets was 10–14%. Processing effects were investigated by measuring the tensile properties and water resistance of specimens. Reduction of water and glycerol in mixtures increased the barrel pressure of the extruder. Mold release was improved by incorporating 0.25 parts tallow per 100 parts of solid material (soy protein and starch). The water absorption of the specimens was reduced by adding acids to adjust the pH to the isoelectric point of soy proteins (pH 4.5). Effects of storage at different relative humidities were studied. The processibility of pellets was stable after a 4‐wk‐storage period, despite some moisture loss. Injection‐molded specimens, after being stored for up to 6 mon at dry conditions [50 and 11% relative humidity (RH)] at room temperature and for 4 wk in a 50°C oven, showed no surface crack. However, humid (93% RH) storage at room temperature promoted fungal growth after storage for 3 mon, indicating that preservatives such as potassium sorbate and propionic acid were needed.