bluuebunny/crossref_metadata_2025 huggingface dataset:
Metabolic Study of Dioecy in Mauritia flexuosa: NMR‐based and Chemometric Approaches
Authors: dos Santos Freitas Deisy , Alcantara Glaucia Braz
Published: January 2018

Introduction

Mauritia flexuosa is a dioecious species native to the Amazon, and the gender identification can currently be determined through the differentiation between female and male flowers in the first flowering.

Objectives

To identify variations in the metabolome profiles of pooled and individual samples of leaves from female and male plants of M. flexuosa in reproductive phase, and the plant in its vegetative phase, using two extraction systems.

Material and Methods

Extractions of leaves were separately conducted using deuterated water and methanol. The extracts were evaluated by NMR spectroscopy and chemometric methods.

Results

Different NMR spectroscopic profiles were observed for females, males, and plants in the vegetative phase. Significant variations were found in the carbohydrate and fatty acid contents for the aqueous and methanolic extracts, respectively. Although principal component analysis (PCA) has not been efficient to distinguish the genders, orthogonal signal correction/partial least squares‐discriminant analysis (OPLS‐DA) was able to successfully differentiate male and female plants in the reproductive phase, independently on the sampling approach. For plants in the vegetative phase, OPLS‐DA method from aqueous extracts of M. flexuosa leaves also distinguished female samples from the others and showed a small overlap between male and young plants, while the classification model was not able to be used for prediction.

Conclusions

NMR spectroscopy and chemometric‐based approach was demonstrated to be useful in the metabolic study of dioecy in M. flexuosa. The extracts of the leaves allowed for differentiation between male and female plants; however, for plants in the vegetative phase, the identification of the gender was not effective. Copyright © 2018 John Wiley & Sons, Ltd.
Halogen‐free flame retarded rigid polyurethane foam: The influence of titanium dioxide modified expandable graphite and ammonium polyphosphate on flame retardancy and thermal stability
Authors: Pang Xiu‐Yan , Chang Ran , Weng Meng‐Qi
Published: January 2018

A titanium dioxide modified expendable graphite (EGT) was prepared and characterized. The synergistic effect between EGT and ammonium polyphosphate (APP) on the combustion characteristics and thermal stability of rigid polyurethane foam (RPUF) were investigated through limiting oxygen index (LOI), vertical‐combustion, microscale combustion calorimeter tests, and thermogravimetric/differential thermal gravimetric (TG/DTG) analysis. Results showed that EGT modified RPUF presented better thermal stability and flame retardancy than the normal expandable graphite (EG) modified RPUF. Addition of EGT improved the LOI value of 80RPUF/20EGT from 19.0% to 26.9%. Furthermore, the combination of EGT and APP caused the 80RPUF/10APP/10EGT to exhibit a LOI value of 27.8%, a vertical burning level of V‐0 and a total heat release of 16.5 kJ g−1. The research gave a body of evidence for synergistic performance between EGT and APP, and the effect of condensed phase mechanism was believed to be the main reason for such synergistic effect. POLYM. ENG. SCI., 58:2008–2018, 2018. © 2018 Society of Plastics Engineers
Assembly of Nanoconjugates as New Kind Inhibitor of the Aggregation of Amyloid Peptides Associated with Alzheimer's Disease
Authors: Li Chao , Lu Jianyang , Hu Xiaolu , Feng Chang , Xiang Yang , Karamanos Yannis , Li Genxi
Published: January 2018

The inhibition of amyloid‐β (Aβ) aggregation has been regarded as the primary therapeutic strategy for Alzheimer's diseases (AD). Currently, many kinds of amyloid inhibitors have been explored, but these inhibitors have their own drawbacks. This study proposes and demonstrates a new kind of inhibitor in this work by making use of protease endowed with high selectivity to prevent Aβ aggregation. To do this, a nanoconjugate that is composed of chymotrypsin, Aβ aptamer, and gold nanoparticle is designed and fabricated. The nanoconjugate can actively capture Aβ through interaction between the aptamer and Aβ, and destroy the target peptides through proteolysis mediated by the adjacent protease molecules. Compared with the conventional inhibitors that only passively bind with Aβ, this new kind of inhibitor may provide a novel insight to control Aβ aggregation. The multivalent binding and efficient enzymatic reaction toward Aβ may also enable a more complete clearance of Aβ, which might achieve a better treatment effect for AD in the future.
Neonatal swallowing assessment using fiberoptic endoscopic evaluation of swallowing (FEES)
Authors: Vetter‐Laracy Susanne , Osona Borja , Roca Antonia , Peña‐Zarza Jose A. , Gil Jose A. , Figuerola Joan
Published: January 2018

Objectives

Swallowing disorders which lead to aspiration are common in premature infants with a postmenstrual age (PMA) of >36 weeks. Aspiration is often silent and the unique symptom is desaturation during feeding. The aim of this study was 1) to determine the number of prematures with desaturations during feeding due to aspiration, using Fiberoptic Endoscopic Evaluation of Swallowing (FEES); 2) to relate clinical factors and FEES findings to aspiration; and 3) to describe type and efficacy of suggested treatments.

Methods

A retrospective review of 62 ex‐premature babies with a median PMA of 40 weeks which underwent FEES due to persistent feeding desaturations. Aspiration was related to other FEES findings and to clinical and demographic data. The efficacy of the treatment was evaluated during the FEES and by comparing recorded desaturations during feeding 7 days before and after FEES.

Results

A total of 44 (71%) infants were diagnosed with aspiration and/or penetration. No relation was found to demographic or clinical data. The accumulation of saliva and residues post‐swallowing were related to aspiration (P < 0.01). In 77.3% of the infants, use of a thickener seemed to reduce aspiration during FEES and was suggested as a treatment. 13.6% of infants received anti‐reflux treatment after FEES and 9.1% required gastrostomy.

Conclusions

Aspiration is very frequent in premature infants who present desaturations during feeding and FEES is a useful method for diagnosing and suggesting treatments.
Genetic risk of prostate cancer in Ugandan men
Authors: Du Zhaohui , Lubmawa Alexander , Gundell Susan , Wan Peggy , Nalukenge Cissy , Muwanga Proscovia , Lutalo Moses , Nansereko Deborah , Ndaruhutse Olivia , Katuku Molly , Nassanga Rosemary ,   African Ancestry Prostate Cancer Consortium (AAPC), Asiimwe Frank , Masaba Benon , Kaggwa Sam , Namuguzi Dan , Kiddu Vicky , Mutema George , Conti David V. , Luke Asiimwe , Job Kuteesa , Henry Dabanja M. , Haiman Christopher A. , Watya Stephen
Published: January 2018

Background

Men of African‐ancestry have elevated prostate cancer (PCa) incidence and mortality compared to men of other racial groups. There is support for a genetic contribution to this disparity, with evidence of genetic heterogeneity in the underlying risk alleles between populations. Studies of PCa among African men may inform the contribution of genetic risk factors to the elevated disease burden in this population.

Methods

We conducted an association study of >100 previously reported PCa risk alleles among 571 incidence cases and 485 controls among Uganda men. Unconditional logistic regression was used to test genetic associations and a polygenic risk score (PRS) was derived to assess the cumulative effect of the known risk alleles in association with PCa risk. In an exploratory analysis, we also tested associations of 17 125 421 genotyped and imputed markers genome‐wide in association with PCa risk.

Results

Of the 111 known risk loci with a frequency >1%, 75 (68%) had effects that were directionally consistent with the initial discovery population,14 (13%) of which were nominally significantly associated with PCa risk at P < 0.05. Compared to men with average risk (25th‐75th percentile in PRS distribution), Ugandan men in the top 10% of the PRS, constructed of alleles outside of 8q24, had a 2.9‐fold (95%CI: 1.75, 4.97) risk of developing PCa; risk for the top 10% increased to 4.86 (95%CI: 2.70, 8.76) with the inclusion of risk alleles at 8q24. In genome‐wide association testing, the strongest associations were noted with known risk alleles located in the 8q24 region, including rs72725854 (OR = 3.37, P = 2.14 × 10−11) that is limited to populations of African ancestry (6% frequency).

Conclusions

The ∼100 known PCa risk variants were shown to effectively stratify PCa risk in Ugandan men, with 10% of men having a >4‐fold increase in risk. The 8q24 risk region was also found to be a major contributor to PCa risk in Ugandan men, with the African ancestry‐specific risk variant rs72725854 estimated to account for 12% of PCa in this population.
A case of erectile dysfunction induced by red yeast rice in lipid‐lowering therapy
Authors: Liu Zhigang , Chen Peijie
Published: January 2018

This paper studies a 39‐year‐old male patient who takes red yeast rice (RYR) for self‐therapy in lipid‐lowering for 3 weeks. Results show that RYR can decrease most of the blood lipid components but without selectivity. During the treatment, the patient developed erectile dysfunction (ED) and accompanied by a dramatic decrease in sexual desire. The ED symptom gradually disappeared within 5 weeks after stopping RYR intake.
Emerging Novel Metal Electrodes for Photovoltaic Applications
Authors: Lu Haifei , Ren Xingang , Ouyang Dan , Choy Wallace C. H.
Published: January 2018

Emerging novel metal electrodes not only serve as the collector of free charge carriers, but also function as light trapping designs in photovoltaics. As a potential alternative to commercial indium tin oxide, transparent electrodes composed of metal nanowire, metal mesh, and ultrathin metal film are intensively investigated and developed for achieving high optical transmittance and electrical conductivity. Moreover, light trapping designs via patterning of the back thick metal electrode into different nanostructures, which can deliver a considerable efficiency improvement of photovoltaic devices, contribute by the plasmon‐enhanced light–mattering interactions. Therefore, here the recent works of metal‐based transparent electrodes and patterned back electrodes in photovoltaics are reviewed, which may push the future development of this exciting field.
Functional Differentiation of Three Pores for Effective Sulfur Confinement in Li–S Battery
Authors: Wang Qian , Yang Minghui , Wang Zhen‐Bo , Li Chao , Gu Da‐Ming
Published: January 2018

Shuttle effect of the dissolved intermediates is regarded as the primary cause that leads to fast capacity degradation of Li–S battery. Herein, a microporous carbon‐coated sulfur composite with novel rambutan shape (R‐S@MPC) is synthesized from microporous carbon‐coated rambutan‐like zinc sulfide (R‐ZnS@MPC), via an in situ oxidation process. The R‐ZnS is employed as both template and sulfur precursor. The carbon frame of R‐S@MPC composite possesses three kinds of pores that are distinctly separated from each other in space and are endowed with the exclusive functions. The central macropore serves as buffer pool to accommodate the dissolved lithium polysulfides (LPSs) and volumetric variation during cycling. The marginal straight‐through mesoporous, connected with the central macropore, takes the responsibility of sulfur storage. The micropores, evenly distributed in the outer carbon shell of the as‐synthesized R‐S@MPC, enable the blockage of LPSs. These pores are expected to perform their respective single function, and collaborate synergistically to suppress the sulfur loss. Therefore, it delivers an outstanding cycling stability, decay rate of 0.013% cycle−1 after 500 cycles at 1 C, when the sulfur loading is kept at 4 mg cm−2.
A hybrid approach for aspect‐oriented business process modeling
Authors: Jalali Amin , Maggi Fabrizio Maria , Reijers Hajo A.
Published: January 2018

Separation of concerns has long been an important strategy to deal with complexity when developing a system. Some concerns (like security) are scattered through the whole system, and different modules are tangled to such concerns. These concerns are known as cross‐cutting concerns. When the system in question is a business process, cross‐cutting concerns are aimed at being encapsulated by Aspect‐Oriented Business Process Modeling. However, the state‐of‐the‐art techniques in this field lack efficient mechanisms that (1) support composition of cross‐cutting concerns that can be defined in parallel to (a part of) a process model and (2) enable specifying both mandatory and optional cross‐cutting concerns. To address these limitations, this paper proposes a new Aspect‐Oriented Business Process Modeling approach. The approach is hybrid since it is based on declarative rules to relate imperative cross‐cutting concerns and imperative business process models. The approach is explained, formally grounded with precise semantics, and used accordingly to implement the artifacts that support modeling and enactment of business processes in the proposed fashion as a proof of concept. In addition, the approach is evaluated on the basis of the Technology Acceptance Model during a workshop session. The result shows that participants perceived the approach usable and easy to use.
Crocin improved amyloid beta induced long‐term potentiation and memory deficits in the hippocampal CA1 neurons in freely moving rats
Authors: Hadipour Mohammadmehdi , Kaka Gholamreza , Bahrami Farideh , Meftahi Gholam Hossein , Pirzad Jahromi Gila , Mohammadi Alireza , Sahraei Hedayat
Published: January 2018

Extracellular beta‐amyloid (Aβ) accumulation and deposition is the main factor, which causes synaptic loss and eventually cells death in Alzheimer's disease (AD). Memory loss and long‐term potentiation (LTP) dysfunction in the hippocampus are involved in the AD. The involvement of crocin, as the main and active constituent of saffron extract in learning and memory processes, has been proposed. Here we investigated the probable therapeutic effect of crocin on memory, LTP, and neuronal apoptosis using in vivo Aβ models of the AD. The Aβ peptide (1–42) was bilaterally administered into the frontal‐cortex using stereotaxic apparatus. Five hours after surgery, rats were given intraperitoneal crocin (30 mg/kg) daily, which repeated for 12 days. Barnes maze results showed that administration of crocin significantly improves spatial memory indicators such as latency time to achieving the target hole and the number of errors when compared to Aβ‐group. Passive avoidance test revealed that crocin significantly increased the step‐through‐latency compared to Aβ‐treated alone. These learning deficits in Aβ‐treated animals correlated with a reduction of LTP in hippocampal CA1 synapses in freely moving rats, which crocin improved population spike amplitude and mean field excitatory postsynaptic potentials (fEPSP) slope reduction induced by Aβ. Neuronal apoptosis was detected by TUNEL assay and the expression levels of c‐Fos proteins were examined by Western blotting. Crocin significantly reduced the number of TUNEL‐positive cells in the CA1 region and decreased c‐Fos in the hippocampus compared to Aβ‐group. In vivo Aβ treatment altered significantly the electrophysiological properties of CA1 neurons and crocin further confirmed a neuroprotective action against Aβ toxicity.
Novel design for heart rate detection using UWB impulse radar on Android platform
Authors: Cho Hui‐Sup , Park Young‐Jin
Published: January 2018

Measuring the physiological functions of the human body in a noncontact manner is useful for healthcare, security, and surveillance. Radar technology can be used for this purpose. In this paper, a new real‐time method for the Android platform is proposed to detect the human heart rate using ultra‐wideband impulse radar. The amplitude spectra of the radar pulse reflected from the human body are accumulated at specific time intervals, and the heartbeat frequency is obtained by applying the fast Fourier transform algorithm. The method offers real‐time heartbeat detection with high frequency resolution in the frequency band of the heartbeat of interest. Experimental results further verify that the heart rate variability can be observed using this method. © 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Syntheses, Crystal Structures, and Optical Properties of the Hexagonal Perovskites Variants ABX3 (B = Ni, A = Gu, FA, MA, X = Cl, Br; B = Mn, A = MA, X = Br)
Authors: Daub Michael , Ketterer Ines , Hillebrecht Harald
Published: January 2018

Herein we report on our systematic investigations on the solution processed synthesis and characterization of transition metal halides (guanidinium, formamidinium, and methylammonium nickel bromides and chlorides as well as methylammonium manganese bromide) with the composition ABX3 (A = organic cation; B = Mn, Ni; X = Cl, Br). The investigations were carried out with respect to possible applications of 3d transition metal compounds for the perovskite solar cell. All the compounds represent different variants of the hexagonal perovskite structure (2H). Crystal structures and symmetry relations are discussed. Additionally, (CH3NH3)2MnI4, which consists of tetrahedral coordinated Mn2+, and the water containing compounds (CH3NH3)MnBr3·2H2O, which forms chains of edge sharing octahedra, as well as (CH3NH3)NiCl3·2H2O, which consists of dimers of octahedra, are presented. Investigations on the crystal structures are supported by vibrational and optical spectroscopy.
Three Phenoxo‐Bridged Dinuclear Lanthanide Complexes: Syntheses, Crystal Structures, and Magnetic Properties
Authors: Zhang Zhi‐Chao , Dai Rui‐Peng , Dong Hui‐Ming , Zhao Xiao‐Jun , Yang En‐Cui
Published: January 2018

Three dinuclear lanthanide complexes [Ln2(H2L)2(NO3)4] [Ln = Dy (1), Tb (2), and Gd (3)] [H3L = 2‐hydroxyimino‐N′‐[(2‐hydroxy‐3‐methoxyphenyl)methylidene]‐propanohydrazone] were solvothermally synthesized by varying differently anisotropic rare earth ions. Single‐crystal structural analyses demonstrate that all the three complexes are crystallographically isostructural with two centrosymmetric LnIII ions aggregated by a pair of monodeprotonated H2L– anions. Weak intramolecular antiferromagnetic interactions with different strength were mediated by a pair of phenoxo bridges due to superexchange and/or single‐ion anisotropy. Additionally, the DyIII‐based entity shows the strongest anisotropy exhibits field‐induced single‐molecule magnetic behavior with two thermally activated relaxation processes. In contrast, 3 with isotropic GdIII ion has a significant cryogenic magnetocaloric effect with the maximum entropy change of 25.7 J·kg–1·K–1 at 2.0 K and 70.0 kOe.
Phospholipids and oxophospholipids in atherosclerotic plaques at different stages of plaque development
Authors: Ravandi Amir , Babaei Saeid , Leung Ramsey , Monge Juan Carlos , Hoppe George , Hoff Henry , Kamido Hiroshi , Kuksis Arnis
Published: January 2018

We identified and quantified the hydroperoxides, hydroxides, epoxides, isoprostanes, and core aldehydes of the major phospholipids as the main components of the oxophospholipids (a total of 5–25 pmol/μmol phosphatidylcholine) in a comparative study of human atheroma from selected stages of lesion development. The developmental stages examined included fatty streak, fibrous plaque, necrotic core, and calcified tissue. The lipid analyses were performed by normal‐phase HPLC with on‐line electrospray MS using conventional total lipid extracts. There was great variability in the proportions of the various oxidation products and a lack of a general trend. Specifically, the early oxidation products (hydroperoxides and epoxides) of the glycerophosphocholines were found at the advanced stages of the plaques in nearly the same relative abundance as the more advanced oxidation products (core aldehydes and acids). The anticipated linear accumulation of the more stable oxidation products with progressive development of the atherosclerotic plaque was not apparent. It is therefore suggested that lipid infiltration and/or local peroxidation is a continuous process characterized by the formation and destruction of both early and advanced products of lipid oxidation at all times. The process of lipid deposition appears to have been subject to both enzymatic and chemical modification of the normal tissue lipids. Clearly, the appearance of new and disproportionate old lipid species excludes randomness in any accumulation of oxidized LDL lipids in atheroma.
Lactational changes in the fatty acid composition of human milk gangliosides
Authors: Martín‐Sosa Samuel , Martín María‐Jesús , Castro María‐Dolores , Cabezas José A. , Hueso Pablo
Published: January 2018

The objectives of this work were to study the FA composition of milk gangliosides, as well as to gain further insight into the characterization of human milk gangliosides. The potential capacity of human milk gangliosides to adhere to human enterotoxigenic Escherichia coli (ETEC‐strains) was also studied. Human milk gangliosides were isolated and identified by high‐performance TLC or immunoassay. The latter also was used to assay bacterial adhesion. The FA composition of gangliosides was studied by GC. The presence of O‐acetyl GD3 (Neu5,9Ac2α2–8 NeuAcα2–3Galβ1–4GlcCer) and trace amounts of GM1 [Galβ1–3GalNAcβ1,−3(NeuAcα2–3)Galβ1–4GlcCer] in human milk was confirmed. Medium‐chain FA were almost absent in colostrum, whereas in the subsequent stages they rose to 20%. The levels of long‐chain FA decreased after colostrum. With respect to the degree of saturation, gangliosides from colostrum were richer in monounsaturated FA than gangliosides synthesized during the rest of the lactation period, opposite to the pattern for PUFA. A human‐ETEC colonization factor antigen II‐expressing strain showed binding capacity to human milk GM3 (NeuAcα2–3Galβ1–4GlcCer). New data on human milk gangliosides have been gathered. A thorough knowledge of their composition is needed since they may have important biological implications in regard to newborns' defense against infection.
Contrasting effects of t10,c12‐ and c9,t11‐conjugated linoleic acid isomers on the fatty acid profiles of mouse liver lipids
Authors: Kelley D. S. , Bartolini G. L. , Warren J. M. , Simon V. A. , Mackey B. E. , Erickson K. L.
Published: January 2018

The purpose of this study was to examine the effects of two purified isomers of CLA (c9,t11‐CLA and t10,c12‐CLA) on the weights and FA compositions of hepatic TG, phospholipids, cholesterol esters, and FFA. Eight‐week‐old female mice (n=6/group) were fed either a control diet or diets supplemented with 0.5% c9,t11‐CLA or t10, c12‐CLA isomers for 8 wk. Weights of liver total lipids and those of individual lipid fractions. did not differ between the control and the c9,t11‐CLA groups. Livers from animals fed the t10,c12‐CLA diet contained four times more lipids than those of the control group; this was mainly due to an increase in the TG fractions (fivefold), but cholesterol (threefold), cholesterol esters (threefold), and FFA (twofold) were also significantly increased. Although c9,t11‐CLA did not significantly alter the weights of liver lipids when compared with the control group, its intake was associated with significant reductions in the weight percentage (wt% of total FAME) of 18∶1n−9 and 18∶1n−7 in the TG fraction and with significant increases in the weight percentage of 18∶2n−6 in the TG, cholesterol ester, and phospholipid fractions. on the other hand, t10,c12‐CLA intake was linked with a significant increase in the weight percentage of 18∶1n−9 and a decrease in that of 18∶2n−6 in all lipid fractions. These changes may be the result of alterations in the activity of Δ9‐desaturase (stearoyl CoA desaturase) and the enzymes involved in the metabolism of 18∶2n−6. Thus, the two isomers differed not only in their effects on the weights of total liver lipids and lipid fractions but also on the FA profile of the lipid fractions.
Modulation of hepG2 cell net apolipoprotein B secretion by the citrus polymethoxyflavone, tangeretin
Authors: Kurowska Elzbieta M. , Manthey John A. , Casaschi Adele , Theriault Andre G.
Published: January 2018

The purpose of the present study was to examine the role of tangeretin, a polymethoxylated flavone from citrus fruits, on the regulation of apolipoprotein B (apoB) and lipid metabolism in the human hepatoma cell‐line HepG2. The marked reduction in apoB secretion observed in cells incubated with 72.8 μM tangeretin was rapid, apoB‐specific, and partly reversible. The reduction also was observed under lipid‐rich conditions and found to be insensitive to proteasomal degradation of nascent apoB. We followed our study by examining lipid synthesis and mass. A 24‐h exposure of cells to 72.8 μM tangeretin decreased intracellular synthesis of cholesteryl esters, free cholesterol, and TAG by 82, 45, and 64%, respectively; tangeretin also reduced the mass of cellular TAG by 37%. The tangeretin‐induced suppression of TAG synthesis and mass were associated with decreased activities of DAG acyltransferase (up to‐39.0±3.0% vs. control) and microsomal triglyceride transfer protein (up to−35.5±2.5% vs. control). Tangeretin was also found to activate the peroxisome proliferator‐activated receptor, a transcription factor with a positive regulatory impact on FA oxidation and TAG availability (up to 36% increase vs. control). The data suggest that tangeretin modulates apoB‐containing lipoprotein metabolism through multiple mechanisms.
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

In 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

Pneumocystis 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

Teliospores 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

In 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

Steroids 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

Two 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

Lamb 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

Robust, 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

Fatty 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

As 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

The 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

A 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

The 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

Lipase‐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

Continuing 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

A 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

Embryonic 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

Our 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.