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1

Comparison of Growth Performance and Whole-body Amino Acid Composition in Red Seabream (Pagrus major) Fed Free or Dipeptide Form of Phenylalanine  

PubMed Central

This study was conducted to evaluate the efficacy of the dipeptide form of phenylalanine as a new source of amino acid in terms of growth performance and whole-body amino acid composition in comparison to the free form for red seabream (Pagrus major). Fish (1.46±0.001 g) were fed four isonitrogenous and isocaloric experimental diets containing 0.7 or 1.4% phenylalanine either in free or dipeptide form. A feeding trial was carried out in three replicates and the fish were fed to apparent satiation for six weeks. At the end of the feeding trial, feed intake of fish was influenced by both phenylalanine form and level and significantly higher values were obtained at an inclusion level of 0.7% and by the use of dipeptide form. However, the other growth parameters did not significantly differ among treatments. Whole-body amino acid compositions revealed no significant changes in concentrations of both essential and non-essential amino acids regardless of the increase in phenylalanine levels or the use of its different forms. The finding in this study indicates that juvenile red seabream can utilize dipeptide phenylalanine as efficiently as free form without any undesirable effects on growth performance or whole-body amino acid composition. PMID:25049673

Kim, Sung-Sam; Rahimnejad, Samad; Song, Jin-Woo; Lee, Kyeong-Jun

2012-01-01

2

Current topics in the biotechnological production of essential amino acids, functional amino acids, and dipeptides.  

PubMed

Amino acids play important roles in both human and animal nutrition and in the maintenance of health. Here, amino acids are classified into three groups: first, essential amino acids, which are essential to nutrition; second, functional amino acids, recently found to be important in the promotion of physiological functions; and third, dipeptides, which are used to resolve problematic features of specific free amino acids, such as their instability or insolubility. This review focusses on recent researches concerning the microbial production of essential amino acids (lysine and methionine), functional amino acids (histidine and ornithine), and a dipeptide (L-alanyl-L-glutamine). PMID:24679256

Mitsuhashi, Satoshi

2014-04-01

3

The Synthesis of a Dipeptide from its Component Amino Acids: Protecting Groups in the Elementary Organic Laboratory.  

ERIC Educational Resources Information Center

A simple, three-step procedure for synthesizing a dipeptide from its component amino acids is described. The dipeptide synthesized uses inexpensive amino acids having hydrocarbon side-chains and can be observed in E/Z forms by nuclear magnetic resonance spectroscopy. Each step in the synthesis produces white crystalline products using standard…

Young, Paul E.; Campbell, Andrew

1982-01-01

4

Reactions of An Aromatic ?,?-Biradical with Amino Acids and Dipeptides in the Gas Phase  

PubMed Central

Gas-phase reactivity of a positively charged aromatic ?,?-biradical (N-methyl-6,8-didehydroquinolinium) was examined toward six aliphatic amino acids and fifteen dipeptides by using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR) and laser-induced acoustic desorption (LIAD). While previous studies have revealed that H-atom and NH2 abstractions dominate the reactions of related monoradicals with aliphatic amino acids and small peptides, several additional, unprecedented reaction pathways were observed for the reactions of the biradical. For amino acids, these are 2H-atom abstraction, H2O abstraction, addition – CO2, addition – HCOOH and formation of a stable adduct. The biradical reacts with aliphatic dipeptides similarly as with aliphatic amino acids, but undergoes also one additional reaction pathway, addition/C-terminal amino acid elimination (addition – CO – NHCHRC). These reactions are initiated by H-atom abstraction by the biradical from the amino acid or peptide, or nucleophilic addition of an NH2 or a HO group of the amino acid or peptide at the radical site at C-6 in the biradical. Reactions of the unquenched C-8 radical site then yield the products not observed for related monoradicals. The biradical reacts with aromatic dipeptides with an aromatic ring in N-terminus (i.e., Tyr-Leu, Phe-Val and Phe-Pro) similarly as with aliphatic dipeptides. However, for those aromatic dipeptides that contain an aromatic ring in the C-terminus (i.e., Leu-Tyr and Ala-Phe), one additional pathway, addition/N-terminal amino acid elimination (addition – CO – NHCHRN), was observed. This reaction is likely initiated by radical addition of the biradical at the aromatic ring in the C-terminus. Related monoradicals add to aromatic amino acids and small peptides, which is followed by C?-C? bond cleavage, resulting in side-chain abstraction by the radical. For biradicals, with one unquenched radical site after the initial addition, the reaction ultimately results in the loss of the N-terminal amino acid. Similar to monoradicals, the C-S bond in amino acids and dipeptides was found to be especially susceptible to biradical attack. PMID:20705478

Fu, Mingkun; Li, Sen; Archibold, Enada; Yurkovich, Michael J.; Nash, John J.; Kenttämaa, Hilkka I.

2010-01-01

5

Synthesis and Conformational Analysis of Hybrid ?/?-Dipeptides Incorporating S-Glycosyl-?(2,2) -Amino Acids.  

PubMed

We synthesized and carried out the conformational analysis of several hybrid dipeptides consisting of an ?-amino acid attached to a quaternary glyco-?-amino acid. In particular, we combined a S-glycosylated ?(2,2) -amino acid and two different types of ?-amino acid, namely, aliphatic (alanine) and aromatic (phenylalanine and tryptophan) in the sequence of hybrid ?/?-dipeptides. The key step in the synthesis involved the ring-opening reaction of a chiral cyclic sulfamidate, inserted in the peptidic sequence, with a sulfur-containing nucleophile by using 1-thio-?-D-glucopyranose derivatives. This reaction of glycosylation occurred with inversion of configuration at the quaternary center. The conformational behavior in aqueous solution of the peptide backbone and the glycosidic linkage for all synthesized hybrid glycopeptides was analyzed by using a protocol that combined NMR experiments and molecular dynamics with time-averaged restraints (MD-tar). Interestingly, the presence of the sulfur heteroatom at the quaternary center of the ?-amino acid induced ? torsional angles close to 180° (anti). Notably, this value changed to 60° (gauche) when the peptidic sequence displayed aromatic ?-amino acids due to the presence of CH-? interactions between the phenyl or indole ring and the methyl groups of the ?-amino acid unit. PMID:25413453

García-González, Iván; Mata, Lara; Corzana, Francisco; Jiménez-Osés, Gonzalo; Avenoza, Alberto; Busto, Jesús H; Peregrina, Jesús M

2015-01-12

6

Application of protein N-terminal amidase in enzymatic synthesis of dipeptides containing acidic amino acids specifically at the N-terminus.  

PubMed

Dipeptides exhibit unique physiological functions and physical properties, e.g., l-aspartyl-l-phenylalanine-methyl ester (Asp-Phe-OMe, aspartame) as an artificial sweetener, and functional studies of peptides have been carried out in various fields. Therefore, to establish a manufacturing process for the useful dipeptides, we investigated its enzymatic synthesis by utilizing an l-amino acid ligase (Lal), which catalyzes dipeptide synthesis in an ATP-dependent manner. Many Lals were obtained, but the Lals recognizing acidic amino acids as N-terminal substrates have not been identified. To increase the variety of dipeptides that are enzymatically synthesized, we proposed a two-step synthesis: Asn-Xaa and Gln-Xaa (Asn, l-asparagine; Gln, l-glutamine; and Xaa, arbitrary amino acids) synthesized by Lals were continuously deamidated by a novel amidase, yielding Asp-Xaa and Glu-Xaa (Asp, l-aspartic acid; and Glu, l-glutamic acid). We searched for amidases that specifically deamidate the N-terminus of Asn or Gln in dipeptides since none have been previously reported. We focused on the protein N-terminal amidase from Saccharomyces cerevisiae (NTA1), and assayed its activity toward dipeptides. Our findings showed that NTA1 deamidated l-asparaginyl-l-valine (Asn-Val) and l-glutaminyl-glycine (Gln-Gly), but did not deamidate l-valyl-l-asparagine and l-alanyl-l-glutamine, suggesting that this deamidation activity is N-terminus specific. The specific activity toward Asn-Val and Gln-Gly were 190 ± 30 nmol min(-1) mg(-1)·protein and 136 ± 6 nmol min(-1) mg(-1)·protein. Additionally, we examined some characteristics of NTA1. Acidic dipeptide synthesis was examined by a combination of Lals and NTA1, resulting in the synthesis of 12 kinds of Asp-Xaa, including Asp-Phe, a precursor of aspartame, and 11 kinds of Glu-Xaa. PMID:23218487

Arai, Toshinobu; Noguchi, Atsushi; Takano, Eriko; Kino, Kuniki

2013-04-01

7

Electrocatalytic Oxidation of Formate with Nickel Diphosphane Dipeptide Complexes: Effect of Ligands Modified with Amino Acids  

SciTech Connect

A series of nickel bis-diphosphine complexes with dipeptides appended to the ligands were investigated for the catalytic oxidation of formate. Typical rates of ~7 s-1 were found, similar to the parent complex (~8 s-1), with amino acid size and positioning contributing very little to rate or operating potential. Hydroxyl functionalities did result in lower rates, which were recovered by protecting the hydroxyl group. The results suggest that the overall dielectric introduced by the dipeptides does not play an important role in catalysis, but free hydroxyl groups do influence activity suggesting contributions from intra- or intermolecular interactions. These observations are important in developing a fundamental understanding of the affect that an enzyme-like outer coordination sphere can have upon molecular catalysts. This work was funded by the US DOE Basic Energy Sciences, Chemical Sciences, Geoscience and Biosciences Division (BRG, AJ, AMA, WJS), the US DOE Basic Energy Sciences, Physical Bioscience program (MLR). Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.

Galan, Brandon R.; Reback, Matthew L.; Jain, Avijita; Appel, Aaron M.; Shaw, Wendy J.

2013-10-28

8

A Molecular Dynamics Simulation Study of Two Dipeptide Based Molecular Micelles: Effect of Amino Acid Order.  

PubMed

Molecular dynamics (MD) simulations were used to compare the structures of the chiral molecular micelles (MM) poly-(sodium undecyl-(L,L)-leucine-valine) (poly(SULV)) and poly-(sodium undecyl-(L,L)-valine-leucine) (poly (SUVL)). Both MM contained polymerized surfactant monomers tenninated by chiral dipeptide headgroups. The study was undertaken to investigate why poly(SULV) is generally a better chiral selector compared to poly(SUVL) in electrokinetic chromatography separations. When comparing poly(SULV) to poly(SUVL), poly(SULV) had the more conformational flexible dipeptide headgroup and hydrogen bond analyses revealed that the poly(SULV) headgroup conformation allowed a larger number of intramolecular hydrogen bonds to form between monomer chains. In addition, a larger number of water molecules surrounded the chiral centers of the poly(SULV) molecular micelle. Poly(SULV) was also found to have a larger solvent accessible surface area (SASA) than poly(SUVL) and fluctuations in the poly(SULV) SASA during the MD simulation allowed dynamic monomer chain motions expected to be important in chiral recognition to be identified. Finally, approximately 50% of the Na(+) counterions were found in the first three solvation shells surrounding both MM, with the remainder located in the bulk. Overall the MD simulations point to both greater headgroup flexibility and solvent and analyte access to the chiral centers of the dipeptide headgroup as factors contributing to the enhanced chiral selectivity observed with poly(SULV). PMID:23951550

Morris, Kevin F; Billiot, Eugene J; Billiot, Fereshteh H; Lipkowitz, Kenny B; Southerland, William M; Fang, Yayin

2013-02-01

9

Preparation and characterization of d 6 tungsten compounds with amino acid derivatized diimine ligands and preparation of dipeptide derivatives using peptide coupling agents  

Microsoft Academic Search

Attempts to prepare dipeptide compounds from organometallic N-substituted amino acids are reported. Condensation of pyridine-2-carboxaldehyde, ?-amino acids (H-l-Ala-OH or H-l-Asp-OH) and W(CO)4(pip)2 leads to formation of W(CO)4(pyca-Et) (1) (pyca refers to the ?-diimine fragment, C5H4NCHN) following decarboxylation of one or two equivalents of CO2. This decarboxylation does not occur for ?-alanine or GABA (?-aminobutyric acid). Coupling of [Hpip][W(CO)4(pyca-?-Ala-O)] (2) or

Richard S. Herrick; Julie Dupont; Iwona Wrona; Julia Pilloni; Matthew Beaver; Mark Benotti; Frank Powers; Christopher J. Ziegler

2007-01-01

10

Microscale Synthesis and Analysis of a Dipeptide.  

ERIC Educational Resources Information Center

Described is a microscale chemistry laboratory in which a dipeptide is synthesized from its component amino acids and analyzed using chiral-phase thin-layer chromatography. Experimental procedures, and materials are discussed. Twelve references are listed. (CW)

Blatchly, Richard A.; And Others

1989-01-01

11

The Synthesis of an Amino Acid Derivative and Spectroscopic Monitoring of Dipeptide Formation.  

ERIC Educational Resources Information Center

Described are experiments to give students experience in the synthesis of peptides from amino acids and to use visible spectroscopy to measure a rate of reaction. The activities were designed for undergraduate courses. (RH)

Simmonds, Richard J.

1987-01-01

12

Genetic analysis of genes involved in dipeptide metabolism and cytotoxicity in Pseudomonas aeruginosa PAO1  

Microsoft Academic Search

The dipeptide transport operon in bacteria comprises genes for the transport and metabolism of amino acids and dipeptides, as well as haem and haem precursors such as aminolaevulinic acid. Such nutrient and mineral sources are vital for bacteria to survive in and colonize a range of niches. In silico analysis of the dipeptide transport systems in sequenced Pseudomonas species identified

Patrick D. Kiely; Julie O'Callaghan; Abdelhamid Abbas; Fergal O'Gara

2008-01-01

13

Micellular Electrokinetic Capillary Chromatography in the Undergraduate Curriculum: Separation and Identification of the Amino Acid Residues in an Unknown Dipeptide Using FMOC Derivatization  

NASA Astrophysics Data System (ADS)

This manuscript describes our efforts to introduce biochemistry students to micellar electrokinetic capillary chromatography (MEKC), a mode of capillary electrophoresis that employs micelles in the operating buffer. Unlike free solution capillary electrophoresis, MEKC is capable of resolving both charged and uncharged analytes because the micellar pseudo stationary phase allows for the separation of uncharged species. The experiment described herein includes a comparison of MEKC, employing sodium dodecyl sulfate (SDS) as the micelle-forming species, with reverse-phase HPLC. Both methods are used to determine the amino acid residues in an unknown dipeptide. Advanced undergraduate chemistry, biochemistry, and biology majors perform this experiment in the Biochemical Methods course at Bucknell University. The students cleave the peptide bond, derivatize the resultant amino acids with 9-fluorenylmethyl chloroformate (FMOC), and separate the FMOC-amino acid derivatives using HPLC and MEKC. This manuscript details the analytical procedures for the MEKC separation and presents typical student data obtained using this relatively new method.

Strein, Timothy G.; Poechmann, James L.; Prudenti, Mark

1999-06-01

14

The amino-acid substituents of dipeptide substrates of cathepsin C can determine the rate-limiting steps of catalysis.  

PubMed

We examined the cathepsin C-catalyzed hydrolysis of dipeptide substrates of the form Yaa-Xaa-AMC, using steady-state and pre-steady-state kinetic methods. The substrates group into three kinetic profiles based upon the broad range observed for k(cat)/K(a) and k(cat) values, pre-steady-state time courses, and solvent kinetic isotope effects (sKIEs). The dipeptide substrate Gly-Arg-AMC displayed large values for k(cat)/K(a) (1.6 ± 0.09 ?M(-1) s(-1)) and k(cat) (255 ± 6 s(-1)), an inverse sKIE on k(cat)/K(a) ((D)(k(cat)/K(a)) = 0.6 ± 0.15), a modest, normal sKIE on k(cat) ((D)k(cat) = 1.6 ± 0.2), and immeasurable pre-steady-state kinetics, indicating an extremely fast pre-steady-state rate (>400 s(-1)). (Errors on fitted values are omitted in the text for clarity but may be found in Table 2.) These results conformed to a kinetic model where the acylation (k(ac)) and deacylation (k(dac)) half-reactions are very fast and similar in value. The second substrate type, Gly-Tyr-AMC and Ser-Tyr-AMC, the latter the subject of a comprehensive kinetic study (Schneck et al. (2008) Biochemistry 47, 8697-8710), were found to be less active substrates compared to Gly-Arg-AMC, with respective k(cat)/K(a) values of 0.49 ± 0.07 ?M(-1 )s(-1) and 5.3 ± 0.5 ?M(-1 )s(-1), and k(cat) values of 28 ± 1 s(-1) and 25 ± 0.5 s(-1). Solvent kinetic isotope effects for Ser-Tyr-AMC were found to be inverse for k(cat)/K(a) ((D)(k(cat)/K(a)) = 0.74 ± 0.05) and normal for k(cat) ((D)k(cat) = 2.3 ± 0.1) but unlike Gly-Arg-AMC, pre-steady-state kinetics of Gly-Tyr-AMC and Ser-Tyr-AMC were measurable and characterized by a single-exponential burst, with fast transient rates (490 s(-1) and 390 s(-1), respectively), from which it was determined that k(ac) ? k(dac) ? k(cat). The third substrate type, Gly-Ile-AMC, gave very low values of k(cat)/K(a) (0.0015 ± 0.0001 ?M(-1) s(-1)) and k(cat) (0.33 ± 0.02 s(-1)), no sKIEs, ((D)(k(cat)/K(a)) = 1.05 ± 0.5 and (D)k(cat) = 1.06 ± 0.4), and pre-steady-state kinetics exhibited a discernible, but negligible, transient phase. For this third class of substrate, kinetic modeling was consistent with a mechanism in which k(dac) > k(ac) ? k(cat), and for which an isotope-insensitive step in the acylation half-reaction is the slowest. The combined results of these studies suggested that the identity of the amino acid at the P(1) position of the substrate is the main determinant of catalysis. On the basis of these kinetic data, together with crystallographic studies of substrate analogues and molecular dynamics analysis with models of acyl-enzyme intermediates, we present a catalytic model derived from the relative rates of the acylation vs deacylation half-reactions of cathepsin C. The chemical steps of catalysis are proposed to be dependent upon the conformational freedom of the amino acid substituents for optimal alignment for thiolation (acylation) or hydrolysis (deacylation). These studies suggest ideas for inhibitor design for papain-family cysteine proteases and strategies to progress drug discovery for other classes of disease-relevant cysteine proteases. PMID:22928782

Rubach, Jon K; Cui, Guanglei; Schneck, Jessica L; Taylor, Amy N; Zhao, Baoguang; Smallwood, Angela; Nevins, Neysa; Wisnoski, David; Thrall, Sara H; Meek, Thomas D

2012-09-25

15

Dipeptide-assisted growth of uniform gallium oxohydroxide spindles  

NASA Astrophysics Data System (ADS)

The catalytic dipeptide His-Ser was used as an additive in mineralizing gallium ions to form GaOOH, a solid precursor of Ga 2O 3. This dipeptide was chosen to mimic the enzyme structure of silicatein, similar to the well-known catalytic triad of chymotrypsin. The dipeptide promoted formation of spindle-structured GaOOH under acidic conditions by behaving as a heterogeneous nucleation seed. In contrast, no well-defined, structured gallium species were produced in the absence of dipeptide. The catalytic function of the dipeptide was most pronounced at pH values in the range 3-5, which are lower than the pKa of imidazole in the His side chain. These results suggest that the catalytic role of dipeptide influences the gallium hydroxide conversion and growth. This study suggests that a designed peptide with active functionality can be further exploited to produce inorganic compounds with controlled nucleation and growth.

Lee, Inho; Kwak, Jinyoung; Haam, Seungjoo; Lee, Sang-Yup

2010-07-01

16

Dietary cyclic dipeptides, apoptosis and psychiatric disorders: a hypothesis.  

PubMed

Cyclic dipeptides from food and intestinal yeast cyclic dipeptides may play a role in causing psychiatric disorders such as schizophrenia. From cancer research, cyclic dipeptides such as cyclo (proline-phenylalanine) have been found to activate the pathways of apoptosis and to cause programmed cell death. Activation of such pathways is also thought to be important in causing the neurodevelopmental abnormalities seen in disorders such as schizophrenia and autistic disorder, and also may be important in Alzheimer's. Cyclic dipeptides are found in foods such as malt and cocoa and beer. The intestinal yeast Candida albicans also synthesizes cyclic dipeptides. These dipeptides may be activating apoptosis pathways throughout fetal development and postnatal development, leading to some of the changes seen in brain in schizophrenia and in other psychiatric disorders. These compounds should be researched further to see if they play a role in causing these brain changes. In addition, these cyclic dipeptides are considered within the larger context of research on amino acids and other cyclic dipeptides in neurotransmission and neurophysiology. A better understanding of the role of these cyclic dipeptides in psychiatric disorders could lead to strategies for prevention and treatment of these disorders. PMID:24717821

Semon, Bruce A

2014-06-01

17

Nucleic acid detection compositions  

DOEpatents

The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

Prudent, James R. (Madison, WI); Hall, Jeff G. (Madison, WI); Lyamichev, Victor I. (Madison, WI); Brow, Mary Ann (Madison, WI); Dahlberg, James L. (Madison, WI)

2008-08-05

18

Peptide transporter isoforms are discriminated by the fluorophore?conjugated dipeptides ??Ala? and d?Ala?Lys?N?7?amino?4?methylcoumarin?3?acetic acid  

PubMed Central

Abstract Peptide transporters of the SLC15 family are classified by structure and function into PEPT1 (low?affinity/high?capacity) and PEPT2 (high?affinity/low?capacity) isoforms. Despite the differences in kinetics, both transporter isoforms are reckoned to transport essentially all possible di? and tripeptides. We here report that the fluorophore?conjugated dipeptide derivatives ??Ala?Lys?N?7?amino?4?methylcoumarin?3?acetic acid (??AK?AMCA) and d?Ala?Lys?N?7?amino?4?methylcoumarin?3?acetic acid (d?AK?AMCA) are transported by distinct PEPT isoforms in a species?specific manner. Transport of the fluorophore peptides was studied (1) in vitro after heterologous expression in Xenopus oocytes of PEPT1 and PEPT2 isoforms from different vertebrate species and of PEPT1 and PEPT2 transporters from Caenorhabditis elegans by using electrophysiological and fluorescence methods and (2) in vivo in C. elegans by using fluorescence methods. Our results indicate that both substrates are transported by the vertebrate “renal?type” and the C. elegans “intestinal?type” peptide transporter only. A systematic analysis among species finds four predicted amino acid residues along the sequence that may account for the substrate uptake differences observed between the vertebrate PEPT1/nematode PEPT2 and the vertebrate PEPT2/nematode PEPT1 subtype. This selectivity on basis of isoforms and species may be helpful in better defining the structure–function determinants of the proteins of the SLC15 family. PMID:24744852

Kottra, Gabor; Spanier, Britta; Verri, Tiziano; Daniel, Hannelore

2013-01-01

19

Peptide transporter isoforms are discriminated by the fluorophore-conjugated dipeptides ?-Ala- and d-Ala-Lys-N-7-amino-4-methylcoumarin-3-acetic acid.  

PubMed

Peptide transporters of the SLC15 family are classified by structure and function into PEPT1 (low-affinity/high-capacity) and PEPT2 (high-affinity/low-capacity) isoforms. Despite the differences in kinetics, both transporter isoforms are reckoned to transport essentially all possible di- and tripeptides. We here report that the fluorophore-conjugated dipeptide derivatives ?-Ala-Lys-N-7-amino-4-methylcoumarin-3-acetic acid (?-AK-AMCA) and d-Ala-Lys-N-7-amino-4-methylcoumarin-3-acetic acid (d-AK-AMCA) are transported by distinct PEPT isoforms in a species-specific manner. Transport of the fluorophore peptides was studied (1) in vitro after heterologous expression in Xenopus oocytes of PEPT1 and PEPT2 isoforms from different vertebrate species and of PEPT1 and PEPT2 transporters from Caenorhabditis elegans by using electrophysiological and fluorescence methods and (2) in vivo in C. elegans by using fluorescence methods. Our results indicate that both substrates are transported by the vertebrate "renal-type" and the C. elegans "intestinal-type" peptide transporter only. A systematic analysis among species finds four predicted amino acid residues along the sequence that may account for the substrate uptake differences observed between the vertebrate PEPT1/nematode PEPT2 and the vertebrate PEPT2/nematode PEPT1 subtype. This selectivity on basis of isoforms and species may be helpful in better defining the structure-function determinants of the proteins of the SLC15 family. PMID:24744852

Kottra, Gabor; Spanier, Britta; Verri, Tiziano; Daniel, Hannelore

2013-12-01

20

Incorporating Amino Acids Composition and Functional Domains for Identifying Bacterial Toxin Proteins  

PubMed Central

Aside from pathogenesis, bacterial toxins also have been used for medical purpose such as drugs for cancer and immune diseases. Correctly identifying bacterial toxins and their types (endotoxins and exotoxins) has great impact on the cell biology study and therapy development. However, experimental methods for bacterial toxins identification are time-consuming and labor-intensive, implying an urgent need for computational prediction. Thus, we are motivated to develop a method for computational identification of bacterial toxins based on amino acid sequences and functional domain information. In this study, a nonredundant dataset of 167 bacterial toxins including 77 exotoxins and 90 endotoxins is adopted to learn the predictive model by using support vector machines (SVMs). The cross-validation evaluation shows that the SVM models trained with amino acids and dipeptides composition could yield an accuracy of 96.07% and 92.50%, respectively. For discriminating endotoxins from exotoxins, the SVM models trained with amino acids and dipeptides composition have achieved an accuracy of 95.71% and 92.86%, respectively. After incorporating functional domain information, the predictive performance is further improved. The proposed method has been demonstrated to be able to more effectively identify and classify bacterial toxins than the other two features on independent dataset, which may aid in bacterial biomedical development. PMID:25110714

Su, Min-Gang; Huang, Chien-Hsun; Lee, Tzong-Yi; Chen, Yu-Ju; Wu, Hsin-Yi

2014-01-01

21

A Comparison of the Effects of Oral Glutamine Dipeptide, Glutamine, and Alanine on Blood Amino Acid Availability in Rats Submitted to Insulin-Induced Hypoglycemia  

PubMed Central

We compared the effects of oral administration of high-dose or low-dose glutamine dipeptide (GDP), alanine (ALA), glutamine (GLN), and ALA + GLN on the blood availability of amino acids in rats submitted to insulin-induced hypoglycemia (IIH). Insulin detemir (1 U/kg) was intraperitoneally injected to produce IIH; this was followed by oral administration of GDP, GLN + ALA, GLN, or ALA. We observed higher blood levels of GLN, 30 min after oral administration of high-dose GDP (1000 mg/kg) than after administration of ALA (381 mg/kg) + GLN (619 mg/kg), GLN (619 mg/kg), or ALA (381 mg/kg). However, we did not observe the same differences after oral administration of low-dose GDP (100 mg/kg) compared with ALA (38.1 mg/kg) + GLN (61.9 mg/kg), GLN (61.9 mg/kg), or ALA (38.1 mg/kg). We also observed less liver catabolism of GDP compared to ALA and GLN. In conclusion, high-dose GDP promoted higher blood levels of GLN than oral ALA + GLN, GLN, or ALA. Moreover, the lower levels of liver catabolism of GDP, compared to ALA or GLN, contributed to the superior performance of high-dose GDP in terms of blood availability of GLN. PMID:25338272

Minguetti-Câmara, Vania C.; Marques, Any de C. R.; Schiavon, Fabiana P. M.; Vilela, Vanessa R.; Brusch, Marcos L.; Bazotte, Roberto Barbosa

2014-01-01

22

The Feasibility of Enzyme Targeted Activation for Amino Acid/Dipeptide Monoester Prodrugs of Floxuridine; Cathepsin D as a Potential Targeted Enzyme  

PubMed Central

The improvement of therapeutic efficacy for cancer agents has been a big challenge which includes the increase of tumor selectivity and the reduction of adverse effects at non-tumor sites. In order to achieve those goals, prodrug approaches have been extensively investigated. In this report, the potential activation enzymes for 5?-amino acid/dipeptide monoester floxuridine prodrugs in pancreatic cancer cells were selected and the feasibility of enzyme specific activation of prodrugs was evaluated. All prodrugs exhibited the range of 3.0–105.7 min of half life in Capan-2 cell homogenate with the presence and the absence of selective enzyme inhibitors. 5?-O-L-Phenylalanyl-L-tyrosyl-floxuridine exhibited longer half life only with the presence of pepstatin A. Human cathepsin B and D selectively hydrolized 5?-O-L-phenylalanyl-L-tyrosylfloxuridine and 5?-O-L-phenylalanyl-L-glycylfloxuridine compared to the other tested prodrugs. The wide range of growth inhibitory effect by floxuridine prodrugs in Capan-2 cells was observed due to the different affinities of prodrug promoieties to enyzmes. In conclusion, it is feasible to design prodrugs which are activated by specific enzymes. Cathepsin D might be a good candidate as a target enzyme for prodrug activation and 5?-O-L-phenylalanyl-L-tyrosylfloxuridine may be the best candidate among the tested floxuridine prodrugs. PMID:22450679

Tsume, Yasuhiro; Amidon, Gordon L.

2013-01-01

23

Dipeptides in nutrition and therapy: cyanophycin-derived dipeptides as natural alternatives and their biotechnological production  

Microsoft Academic Search

The numerous physiological functions of the nonessential amino acid L-aspartate, the semi-essential amino acid L-arginine,\\u000a and the essential amino acid L-lysine, made them attractive for a wide range of nutritional and\\/or therapeutic applications.\\u000a Furthermore, the administration of these amino acids as mixtures or as dipeptides for higher bioavailability is scientifically\\u000a approved, and various commercial products of these forms are already

Ahmed Sallam; Alexander Steinbüchel

2010-01-01

24

ON THE FORMATION OF DIPEPTIDES IN INTERSTELLAR MODEL ICES  

SciTech Connect

The hypothesis of an exogenous origin and delivery of biologically important molecules to early Earth presents an alternative route to their terrestrial in situ formation. Dipeptides like Gly-Gly detected in the Murchison meteorite are considered as key molecules in prebiotic chemistry because biofunctional dipeptides present the vital link in the evolutionary transition from prebiotic amino acids to early proteins. However, the processes that could lead to the exogenous abiotic synthesis of dipeptides are unknown. Here, we report the identification of two proteinogenic dipeptides-Gly-Gly and Leu-Ala-formed via electron-irradiation of interstellar model ices followed by annealing the irradiated samples to 300 K. Our results indicate that the radiation-induced, non-enzymatic formation of proteinogenic dipeptides in interstellar ice analogs is facile. Once synthesized and incorporated into the ''building material'' of solar systems, biomolecules at least as complex as dipeptides could have been delivered to habitable planets such as early Earth by meteorites and comets, thus seeding the beginning of life as we know it.

Kaiser, R. I.; Kim, Y. S. [Department of Chemistry, University of Hawaii at Manoa, Honolulu, HI 96822 (United States); Stockton, A. M.; Jensen, E. C.; Mathies, R. A. [Department of Chemistry, University of California, Berkeley, CA 94720 (United States)

2013-03-10

25

Dipeptide hydrolysis by the dinuclear zinc enzyme human renal dipeptidase: Mechanistic insights from DFT calculations  

E-print Network

Dipeptide hydrolysis by the dinuclear zinc enzyme human renal dipeptidase: Mechanistic insights dipeptidase is investigated using hybrid density functional theory. This enzyme catalyzes the hydrolysis the hydrolysis of dipeptides with D-, L-, or dehydro-amino acids at the C-terminus (Scheme 1) [1­3]. It plays

Liao, Rongzhen

26

Gelled acidic well treating composition and process  

SciTech Connect

Gelled acidic compositions suitable for either matrix-acidizing or fracture-acidizing of subterranean formations comprising water , a water-dispersible polymer selected from cellulose ethers and polymers of acrylamides, an acid, an aldehyde, and a phenolic compound capable of causing gelation of an aqueous dispersion of the polymer, acid, aldehyde, and phenolic compound are provided. In another embodiment, guar gum, polyvinylpyrrolidone and biopolysaccharides can also be used as the polymeric component in said compositions.

Swanson, B.L.

1981-01-13

27

Two-dimensional surface properties of PEO-PPO-PEO triblock copolymer film at the air/water interface in the absence and presence of Tyr-Phe dipeptide, Val-Tyr-Val tripeptide, SDS and stearic acid.  

PubMed

Two-dimensional surface properties of PEO-PPO-PEO triblock copolymer film (Mol.Wt. 2800) in the absence and presence of Tyr-Phe dipeptide, Val-Tyr-Val tripeptide, sodium dodecylsulfate and stearic acid have been investigated for the first time at the air/water interface using Langmuir film balance technique. It is observed that the above polymer forms fairly stable film at the air/water interface. There are no significant changes observed in the surface pressure-area (?-A) isotherms of polymer in the presence of SDS. However, more expanded film was formed in presence of SDS since the solubility of the polymer is more in SDS and the polymer network is disturbed in presence of SDS, which results in the increase in surface area of the polymer films. In the presence of dipeptide and tripeptide, the surface area of the polymer film decreased with a slight increase in the surface pressure indicating the binding of these peptides to polymer, which enhances the stability of the polymer film. Thermodynamic studies on the change in surface area (?A) and excess free energy of mixing (?G(mix)(E)) associated with the formation of the mixed film suggest the occurrence of a thermodynamically unstable mixed film. The presence of SDS slightly decreases the formation of mixed film of stearic acid with triblock copolymer and peptides due to the solubilization of these compounds in SDS. However, the hydrophobicity of the polymer films increases in the presence of stearic acid, leading to the increase in surface pressure. The positive deviation of ?A and the positive ?G(mix)(E) values show the non-ideality and incompatibility of thermodynamically unstable mixed films. The thermodynamic results suggest that the stability and compatibility of the polymer, peptides and their mixed films with stearic acid in the presence of SDS are decreased, which is in good agreement with the results obtained for other polymeric systems. PMID:20888193

James, Jilly; Ramalechume, Chidambaram; Mandal, Asit Baran

2011-02-01

28

Compositions for acid treating subterranean formations  

SciTech Connect

This patent describes a high viscosity acid composition. It comprises: an aqueous acid solution; one or more acrylamide polymers dissolved in the acid solution in an amount sufficient to increase the viscosity of the acid solution; a liquid hydrocarbon dispersed in the acid solution; and one or more nonionic surface active agents having at least one reactive hydroxyl group per molecule present in the composition in an amount sufficient to interact with the acrylamide polymer or polymers in the presence of the liquid hydrocarbon whereby the viscosity of the acid solution is further increased and stabilized.

Clark, E. Jr.; Swanson, B.L.

1991-03-05

29

Using the concept of Chou's pseudo amino acid composition to predict protein solubility: an approach with entropies in information theory.  

PubMed

Protein solubility plays a major role and has strong implication in the proteomics. Predicting the propensity of a protein to be soluble or to form inclusion body is a fundamental and not fairly resolved problem. In order to predict the protein solubility, almost 10,000 protein sequences were downloaded from NCBI. Then the sequences were eliminated for the high homologous similarity by CD-HIT. Thus, there were 5692 sequences remained. Based on protein sequences, amino acid and dipeptide compositions were generally extracted to predict protein solubility. In this study, the entropy in information theory was introduced as another predictive factor in the model. Experiments involving nine different feature vector combinations, including the above-mentioned three kinds of factors, were conducted with support vector machines (SVMs) as prediction engine. Each combination was evaluated by re-substitution test and 10-fold cross-validation test. According to the evaluation results, the accuracies and Matthew's Correlation Coefficient (MCC) values were boosted by the introduction of the entropy. The best combination was the one with amino acid, dipeptide compositions and their entropies. Its accuracy reached 90.34% and Matthew's Correlation Coefficient (MCC) value was 0.7494 in re-substitution test, while 88.12% and 0.7945 respectively for 10-fold cross-validation. In conclusion, the introduction of the entropy significantly improved the performance of the predictive method. PMID:23524162

Xiaohui, Niu; Nana, Li; Jingbo, Xia; Dingyan, Chen; Yuehua, Peng; Yang, Xiao; Weiquan, Wei; Dongming, Wang; Zengzhen, Wang

2013-09-01

30

The Composition of Arylstibonic Acids.  

E-print Network

??This thesis describes a detailed ESI-MS investigation into the arylstibonic acids, organo-antimony-containing compounds that are currently of interest as anticancer reagents. Four arylstibonic acids, of… (more)

Wright, Cody Elvin

2010-01-01

31

Composition for nucleic acid sequencing  

DOEpatents

The present invention is directed to a method of sequencing a target nucleic acid molecule having a plurality of bases. In its principle, the temporal order of base additions during the polymerization reaction is measured on a molecule of nucleic acid, i.e. the activity of a nucleic acid polymerizing enzyme on the template nucleic acid molecule to be sequenced is followed in real time. The sequence is deduced by identifying which base is being incorporated into the growing complementary strand of the target nucleic acid by the catalytic activity of the nucleic acid polymerizing enzyme at each step in the sequence of base additions. A polymerase on the target nucleic acid molecule complex is provided in a position suitable to move along the target nucleic acid molecule and extend the oligonucleotide primer at an active site. A plurality of labelled types of nucleotide analogs are provided proximate to the active site, with each distinguishable type of nucleotide analog being complementary to a different nucleotide in the target nucleic acid sequence. The growing nucleic acid strand is extended by using the polymerase to add a nucleotide analog to the nucleic acid strand at the active site, where the nucleotide analog being added is complementary to the nucleotide of the target nucleic acid at the active site. The nucleotide analog added to the oligonucleotide primer as a result of the polymerizing step is identified. The steps of providing labelled nucleotide analogs, polymerizing the growing nucleic acid strand, and identifying the added nucleotide analog are repeated so that the nucleic acid strand is further extended and the sequence of the target nucleic acid is determined.

Korlach, Jonas (Ithaca, NY); Webb, Watt W. (Ithaca, NY); Levene, Michael (Ithaca, NY); Turner, Stephen (Ithaca, NY); Craighead, Harold G. (Ithaca, NY); Foquet, Mathieu (Ithaca, NY)

2008-08-26

32

Structural insight into the aggregation of l-prolyl dipeptides and its effect on organocatalytic performance.  

PubMed

NMR and organocatalytic studies of four dipeptides derived from l-proline are described. Results indicate that important conformational changes around the catalytic l-proline moiety are observed for free dipeptides upon changing the adjacent amino acid. Also, an aggregation process is detected as the concentration increases. The self-association of the dipeptides has been fitted to a cooperative binding model. All the compounds have been assayed as catalysts for the conjugated addition of cyclohexanone to trans-?-nitrostyrene in toluene. In agreement with the structural studies, noticeable changes in the catalytic performance are detected upon changing the catalyst concentration, as the catalyst is activated by self-aggregation. PMID:25382228

Berdugo, Cristina; Escuder, Beatriu; Miravet, Juan F

2015-01-14

33

Self-assembled nanoparticles based on modified cationic dipeptides and DNA: novel systems for gene delivery  

PubMed Central

Background Gene therapy is most effective when delivery is both efficient and safe. However, it has often proven difficult to find a balance between efficiency and safety in case of viral or polymeric vectors for gene therapy. Peptide based delivery systems may be attractive alternatives but their relative instability to proteolysis is a major concern in realizing their potential application in biomedical sciences. In this work we report gene delivery potential of nanoparticles (Nps) synthesized from cationic dipeptides containing a non-protein amino acid ?, ?-dehydrophenylalanine (?Phe) residue. Methods Dipeptides were synthesized using solution phase peptide synthesis method. Nps were formed using self-assembly. Nps were characterized using light scattering, electron microscopy. Transfection efficiency was tested in hepatocellular carcinoma (HuH 7) cells. Results The cationic dipeptides condensed plasmid DNA into discrete vesicular nanostructures. Dipeptide Nps are non-cytotoxic, protected the condensed DNAs from enzymatic degradation and ferried them successfully inside different types of cells. GFP encoding plasmid DNA loaded dipeptide Nps showed positive transfection and gene expression in HuH 7 cells. Conclusions The cationic dipeptide Nps can successfully deliver DNA without exerting any cytotoxic effect. Owing to their simple dipeptide origin, ease of synthesis, enhanced enzymatic stability as well unmatched biocompatibility, these could be successfully developed as vehicles for effective gene therapy. PMID:23800286

2013-01-01

34

Prebiotically plausible mechanisms increase compositional diversity of nucleic acid sequences  

E-print Network

Prebiotically plausible mechanisms increase compositional diversity of nucleic acid sequences of life, the biological information of nucleic acid polymers must have increased to encode functional work suggests that prebiotically plausible chemical mechanisms of nucleic acid polymerization

Nowak, Martin A.

35

Enhanced Cancer Cell Growth Inhibition by Dipeptide Prodrugs of Floxuridine: Increased Transporter Affinity and Metabolic Stability  

PubMed Central

Dipeptide monoester prodrugs of floxuridine were synthesized, and their chemical stability in buffers, resistance to glycosidic bond metabolism, affinity for PEPT1, enzymatic activation and permeability in cancer cells were determined and compared to those of mono amino acid monoester floxuridine prodrugs. Prodrugs containing glycyl moieties were the least stable in pH 7.4 buffer (t1/2 < 100 min). The activation of all floxuridine prodrugs was 2- to 30-fold faster in cell homogenates than their hydrolysis in buffer, suggesting enzymatic action. The enzymatic activation of dipeptide monoester prodrugs containing aromatic promoieties in cell homogenates was 5- to 20-fold slower than that of other dipeptide and most mono amino acid monoester prodrugs (t1/2 ? 40 to 100 min). All prodrugs exhibited enhanced resistance to glycosidic bond metabolism by thymidine phosphorylase compared to parent floxuridine. In general, the 5?-O-dipeptide monoester floxuridine prodrugs exhibited higher affinity for PEPT1 than the corresponding 5?-O-mono amino acid ester prodrugs. The permeability of dipeptide monoester prodrugs across Caco-2 and Capan-2 monolayers was 2- to 4-fold higher than the corresponding mono amino acid ester prodrug. Cell proliferation assays in AsPC-1 and Capan-2 pancreatic ductal cell lines indicated that the dipeptide monoester prodrugs were equally as potent as mono amino acid prodrugs. The transport and enzymatic profiles of 5?-l-phenylalanyl-l-tyrosyl-floxuridine, 5?-l-phenylalanyl-l-glycyl-floxuridine, and 5?-l-isoleucyl-l-glycyl-floxuridine suggest their potential for increased oral uptake, delayed enzymatic bioconversion and enhanced resistance to metabolism to 5-fluorouracil, as well as enhanced uptake and cytotoxic activity in cancer cells, attributes that would facilitate prolonged systemic circulation for enhanced therapeutic action. PMID:18652477

2008-01-01

36

Analyzing a dipeptide library to identify human dipeptidyl peptidase IV inhibitor.  

PubMed

Human dipeptidyl peptidase IV (hDPPIV) inhibitors provide an effective strategy for the treatment of type 2 diabetes. Because certain peptides are known to act as hDPPIV inhibitors, a dataset of possible peptides with their inhibition intensities will facilitate the development of functional food for type 2 diabetes. In this study, we examined a total of 337 dipeptides with respect to their hDPPIV inhibitory effects. Amino acid residues at N-termini dominated their inhibition intensities. Particularly highly inhibitory dipeptides discovered included the following novel dipeptides: Thr-His, Asn-His, Val-Leu, Met-Leu, and Met-Met. Using our dataset, prime candidates contributing to the hDPPIV inhibitory effect of soy protein hydrolyzates were successfully identified. Possible dietary proteins potentially able to produce particularly highly hDPPIV inhibitory peptides are also discussed on the basis of the dataset. PMID:25577052

Lan, Vu Thi Tuyet; Ito, Keisuke; Ohno, Masumi; Motoyama, Takayasu; Ito, Sohei; Kawarasaki, Yasuaki

2015-05-15

37

157 nm Photodissociation of a Complete Set of Dipeptide Ions Containing C-Terminal Arginine  

NASA Astrophysics Data System (ADS)

Twenty singly-charged dipeptide ions with C-terminal arginine were photodissociated with 157 nm light and their tandem mass spectra recorded. Many of the small product ions that were observed are standard peptide fragments that have been commonly seen in VUV photodissociation studies. However, the study of a library of dipeptides containing all 20 N-terminal amino acids enabled the recognition of trends associated with the occurrence of w-, v-, and immonium ions, the observation of competition between forming N- and C-terminal fragments in dipeptide RR, and the identification of some unusual fragment ions appearing at masses of 183, 187, 196, and 197 Da. A highly accurate internal calibration of the photodissociation TOF-TOF data enabled molecular formulae for these four product ions to be derived. Their proposed structures reflect the rather high-energy nature of this fragmentation phenomenon.

He, Yi; Webber, Nathaniel; Reilly, James P.

2013-05-01

38

Structural study and characterization of the dipeptide 2-[[5-amino-5-oxo-2-(phenylmethoxycarbonylamino) pentanoyl] amino] acetic acid by vibrational spectroscopy and DFT calculations  

NASA Astrophysics Data System (ADS)

We have studied 2-[[5-amino-5-oxo-2-(phenylmethoxycarbonylamino) pentanoyl] amino] acetic acid and characterized it by infrared and Raman spectroscopies in the solid phase. The Density Functional Theory (DFT) method and Pople's basis set have been used to study its structure and vibrational properties. These calculations have given us a precise understanding of the normal modes of vibration, taking into account the neutral and zwitterionic forms of the compound. The harmonic vibrational wavenumbers for the optimized geometries of both structures were calculated at the B3LYP/6-31G*and B3LYP/6-311G** levels for an isolated molecule. For a complete assignment of the vibrational spectra, DFT calculations were combined with Pulaýs Scaled Quantum Mechanics Force Field (SQMFF) methodology to fit the theoretical and experimental wavenumber values. In this context, an assignment of the observed spectral features is proposed. Four intense bands in the infrared spectrum at 3332, 1734, 1654 and 1534 cm-1 and three bands in the Raman spectrum at 3332, 2928 and 985 cm-1 are reported to characterize both forms of the compound. The theoretical vibrational calculations allowed us to obtain a set of scaled force constants. A Natural Bond Orbital (NBO) study revealed the characteristics of the electronic delocalization of both structures, while the corresponding topological properties of electronic charge density were analyzed by employing Bader's Atoms in the Molecules theory (AIM).

Leyton, Patricio; Paipa, Carolina; Berrios, Andrés; Zárate, Antonio; Castillo, María Victoria; Brandán, Silvia Antonia

2013-01-01

39

Profiling histidine dipeptides in plasma and urine after ingesting beef, chicken or chicken broth in humans  

Technology Transfer Automated Retrieval System (TEKTRAN)

Reactive carbonyl species (RCS), oxidation products of polyunsaturated fatty acids, protein & sugars, play a role in the etiology of certain chronic diseases. Our previous studies revealed that histidine-dipeptides such as carnosine and anserine detoxify cytotoxic carbonyls such as 4-hydroxy-trans-...

40

Effect of diet on fatty acid compositions in Sciaenops ocellatus  

Microsoft Academic Search

The role of dietary polyunsaturated fatty acids (PUFAs) on the fatty acid composition of juvenile red drum Sciaenops ocellatus was investigated. Individuals (n ¼ 435) were fed three natural diets (Gulf menhaden Brevoortia patronus, brown shrimp Farfantapenaeus aztecus and Atlantic brief squid Lolliguncula brevis) that had significantly different proximate composi- tion, energy density and PUFA compositions for 40 days. Diets

J. P. T URNER; J. R. R OOKER

2005-01-01

41

Enzymatical and microbial degradation of cyclic dipeptides (diketopiperazines)  

PubMed Central

Diketopiperazines (DKPs) are cyclic dipeptides, representing an abundant class of biologically active natural compounds. Despite their widespread occurrence in nature, little is known about their degradation. In this study, the enzymatical and microbial cleavage of DKPs was investigated. Peptidase catalyzed hydrolysis of certain DKPs was formerly reported, but could not be confirmed in this study. While testing additional peptidases and DKPs no degradation was detected, indicating peptidase stability of the peptide bond in cyclic dipeptides. Besides confirmation of the reported degradation of cyclo(l-Asp-l-Phe) by Paenibacillus chibensis (DSM 329) and Streptomyces flavovirens (DSM 40062), cleavage of cyclo(l-Asp-l-Asp) by DSM 329 was detected. Other DKPs were not hydrolyzed by both strains, demonstrating high substrate specificity. The degradation of cyclo(l-Asp-l-Phe) by DSM 40062 was shown to be inducible. Three strains, which are able to hydrolyze hydantoins and dihydropyrimidines, were identified for the degradation of DKPs: Leifsonia sp. K3 (DSM 27212) and Bacillus sp. A16 (DSM 25052) cleaved cyclo(dl-Ala-dl-Ala) and cyclo(l-Gly-l-Phe), and Rhizobium sp. NA04-01 (DSM 24917) degraded cyclo(l-Asp-l-Phe), cyclo(l-Gly-l-Phe) and cyclo(l-Asp-l-Asp). The first enantioselective cleavage of cyclo(dl-Ala-dl-Ala) was detected with the newly isolated strains Paenibacillus sp. 32A (DSM 27214) and Microbacterium sp. 40A (DSM 27211). Cyclo(l-Ala-d-Ala) and cyclo(l-Ala-l-Ala) were completely degraded, whereas the enantiomer cyclo(d-Ala-d-Ala) was not attacked. Altogether, five bacterial strains were newly identified for the cleavage of DKPs. These bacteria may be of value for industrial purposes, such as degradation of undesirable DKPs in food and drugs and production of (enantiopure) dipeptides and amino acids. PMID:24001323

2013-01-01

42

Organic acids and sugars composition of harvested pomegranate fruits  

Microsoft Academic Search

For two consecutive seasons, 40 Spanish pomegranate cultivars (cvs) were analysed and their individual organic acids and\\u000a sugars compositions were examined. Intervarietal differences in acidity content reported by different authors were confirmed.\\u000a According to organoleptic characteristics and chemical compositions three groups of varieties were established: sweet (SWV),\\u000a soursweet (SSWV) and sour (SV). On average, for two seasons, total organic acids

Pablo Melgarejo; Domingo Manuel Salazar; F. Artés

2000-01-01

43

Isotope composition of carbon in amino acids of solid bitumens  

NASA Astrophysics Data System (ADS)

Primary data are presented on the isotope composition of carbon in individual amino acids from solid bitumens and several biological objects. The amino acids of biological objects are characterized by wide variations of the isotope composition of carbon. This fact occurs owing to the difference in biochemical paths of metabolism resulting in the synthesis of individual amino acids. The ?13C values are somewhat decreased for individual amino acids in asphaltenes, varying from -7.7 to -31.7‰. The carbon of amino acids is weighted in kerits from Bad'el' compared to asphaltenes. All the natural bitumens retain the characteristic trend for natural substances: the isotopically heavy and light amino acids by carbon are glycine and leucine, respectively. The isotope composition of amino-acid carbon is lightened compared to natural bitumens in the samples formed under a pronounced thermal impact (asphalt-like crust and kirishite).

Shanina, S. N.; Bushnev, D. A.

2014-06-01

44

Deoxyribonucleic Acid Base Composition in Yeasts  

PubMed Central

The deoxyribonucleic acid base composition of 15 species of yeasts was determined to obtain further clues to or supporting evidence for their taxonomic position. Species examined belonged to the genera Saccharomyces, Debaryomyces, Lodderomyces, Metschnikowia, and Candida. The range of moles per cent guanine plus cytosine (GC content) for all yeasts examined extended from 34.9 to 48.3%. The sporogenous species and the asporogenous yeasts spanned the range with 36.6 to 48.3% GC and 34.9 to 48% GC, respectively. Three Saccharomyces species (S. rosei and related species) exhibited significantly higher GC contents than S. cerevisiae, whereas the fermentative species D. globosus revealed a%GC more aligned to the S. rosei group than to the nonfermentative D. hansenii. Similar GC contents were demonstrated by L. elongasporus and its proposed imperfect form C. parapsilosis. The range of GC contents of various strains of three Metschnikowia species studied was 6.1%, with the type strain of M. pulcherrima having the highest GC content (48.3%) of all of the yeasts examined. PMID:5764346

Meyer, Sally A.; Phaff, H. J.

1969-01-01

45

iNitro-Tyr: Prediction of Nitrotyrosine Sites in Proteins with General Pseudo Amino Acid Composition  

PubMed Central

Nitrotyrosine is one of the post-translational modifications (PTMs) in proteins that occurs when their tyrosine residue is nitrated. Compared with healthy people, a remarkably increased level of nitrotyrosine is detected in those suffering from rheumatoid arthritis, septic shock, and coeliac disease. Given an uncharacterized protein sequence that contains many tyrosine residues, which one of them can be nitrated and which one cannot? This is a challenging problem, not only directly related to in-depth understanding the PTM’s mechanism but also to the nitrotyrosine-based drug development. Particularly, with the avalanche of protein sequences generated in the postgenomic age, it is highly desired to develop a high throughput tool in this regard. Here, a new predictor called “iNitro-Tyr” was developed by incorporating the position-specific dipeptide propensity into the general pseudo amino acid composition for discriminating the nitrotyrosine sites from non-nitrotyrosine sites in proteins. It was demonstrated via the rigorous jackknife tests that the new predictor not only can yield higher success rate but also is much more stable and less noisy. A web-server for iNitro-Tyr is accessible to the public at http://app.aporc.org/iNitro-Tyr/. For the convenience of most experimental scientists, we have further provided a protocol of step-by-step guide, by which users can easily get their desired results without the need to follow the complicated mathematics that were presented in this paper just for the integrity of its development process. It has not escaped our notice that the approach presented here can be also used to deal with the other PTM sites in proteins. PMID:25121969

Xu, Yan; Wen, Xin; Wen, Li-Shu; Wu, Ling-Yun; Deng, Nai-Yang; Chou, Kuo-Chen

2014-01-01

46

Fatty Acid Composition and Volatile Constituents of Protaetia brevitarsis Larvae  

PubMed Central

A total of 48 different volatile oils were identified form P. brevitarsis larvae by gas chromatography/mass spectrometry (GC/MS). Acids (48.67%) were detected as the major group in P. brevitarsis larvae comprising the largest proportion of the volatile compounds, followed by esters (19.84%), hydrocarbons (18.90%), alcohols (8.37%), miscellaneous (1.71%), aldehydes (1.35%) and terpenes (1.16%). The major volatile constituents were 9-hexadecenoic acid (16.75%), 6-octadecenoic acid (14.88%) and n-hexadecanoic acid (11.06%). The composition of fatty acid was also determined by GC analysis and 16 fatty acids were identified. The predominant fatty acids were oleic acid (C18:1, 64.24%) followed by palmitic acid (C16:0, 15.89%), palmitoleic acid (C16:1, 10.43%) and linoleic acid (C18:2, 4.69%) constituting more than 95% of total fatty acids. The distinguished characteristic of the fatty acid profile of P. brevitarsis larvae was the high proportion of unsaturated fatty acid (80.54% of total fatty acids) versus saturated fatty acids (19.46% of total fatty acids). Furthermore, small but significant amounts of linoleic, linolenic and ?-linolenic acids bestow P. brevitarsis larvae with considerable nutritional value. The novel findings of the present study provide a scientific basis for the comprehensive utilization of the insect as a nutritionally promising food source and a possibility for more effective utilization. PMID:24471125

Yeo, Hyelim; Youn, Kumju; Kim, Minji; Yun, Eun-Young; Hwang, Jae-Sam; Jeong, Woo-Sik; Jun, Mira

2013-01-01

47

Amino acid composition of proteins reduces deleterious impact of mutations  

PubMed Central

The evolutionary origin of amino acid occurrence frequencies in proteins (composition) is not yet fully understood. We suggest that protein composition works alongside the genetic code to minimize impact of mutations on protein structure. First, we propose a novel method for estimating thermodynamic stability of proteins whose sequence is constrained to a fixed composition. Second, we quantify the average deleterious impact of substituting one amino acid with another. Natural proteome compositions are special in at least two ways: 1) Natural compositions do not generate more stable proteins than the average random composition, however, they result in proteins that are less susceptible to damage from mutations. 2) Natural proteome compositions that result in more stable proteins (i.e. those of thermophiles) are also tuned to have a higher tolerance for mutations. This is consistent with the observation that environmental factors selecting for more stable proteins also enhance the deleterious impact of mutations. PMID:24108121

Hormoz, Sahand

2013-01-01

48

Biliary lipid composition in idiopathic bile acid malabsorption  

PubMed Central

Background—Chronic diarrhoea is the clinical hallmark of patients presenting with idiopathic bile acid malabsorption. Its pathogenesis is unknown; colonic water secretion can be induced by dihydroxy bile acids, but it is not known whether enrichment of the bile acid pool with these bile acids occurs in such patients. Furthermore, bile acid malabsorption is known to affect biliary lipid composition, but no information is available for the idiopathic type. ?Aims—To verify: (a) whether diarrhoea in patients with idiopathic bile acid malabsorption is associated with enrichment of the bile acid pool with dihydroxy bile acids; and (b) whether supersaturation with cholesterol of duodenal bile occurs in such patients as a result of chronic bile acid depletion. ?Patients—Thirteen patients with idiopathic bile acid malabsorption diagnosed according to abnormal 75SeHCAT test and absence of other organic diseases, and 23 control subjects. ?Methods—Bile rich duodenal fluid was collected during intravenous ceruletide infusion in the fasting state. Biliary lipids were analysed by enzymatic assays and bile acids by high performance liquid chromatography. ?Results—Patients with idiopathic bile acid malabsorption had a cholesterol saturation index similar to controls. Bile acid composition showed only a decrease in percentage cholic acid (29(2)% versus 36 (2)%; p<0.05); the dihydroxy:trihydroxy bile acid ratio was similar to controls. ?Conclusions—Patients with idiopathic bile acid malabsorption do not have an increased risk of forming cholesterol gallstones. The mechanism of diarrhoea does not seem to depend on an enrichment of the bile acid pool with dihydroxy bile acids. ?? Keywords: primary bile acid malabsorption; bile acids; diarrhoea; 75SeHCAT; biliary lipids; cholesterol saturation index PMID:9824609

Fracchia, M; Pellegrino, S; Secreto, P; Pera, A; Galatola, G

1998-01-01

49

Method for isomerizing olefins using acidic composite catalysts  

SciTech Connect

This patent describes a method for isomerizing olefins comprising the steps of contacting at least one olefin with a catalyst composite comprising a perfluorinated-polymersulfonic acid and an anion-stabilizing agent and recovering the isomerized olefins.

Farcasiu, D.

1987-06-09

50

Conjugated linoleic acid modulates hepatic lipid composition in mice  

Microsoft Academic Search

Conjugated linoleic acid (CLA) is a chemoprotective fatty acid that inhibits mammary, colon, forestomach, and skin carcinogenesis\\u000a in experimental animals. We hypothesize that the ubiquitous chemoprotective actions of dietary CLA in extrahepatic tissues\\u000a are dependent upon its role in modulating fatty acid composition and metabolism in liver, the major organ for lipid metabolism.\\u000a This study begins to evaluate the role

Martha A. Belury; Anna Kempa-Steczko

1997-01-01

51

Fatty acid composition of two Tunisian pine seed oils.  

PubMed

Oils were extracted from fully ripen Pinus pinea L. and Pinus halepensis Mill seeds and fatty acid composition has been established by capillary gas chromatography. Seeds are rich in lipids, 34.63-48.12% on a dry weight basis. Qualitatively, fatty acid composition of both species is identical. For P. halepensis linoleic acid is the major fatty acid (56.06% of total fatty acids) followed by oleic (24.03%) and palmitic (5.23%) acids. For P. pinea, the same fatty acids are found with the proportions 47.28%, 36.56%, and 6.67%, respectively. Extracted fatty acids from both species are mainly unsaturated, respectively, 89.87% and 88.01%. Pinus halepensis cis-5 olefinic acids are more abundant (7.84% compared to 2.24%). Results will be important as a good indication of the potential nutraceutical value of Pinus seeds as new sources of fruit oils rich in polyunsaturated fatty acids and cis-5 olefinic acids. PMID:15932286

Nasri, Nizar; Khaldi, Abdelhamid; Hammami, Mohamed; Triki, Saida

2005-01-01

52

LDL and HDL oxidation and fatty acid composition in vegetarians.  

PubMed

The oxidation of low-density lipoproteins (LDL) and high-density lipoproteins (HDL) and fatty acid composition, which may affect the resistance of lipoproteins to oxidation, were determined in 24 lacto-ovo vegetarians. Vegetarian diets contain more essential polyunsaturated fatty acids (PUFAs). Therefore, the relationship between LDL and HDL oxidation resistance measured by the kinetics of the formation of fatty acid conjugated dienes (lag time, maximal rate of oxidation and maximal amount of conjugated dienes), LDL and HDL fatty acid composition and vitamin E content were evaluated. All parameters of in vitro oxidation were significantly lower in HDL when compared with LDL. The relative values of arachidonic, dihomo-gamma-linoleic and docosahexaenoic acid were significantly higher in HDL, alpha-linolenic acid content significantly lower, when compared with LDL; the peroxidizability index was significantly higher in HDL. The content of vitamin E was found more than 2-fold lower in HDL particles. The results show the importance of fatty acid composition in the resistance of LDL and HDL to oxidation and from this aspect, the composition of LDL isolated from vegetarians seems to be more favourable compared to HDL. PMID:11463997

Nagyová, A; Krajcovicová-Kudlácková, M; Klvanová, J

2001-01-01

53

Apple juice composition: sugar, nonvolatile acid, and phenolic profiles.  

PubMed

Apples from Michigan, Washington, Argentina, Mexico, and New Zealand were processed into juice; the 8 samples included Golden Delicious, Jonathan, Granny Smith, and McIntosh varieties. Liquid chromatography was used for quantitation of sugars (glucose, fructose, sucrose, and sorbitol), nonvolatile acids (malic, quinic, citric, shikimic, and fumaric), and phenolics (chlorogenic acid and hydroxymethylfurfural [HMF]). Other determinations included pH, 0Brix, and L-malic acid. A number of compositional indices for these authentic juices, e.g., chlorogenic acid content, total malic - L-malic difference, and the HMF:chlorogenic ratio, were at variance with recommended standards. The phenolic profile was shown to be particularly influenced by gelatin fining, with peak areas decreasing by as much as 50%. The L-malic:total malic ratio serves as a better index for presence of synthetic malic acid than does the difference between the 2 determinations. No apparent differences in chemical composition could be attributed to geographic origin. PMID:3417603

Lee, H S; Wrolstad, R E

1988-01-01

54

Analysis of fatty acid content and composition in microalgae.  

PubMed

A method to determine the content and composition of total fatty acids present in microalgae is described. Fatty acids are a major constituent of microalgal biomass. These fatty acids can be present in different acyl-lipid classes. Especially the fatty acids present in triacylglycerol (TAG) are of commercial interest, because they can be used for production of transportation fuels, bulk chemicals, nutraceuticals (?-3 fatty acids), and food commodities. To develop commercial applications, reliable analytical methods for quantification of fatty acid content and composition are needed. Microalgae are single cells surrounded by a rigid cell wall. A fatty acid analysis method should provide sufficient cell disruption to liberate all acyl lipids and the extraction procedure used should be able to extract all acyl lipid classes. With the method presented here all fatty acids present in microalgae can be accurately and reproducibly identified and quantified using small amounts of sample (5 mg) independent of their chain length, degree of unsaturation, or the lipid class they are part of. This method does not provide information about the relative abundance of different lipid classes, but can be extended to separate lipid classes from each other. The method is based on a sequence of mechanical cell disruption, solvent based lipid extraction, transesterification of fatty acids to fatty acid methyl esters (FAMEs), and quantification and identification of FAMEs using gas chromatography (GC-FID). A TAG internal standard (tripentadecanoin) is added prior to the analytical procedure to correct for losses during extraction and incomplete transesterification. PMID:24121679

Breuer, Guido; Evers, Wendy A C; de Vree, Jeroen H; Kleinegris, Dorinde M M; Martens, Dirk E; Wijffels, René H; Lamers, Packo P

2013-01-01

55

Polyunsaturated fatty acid saturation by gut lactic acid bacteria affecting host lipid composition  

PubMed Central

In the representative gut bacterium Lactobacillus plantarum, we identified genes encoding the enzymes involved in a saturation metabolism of polyunsaturated fatty acids and revealed in detail the metabolic pathway that generates hydroxy fatty acids, oxo fatty acids, conjugated fatty acids, and partially saturated trans-fatty acids as intermediates. Furthermore, we observed these intermediates, especially hydroxy fatty acids, in host organs. Levels of hydroxy fatty acids were much higher in specific pathogen-free mice than in germ-free mice, indicating that these fatty acids are generated through polyunsaturated fatty acids metabolism of gastrointestinal microorganisms. These findings suggested that lipid metabolism by gastrointestinal microbes affects the health of the host by modifying fatty acid composition. PMID:24127592

Kishino, Shigenobu; Takeuchi, Michiki; Park, Si-Bum; Hirata, Akiko; Kitamura, Nahoko; Kunisawa, Jun; Kiyono, Hiroshi; Iwamoto, Ryo; Isobe, Yosuke; Arita, Makoto; Arai, Hiroyuki; Ueda, Kazumitsu; Shima, Jun; Takahashi, Satomi; Yokozeki, Kenzo; Shimizu, Sakayu; Ogawa, Jun

2013-01-01

56

Mycolic Acid Composition and Thermally Adaptative Changes in Nocardia asteroides  

PubMed Central

The nocardomycolic acid compositions of extractable and the cell wall-bound lipids from five strains of Nocardia asteroides (A-23007, A-23094, B-23006, B-23095, and IFO 3384) were compared by using gas chromatography-mass spectrometry. The molecular species composition of mycolic acid differed significantly among the strains of N. asteroides. The A-23007 strain possessed the shortest species, centering at C44(46), and the A-23094 and IFO-3384 strains followed, each centering at C52. The B-23006 and B-23095 strains possessed the longest species, centering at C56 or C54, thus indicating that N. asteroides strains accommodate a heterogeneous group in respect to carbon numbers of mycolic acids. The doublebond isomers of mycolic acids from the representative strain IFO 3384 were fully separated and analyzed by argentation thin-layer chromatography, followed by gas chromatography-mass spectrometry. The reference strain (IFO 3384) possessed up to four double bonds on the straight chain of mycolic acids ranging from C46 to C60. All of the species possessed a C14 alkyl branch at C-2. The more highly unsaturated subclasses consisted of the longer-chain mycolic acids. Marked changes in mycolic acid composition were induced by altering the growth temperature of strain IFO 3384. The cells grown at the higher temperature (50°C) contained more saturated mycolic acids, whereas those grown at the lower temperature (17°C) had more polyunsaturated (up to tetraenoic) mycolic acids, although a significant difference in carbon chain length was not detected. These changes in the degree of unsaturation of mycolic acids occurred shortly after shifting the growth temperature from 17 to 50°C at logarithmic stages of the bacterial growth, thus indicating that N. asteroides can adapt to changes in the environmental temperature by altering the structure of mycolic acids of the cell walls. Images PMID:7047498

Tomiyasu, Ikuko

1982-01-01

57

Nucleic acid compositions and the encoding proteins  

SciTech Connect

The subject invention provides at least one nucleic acid sequence encoding an aldouronate-utilization regulon isolated from Paenibacillus sp. strain JDR-2, a bacterium which efficiently utilizes xylan and metabolizes aldouronates (methylglucuronoxylosaccharides). The subject invention also provides a means for providing a coordinately regulated process in which xylan depolymerization and product assimilation are coupled in Paenibacillus sp. strain JDR-2 to provide a favorable system for the conversion of lignocellulosic biomass to biobased products. Additionally, the nucleic acid sequences encoding the aldouronate-utilization regulon can be used to transform other bacteria to form organisms capable of producing a desired product (e.g., ethanol, 1-butanol, acetoin, 2,3-butanediol, 1,3-propanediol, succinate, lactate, acetate, malate or alanine) from lignocellulosic biomass.

Preston, III, James F.; Chow, Virginia; Nong, Guang; Rice, John D.; St. John, Franz J.

2014-09-02

58

Fatty Acid Composition of Pistachio Nuts in Turkey  

Microsoft Academic Search

In this study oil yields and fatty acid compositions in the kernels of two varieties (Uzun and Siirt) of pistachio grown in different region of Turkey were investigated. Kernel oils were obtained by Soxhlet extraction using petroleum ether. The yields were found to be 57.1-58.9% and 56.1-62.6 respectively for the Uzun and Siirt varieties, on a moisture-free basis. Fatty acid

F. Satil; N. Azcan; K. H. C. Baser

2003-01-01

59

Proximate Composition and Fatty Acid Profile in Brazilian Poultry Sausages  

Microsoft Academic Search

Moisture, protein, ash, cholesterol and lipid contents, as well as the fatty acids composition of turkey, Chester®, chicken and common-type sausages from main Brazilian brands were determined. Analyses of cholesterol and fatty acids methyl esters were made by capillary gas chromatography. Sausages presented a lipid content between 4% (turkey) and 17% (common-type sausages). The cholesterol content was 44 for Chester®and

Nadia R. Pereira; Cesar R. T. Tarley; Makoto Matsushita; Nilson E. de Souza

2000-01-01

60

Eicosapentaenoic Acid Supplementation Changes Fatty Acid Composition and Corrects Endothelial Dysfunction in Hyperlipidemic Patients  

PubMed Central

We investigated the effects of purified eicosapentaenoic acid (EPA) on vascular endothelial function and free fatty acid composition in Japanese hyperlipidemic subjects. In subjects with hyperlipidemia (total cholesterol ?220?mg/dL and/or triglycerides ?150?mg/dL), lipid profile and forearm blood flow (FBF) during reactive hyperemia were determined before and 3 months after supplementation with 1800?mg/day EPA. Peak FBF during reactive hyperemia was lower in the hyperlipidemic group than the normolipidemic group. EPA supplementation did not change serum levels of total, HDL, or LDL cholesterol, apolipoproteins, remnant-like particle (RLP) cholesterol, RLP triglycerides, or malondialdehyde-modified LDL cholesterol. EPA supplementation did not change total free fatty acid levels in serum, but changed the fatty acid composition, with increased EPA and decreased linoleic acid, ?-linolenic acid, and dihomo-?-linolenic acid. EPA supplementation recovered peak FBF after 3 months. Peak FBF recovery was correlated positively with EPA and EPA/arachidonic acid levels and correlated inversely with dihomo-?-linolenic acid. EPA supplementation restores endothelium-dependent vasodilatation in hyperlipidemic patients despite having no effect on serum cholesterol and triglyceride patterns. These results suggest that EPA supplementation may improve vascular function at least partly via changes in fatty acid composition. PMID:23326753

Yamakawa, Ken; Shimabukuro, Michio; Higa, Namio; Asahi, Tomohiro; Ohba, Kageyuki; Arasaki, Osamu; Higa, Moritake; Oshiro, Yoshito; Yoshida, Hisashi; Higa, Tohru; Saito, Taro; Ueda, Shinichiro; Masuzaki, Hiroaki; Sata, Masataka

2012-01-01

61

Discriminability of tryptophan containing dipeptides using quantum control  

NASA Astrophysics Data System (ADS)

We show that the coherent manipulation of molecular wavepackets in the excited states of trp-containing dipeptides allows efficient discrimination among them. Optimal dynamic discrimination fails, however, for some dipeptide couples. When considering the limited spectral resources at play (3 nm bandwidth at 266 nm), we discuss the concept of discriminability, which appears uncorrelated to both static spectra and relaxation lifetimes.

Afonina, S.; Nenadl, O.; Rondi, A.; Bonacina, L.; Extermann, J.; Kiselev, D.; Dolamic, I.; Burgi, T.; Wolf, J. P.

2013-06-01

62

Fatty acid composition of frequently consumed foods in Turkey with special emphasis on trans fatty acids.  

PubMed

Fatty acid compositions of frequently consumed foods in Turkey were analyzed by capillary gas chromatography with particular emphasis on trans fatty acids. The survey was carried out on 134 samples that were categorized as meat products, chocolates, bakery products and others. The meat products except chicken-based foods have trans fatty acids, arising as a result of ruminant activity, with an average content of 1.45 g/100 g fatty acids. The conjugated linoleic acid content of meat and chicken doner kebabs were found higher than other meat products. Chocolate samples contained trans fatty acids less than 0.17 g/100 g fatty acids, with the exceptional national product of chocolate bars and hazelnut cocoa cream (2.03 and 3.68 g/100 g fatty acids, respectively). Bakery products have the highest trans fatty acid contents and ranged from 0.99 to 17.77 g/100 g fatty acids. The average trans fatty acid contents of infant formula and ice-cream, which are milk-based products, were 0.79 and 1.50 g/100 g fatty acids, respectively. Among the analyzed foods, it was found that coffee whitener and powdered whipped topping had the highest saturated fatty acid contents, with an average content of 98.71 g/100 g fatty acids. PMID:17852509

Karabulut, Ihsan

2007-12-01

63

Oleuropein on lipid and fatty acid composition of rat heart  

Microsoft Academic Search

Male rats of the Wistar strain were given oleuropein for 3 weeks at a dose of 25 or 50 mg\\/kg of body weight. Heart samples were analyzed for the lipid composition by the Iatroscan TLCFID technique and for the fatty acid profile of neutral and polar lipids by the capillary gas chromatography. In addition, the oleuropein, ?- and ?-tocopherol content

Valentina Ruíz-Gutiérrez; Francisco J. G. Muriana; Roberto Maestro; Enrique Graciani

1995-01-01

64

Corrosion of graphite composites in phosphoric acid fuel cells  

NASA Technical Reports Server (NTRS)

Polymers, polymer-graphite composites and different carbon materials are being considered for many of the fuel cell stack components. Exposure to concentrated phosphoric acid in the fuel cell environment and to high anodic potential results in corrosion. Relative corrosion rates of these materials, failure modes, plausible mechanisms of corrosion and methods for improvement of these materials are investigated.

Christner, L. G.; Dhar, H. P.; Farooque, M.; Kush, A. K.

1986-01-01

65

Factors Affecting Fatty Acid Composition in Forage and Milk  

E-print Network

Factors Affecting Fatty Acid Composition in Forage and Milk Katarina Arvidsson Faculty of Natural in Forage and Milk Abstract The aims of the studies underlying this thesis were to evaluate variations on the FA contents of the milk. Initially, samples of timothy (Phleum pratense L.) were subjected

66

Nanofiber composite membranes with low equivalent weight perfluorosulfonic acid polymers  

E-print Network

Nanofiber composite membranes with low equivalent weight perfluorosulfonic acid polymers Jonghyun February 2010, Accepted 5th May 2010 DOI: 10.1039/c0jm00441c Two low equivalent weight perfluorosulfonic as little as 0.3 wt% of high molecular weight poly(ethylene oxide) as a carrier polymer. The electrospun

Mather, Patrick T.

67

Water structure around dipeptides in aqueous solutions  

Microsoft Academic Search

The bulk water structure around small peptide fragments—glycyl-l-alanine, glycyl-l-proline and l-alanyl-l-proline—has been determined by a combination of neutron diffraction with isotopic substitution and empirical potential structural\\u000a refinement techniques. The addition of each of the dipeptides to water gives rise to decreased water–water coordination in\\u000a the surrounding water solvent. Additionally, both the Ow–Ow radial distribution functions and the water–water spatial density

Sylvia E. McLain; Alan K. Soper; Anthony Watts

2008-01-01

68

The Compositional Adjustment of Amino Acid Substitution Matrices  

NASA Astrophysics Data System (ADS)

Amino acid substitution matrices are central to protein comparison methods. In most commonly used matrices, the substitution scores take a log-odds form, involving the ratio of "target" to "background" frequencies derived from large, carefully curated sets of protein alignments. However, such matrices often are used to compare protein sequences with amino acid compositions that differ markedly from the background frequencies used for the matrices' construction. Of course the target frequencies should be adjusted in such cases, but the lack of an appropriate way to do this has been a long-standing problem. We show that if one demands consistency between target and background frequencies, then a log-odds substitution matrix implies a unique set of target and background frequencies, as well as a unique scale. Standard substitution matrices therefore are truly appropriate only for the comparison of proteins with standard amino acid composition. Accordingly, we present and evaluate a rationale for transforming the target frequencies implicit in a standard matrix to frequencies appropriate for a non-standard context. This rationale yields asymmetric matrices for the comparison of proteins with divergent compositions. Earlier approaches are unable to deal with this case in a fully consistent manner. Composition-specific substitution matrix adjustment is shown to be of utility for comparing compositionally biased proteins, including those of organisms with nucleotide-biased, and therefore codon-biased, genomes or isochores.

Yu, Yi-Kuo; Wootton, John; Altschul, Stephen

2004-03-01

69

Perfluoroalkyl acid contamination and polyunsaturated fatty acid composition of French freshwater and marine fishes.  

PubMed

In this study, French marine and freshwater fish perfluoroalkyl acid (PFAA) contamination are presented along with their fatty acid (FA) composition to provide further elements for a risk/benefit balance of fish consumption to be assessed. The 29 most consumed marine fish species were collected in four metropolitan French coastal areas in 2004 to constitute composite samples. Geographical differences in terms of consumed species and contamination level were taken into account. Three hundred and eighty-seven composite samples corresponding to 16 freshwater fish species collected between 2008 and 2010 in the six major French rivers or their tributaries were selected among the French national agency for water and aquatic environments freshwater fish sample library. The raw edible parts were analyzed for FA composition and PFAA contamination. Results show that freshwater fishes are more contaminated by PFAAs than marine fishes and do not share the same contamination profile. Freshwater fish contamination is mostly driven by perfluorooctane sulfonate (PFOS) (75%), whereas marine fish contamination is split between perfluorooctanoic acid (PFOA) (24%), PFOS (20%), perfluorohexanoic acid (PFHxA) (15%), perfluoropentanoic acid (PFHpA) (11%), and perfluorobutanoic acid (PFBA) (11%). Common carp, pike-perch, European perch, thicklip grey mullet, and common roach presented the most unfavorable balance profile due to their high level of PFAAs and low level of n-3 long-chain polyunsaturated fatty acids (LC-PUFAs). These data could be used, if needed, in an updated opinion on fish consumption that takes into account PFAA contamination. PMID:25004121

Yamada, Ami; Bemrah, Nawel; Veyrand, Bruno; Pollono, Charles; Merlo, Mathilde; Desvignes, Virginie; Sirot, Véronique; Oseredczuk, Marine; Marchand, Philippe; Cariou, Ronan; Antignac, Jean-Phillippe; Le Bizec, Bruno; Leblanc, Jean-Charles

2014-07-30

70

Dynamics of membrane fatty acid composition of succinic acid-producing Anaerobiospirillum succiniciproducens.  

PubMed

The dynamics of the membrane fatty acid composition of a succinic acid-producing bacterium, Anaerobiospirillum succiniciproducens, was studied using continuous and batch cultures. In both batch and chemostat continuous culture conditions, A. succiniciproducens grown on glucose or glycerol responded to acid stress by lowering the content of saturated fatty acids (SFAs) and increasing the content of unsaturated fatty acids (UFAs). Notably, A. succiniciproducens elongated C16:0 (SFA) and converted it to C18:1 (UFA) in the pH-uncontrolled culture, which is a common bacterial adaptation strategy to combat acid stress. Interestingly, A. succiniciproducens did not exhibit a significant increase in cyclic FA content, which is another common strategy to cope with acidic conditions. PMID:25483318

Hwang, Hee Jin; Choi, Seung Phill; Lee, Sang Yup; Choi, Joing-Il; Han, Se Jong; Lee, Pyung Cheon

2015-01-10

71

Chemical composition of acid rains in the Venezuelan savannah region  

NASA Astrophysics Data System (ADS)

The chemical composition of rain events has been determined at 6 sites in the Venezuelan savannah region. The results indicate that precipitations are little affected by anthropogenic emissions and that rain concentrations of anions and cations are similar to those observed at "remote" continental sites. At each location, the rain is acidic with average pHs ranging from 4.4 to 5.4. Over 50% of the free acidity may be due to formic and acetic acids. HNO3 and H2SO4 contribute only less than 36%. NH3 plays a significant role as neutralizing compound; Ca and Mg carbonates may also, in some cases, reduce the acidity of the rain solution. A complete evaluation of the ions that take part in the acid-base equilibrium is given. The participation of organic acid is discussed in detail. The first rains of the season, during biomass burning periods, are heavily loaded with several compounds, showing that emissions and/or atmospheric production are enhanced during vegetation fires. No significant variation in rain acidity was observed; it is likely that the larger atmospheric photochemical formation of organic and inorganic acids during burning is neutralized by a large primary emission of NH3. The study of these "particular" rains is useful in searching for pollutants emitted by fires and/or possible atmospheric processes that may occur in the associated haze layer.

Sanhueza, E.; Arias, M. C.; Donoso, L.; Graterol, N.; Hermoso, M.; Martí, I.; Romero, J.; Rondón, A.; Santana, M.

1992-02-01

72

Proline-beta(3)-amino-ester dipeptides as efficient catalysts for enantioselective direct aldol reaction in aqueous medium.  

PubMed

Dipeptides obtained from l-proline and beta(3)-l-amino acids are reported to catalyze enantioselective direct aldol reaction in aqueous medium, leading to significant anti:syn diastereomeric ratios and enantiomeric excesses. The simple introduction of a polar substituent at the C-2 position of the beta(3)-l-amino acid was also found to enhance appreciably both diastereo- and enantioselectivity of the catalyst. PMID:19938836

De Nisco, Mauro; Pedatella, Silvana; Ullah, Hidayat; Zaidi, Javid H; Naviglio, Daniele; Ozdamar, Ozgür; Caputo, Romualdo

2009-12-18

73

Fatty acid composition of fat depots in wintering Canada geese  

USGS Publications Warehouse

I determined the fatty acid composition of subcutaneous, abdominal, visceral, and leg saddle depots in adult female Canada Geese (Branta canadensis) wintering in north-central Missouri during October 1984-March 1985. Mean levels of C14:0, C16:0, C16:1, C18:0, C18:1, C18:2, and C18:3 generally were highest in the subcutaneous and abdominal depots. The ratio of saturated to unsaturated fats was highest in the leg saddle depot and lowest in the abdominal depot. I also assessed the differences among sexes, seasons, and years in fatty acid composition of abdominal fat depots in adult geese collected during October-March, 1985-1987. Adult females had consistently higher levels of C14:0 in abdominal depots than males. Fatty acid composition of the abdominal depot differed among years but not by season. In the abdominal depot, C14:0, C16:0, C16:1, and C18:1 were higher in 1986-1987 compared with the previous two years, whereas C18:3 was highest in 1984-1985. Differences among years reflected changes in winter diet. Fatty acids of wintering geese were similar to those previously found in breeding Canada Geese.

Austin, J.E.

1993-01-01

74

Fatty acid composition of Swedish bakery products, with emphasis on trans-fatty acids.  

PubMed

Trans-fatty acids (TFA) have been associated with increased risk of coronary heart disease, by affecting blood lipids and inflammation factors. Current nutrition recommendations emphasise a limitation of dietary TFA intake. The aim of this study was to investigate fatty acid composition in sweet bakery products, with emphasis on TFA, on the Swedish market and compare fatty acid composition over time. Products were sampled in 2001, 2006 and 2007 and analysed for fatty acid composition by using GC. Mean TFA levels were 0.7% in 2007 and 5.9% in 2001 of total fatty acids. In 1995-97, mean TFA level was 14.3%. In 2007, 3 of 41 products had TFA levels above 2% of total fatty acids. TFA content had decreased in this product category, while the proportion of saturated (SFA) and polyunsaturated (PUFA) fatty acids had increased, mostly through increased levels of 16:0 and 18:2 n-6, respectively. The total fat content remained largely unchanged. PMID:25577101

Trattner, Sofia; Becker, Wulf; Wretling, Sören; Öhrvik, Veronica; Mattisson, Irene

2015-05-15

75

Kinetics of degradation and oil solubility of ester prodrugs of a model dipeptide (Gly-Phe).  

PubMed

Oil-based depot formulations may constitute a future delivery method for small peptides. Thus, a requirement is attainment of sufficient oil solubility for such active compounds. A model dipeptide (Gly-Phe) has been converted into lipophilic prodrugs by esterification at the C-terminal carboxylic acid group. The decomposition kinetics of octyl ester of Gly-Phe (IV) has been investigated at pH 7.4 (37 degrees C) and IV was shown to degrade by first-order kinetics via two parallel pathways (1) intramolecular aminolysis resulting in formation of a 2,5-diketopiperazine and (2) hydrolysis of the ester bond producing the dipeptide. The cyclisation reaction was dominating in the decomposition of methyl (II) butyl (III) octyl (IV) decyl (V) and dodecyl (VI) esters of Gly-Phe at pH 7.4. However, this degradation pathway was almost negligible for pH below 6. During degradation of the dipeptide esters in 80% human plasma pH 7.4 (37 degrees C) a minimal amount of cyclo(-Gly-Phe) was formed. A faster degradation of the esters in 80% human plasma pH 7.4 compared to those in aqueous solution pH 7.4 was suggested to be due to fast cleavage of the peptide bond. Low oil solubilities for Gly-Phe and the hydrochlorides of the dipeptide esters III and VI were observed. Although the solubility of Gly-Phe in oil solutions was enhanced by hydrophobic ion pairing with sodium decyl sulfonate the oil solubility was still less than 1 mg Gly-Phe/ml. By addition of a solubiliser, 10% N,N-dimethylacetamide (DMA), to Viscoleo the solubility of the HIP complexes increased significantly. The present study indicates that sufficient oil solubility might only be obtained for relatively small peptides by using the prodrug approach in combination with solubility enhancing organic solvents like DMA. PMID:15265509

Larsen, Susan Weng; Ankersen, Michael; Larsen, Claus

2004-08-01

76

A molecular dynamics study of the dielectric properties of aqueous solutions of alanine and alanine dipeptide  

NASA Astrophysics Data System (ADS)

Molecular dynamics simulations were used to compute the frequency-dependent dielectric susceptibility of aqueous solutions of alanine and alanine dipeptide. We studied four alanine solutions, ranging in concentration from 0.13-0.55 mol/liter, and two solutions of alanine dipeptide (0.13 and 0.27 mol/liter). In accord with experiment we find a strong dielectric increment for both solutes, whose molecular origin is shown to be the zwitterionic nature of the solutes. The dynamic properties were analyzed based on a dielectric component analysis into solute, a first hydration shell, and all remaining (bulk) waters. The results of this three component decomposition were interpreted directly, as well as by uniting the solute and hydration shell component to a "suprasolute" component. In both approaches three contributions to the frequency-dependent dielectric properties can be discerned. The quantitatively largest and fastest component arises from bulk water [i.e., water not influenced by the solute(s)]. The interaction between waters surrounding the solute(s) (the hydration shell) and bulk water molecules leads to a relaxation process occurring on an intermediate time scale. The slowest relaxation process originates from the solute(s) and the interaction of the solute(s) with the first hydration shell and bulk water. The primary importance of the hydration shell is the exchange of shell and bulk waters; the self-contribution from bound water molecules is comparatively small. While in the alanine solutions the solute-water cross-terms are more important than the solute self-term, the solute contribution is larger in the dipeptide solutions. In the latter systems a much clearer separation of time scales between water and alanine dipeptide related properties is observed. The similarities and differences of the dielectric properties of the amino acid/peptide solutions studied in this work and of solutions of mono- and disaccharides and of the protein ubiquitin are discussed.

Boresch, Stefan; Willensdorfer, Martin; Steinhauser, Othmar

2004-02-01

77

An efficient method for the synthesis of phenacyl ester-protected dipeptides using neutral alumina-supported sodium carbonate 'Na2 CO3 /n-Al2 O3 '.  

PubMed

In the synthesis of dipeptides (Boc-AA(1)-AA(2)-OPac: AA(1) and AA(2) represent amino acids) protected by phenacyl (Pac) ester, amines and solid bases as the base for the conversion of the trifluoroacetic acid (TFA) salt of the amino component (TFA·H-AA(2)-OPac) into the corresponding free amino component (H-AA(2)-OPac) were examined. The synthesis of a dipeptide (Boc-Ala-Gly-OPac) using amines for the conversion afforded an unsatisfactory yield with by-products. On the other hand, the use of neutral alumina-supported Na(2) CO(3) (Na(2)CO(3) /n-Al(2)O(3)) as a solid base for the conversion provided the dipeptide in a quantitative yield without by-products. The application of Na(2)CO(3) /n-Al2 O3 to the synthesis of some dipeptides protected by Pac ester gave the desired peptides in excellent yields. PMID:23982992

Hashimoto, Chikao; Sugimoto, Kazuhiro; Takahashi, Youhei; Kodomari, Mitsuo

2013-10-01

78

Fatty acid composition of spermatozoa and immature germ cells.  

PubMed

A great deal of attention has recently been given to the essential role of polyunsaturated fatty acids (PUFA) of sperm membranes. We studied the fatty acid composition of the immature germ cells (IGC) and of the sperm populations separated by Percoll gradient in the ejaculate of normozoospermic patients. Fatty acid pattern was analysed by combined gas chromatography-mass spectrometry on a capillary column. In IGC, differences were found compared with mature spermatozoa, with a higher percentage of saturated fatty acids and of essential fatty acids. On the contrary, the long-chain PUFA were significantly lower in IGC. The highest concentration of n3 PUFA docohexaenoic acid (DHA) was detected in the spermatozoa deriving from 70-100% Percoll layers and a direct linear correlation was found between the increase of DHA and increased percentage of Percoll gradient. An inverse relationship between the percentage of atypical sperm forms in each layer and the percentage of DHA was also observed. This study demonstrates that the human germ cell line can elongate and desaturate essential fatty acids and that the percentage of long-chain PUFA is correlated with the normal morphology of sperm cells. PMID:10694269

Lenzi, A; Gandini, L; Maresca, V; Rago, R; Sgrò, P; Dondero, F; Picardo, M

2000-03-01

79

The Dipeptide H-Trp-Arg-OH (WR) Is a PPAR? Agonist and Reduces Hepatic Lipid Accumulation in Lipid-Loaded H4IIE Cells.  

PubMed

Dipeptides absorbed by the intestinal epithelium are delivered to circulation, but their metabolic roles are not yet clearly understood. We investigated the biological activities of a dietary dipeptide, H-Trp-Arg-OH (WR), on the regulation of peroxisome proliferator-activated receptor (PPAR) ? activity. Reporter gene assays revealed that WR dose-dependently induced PPAR? transactivation. Surface plasmon resonance experiments demonstrated that WR interacts directly with the PPAR? ligand binding domain, and time-resolved fluorescence energy transfer analyses revealed recruitment of a co-activator peptide, fluorescein-PGC1?, to PPAR?, confirming the direct binding of WR to PPAR? and occurrence of conformational changes. WR induced cellular fatty acid uptake and the expression of PPAR? response genes in fatty acid oxidation, thus reducing intracellular triglyceride accumulation in lipid-loaded hepatocytes. In conclusion, the dietary dipeptide WR activates PPAR? and reduces hepatic lipid accumulation in lipid-loaded hepatocytes. PMID:25377249

Jia, Yaoyao; Kim, Jong-Ho; Nam, Bora; Kim, Jiyoung; Lee, Ji Hae; Kim, Kyung Ok; Hwang, Kwang Yeon; Lee, Sung-Joon

2015-01-01

80

Fatty acid composition of meat from ruminants, with special emphasis on trans fatty acids  

Microsoft Academic Search

The fatty acid composition was determined in 39 samples of beef, 20 samples of veal, and 34 samples of lamb, representative\\u000a of the supply of ruminant meat in Denmark. Five cuts of beef and veal and three cuts of lamb with increasing fat content were\\u000a selected, and analysis of the fatty acid methyl esters was performed by gas-liquid chromatography (GLC)

Torben Leth; Lars Ovesen; Kirsten Hansen

1998-01-01

81

The effect of conjugated linoleic acid on plasma lipoproteins and tissue fatty acid composition in humans  

Microsoft Academic Search

Conjugated linoleic acid (CLA) has been suggested by some animal studies to possess antiatherogenic properties. To determine,\\u000a in humans, the effect of dietary CLA on blood lipids, lipoproteins, and tissue fatty acid composition, we conducted a 93-d\\u000a study with 17 healthy female volunteers at the Metabolic Research Unit of the Western Human Nutrition Research Center. Throughout\\u000a the study, subjects were

P. Benito; G. J. Nelson; D. S. Kelley; G. Bartolini; P. C. Schmidt; V. Simon

2001-01-01

82

What shapes amino acid and sugar composition in Mediterranean floral nectars?  

E-print Network

What shapes amino acid and sugar composition in Mediterranean floral nectars? Theodora Petanidou. 2006. What shapes amino acid and sugar composition in Mediterranean floral nectars? Á Oikos 115: 155Á169. We studied the amino acid (AA) composition of the floral nectars of 73 plant species occurring

Petanidou, Theodora

83

Amino Acid Composition-Dependent Elasticity of SPIDER Silk  

NASA Astrophysics Data System (ADS)

Spider silk exhibits excellent mechanical features in both toughness and extensibility. In recent years considerable investigations have focused on it. The understanding of spider silk protein is important for the development bionic silk. In this paper, we study by Monte Carlo simulation the force-of-extension property of spider silk proteins as a function of the residue composition for major and minor ampullate glands of typical Araneid orb weaver as well as that for one artificial spider silk. The results are also compared with those from a designed protein whose amino acid composition is uniform. The results clearly show that the major and minor ampullate gland proteins are much tougher than the designed protein, whereas the artificial protein, as a model of a nature spider silk, does have good mechanical properties. Our simulation reveals that mechanical property of a spider silk protein is dependent on its amino acid composition and that an excellent result of natural evolution is manifest in the composition of the spider silk protein.

Zhang, Yong; Dai, Luru; Ou-Yang, Zhong-Can

84

Fatty acid composition and cyclopropene fatty acid content of China-chestnuts ( Sterculia monosperma , ventenat)  

Microsoft Academic Search

The China-chestnuts (Sterculia monosperma, Ventenat) were examined for their fatty acid composition by gas liquid chromatography, infrared and nuclear magnetic resonance\\u000a spectroscopy. The oil in nuts contained cyclopropene fatty acids (CPFA) determined as silver nitrate derivatives of their\\u000a esters. The values (area %) for the major fatty acids as methyl esters were 23.47% C16:0, 1.25% C16:1, 2.56% C18:0, 24.89%\\u000a C18:1,

S. K. Berry

1982-01-01

85

Postnatal changes in fatty acids composition of brown adipose tissue  

NASA Astrophysics Data System (ADS)

It has been demonstrated that thermogenic activity of brown adipose tissue (BAT) is higher during the early postnatal period, decreasing towards a low adult level. The present study examined postnatal changes in the lipid composition of BAT. BAT from pre-weaning rats at 4 and 14 days old showed the following differences in lipid composition compared to that from adults of 12 weeks old. (i) Relative weight of interscapular BAT to body weight was markedly greater. (ii) BAT-triglyceride (TG) level was lower, while BAT-phospholipid (PL)level was higher. (iii) In TG fatty acids (FA) polyunsaturated fatty acids (PU; mol %), arachidonate index (AI), unsaturation index (UI) and PU/saturated FA (SA) were higher; rare FA such as eicosadienoate, bishomo- ?-linolenic acid and lignoceric acid in mol % were also higher. (iv) In PL-FA monounsaturated FA (MU) in mol % was lower; PU mol %, AI and UI were higher. These features in BAT of pre-weaning rats resembled those in the cold-acclimated adults, suggesting a close relationship of the PL-FA profile to high activity of BAT.

Ohno, T.; Ogawa, K.; Kuroshima, A.

1992-03-01

86

Cyclic dipeptides: from bugs to brain.  

PubMed

Cyclic dipeptides (CDPs) are a group of hormone-like molecules that are evolutionarily conserved from bacteria to humans. In bacteria, CDPs are used in quorum sensing (QS) to communicate information about population size and to regulate a behavioural switch from symbiosis with their host to virulence. In mammals, CDPs have been shown to act on glial cells (macrophage-like cells) to control a conceptually homologous behavioural switch between homeostatic and inflammatory modes, with implications for the control of neurodegenerative disease. Here we argue that, because of their capacity to regulate inflammation via glial cells and induce a protective response in neuronal cells, CDPs have potential therapeutic utility in an array of inflammatory diseases. PMID:25217340

Bellezza, Ilaria; Peirce, Matthew J; Minelli, Alba

2014-10-01

87

TRIACYLGLYCEROL AND PHOSPHOLIPID FATTY ACID COMPOSITIONS OF THE SILVERLEAF WHITEFLY, BEMISIA ARGENTIFOLII  

Technology Transfer Automated Retrieval System (TEKTRAN)

The identification and composition of the fatty acids associated with the major lipid classes (triacylglycerols, free fatty acids, phospholipids) within Bemisia argentifolii Bellows and Perring (Homoptera: Aleyrodidae) nymphs were determined. Comparisons were made to the fatty acids from the interna...

88

The tRNA-Dependent Biosynthesis of Modified Cyclic Dipeptides  

PubMed Central

In recent years it has become apparent that aminoacyl-tRNAs are not only crucial components involved in protein biosynthesis, but are also used as substrates and amino acid donors in a variety of other important cellular processes, ranging from bacterial cell wall biosynthesis and lipid modification to protein turnover and secondary metabolite assembly. In this review, we focus on tRNA-dependent biosynthetic pathways that generate modified cyclic dipeptides (CDPs). The essential peptide bond-forming catalysts responsible for the initial generation of a CDP-scaffold are referred to as cyclodipeptide synthases (CDPSs) and use loaded tRNAs as their substrates. After initially discussing the phylogenetic distribution and organization of CDPS gene clusters, we will focus on structural and catalytic properties of CDPSs before turning to two recently characterized CDPS-dependent pathways that assemble modified CDPs. Finally, possible applications of CDPSs in the rational design of structural diversity using combinatorial biosynthesis will be discussed before concluding with a short outlook. PMID:25196600

Giessen, Tobias W.; Marahiel, Mohamed A.

2014-01-01

89

Polylactic acid composites incorporating casein functionalized cellulose nanowhiskers  

PubMed Central

Background Polylactic acid (PLA) is considered to be a sustainable alternative to petroleum-based polymers for many applications. Using cellulose fiber to reinforce PLA is of great interest recently due to its complete biodegradability and potential improvement of the mechanical performance. However, the dispersion of hydrophilic cellulose fibers in the hydrophobic polymer matrix is usually poor without using hazardous surfactants. The goal of this study was to develop homogenously dispersed cellulose nanowhisker (CNW) reinforced PLA composites using whole milk casein protein, which is an environmentally compatible dispersant. Results In this study, whole milk casein was chosen as a dispersant in the PLA-CNW system because of its potential to interact with the PLA matrix and cellulose. The affinity of casein to PLA was studied by surface plasmon resonance (SPR) imaging. CNWs were functionalized with casein and used as reinforcements to make PLA composites. Fluorescent staining of CNWs in the PLA matrix was implemented as a novel and simple way to analyze the dispersion of the reinforcements. The dispersion of CNWs in PLA was improved when casein was present. The mechanical properties of the composites were studied experimentally. Compared to pure PLA, the PLA composites had higher Young’s modulus. Casein (CS) functionalized CNW reinforced PLA (PLA-CS-CNW) at 2 wt% filler content maintained higher strain at break compared to normal CNW reinforced PLA (PLA-CNW). The Young’s modulus of PLA-CS-CNW composites was also higher than that of PLA-CNW composites at higher filler content. However, all composites exhibited lower strain at break and tensile strength at high filler content. Conclusions The presence of whole milk casein improved the dispersion of CNWs in the PLA matrix. The improved dispersion of CNWs provided higher modulus of the PLA composites at higher reinforcement loading and maintained the strain and stress at break of the composites at relatively low reinforcement loading. The affinity of the dispersant to PLA is important for the ultimate strength and stiffness of the composites. PMID:24341897

2013-01-01

90

Metal-ion-assisted hydrolysis of dipeptides involving a serine residue in a neutral aqueous solution.  

PubMed

Dipeptides having a serine residue at the C-terminus, X-Ser, where X is an appropriate amino acid residue, were efficiently hydrolyzed in the presence of ZnCl2 at pH 7.0. The rapid hydrolysis of X-Ser is due to an autocatalysis of the hydroxy group in the serine residue, and is found to be accelerated by a metal ion, in particular by ZnCl2. Roles of the metal ion in the hydrolysis of peptides involving a serine residue, in relation to the recently reported protein cleavages, are discussed. PMID:12929447

Yashiro, Morio; Sonobe, Yoko; Yamamura, Ai; Takarada, Tohru; Komiyama, Makoto; Fujii, Yuki

2003-02-21

91

Evaluation of Fatty Acid and Amino Acid Compositions in Okra (Abelmoschus esculentus) Grown in Different Geographical Locations  

PubMed Central

Okra has different uses as a food and a remedy in traditional medicine. Since it produces many seeds, distribution of the plant is also quite easy. Although seed oil yield is low (4.7%), since the linoleic acid composition of the seed oil is quiet high (67.5%), it can still be used as a source of (UNSAT) unsaturated fatty acids. In this study, samples of okra grown in four different locations were analyzed to measure fatty acid and amino acid compositions. The content of the lipid extraction ranged from 4.34% to 4.52% on a dry weight basis. Quantitatively, the main okra fatty acids were palmitic acid (29.18–43.26%), linoleic acid (32.22–43.07%), linolenic acid (6.79–12.34%), stearic acid (6.36–7.73%), oleic acid (4.31–6.98%), arachidic acid (ND–3.48%), margaric acid (1.44–2.16%), pentadecylic acid (0.63–0.92%), and myristic acid (0.21–0.49%). Aspartic acid, proline, and glutamic acids were the main amino acids in okra pods, while cysteine and tyrosine were the minor amino acids. Statistical methods revealed how the fatty acid and amino acid contents in okra may be affected by the sampling location. PMID:24171167

Sami, Rokayya; Lianzhou, Jiang; Yang, Li; Ma, Ying; Jing, Jing

2013-01-01

92

Composition of Humic Acids of the Lake Baikal Sediments  

NASA Astrophysics Data System (ADS)

Humic substances are the final stage of the biogeochemical transformation of organic matter in the biosphere. Its natural compounds are found not only in soil, peat, coal, and sediments of basins. Chemical composition and properties of humic substances are determined by the functioning of the ecosystem as a whole. Therefore the study of the unique Lake Baikal sediments can provide information about their genesis, as well as the processes of organic matter transformation. For this purpose, preparations of humic acids (HA) were isolated by alkaline extraction method. The composition of HA was investigated by the elemental analyzer CHNS/O PerkinElmer Series II. Various located sediments of the Lake Baikal were the objects of the study: 1 - Chivyrkuisky Bay, 2 - Kotovo Bay, 3 - Selenga river delta near Dubinino village, 4 - Selenga river delta near Murzino village. Data on the elemental composition of HA in terms of ash-free portion show that the carbon content (CC) is of 50-53% with a maximum value in a sample 3, and minimum - in a sample 2. Such values are characteristic also for the soils with low biochemical activity. The hydrogen content is of 4,2-5,3%, a maximum value is in a sample 1. Data recalculation to the atomic percentages identified following regularities. The CC of HA is of 35-39 at. %. Hydrogen content is of 37-43 at. %. According to the content of these elements investigated substances are clearly divided into two groups: HA of the sediments of the Lake Baikal and river Selenga delta. The magnitude of the atomic ratio H/C can be seen varying degrees of condensation of the molecules of humic acids. The high atomic ratio H/C in HA of the former group indicates the predominance of aliphatic structures in the molecules. Humic acids of the later group are characterized by a low value H/C (<1), suggesting a large proportion of aromatic components in HA composition. In sediments of the Selenga river delta there is an addition of organic matter of terrigenous origin, the remains of higher plants are the most source of it. In the bays of the Lake Baikal the remains of aquatic animal organisms, other than algae, are the source of organic matter, that explain the marked differences in the HA composition. The nitrogen content in the studied HA is of 3,5-4,0 % (2 at. %), that corresponds to the lower boundary values for the soil HA. No significant differences in nitrogen content between preparations were found. HA of sediments vary widely in sulfur content: 0,5-4,6 %. Maximum sulfur content is observed in the HA of Chivyrkuy Bay, which is higher than this element content in the soil HA. Likely sources of organic matter in the sample 1 are enriched in sulfur-containing amino acids such as cystine, cysteine, methionine, which is reflected in the composition of HA. Oxygen content is about 33,8-39,1% (17-22 at. %). Data analysis of the elemental composition of humic acids of studied sediments indicates that the HA formed in subaqueous conditions of bays are slightly condensed, contain less carbon and more hydrogen, compared with HA of delta part sediments, which are more carbonized and enriched in aromatic components. Thus the last group of sediments is of mixed subaqueous and terrigenous origin.

Vishnyakova, O.; Chimitdorzhieva, G.; Andreeva, D.

2012-04-01

93

An amino acid composition criterion for membrane active antimicrobials  

NASA Astrophysics Data System (ADS)

Membrane active antimicrobials (AMPs) are short amphipathic peptides with broad spectrum anti microbial activity. While it is believed that their hydrophobic and cationic moieties are responsible for membrane-based mechanisms of action, membrane disruption by AMPs is manifested in a diversity of outcomes, such as pore formation, blebbing, and budding. This complication, along with others, have made a detailed, molecular understanding of AMPs difficult. We use synchrotron small angle xray scattering to investigate the interaction of model bacterial and eukaryotic cell membranes with archetypes from beta-sheet AMPs (e.g. defensins) and alpha-helical AMPs (e.g. magainins). The relationship between membrane composition and peptide induced changes in membrane curvature and topology is examined. By comparing the membrane rearrangement and phase behavior induced by these different peptides we will discuss the importance of amino acid composition on AMP design.

Schmidt, Nathan; Hwee Lai, Ghee; Mishra, Abhijit; Bong, Dennis; McCray, Paul, Jr.; Selsted, Michael; Ouellette, Andre; Wong, Gerard

2011-03-01

94

Acid gas scrubbing by composite solvent-swollen membranes  

DOEpatents

A composite immobilized liquid membrane suitable for acid gas scrubbing is disclosed. The membrane is a solvent-swollen polymer and a microporous polymeric support, the solvent being selected from a class of highly polar solvents containing at least one atom selected from nitrogen, oxygen, phosphorous and sulfur, and having a boiling point of at least 100.degree. C. and a solubility parameter of from about 7.5 to about 13.5 (cal/cm.sup.3 -atm).sup.1/2. Such solvents are homogeneously distributed through the solvent-swollen polymer from 20% to 95% by weight. Also disclosed are methods of acid gas scrubbing of high- and low-Btu gas effluents with such solvent-swollen membranes.

Matson, Stephen L. (Harvard, MA); Lee, Eric K. L. (Acton, MA); Friesen, Dwayne T. (Bend, OR); Kelly, Donald J. (Bend, OR)

1988-01-01

95

Effect of ursodeoxycholic acid administration on bile acid composition in hamster bile.  

PubMed

The modification in the composition of bile acids in hamster by the administration of high dose of ursodeoxycholic acid (UDCA) was investigated. Male Golden Syrian hamsters were divided into five groups: a control group, two groups that received 0.5 g of UDCA per 100 g of standard diet during 30 and 60 days and another two groups that received 1 g of UDCA per 100 g of standard diet during 30 and 60 days. After ether anaesthesia the gallbladder was removed and bile was immediately aspirated. Bile acids were determined by high performance liquid chromatography (HPLC). Taurolithocholic (TLCA) and glycolithocholic acids (GLCA) increased significantly in all treated groups. The glyco/tauro ratio of 0.69 in controls became more than 1 in treated animals except in the case of lithocholic acid (LCA) conjugates which remained less than 1. UDCA derivatives increased proportionally to the administered dose and the cholic/cheno ratio diminished significantly. A moderate increase of 3- and 7-keto derivatives of chenodeoxycholic acid (CDCA) was observed in all treated groups but the above mentioned increment was especially evident in 3-keto derivatives. A high percentage of UDCA administered in the hamster was likely transformed to CDCA and the glyco conjugates of the bile acids were the predominant species except for the LCA derivatives. PMID:2367280

Matejka, M; Vescina, C; Carducci, C N; Alayón, A; Dios, A; Scarlatto, E; Mamianetti, A

1990-01-01

96

Changes in fatty acid composition of Chlorella vulgaris by hypochlorous acid.  

PubMed

Hypochlorous acid treatment of a microalga, Chlorella vulgaris, was investigated to improve the quality of microalgal lipid and to obtain high biodiesel-conversion yield. Because chlorophyll deactivates the catalyst for biodiesel conversion, its removal in the lipid-extraction step enhances biodiesel productivity. When microalgae contacted the hypochlorous acid, chlorophyll was removed, and resultant changes in fatty acid composition of microalgal lipid were observed. The lipid-extraction yield after activated clay treatment was 32.7 mg lipid/g cell; after NaClO treatment at 0.8% available chlorine concentration, it was 95.2 mg lipid/g cell; and after NaCl electrolysis treatment at the 1 g/L cell concentration, it was 102.4 mg lipid/g cell. While the contents of all of the unsaturated fatty acids except oleic acid, in the microalgal lipid, decreased as the result of NaClO treatment, the contents of all of the unsaturated fatty acids including oleic acid decreased as the result of NaCl electrolysis treatment. PMID:24785789

Park, Ji-Yeon; Choi, Sun-A; Jeong, Min-Ji; Nam, Bora; Oh, You-Kwan; Lee, Jin-Suk

2014-06-01

97

Proximate, Fatty Acid, and Amino Acid Compositions of Fish Muscle and Egg Tissue of Hilsa (Tenualosa) ilisha  

Microsoft Academic Search

The total lipid profile including the fatty acid composition and amino acid composition in eggs of Hilsa (Tenualosa) ilisha was studied in comparison with its muscle tissue. The eggs contained 30.4% lipid (on dry basis), which was 1.2 times higher than that of the muscle tissue lipid. The major portion of the egg lipid was composed of wax ester (about

Moumita Pal; Tapas Mukhopadhyay; Santinath Ghosh

2011-01-01

98

Three-Year Tracking of Fatty Acid Composition of Plasma Phospholipids in Healthy Children  

Microsoft Academic Search

Objectives: The fatty acid composition of plasma phospholipids reflects the dietary fatty acid intake as well as endogenous turnover. We aimed at investigating the potential tracking of plasma phospholipid fatty acid composition in children that participated in a prospective cohort study. Methods: 26 healthy children participated in a longitudinal study on health risks and had been enrolled after birth. All

António Guerra; Hans Demmelmair; André Michael Toschke; Berthold Koletzko

2007-01-01

99

Drought and heat stress effects on soybean fatty acid composition and oil stability  

Technology Transfer Automated Retrieval System (TEKTRAN)

Previous studies have shown that oil concentration and fatty acid profile (composition) change with genotype, environment (mainly heat and drought), and geographical location. The changes in fatty acid composition under these conditions affect fatty acid stability, creating a challenge to oil proces...

100

Fatty Acid\\/Expanded Graphite Composites as Phase Change Material for Latent Heat Thermal Energy Storage  

Microsoft Academic Search

The fatty acid\\/expanded graphite (EG) composites as phase change material (PCM) for latent heat thermal energy storage were prepared by means of vacuum impregnation method and their thermal properties and heat charging\\/discharging characteristics were determined. In the composites, the fatty acids (capric, lauric, and myristic acids) act as a phase change latent heat storage material, and the EG serves like

A. Sari; A. Karaipekli; K. Kaygusuz

2008-01-01

101

Effects of glycyl-glutamine dipeptide supplementation on myocardial damage and cardiac function in rats after severe burn injury.  

PubMed

Glutamine decreases myocardial damage in ischemia/reperfusion injury. However, the cardioprotective effect of glutamine after burn injury remains unclear. Present study was to explore the protective effect of glycyl-glutamine dipeptide on myocardial damage in severe burn rats. Seventy-two Wistar rats were randomly divided into three groups: normal control (C), burned control (B) and glycyl-glutamine dipeptide-treated (GG) groups. B and GG groups were inflicted with 30% total body surface area of full thickness burn. The GG group was given 1.5 g/kg glycyl-glutamine dipeptide per day and the B group was given the same dose of alanine via intraperitoneal injection for 3 days. The serum CK, LDH, AST, and, blood lactic acid levels, as well as the myocardium ATP and GSH contents, were measured. The indices of cardiac contractile function and histopathological change were analyzed at 12, 24, 48, and 72 post-burn hours (PBH). The serum CK, LDH, AST and blood lactic acid levels increased, and the myocardium ATP and GSH content decreased in both burned groups. Compared with B group, the CK, LDH, AST and blood lactic acid levels reduced, myocardium ATP and GSH content increased in GG group. Moreover, the inhibition of cardiac contractile function and myocardial histopathological damage were reduced significantly in GG group. We conclude that myocardial histological structure and function were damaged significantly after burn injury, glycyl-glutamine dipeptide supplementation is beneficial to myocardial preservation by improving cardiocyte energy metabolism, increasing ATP and glutathione synthesis. PMID:23638213

Zhang, Yong; Yan, Hong; Lv, Shang-Gun; Wang, Lin; Liang, Guang-Ping; Wan, Qian-Xue; Peng, Xi

2013-01-01

102

Effects of feeding bile acids and a bile acid sequestrant on hepatic bile acid composition in mice.  

PubMed

An improved ultra performance liquid chromatography-tandem mass spectrometry (UPLC/MS/MS) method was established for the simultaneous analysis of various bile acids (BA) and applied to investigate liver BA content in C57BL/6 mice fed 1% cholic acid (CA), 0.3% deoxycholic acid (DCA), 0.3% chenodeoxycholic acid (CDCA), 0.3% lithocholic acid (LCA), 3% ursodeoxycholic acid (UDCA), or 2% cholestyramine (resin). Results indicate that mice have a remarkable ability to maintain liver BA concentrations. The BA profiles in mouse livers were similar between CA and DCA feedings, as well as between CDCA and LCA feedings. The mRNA expression of Cytochrome P450 7a1 (Cyp7a1) was suppressed by all BA feedings, whereas Cyp7b1 was suppressed only by CA and UDCA feedings. Gender differences in liver BA composition were observed after feeding CA, DCA, CDCA, and LCA, but they were not prominent after feeding UDCA. Sulfation of CA and CDCA was found at the 7-OH position, and it was increased by feeding CA or CDCA more in male than female mice. In contrast, sulfation of LCA and taurolithocholic acid (TLCA) was female-predominant, and it was increased by feeding UDCA and LCA. In summary, the present systematic study on BA metabolism in mice will aid in interpreting BA-mediated gene regulation and hepatotoxicity. PMID:20671298

Zhang, Youcai; Klaassen, Curtis D

2010-11-01

103

Anticancer activity of the liposome-encapsulated cyclic dipeptides, cyclo(His-Gly) and cyclo(His-Ala).  

PubMed

Cyclic dipeptides have been well characterized for their biological activity, including antimicrobial and anticancer activities. Cyclo(His-Gly) and cyclo(His-Ala) have also recently demonstrated significant anticancer activity against a range of cell lines, however, as a result of their physicochemistry, namely high solubility and low lipophilicity, it can be predicted that cellular permeability would be low, making them ideal candidates for liposome drug delivery. Liposomes were composed of phosphatidylcholine, hydrogenated soy phosphatidylcholine (HSPC), stearylamine, alpha-tocopherol and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000] (PEG-DSPE) or folate-polyethylene glycol-cholesteryl hemisuccinate (F-PEG-CHEMS) using the thin-film hydration method and characterized for size and encapsulation. The cytotoxic activity of the encapsulated cyclic dipeptides was tested against HeLa, low folate HeLa and MCF-7 cells and found to have limited improvement in activity. However, modification of the polyethylene glycol with folic acid to target folate receptors significantly decreased the IC50 values recorded in all cells lines tested, particularly HeLa cells cultured in media containing physiological concentrations of folic acid with the lowest IC50 being recorded as 0.0962 mM for folate-targeted cyclo(His-Ala). Therefore, hydrophilic cyclic dipeptides are ideal candidates for inclusion into targeted drug delivery systems such as liposomes. PMID:23556340

Kilian, G; Davids, H; Milne, P J

2013-03-01

104

Effect of Dipeptides on In vitro Maturation, Fertilization and Subsequent Embryonic Development of Porcine Oocytes.  

PubMed

The effects of amino acids and dipeptides on in vitro production of porcine embryos and accumulation of ammonia in culture medium during developmental stages were examined in this study. The maturation, fertilization and development of embryonic cultures were performed in modified Tissue culture medium (mTCM)-199 supplemented with 10% (v/v) porcine follicular fluid, modified Tyrode's albumin lactate pyruvate (mTALP) medium, and modified North Carolina State University (mNCSU)-23 medium, respectively. In addition, amino acids and dipeptides of different concentrations and combinations were used to treat the embryos. The addition of L-alanyl-L-glutamine (AlnGln)+L-glycyl-L-glutamine (GlyGln) significantly (p<0.05) improved oocyte maturation, fertilization and the incorporation and oxidation of (14)C(U)-glucose when compared to the control group and other treatment groups. Additionally, 2-4 cell, 8-16 cell, morula and blastocyst development increased significantly (p<0.05) following treatment with AlnGln+GlyGln when compared to the control group and other treatment groups, while this treatment reduced the accumulation of ammonia. Taken together, these findings suggest that treatment with AlnGln+GlyGln may play an important role in increasing the rate of porcine oocyte maturation, fertilization and embryonic development by reducing the level of accumulated ammonia measured in the culture media. PMID:25049815

Tareq, K M A; Akter, Quzi Sharmin; Tsujii, Hirotada; Khandoker, M A M Yahia; Choi, Inho

2013-04-01

105

Electron attachment to the dipeptide alanyl-glycine  

NASA Astrophysics Data System (ADS)

Dissociative electron attachment (DEA) to the simplest hetero dipeptide (alanyl-glycine) is studied by means of a beam experiment. The results are compared with those previously obtained from the single compounds alanine and glycine from which the dipeptide is formed. In addition to the resonances and DEA products formed from the single molecules, alanyl-glycine exhibits new resonant features right at threshold (?0 eV energy) and additional fragments which arise from the cleavage of the peptide and N-C? bond. A further strong reaction leads to the loss of a neutral water molecule. These results clearly demonstrate that the dipeptide is considerably more sensitive towards low energy electrons than its components, which is of particular relevance with respect of radiation damage of biomolecular systems.

Kopyra, Janina; König-Lehmann, Constanze; Illenberger, Eugen

2013-07-01

106

Biotechnological Process for Production of ?-Dipeptides from Cyanophycin on a Technical Scale and Its Optimization ?  

PubMed Central

A triphasic process was developed for the production of ? dipeptides from cyanophycin (CGP) on a large scale. Phase I comprises an optimized acid extraction method for technical isolation of CGP from biomass. It yielded highly purified CGP consisting of aspartate, arginine, and a little lysine. Phase II comprises the fermentative production of an extracellular CGPase (CphEal) from Pseudomonas alcaligenes strain DIP1 on a 500-liter scale in mineral salts medium, with citrate as the sole carbon source and CGP as an inductor. During optimization, it was shown that 2 g liter?1 citrate, pH 6.5, and 37°C are ideal parameters for CphEal production. Maximum enzyme yields were obtained after induction in the presence of 50 mg liter?1 CGP or CGP dipeptides for 5 or 3 h, respectively. Aspartate at a concentration of 4 g liter?1 induced CphEal production with only about 30% efficiency in comparison to that with CGP. CphEal was purified utilizing its affinity for the substrate and its specific binding to CGP. CphEal turned out to be a serine protease with maximum activity at 50°C and at pH 7 to 8.5. Phase III comprises degradation of CGP to ?-aspartate-arginine and ?-aspartate-lysine dipeptides with a purity of over 99% (by thin-layer chromatography and high-performance liquid chromatography), employing a crude CphEal preparation. Optimum degradation parameters were 100 g liter?1 CGP, 10 g liter?1 crude CphEal powder, and 4 h of incubation at 50°C. The overall efficiency of phase III was 91%, while 78% (wt/wt) of the used CphEal powder with sustained activity toward CGP was recovered. The optimized process was performed with industrial materials and equipment and is applicable to any desired scale. PMID:18978083

Sallam, Ahmed; Kast, Alene; Przybilla, Simon; Meiswinkel, Tobias; Steinbüchel, Alexander

2009-01-01

107

Chemical characteristics, fatty acid composition and conjugated linoleic acid (CLA) content of traditional Greek yogurts.  

PubMed

Many studies with conjugated linoleic acid (CLA) indicate that it has a protective effect against mammary cancer. Because dairy products are the most important dietary sources of CLA, we have investigated the CLA concentrations and additionally the fatty acid profiles and chemical composition of several commercial, traditional, Greek yogurts from different geographical origin. The fat content of yogurts was in the order of goatacids (SFA) were found in low-fat yogurts, of monounsaturated fatty acids (MUFA) in sheep milk yogurts and of polyunsaturated fatty acid (PUFA) in low-fat cow milk yogurts. PMID:23442628

Serafeimidou, Amalia; Zlatanos, Spiros; Laskaridis, Kostas; Sagredos, Angelos

2012-10-15

108

Incorporation of fatty acids by concanavalin A-stimulated lymphocytes and the effect on fatty acid composition and membrane fluidity.  

PubMed Central

The fatty acid compositions of the neutral lipid and phospholipid fractions of rat lymph node lymphocytes were characterized. Stimulation of rat lymphocytes with the T-cell mitogen concanavalin A resulted in significant changes in the fatty acid composition of both neutral lipids and phospholipids (a decrease in the proportions of stearic, linoleic and arachidonic acids and an increase in the proportion of oleic acid). Membrane fluidity was measured using nitroxide spin-label e.s.r., and increased during culture with concanavalin A. Culturing the lymphocytes in the absence of mitogen did not affect fatty acid composition or membrane fluidity. The uptake and fate of palmitic, oleic, linoleic and arachidonic acids were studied in detail; there was a time-dependent incorporation of each fatty acid into all lipid classes but each fatty acid had a characteristic fate. Palmitic and arachidonic acids were incorporated principally into phospholipids whereas oleic and linoleic acids were incorporated in similar proportions into phospholipids and triacylglycerols. Oleic acid was incorporated mainly into phosphatidylcholine, palmitic and linoleic acids were incorporated equally into phosphatidylcholine and phosphatidylethanolamine, and arachidonic acid was incorporated mainly into phosphatidylethanolamine. Supplementation of the culture medium with particular fatty acids (myristic, palmitic, stearic, oleic, linoleic, alpha-linolenic, arachidonic, eicosapentaenoic or docosahexaenoic acid) led to enrichment of that fatty acid in both neutral lipids and phospholipids. This generated lymphocytes with phospholipids differing in saturated/unsaturated fatty acid ratio, degree of polyunsaturation, index of unsaturation and n - 6/n - 3 ratio. This method allowed the introduction into lymphocyte phospholipids of fatty acids not normally present (e.g. alpha-linolenic) or usually present in low proportions (eicosapentaenoic and docosahexaenoic). These three n - 3 polyunsaturated fatty acids replaced arachidonic acid in lymphocyte phospholipids. Fatty acid incorporation led to an alteration in lymphocyte membrane fluidity: palmitic and stearic acids decreased fluidity whereas the unsaturated fatty acids increased fluidity. It is proposed that the changes in lymphocyte phospholipid fatty acid composition and membrane fluidity brought about by culture in the presence of polyunsaturated fatty acids are responsible for the inhibition of lymphocyte functions caused by these fatty acids. PMID:8002957

Calder, P C; Yaqoob, P; Harvey, D J; Watts, A; Newsholme, E A

1994-01-01

109

The fatty acid composition of milk fat as influenced by feeding oilseeds  

Microsoft Academic Search

The fatty acid composition of bovine milk fat can be substantially altered by feeding lipid sources which alter the fatty acid profile of lipid entering the intestine from the rumen. As long-chain fatty acids of dietary origin can be incorporated directly into milk fat the opportunity exists to alter the ratio of short and long-chain fatty acids as well as

John J. Kennelly

1996-01-01

110

Predicting conjugated linoleic acid (CLA) composition in Brazilian dairy products by multiple regression  

E-print Network

NOTE Predicting conjugated linoleic acid (CLA) composition in Brazilian dairy products by multiple-Verlag, France 2012 Abstract The analysis of conjugated linoleic acids (CLA) in dairy products is of concern linoleic acid FAME fatty acid methyl ester GC gas chromatography GC-FID gas chromatography with flame

Paris-Sud XI, Université de

111

Fatty acid composition of five candidate aquaculture species in Central Philippines  

Microsoft Academic Search

Fatty acid composition was determined in five candidate aquaculture species, mangrove red snapper (Lutjanus argentimaculatus), two rabbitfish (Siganus guttatus and S. canaliculatus), coral trout (Plectropomus leopardus) and striped jack (Caranx fulvoguttatus) sampled in the Central Philippines. Special attention was paid to arachidonic acid (ARA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Total lipids of hatchery-produced eggs and newly hatched larvae

Hiroshi Y Ogata; Arnil C Emata; Esteban S Garibay; Hirofumi Furuita

2004-01-01

112

Lipids in Arctic benthos: does the fatty acid and alcohol composition reflect feeding and trophic interactions?  

Microsoft Academic Search

Arctic benthic organisms of various taxa (Anthozoa, Polychaeta, Pantopoda, Crustacea, Echinodermata) were collected on the\\u000a shelves off northeast Greenland, Spitsbergen and the western Barents Sea. Their fatty acid compositions were generally characterised\\u000a by the predominance of the polyunsaturated fatty acids 20:5(n-3) and 22:6(n-3) together with the saturated fatty acid 16:0,\\u000a which reflect the dominance of phospholipids. The fatty acid compositions

M. Graeve; G. Kattner; D. Piepenburg

1997-01-01

113

Enantiomeric Selective Adsorption of Amino Acid by Polysaccharide Composite Materials  

PubMed Central

A composite containing cellulose (CEL) and chitosan (CS) synthesized by a simple and recyclable method by using butylmethylimmidazolium chloride, an ionic liquid, was found to exhibit remarkable enantiomeric selectivity toward adsorption of amino acids. 100%CS shows the highest adsorption capacity and enantiomeric selectivity. A racemic amino acid can be enantiomerically resolved by 100%CS in about 96–120 hrs. Interestingly, adsorption by 50:50 CEL:CS is more similar to that by 100%CS than to 100%CEL. Specifically, while 100% CEL shows lowest adsorption capacity and enantiomeric selectivity, 50:50 CEL:CS has sufficient enantiomeric selectivity to enable it to be used for chiral resolution. This is very significant because in spite of its high enantiomeric selectivity, 100%CS cannot practically be used because it has relatively poor mechanical properties and undergoes extensive swelling. Adding 50% of CEL to CS substantially improves the mechanic properties and reduces its swelling while retains sufficient enantiomeric selectivity to enable it to be used for routine chiral separations. Kinetic results indicate that the enantiomeric selective adsorption is due not to the initial surface adsorption but rather to the subsequent stage in which the adsorbate molecules diffuse into the pores within the particle of the composites and consequently got adsorbed by the interior of each particle. The strong inter- and intramolecular hydrogen bond network in CEL enables it to adopt a very dense structure which makes it difficult for adsorbate molecules to diffuse to its interior thereby leading to low enantiomeric selectivity. Compared to hydroxy group, amino group cannot form strong hydrogen bond. The hydrogen bond network in CS is not as extensive as in CEL, and its inner structure is relatively less dense than CEL. Adsorbate molecules can, therefore, diffuse from the outer surface to its inner structure relatively easier than in CEL, thereby leading to higher enantiomeric selectivity for 100%CS. PMID:24377940

Duri, Simon; Tran, Chieu D.

2014-01-01

114

Regulation of membrane fatty acid composition by temperature in mutants of Arabidopsis with alterations in membrane lipid composition  

PubMed Central

Background A wide range of cellular responses occur when plants are exposed to elevated temperature, including adjustments in the unsaturation level of membrane fatty acids. Although membrane bound desaturase enzymes mediate these adjustments, it is unknown how they are regulated to achieve these specific membrane compositions. Furthermore, the precise roles that different membrane fatty acid compositions play in photosynthesis are only beginning to be understood. To explore the regulation of the membrane composition and photosynthetic function in response to temperature, we examined the effect of temperature in a collection of mutants with altered membrane lipid fatty acid composition. Results In agreement with previous studies in other species, the level of unsaturation of membrane fatty acids in Arabidopsis was inversely correlated with growth temperature. The time required for the membrane fatty acids to attain the composition observed at elevated temperature was consistent with the timing required for the synthesis of new fatty acids. Comparisons of temperature-induced fatty acid alterations in membranes were made among several Arabidopsis lines including wild-type Columbia, and the compositional mutants, fad5, fad6, act1 and double mutants, fad7 fad8 and act1 fad6. The results revealed key changes that occur in response to elevated temperature regardless of the specific mutations in the glycerolipid pathway, including marked decreases in trienoic fatty acids and consistent increases in unsaturated 16:0 and in dienoic 18:2 levels. Fluorescence measurements of various mutants indicated that photosynthetic stability as well as whole plant growth at elevated temperature is influenced by certain membrane fatty acid compositions. Conclusions The results of this study support the premise that defined proportions of saturated and unsaturated fatty acids in membrane lipids are required for photosynthetic thermostability and acclimation to elevated temperature. The results also suggest that changes in the membrane fatty acid composition brought about in response to temperature are regulated in such a way so as to achieve highly similar unsaturation levels despite mutations that alter the membrane composition prior to a high-temperature exposure. The results from examination of the mutant lines also suggest that interorganellar transfer of fatty acids are involved in mediating temperature-induced membrane alterations, and reveal steps in the fatty acid unsaturation pathway that appear to have key roles in the acclimatization of membranes to high temperature. PMID:15377388

Falcone, Deane L; Ogas, Joseph P; Somerville, Chris R

2004-01-01

115

The role of a dipeptide outer-coordination sphere on H2-production catalysts: influence on catalytic rates and electron transfer.  

PubMed

The outer-coordination sphere of enzymes acts to fine-tune the active site reactivity and control catalytic rates, suggesting that incorporation of analogous structural elements into molecular catalysts may be necessary to achieve rates comparable to those observed in enzyme systems at low overpotentials. In this work, we evaluate the effect of an amino acid and dipeptide outer-coordination sphere on [Ni(P(Ph)(2)N(Ph-R)(2))(2)](2+) hydrogen production catalysts. A series of 12 new complexes containing non-natural amino acids or dipeptides was prepared to test the effects of positioning, size, polarity and aromaticity on catalytic activity. The non-natural amino acid was either 3-(meta- or para-aminophenyl)propionic acid terminated as an acid, an ester or an amide. Dipeptides consisted of one of the non-natural amino acids coupled to one of four amino acid esters: alanine, serine, phenylalanine or tyrosine. All of the catalysts are active for hydrogen production, with rates averaging ?1000?s(-1), 40?% faster than the unmodified catalyst. Structure and polarity of the aliphatic or aromatic side chains of the C-terminal peptide do not strongly influence rates. However, the presence of an amide bond increases rates, suggesting a role for the amide in assisting catalysis. Overpotentials were lower with substituents at the N-phenyl meta position. This is consistent with slower electron transfer in the less compact, para-substituted complexes, as shown in digital simulations of catalyst cyclic voltammograms and computational modeling of the complexes. Combining the current results with insights from previous results, we propose a mechanism for the role of the amino acid and dipeptide based outer-coordination sphere in molecular hydrogen production catalysts. PMID:23233438

Reback, Matthew L; Ginovska-Pangovska, Bojana; Ho, Ming-Hsun; Jain, Avijita; Squier, Thomas C; Raugei, Simone; Roberts, John A S; Shaw, Wendy J

2013-02-01

116

The Role of a Dipeptide Outer-Coordination Sphere on H2 -Production Catalysts: Influence on Catalytic Rates and Electron Transfer  

SciTech Connect

The outer-coordination sphere of enzymes acts to fine-tune the active site reactivity and control catalytic rates, suggesting that incorporation of analogous structural elements into molecular catalysts may be necessary to achieve rates comparable to those observed in enzyme systems at low overpotentials. In this work, we evaluate the effect of an amino acid and dipeptide outer-coordination sphere on [Ni(PPh2NPh-R2)2]2+ hydrogen production catalysts. A series of 12 new complexes containing non-natural amino acids or dipeptides were prepared to test the effects of positioning, size, polarity and aromaticity on catalytic activity. The non-natural amino acid was either 3-(meta- or para-aminophenyl)propionic acid terminated as an acid, an ester or an amide. Dipeptides consisted of one of the non-natural amino acids coupled to one of four amino acid esters: alanine, serine, phenylalanine or tyrosine. All of the catalysts are active for hydrogen production, with rates averaging ~1000 s-1, 40% faster than the unmodified catalyst. Structure and polarity of the aliphatic or aromatic side chains of the C-terminal peptide do not strongly influence rates. However, the presence of an amide bond increases rates, suggesting a role for the amide in assisting catalysis. Overpotentials were lower with substituents at the N-phenyl meta position. This is consistent with slower electron transfer in the less compact, para-substituted complexes, as shown in digital simulations of catalyst cyclic voltammograms and computational modeling of the complexes. Combining the current results with insights from previous results, we propose a mechanism for the role of the amino acid and dipeptide based outer-coordination sphere in molecular hydrogen production catalysts.

Reback, Matthew L.; Ginovska-Pangovska, Bojana; Ho, Ming-Hsun; Jain, Avijita; Squier, Thomas C.; Raugei, Simone; Roberts, John A.; Shaw, Wendy J.

2013-02-04

117

Distribution and enantiomeric composition of amino acids in the Murchison meteorite  

NASA Technical Reports Server (NTRS)

Studies of the amino acid contents and enantiomeric compositions of a single stone from the Murchison meteorite are reported. Water-extracted and 6M HCl-extracted samples from the meteorite interior of meteorite fragments were analyzed by gas chromatography and combined gas chromatography-chemical ionization mass spectrometry. Examination of the D/L ratios of glutamic acid, aspartic acid, proline, leucine and alanine reveals those amino acids extractable by water to be partially racemized, whereas the acid-extracted amino acids were less racemized. The amino acid composition of the stone is similar to those previously reported, including the absence of serine, threonine, tyrosine phenylalanine and methionine and the presence of unusual amino acids including such as isovaline, alpha-aminoisobutyric acid and pseudoleucine. It is concluded that the most likely mechanism accounting for the occurrence of nonracemic amino acid mixtures in the Murchison meteorite is by extraterrestrial stereoselective synthesis or decomposition reactions.

Engel, M. H.; Nagy, B.

1982-01-01

118

A dipeptide and two glycosides from Streptocaulon griffithii  

Microsoft Academic Search

Phytochemical investigation of the roots of Streptocaulon griffithii afforded a novel dipeptide, streptin (1), a new hemiterpenoid, (R)-3-ethyl-4-methylpentyl-?-rutinoside (2), and a new disaccharide, 1-methoxyl-4-O-?-glucopyronosyl-?-digitoxose (3), along with five known compounds. Their structures were identified by spectroscopic methods and comparison with literature values.

Xiao-Hui Zhang; Tong Zhou; Li-Jiang Xuan

2008-01-01

119

Use of Near-Infrared Spectroscopy for Estimating Fatty Acid Composition in Intact Seeds of Rapeseed  

Microsoft Academic Search

Near-infrared spectroscopy (NIRS) was used as a rapid and nondestructive method to determine the fatty acid composition in intact seed samples of rapeseed (Brassica napus L.). A total of 349 samples (about 2 g of intact seeds) were scanned in the reflectance mode of a scanning monochro- mator, and the reference values for fatty acid composition were measured by gas-liquid

Kwan Su Kim; Si Hyung Park; Myoung Gun Choung; Young Seok Jang

120

In vivo milk digestion in the calf abomasum. III. Amino acid compositions of the digesta leaving  

E-print Network

In vivo milk digestion in the calf abomasum. III. Amino acid compositions of the digesta leaving different test meals : whole milk, skim milk, 3 % whole casein solution, 3 % whole casein in simulated milk the first 10 min following the ingestion of whole or skim milk, the amino acid composition of the sediment

Paris-Sud XI, Université de

121

Effect of GxE interaction on oil content and fatty acid composition of cultivated peanuts  

Technology Transfer Automated Retrieval System (TEKTRAN)

Twenty-nine entries of varieties and advanced breeding lines were grown in two locations in three years with three replications to estimate the effects of G x E interaction on oil content and fatty acid composition of cultivated peanuts. Oil content and fatty acid composition were quantified by NMR ...

122

Changing the direction of intramolecular electron transfer in oxidized dipeptides containing tryptophan and tyrosine.  

PubMed

Intramolecular electron transfer (IET) in the oxidized dipeptide Tyr-Trp was investigated in the pH range from 1.0 to 3.1 by the method of time-resolved chemically induced dynamic nuclear polarization. The results were compared with data obtained earlier for Trp-Tyr. Surprisingly, it was found that the direction of IET changes with the order of the amino acid residues in the peptide. For Tyr-Trp, the rate constant of electron transfer from tyrosine residue to tryptophanyl cation radical is below 1.2 × 10(4) s(-1), whereas for Trp-Tyr, the value of this rate constant is 5.5 × 10(5) s(-1). Conversely, for oxidized Tyr-Trp at pH range 2.1 and lower, electron transfer from tryptophan residue to tyrosyl radical is observed. The rate constant of this reaction is proportional to the concentration of protons in aqueous solution, and at pH 1.0 is equal to 6.5 × 10(5) s(-1). The change in direction of IET observed for oxidized Tyr-Trp dipeptide is presumably due to the positive charge at the N-terminal amino group of the peptide, which promotes electron transfer in the direction of the N-terminus. PMID:22978479

Morozova, Olga B; Kaptein, Robert; Yurkovskaya, Alexandra V

2012-10-11

123

Dipeptide prodrug approach to evade efflux pumps and CYP3A4 metabolism of lopinavir.  

PubMed

Oral absorption of lopinavir (LPV) is limited due to P-glycoprotein (P-gp) and multidrug resistance-associated protein2 (MRP2) mediated efflux by intestinal epithelial cells. Moreover, LPV is extensively metabolized by CYP3A4 enzymes. In the present study, dipeptide prodrug approach was employed to circumvent efflux pumps (P-gp and MRP2) and CYP3A4 mediated metabolism of LPV. Valine-isoleucine-LPV (Val-Ile-LPV) was synthesized and identified by LCMS and NMR techniques. The extent of LPV and Val-Ile-LPV interactions with P-gp and MRP2 was studied by uptake and transport studies across MDCK-MDR1 and MDCK-MRP2 cells. To determine the metabolic stability, time and concentration dependent degradation study was performed in liver microsomes. Val-Ile-LPV exhibited significantly higher aqueous solubility relative to LPV. This prodrug generated higher stability under acidic pH. Val-Ile-LPV demonstrated significantly lower affinity toward P-gp and MRP2 relative to LPV. Transepithelial transport of Val-Ile-LPV was significantly higher in the absorptive direction (apical to basolateral) relative to LPV. Importantly, Val-Ile-LPV was recognized as an excellent substrate by peptide transporter. Moreover, Val-Ile-LPV displayed significantly higher metabolic stability relative to LPV. Results obtained from this study suggested that dipeptide prodrug approach is a viable option to elevate systemic levels of LPV following oral administration. PMID:25261710

Patel, Mitesh; Sheng, Ye; Mandava, Nanda K; Pal, Dhananjay; Mitra, Ashim K

2014-09-26

124

Muramyl dipeptide and its derivatives: peptide adjuvant in immunological disorders and cancer therapy  

PubMed Central

Muramyl dipeptide (MDP) is a synthetic immunoreactive peptide consisting of N-acetyl muramic acid attached to a short amino acid chain of L-Ala-D-isoGln. It was first identified in bacterial cell wall peptidoglycan as an active component in Freund’s complete adjuvant. In the cell, MDP is detected by NOD2, a cytoplasmic receptor belonging to the human innate immune system. NOD2 mutations are frequently observed in patients with Crohn’s disease, an autoimmune disorder, suggesting the significance of the MDP-NOD2 pathway in activating immunity. For this reason, structural modifications of MDP and its derivatives have been extensively studied in an attempt to increase adjuvant activity and boost the immune response effectively for clinical use in the treatment of cancer and other diseases. This review summarizes the synthetic chemistry of MDP and its derivatives and discusses their pharmacological action and stereoselective synthesis. PMID:22180736

Ogawa, Chikako; Liu, Yuen-Joyce; Kobayashi, Koichi S.

2011-01-01

125

The S isotope composition of methanesulfonic acid in Arctic aerosols  

NASA Astrophysics Data System (ADS)

Methanesulfonic acid (MSA) in aerosols over the ocean is the main oxidation product of dimethyl sulfide (DMS). In addition, a small part of MSA in the atmosphere is derived from anthropogenic sources such as biomass burning which produces dimethyl disulfide (DMDS) that is oxidized to MSA. MSA and sulfate concentrations and the S isotope composition of MSA and sulfate for aerosol samples collected at Alert, Nunavut in the high Arctic from 1994 to 2002 are reported here. The S isotope composition of MSA and sulfate varies with season. Spring and summer samples have delta 34S values ranging from +12.5 to +16.6 per mill for MSA and from +9.2 to +12.7 per mill for sulfate. Samples from fall and winter have delta 34S that range from +8.2 to 10.5 per mill for MSA and from +4.2 to +7.9 per mill for sulfate. Delta 34S values for MSA are always higher (about 2 to 3 per mill) than those for the corresponding aerosol sulfate. The delta 34S value of MSA should be the same as that for DMS (+15.8 to 18.7 per mill), but measured delta 34S values for MSA were lower (+8.2 to 16.6 per mill). Differences in delta 34S values between MSA and sulfate may due be to sulfur (S) origin for each compound and/or isotope fractionation. The source of this discrepancy and its implications are examined.

Siauw, A.; Norman, A.

2006-12-01

126

Exploiting Amino Acid Composition for Predicting Protein-Protein Interactions  

PubMed Central

Background Computational prediction of protein interactions typically use protein domains as classifier features because they capture conserved information of interaction surfaces. However, approaches relying on domains as features cannot be applied to proteins without any domain information. In this paper, we explore the contribution of pure amino acid composition (AAC) for protein interaction prediction. This simple feature, which is based on normalized counts of single or pairs of amino acids, is applicable to proteins from any sequenced organism and can be used to compensate for the lack of domain information. Results AAC performed at par with protein interaction prediction based on domains on three yeast protein interaction datasets. Similar behavior was obtained using different classifiers, indicating that our results are a function of features and not of classifiers. In addition to yeast datasets, AAC performed comparably on worm and fly datasets. Prediction of interactions for the entire yeast proteome identified a large number of novel interactions, the majority of which co-localized or participated in the same processes. Our high confidence interaction network included both well-studied and uncharacterized proteins. Proteins with known function were involved in actin assembly and cell budding. Uncharacterized proteins interacted with proteins involved in reproduction and cell budding, thus providing putative biological roles for the uncharacterized proteins. Conclusion AAC is a simple, yet powerful feature for predicting protein interactions, and can be used alone or in conjunction with protein domains to predict new and validate existing interactions. More importantly, AAC alone performs at par with existing, but more complex, features indicating the presence of sequence-level information that is predictive of interaction, but which is not necessarily restricted to domains. PMID:19936254

Roy, Sushmita; Martinez, Diego; Platero, Harriett; Lane, Terran; Werner-Washburne, Margaret

2009-01-01

127

Relationships between dietary fatty acid composition and either melting point or fatty acid profile of adipose tissue in broilers  

Microsoft Academic Search

Data on the fatty acid composition of the diet and that of the adipose tissue in broilers were collected from the literature. The linear regression between the dietary and the adipose tissue unsaturated to saturated fatty acids ratio (U\\/S ratio) was calculated because the U\\/S ratio of adipose tissue fat determines its melting point, which is an indicator of the

F. J. Bavelaar; A. C. Beynen

2003-01-01

128

Softness and fatty acid composition of subcutaneous adipose tissue, and methylmalonic acid concentrations in the plasma of intensively reared lambs  

Microsoft Academic Search

The aim of the present work was to study the relationships between lamb growth performance, soft adipose tissue and fatty acid composition of subcutaneous adipose tissue of intensively reared lambs, and to determine if the occurrence of soft fat, and of odd numbered (Odd FA) and methyl-branched-chain fatty acids in subcutaneous adipose tissue was related to plasma concentrations of methylmalonic

V Berthelot; J Normand; P Bas; N. B Kristensen

2001-01-01

129

Optimal growth temperature of prokaryotes correlates with class II amino acid composition.  

PubMed

Partitioning of aminoacyl-tRNA synthetases and their associated amino acids into two classes allows us to distinguish between thermophilic and mesophilic species based only on amino acids composition. The CLASSDB program has been developed for amino acid content analysis in organisms treated individually or pooled together to form a pattern of characteristic properties. A strong correlation has been observed between optimal growth temperature (OGT) of organisms and class II amino acids content. Amino acid composition in organisms closely related phylogenetically but dissimilar in their OGT testifies that thermo-adaptation happens rather rapidly on the time scale of evolution. PMID:16497302

Klipcan, Liron; Safro, Ilya; Temkin, Boris; Safro, Mark

2006-03-01

130

Fatty acid composition of unicellular strains of blue-green algae.  

PubMed

The fatty acids of 34 strains of unicellular blue-green algae provisionally assigned to the genera Synechococcus, Aphanocapsa, Gloeocapsa, Microcystis, and Chlorogloea by Stanier et al. have been chemically characterized. The strains analyzed can be divided into a series of compositional groups based upon the highest degree of unsaturation of the major cellular fatty acids. Twenty strains fall into the group characterized by one trienoic fatty acid isomer (alpha-linolenic acid), and seven strains fall into a group characterized by another trienoic acid isomer (gamma-linolenic acid). These groups in many cases correlate well with groupings based upon other phenotypic characters of the strains, e.g., deoxyribonucleic acid base composition. The assignment of a strain to a compositional group is not altered when the strain is grown under a variety of different culture conditions. All strains contain glycolipids with the properties of mono- and digalactosyldiglycerides. PMID:4621688

Kenyon, C N

1972-02-01

131

Fatty acid composition of Drosophila photoreceptor light-sensitive microvilli.  

PubMed

Phototransduction, the mechanism underlying the electrical response to light in photoreceptor cells, has been thoroughly investigated in Drosophila melanogaster, an essential model in signal transduction research. These cells present a highly specialized photosensitive membrane consisting of thousands of microvilli forming a prominent structure termed a rhabdomere. These microvilli encompass the phototransduction proteins, most of which are transmembrane and exclusively rhabdomeric. Rhabdomere membrane lipids play a crucial role in the activation of the transient receptor potential ionic channels (TRP and TRPL) responsible for initiating the photoresponse. Despite its importance, rhabdomere lipid composition has not been established. We developed a novel preparation enriched in rhabdomere membranes to perform a thorough characterization of the lipidomics of Drosophila rhabdomeres. Isolated eyes (500) were homogenized and subjected to a differential centrifugation protocol that generates a fraction enriched in rhabdomere membrane. Lipids extracted from this preparation were identified and quantified by gas chromatography coupled to mass spectrometry. We found an abundance of low sterol esters (C16:0, C18:0), highly abundant and diverse triglycerides, free fatty acids, a moderate variety of mono and diacyglycerols (C:16:0, 18:0, C18:1) and abundant phospholipids (principally C18:2). This preparation opens a new avenue for investigating essential aspects of phototransduction. PMID:24346077

Muñoz, Yorka; Fuenzalida, Karen; Bronfman, Miguel; Gatica, Arnaldo; Sepúlveda, Marcelo; Bacigalupo, Juan; Roth, Alejandro D; Delgado, Ricardo

2013-01-01

132

Plant Physiol. (1995) 108: 399-409 Alteration of Seed Fatty Acid Composition by an Ethyl  

E-print Network

Plant Physiol. (1995) 108: 399-409 Alteration of Seed Fatty Acid Composition by an Ethyl in the formation of very long-chain fatty acids (VLCFAs) in the Brassicaceae, we have gen- erated a series and accumulates 18:3 as the major fatty acid in triacylglycerols. Proportions of 18:2 remain similar to WT. Ce

Kunst, Ljerka

133

Fatty acid composition and volatile compounds of caviar from farmed white sturgeon ( Acipenser transmontanus)  

Microsoft Academic Search

The present study was conducted to characterize caviar obtained from farmed white sturgeons (Acipenser transmontanus) subjected to different dietary treatments. Twenty caviar samples from fish fed two experimental diets containing different dietary lipid sources have been analysed for chemical composition, fatty acids and flavour volatile compounds. Fatty acid make up of caviar was only minimally influenced by dietary fatty acid

Fabio Caprino; Vittorio Maria Moretti; Federica Bellagamba; Giovanni Mario Turchini; Maria Letizia Busetto; Ivan Giani; Maria Antonietta Paleari; Mario Pazzaglia

2008-01-01

134

Effect of dietary fat on the fatty acid composition and fertilizing ability of fowl semen.  

PubMed

Broiler breeder roosters received two diets, containing either 5% salmon oil (SO) or 5% corn oil (CO). The diets differed essentially in their polyunsaturated fatty acid (PUFA) composition, with n-6:n-3 fatty acid ratios of 41.6 in SO and 1.5 in CO. The effects of these diets on the fatty acid composition of spermatozoa and seminal plasma, and on fertility evaluated after artificial insemination were observed. Whatever the diet, the fatty acid composition of spermatozoa showed notable amounts of 20:4n-6 (5-9%) and 22:4n-6 (15-21%). These essential fatty acids were not detected in the diets and were synthesized from 18:2n-6, which was abundant in the diet (15-16%) but low in spermatozoa (2-3%). Spermatozoa were also very rich in saturated fatty acids (39%). There was a clear influence of dietary lipids on the spermatozoa fatty acid profile: the proportion of n-3 fatty acids in spermatozoa from males fed SO compared to CO was higher (9.6% vs. 4.3%) and that of n-6 fatty acids was lower (22.4% vs. 33.3%). The fatty acid composition of seminal plasma included a higher proportion of saturated fatty acids (49%) than the proportion in spermatozoa, whereas minor fatty acids (14:0, 16:1n-7, 16:1n-9, 22:5n-3) were not detected. The influence of dietary lipids on the seminal plasma fatty acid profile was the same as for the spermatozoa, especially in the PUFA profile. In addition, the SO diet gave significantly higher fertility rates (96%) than the CO diet (91.6%). These results clearly show that the lipid composition of the diet may modify the fatty acid composition of the semen and its fertilizing ability. PMID:9160721

Blesbois, E; Lessire, M; Grasseau, I; Hallouis, J M; Hermier, D

1997-05-01

135

Gender Differences in Rat Erythrocyte and Brain Docosahexaenoic Acid Composition: Role of Ovarian Hormones and Dietary Omega-3 Fatty Acid Composition  

PubMed Central

The two-fold higher prevalence rate of major depression in females may involve vulnerability to omega-3 fatty acid deficiency secondary to a dysregulation in ovarian hormones. However, the role of ovarian hormones in the regulation of brain omega-3 fatty acid composition has not been directly evaluated. Here we determined erythrocyte and regional brain docosahexaenoic acid (DHA, 22:6n-3) composition in intact male and female rats, and in chronically ovariectomized (OVX) rats with or without cyclic estradiol treatment (2 ?g/4 d). All groups were maintained on diets with or without the DHA precursor alpha-linolenic acid (ALA, 18:3n-3). We report that both male (?21%) and OVX (?19%) rats on ALA+ diet exhibited significantly lower erythrocyte DHA composition relative to female controls. Females on ALA+ diet exhibited lower DHA composition in the prefrontal cortex (PFC) relative males (?5%). OVX rats on ALA+ diet exhibited significantly lower DHA composition in the hippocampus (?6%), but not in the PFC, hypothalamus, or midbrain. Lower erythrocyte and hippocampus DHA composition in OVX rats was not prevented by estrogen replacement. All groups maintained on ALA? diet exhibited significantly lower erythrocyte and regional brain DHA composition relative to groups on ALA+ diet, and these reductions were greater in males but not in OVX rats. These preclinical data corroborate clinical evidence for gender differences in peripheral DHA composition (female>male), demonstrate gender differences in PFC DHA composition (male>female), and support a link between ovarian hormones and erythrocyte and region-specific brain DHA composition. PMID:19046819

McNamara, Robert K.; Able, Jessica; Jandacek, Ronald; Rider, Therese; Tso, Patrick

2009-01-01

136

Predicting membrane protein types by fusing composite protein sequence features into pseudo amino acid composition.  

PubMed

Membrane proteins are vital type of proteins that serve as channels, receptors, and energy transducers in a cell. Prediction of membrane protein types is an important research area in bioinformatics. Knowledge of membrane protein types provides some valuable information for predicting novel example of the membrane protein types. However, classification of membrane protein types can be both time consuming and susceptible to errors due to the inherent similarity of membrane protein types. In this paper, neural networks based membrane protein type prediction system is proposed. Composite protein sequence representation (CPSR) is used to extract the features of a protein sequence, which includes seven feature sets; amino acid composition, sequence length, 2 gram exchange group frequency, hydrophobic group, electronic group, sum of hydrophobicity, and R-group. Principal component analysis is then employed to reduce the dimensionality of the feature vector. The probabilistic neural network (PNN), generalized regression neural network, and support vector machine (SVM) are used as classifiers. A high success rate of 86.01% is obtained using SVM for the jackknife test. In case of independent dataset test, PNN yields the highest accuracy of 95.73%. These classifiers exhibit improved performance using other performance measures such as sensitivity, specificity, Mathew's correlation coefficient, and F-measure. The experimental results show that the prediction performance of the proposed scheme for classifying membrane protein types is the best reported, so far. This performance improvement may largely be credited to the learning capabilities of neural networks and the composite feature extraction strategy, which exploits seven different properties of protein sequences. The proposed Mem-Predictor can be accessed at http://111.68.99.218/Mem-Predictor. PMID:21110985

Hayat, Maqsood; Khan, Asifullah

2011-02-21

137

SCMHBP: prediction and analysis of heme binding proteins using propensity scores of dipeptides  

PubMed Central

Background Heme binding proteins (HBPs) are metalloproteins that contain a heme ligand (an iron-porphyrin complex) as the prosthetic group. Several computational methods have been proposed to predict heme binding residues and thereby to understand the interactions between heme and its host proteins. However, few in silico methods for identifying HBPs have been proposed. Results This work proposes a scoring card method (SCM) based method (named SCMHBP) for predicting and analyzing HBPs from sequences. A balanced dataset of 747 HBPs (selected using a Gene Ontology term GO:0020037) and 747 non-HBPs (selected from 91,414 putative non-HBPs) with an identity of 25% was firstly established. Consequently, a set of scores that quantified the propensity of amino acids and dipeptides to be HBPs is estimated using SCM to maximize the predictive accuracy of SCMHBP. Finally, the informative physicochemical properties of 20 amino acids are identified by utilizing the estimated propensity scores to be used to categorize HBPs. The training and mean test accuracies of SCMHBP applied to three independent test datasets are 85.90% and 71.57%, respectively. SCMHBP performs well relative to comparison with such methods as support vector machine (SVM), decision tree J48, and Bayes classifiers. The putative non-HBPs with high sequence propensity scores are potential HBPs, which can be further validated by experimental confirmation. The propensity scores of individual amino acids and dipeptides are examined to elucidate the interactions between heme and its host proteins. The following characteristics of HBPs are derived from the propensity scores: 1) aromatic side chains are important to the effectiveness of specific HBP functions; 2) a hydrophobic environment is important in the interaction between heme and binding sites; and 3) the whole HBP has low flexibility whereas the heme binding residues are relatively flexible. Conclusions SCMHBP yields knowledge that improves our understanding of HBPs rather than merely improves the prediction accuracy in predicting HBPs. PMID:25522279

2014-01-01

138

3H-L-histidine and 65Zn(2+) are cotransported by a dipeptide transport system in intestine of lobster Homarus americanus.  

PubMed

The tubular intestine of the American lobster Homarus americanus was isolated in vitro and perfused with a physiological saline whose composition was based on hemolymph ion concentrations and contained variable concentrations of (3)H-l-histidine, (3)H-glycyl-sarcosine and (65)Zn(2+). Mucosa to serosa (M-->S) flux of each radiolabelled substrate was measured by the rate of isotope appearance in the physiological saline bathing the tissue on the serosal surface. Addition of 1-50 micromol l(-1) zinc to the luminal solution containing 1-50 micromol l(-1) (3)H-l-histidine significantly (P<0.01) increased M-->S flux of amino acid compared to controls lacking the metal. The kinetics of M-->S (3)H-l-histidine flux in the absence of zinc followed Michaelis-Menten kinetics (K(m)=6.2+/-0.8 micromol l(-1); J(max) =0.09+/-0.004 pmol cm(-2) min(-1)). Addition of 20 micromol l(-1) zinc to the luminal perfusate increased both kinetic constants (K(m)=19+/-3 micromol l(-1); J(max)=0.28+/-0.02 pmol cm(-2) min(-1)). Addition of both 20 micromol l(-1) zinc and 100 micromol l(-1) l-leucine abolished the stimulatory effect of the metal alone (K(m)=4.5+/-1.7 micromol l(-1); J(max)=0.08+/-0.008 pmol cm(-2) min(-1)). In the absence of l-histidine, M-->S flux of (65)Zn(2+) also followed the Michaelis-Menten relationship and addition of l-histidine to the perfusate significantly (P<0.01) increased both kinetic constants. Addition of either 50 micromol l(-1) Cu(+) or Cu(2+) and 20 micromol l(-1) l-histidine simultaneously abolished the stimulatory effect of l-histidine alone on transmural (65)Zn(2+) transport. Zinc-stimulation of M-->S (3)H-l-histidine flux was significantly (P<0.01) reduced by the addition of 100 micromol l(-1) glycyl-sarcosine to the perfusate, as a result of the dipeptide significantly (P<0.01) reducing both l-histidine transport K(m) and J(max). Transmural transport of (3)H-glycyl-sarcosine was unaffected by the presence of either l-histidine or l-leucine when either amino acid was added to the perfusate alone, but at least a 50% reduction in peptide transport was observed when zinc and either of the amino acids were added simultaneously. These results show that (3)H-l-histidine and (65)Zn(2+) are cotransported across the lobster intestine by a dipeptide carrier protein that binds both substrates in a bis-complex (Zn-[His](2)) resembling the normal dipeptide substrate. In addition, the transmural transports of both substrates may also occur by uncharacterized carrier processes that are independent of one another and appear relatively specific to the solutes used in this study. PMID:15634848

Conrad, Erik M; Ahearn, Gregory A

2005-01-01

139

Acid Rain Affecting the Electrical Properties of Outdoor Composite Dielectric Materials  

NASA Astrophysics Data System (ADS)

Acid rain is precipitation with acidity, i.e., pH, below 5.6. There is an increasing interest in the degradation of the electrical properties of outdoor composite dielectric materials under severe contaminant conditions such as acid rain. In this study, the degradation effects of acid rain on the outdoor composite dielectrics are investigated by accelerated aging due to artificial acid rain. Based on the investigation of acid rain, the composition of artificial acid rain is chosen to agree with the actual composition of precipitation. The surface potential, breakdown voltage, tracking resistance, and surface discharge current of dielectric materials are studied. Furthermore, the degradation mechanisms of electrical properties of composite dielectrics are discussed by investigating the degradation of the chemical and physical microstructures of material surface using Fourier transform infrared (FTIR), the X-ray diffraction spectrum (XDS), and the metalloscope. Experimental results show that the outdoor polymeric dielectrics suffer severely and degrade due to acid rain so that their surface electrical properties deteriorate after aging. The erosion, by acid rain, of the energized dielectric materials is larger than that of outdoor materials used for other purposes.

Wang, Xinsheng; Kumagai, Seiji; Yoshimura, Noboru

1998-12-01

140

Total and "free" lipids in commercial infant formulas: fatty acid composition and their stability to oxidation.  

PubMed

The aim of this paper was to study the fatty acid composition of total and "free" lipids in powdered infant milks and to evaluate the fatty acid oxidation after package opening. In its first step the application of Principal Component Analysis and Design of Experiments has allowed to take a comprehensive picture of powdered infant formulas on sale in Italy on the basis of their labelled composition and to select a limited number of representative samples. Both total and "non encapsulated" or "free" lipids were considered and analysed and no significant differences were found between their fatty acids contents. The possible modification of the fatty acid composition in the "free" lipids caused by oxidation was also studied, simulating the domestic habits after opening. No significant changes were observed up to 30 days even when formulas had an high content of unsaturated fatty acids and valuable Long Chain Polyunsaturated fatty acids. PMID:25466030

Zunin, Paola; Boggia, Raffaella; Turrini, Federica; Leardi, Riccardo

2015-04-15

141

A comparative study of the fatty acid composition of prochloron lipids  

NASA Technical Reports Server (NTRS)

The chemical analysis of lipids of Prochloron isolated from several hosts is discussed. The object was to determine whether differences in lipid composition could be used to characterize organisms from different sources. Major lipid components are given. An analysis of fatty acid composition of individual lipids slowed a distinctive disstribution of fatty acids. While present results do not justify the use of fatty acid content in the taxonomy of Prochlon, the variations found in the lipids of cells from the same host harvested from different areas, or at different times in the same area, suggest that a study of the effects of temperature and light intensity on lipid composition would be rewarding.

Kenrick, J. R.; Deane, E. M.; Bishop, D. G.

1983-01-01

142

“Click dipeptide”: A novel stationary phase applied in two-dimensional liquid chromatography  

Microsoft Academic Search

2D-HPLC is an important technique for the separation of complex samples. Developing new types of stationary phases is of great interest to construct 2D-LC systems with high orthogonality. In this study, a novel stationary phase-Click dipeptide (l-phenylglycine dipeptide) was prepared by immobilization of ?-azido l-phenylglycine dipeptide on alkyne-silica via click chemistry. In the preparation of this new material, an efficient,

Meiyun Xue; Hongxue Huang; Yanxiong Ke; Changhu Chu; Yu jin; Xinmiao Liang

2009-01-01

143

Fatty acid composition of the millipede graphidostreptus tumuliporus (karsch) (myriapoda: diplopoda)  

Microsoft Academic Search

1. 1. The fatty acid composition of female specimens of the millipede Graphidostreptus tumuliporus is investigated.\\u000a\\u000a\\u000a\\u000a2. 2. This composition differs remarkably from the composition of the male specimens of Graphidostreptus, as given in an earlier paper.\\u000a\\u000a\\u000a\\u000a3. 3. Over 60 per cent of the total fatty acid composition in the study is saturated, nearly half of it of an

R. C. H. M. Oudejans; D. J. van der Horst; D. I. Zandee

1971-01-01

144

A robust synthesis of N-glycolyl muramyl dipeptide via azidonitration/reduction.  

PubMed

A novel synthetic route leading to N-glycolyl muramyl dipeptide (MDP), a bacterial glycopeptide of particular interest in studies of nucleotide-binding oligomerization domain-containing protein 2 (NOD2), is described. The synthetic strategy hinges on the alkylation of benzylidene-protected glucal with 2-bromopropionic acid and thus circumvents a challenging and non-reproducible SN2 step at the C-3 position of glucosamine derivatives. The subsequent sequence includes an azidonitration and an unusual azide reduction/acylation step via an aza ylide/oxaphospholidine intermediate. This approach generates a protected N-glycolyl MDP that can be either subjected to a one-step global deprotection or differentially deprotected to obtain further derivatives. PMID:25476476

Xing, Shuo; Gleason, James L

2015-01-21

145

Trifluoromethyl-modified dipeptides by ZrCl4-promoted aza-Henry reactions.  

PubMed

Chiral (R)-1-phenylethylamine was successfully employed in a tandem aza-Henry addition-reduction reaction to give chiral ?-nitro ?-trifluoromethyl amines. A subsequent coupling reaction with N-Boc-protected amino acids leads to obtain optically pure CF3-modified dipeptides carrying two different N-protecting groups. These peptidomimetic units are characterized by the presence of the [CH(CF3)NH] group as mimetic of the natural [CONH] peptidic bond and can be used for the synthesis of more complex CF3-modified peptides after selective deprotection of one of the two amine functions. 2D NMR spectral analyses were employed to determine the absolute configurations of all newly synthesized chiral compounds. PMID:24802246

Fioravanti, Stefania; Pelagalli, Alessia; Pellacani, Lucio; Sciubba, Fabio; Vergari, Maria Cecilia

2014-08-01

146

Experimental protein and energy deficiencies: effects on brain free amino acid composition in rats.  

PubMed

1. The effects of protein-energy malnutrition on brain free amino acids of acidic and neutral groups were investigated in experimental rats. 2. Severe energy restriction did not modify the free amino acid composition of the brain while protein deficiency affected certain amino acids of the brain in opposite directions. Significant decreases in the levels of aspartic acid, threonine and tyrosine were observed in the protein-deficient rats. 3. These changes in brain amino acids appear to be specific to protein deficiency and not affected by energy deficiency. PMID:407922

Kaladhar, M; Rao, B S

1977-07-01

147

Omega3 Fatty Acid Composition of Persian Gulf Fishes  

Microsoft Academic Search

The aim of this study was to investigate the content of omega-3 fatty acids in Persian Gulf fishes. The fishes were collected from Persian Gulf and the content of fatty acids in the head, muscle, and liver of fishes were determined. Quantitative analysis of fatty acids was performed by gas chromatography (GC) and methylmyristate was used as the reference material.

M. J. Zibaee-Nezhad; M. Khosravi; S. Akbari; N. Bani-Asadi; Elnaz Golboostan

2010-01-01

148

Effects of dietary fatty acid composition on the regulation of carnitine palmitoyltransferase (CPT) I in rainbow trout (Oncorhynchus mykiss)  

E-print Network

polyunsaturated fatty acid (PUFA) diet, a high saturated fatty acid (SFA) diet or a mixed fatty acid control (CTL Peroxisome proliferator activated receptor Polyunsaturated fatty acids Rainbow trout Dietary fatty acid composition, particularly polyunsaturated fatty acids, can affect both genetic and non- genetic regulatory

McClelland, Grant B.

149

Sulfonated mesoporous silica-carbon composites and their use as solid acid catalysts  

NASA Astrophysics Data System (ADS)

The synthesis of highly functionalized porous silica-carbon composites made up of sulfonic groups attached to a carbon layer coating the pores of three types of mesostructured silica (i.e. SBA-15, KIT-6 and mesocellular silica) is presented. The synthesis procedure involves the following steps: (a) removal of the surfactant, (b) impregnation of the silica pores with a carbon precursor, (c) carbonization and (d) sulfonation. The resulting silica-carbon composites contain ˜30 wt % of carbonaceous matter with a high density of acidic groups attached to the deposited carbon (i.e.sbnd SO3H, sbnd COOH and sbnd OH). The structural characteristics of the parent silica are retained in the composite materials, which exhibit a high surface area, a large pore volume and a well-ordered porosity made up uniform mesopores. The high density of the sulfonic groups in combination with the mesoporous structure of the composites ensures that a large number of active sites are easily accessible to reactants. These sulfonated silica-carbon composites behave as eco-friendly, active, selective, water tolerant and recyclable solid acids. In this study we demonstrate the usefulness of these composites as solid acid catalysts for the esterification of maleic anhydride, succinic acid and oleic acid with ethanol. These composites exhibit a superior intrinsic catalytic activity to other commercial solid acids such as Amberlyst-15.

Valle-Vigón, Patricia; Sevilla, Marta; Fuertes, Antonio B.

2012-11-01

150

Polyunsaturated Fatty Acid Composition of Surgically Removed Hard Exudates in Diabetic Macular Edema.  

PubMed

Three eyes of 2 patients with diabetic macular edema underwent a vitrectomy to remove subfoveal hard exudates. Fatty acid compositions of hard exudates and plasma phospholipids (PL) as an objective estimation of dietary intake were analyzed. Polyunsaturated fatty acids (PUFA) were relatively consistent in hard exudates and PL, but were less abundant in hard exudates. The hard exudates had lower levels of eicosapentaenoic acid (EPA, C20:5 omega3) and docosahexaenoic acid (DHA, C22:6 omega3), which oxidized more readily than other PUFA. Dietary PUFA may be associated with the composition of retinal hard exudates. PMID:20337342

Byeon, Suk Ho; Chung, Hae-Yun; Kwon, Oh W

2010-03-01

151

Synthesis and characterization of novel dipeptide ester prodrugs of acyclovir  

NASA Astrophysics Data System (ADS)

Four dipeptide (Gly-Gly, Gly-Val, Val-Val, Val-Gly) ester prodrugs of 9-[(2-hydroxyethoxy)methyl]guanine (acyclovir, ACV) were synthesized. LC/MS was used to characterize the new prodrugs. Both 1H NMR and 13C NMR spectra of the four prodrugs of ACV were measured and assigned based on spectral comparison with compounds of similar structures.

Nashed, Yasser E.; Mitra, Ashim K.

2003-07-01

152

Brain and liver fatty acid composition changes upon consumption of Lactobacillus rhamnosus LA68.  

PubMed

Abstract Recent reports suggest that the metabolic activity of the enteric microbiota may influence the fatty acid composition of the host tissue. There are many studies dealing with the influence of lactobacilli on various pathological conditions, and some of the effects are strain-specific. This study was designed to test the effects of a particular Lactobacillus strain, Lactobacillus rhamnosus LA68 on fatty acid composition of the liver and the brain of C57BL/6 mice in the absence of an underlying pathological condition. Female mice were supplemented with live L. rhamnosus LA68 bacteria for the duration of 1 month. Serum biochemistry was analyzed and liver and brain fatty acid composition was assessed by gas-liquid chromatography. Significant changes in liver and brain fatty acid composition were detected. In the liver tissue we detected an increase in palmitoleic acid (p?=?0.038), while in the brain compartment we found an increase in palmitic (p?=?0.042), stearic (p?=?0.017), arachidonic acid (p?=?0.009) and docosahexaenoic acid (p?=?0.004) for control versus experimental group. These results show discrete changes caused by LA68 strain consumption. Even short duration of administration of LA68 influences the fatty acid composition of the host which adds to the existing knowledge about Lactobacillus host interaction, and adds to the growing knowledge of metabolic intervention possibilities. PMID:25431181

Ivanovic, Nevena; Minic, Rajna; Djuricic, Ivana; Dimitrijevic, Ljiljana; Sobajic, Sladjana; Zivkovic, Irena; Djordjevic, Brizita

2015-02-01

153

Effect of treatment with electrolyzed NaCl solutions and essential oil compounds on the proximate composition, amino acid and fatty acid composition of carp fillets  

Microsoft Academic Search

This investigation was undertaken to evaluate the effect of treatment with electrolyzed NaCl solutions and 1% essential oil (0.5% carvacrol+0.5% thymol) on the proximate composition and nutritional components (amino acids and fatty acids) of carp fillets at room temperature (25°C). Carp fillet samples were treated with anodic electrolyzed NaCl solution [EW (+)], cathodic electrolyzed NaCl solution [EW (?)] followed by

Barakat S. M. Mahmoud; Y. Kawai; K. Yamazaki; K. Miyashita; T. Suzuki

2007-01-01

154

Energetics of Cyclic Dipeptide Crystal Packing and Solvation  

PubMed Central

Calculations of the thermodynamics of transfer of the cyclic alanine-alanine (cAA) and glycine-glycine (cGG) dipeptides between the gas, water, and crystal phases were carried out using a combination of molecular mechanics, normal mode analysis, and continuum electrostatics. The experimental gas-to-water solvation free energy and the enthalpy of gas-to-crystal transfer of cGG are accurately reproduced by the calculations. The enthalpies of cGG and cAA crystal-to-water transfer are also close to the experimental values. A combination of experimental data and normal mode analysis of cGG provides an accurate estimate of the association entropy penalty (loss of rotational and translational entropy and gain in vibrational entropy) for “binding” in the crystalline phase of -14.1 cal/mol/K. This is a smaller number than most previous theoretical estimates, but it is similar to previous experimental estimates. Calculated entropies of the crystal phase under-estimate the experimental entropy by about 15 cal/mol/K because of neglect of longe-range lattice motions. Comparison of the intermolecular interactions in the crystals of cGG and cAA provides a possible explanation of the puzzling decrease in enthalpy, with increasing hydrophobicity seen previously for both cyclic dipeptide dissolution and protein unfolding. This decrease arises from a favorable long-range electrostatic interaction between dipeptide molecules in the crystals, which is attenuated by the more hydrophobic side chains. PMID:9017216

Brady, G. Patrick; Sharp, Kim A.

1997-01-01

155

Fatty acid composition as a tool for screening alternative feedstocks for production of biodiesel  

Technology Transfer Automated Retrieval System (TEKTRAN)

Fatty acid (FA) composition was used as a screening tool for the selection of feedstocks high in monounsaturated content for evaluation as biodiesel. The feedstocks were ailanthus (Ailanthus altissima), anise (Pimpinella anisum), arugula (Eruca vesicaria), camelina (Camelina sativa), coriander (Cori...

156

Amino acid composition of proteins from the elevated part of Orthilia secunda (L.)  

Microsoft Academic Search

This study is devoted to investigations of the amino acid composition of proteins from the elevated part of Orthilia secunda (L.) that was collected in summer with the aim of determination of the optimal period of plant harvesting.

E. N. Aeshina; Zh. A. Plynskaya; N. A. Velichko

2010-01-01

157

Conjugated linoleic acids alter bone fatty acid composition and reduce ex vivo prostaglandin E 2 biosynthesis in rats fed n-6 or n-3 fatty acids  

Microsoft Academic Search

This study evaluated the effects of conjugated linoleic acids (CLA) on tissue fatty acid composition and ex vivo prostaglandin E2 (PGE2) production in rats given diets varying in n-6 and n-3 fatty acids. Four groups of rats were given a basal semipurified diet\\u000a (AIN-93G) containing 70 g\\/kg of added fat for 42 d. The fat treatments were formulated to contain

Yong Li; Bruce A. Watkins

1998-01-01

158

Some applications of deoxyribonucleic acid base composition in bacterial taxonomy  

Microsoft Academic Search

The “melting point”Tm, the mean molar (guanine+cytosine) composition and the compositional distribution of purified DNA from several strains ofXanthomonas, Chromobacterium and yellow-pigmented marine bacteria have been determined. These groups were selected because they had been analyzed adansonially. Ten strains ofXanthomonas had an average molar (guanine+cytosine) composition within the range 66.0–68.2%, which was very close to that ofPseudomonas (60–68%), as expected.

J. De Ley; J. Van Muylem

1963-01-01

159

Characterization and Differentiation of Filamentous Fungi Based on Fatty Acid Composition  

PubMed Central

Cellular fatty acid composition of 100 different filamentous fungi, including oomycetes, zygomycetes, ascomycetes, basidiomycetes, and sterile mycelia, was analyzed to determine if they can be differentiated from one another on this basis and how minor variations in culture temperature and age affect this characteristic. Many fungi were found to possess the same fatty acids but produced different relative concentrations of each. Some fungi differed in both the fatty acids produced and in the relative concentrations of others. Multivariate discriminant analysis demonstrated that all of the species included in this study had significantly different (P < 0.001) fatty acid profiles. Each of the three phyla from which representative species were analyzed and the sterile forms had distinctive fatty acid profiles. Significant differences in fatty acid composition were also found at the intraspecific level. Both culture temperature and age affected fatty acid composition in the fungi examined, but when these factors were held constant, variance in fatty acid composition was not a problem and fungal fatty acid profiles could be differentiated statistically. PMID:16535442

Stahl, P. D.; Klug, M. J.

1996-01-01

160

Fatty Acid Composition and Conjugated Linoleic Acid Content in Different Carcass parts of Da?l?ç Lambs  

PubMed Central

This study was conducted to compare fatty acid composition and content of conjugated linoleic acid (CLA) in different regions of sheep carcasses. Lambs of the Da?l?ç breed were used for this purpose. Subsequent to a 68-day period of intensive fattening, fatty acids were examined in samples taken from the legs, shoulders, breasts, and ribs of lamb carcasses. According to the analysis, in leg, shoulder, breast, and rib, respectively, total saturated fatty acids (SFA) were found to be 40.38, 42.69, 42.56, and 40.27%, unsaturated fatty acids (MUFA) were found to be 40.38, 44.17, 46.17, and 49.50%, polyunsaturated fatty acids (PUFA) were found to be 4.79, 4.29, 3.80, and 3.72%, and CLAs were found to be 1.49, 1.69, 1.53, and 1.59%. PMID:24523647

Karabacak, Ali; Boztepe, Saim

2014-01-01

161

Superabsorbent hydrogel composite made of cellulose nanofibrils and chitosan- graft-poly(acrylic acid)  

Microsoft Academic Search

Superabsorbent hydrogel composites based on cellulose nanofibrils and chitosan-graft-poly(acrylic acid) copolymer were developed in this work. The FTIR data showed that the copolymerization and the composite formation reaction were successfully performed. In addition, the XRD pattern indicated that the nanofibrils crystallinity was as high as 90%. A 24?1 fractional factorial design was employed to evaluate the effect of acrylic acid\\/chitosan

Cristiane Spagnol; Francisco H. A. Rodrigues; Antonio G. B. Pereira; André R. Fajardo; Adley F. Rubira; Edvani C. Muniz

162

Analysis of Human Oral Mucosa Ex Vivo for Fatty Acid Compositions Using Fouriertransform Infrared Spectroscopy  

Microsoft Academic Search

The purpose of this research was to develop an infrared spectroscopic technique (Fourier transform infrared spectroscopy with\\u000a attenuated total reflectance system; FTIR-ATR) for non-invasive measurement of saturated and unsaturated fatty acid compositions\\u000a in human oral mucosa obtained from three nationalities; Iranian, Vietnamese, and Indonesian. The histogram patterns of fatty\\u000a acid compositions for three nationalities suggest that the pattern of unsaturated

Satoshi Yoshida; Yuhki Okazaki; Takumi Yamashita; Hiroshi Ueda; Reza Ghadimi; Akihiro Hosono; Tsutomu Tanaka; Kiyonori Kuriki; Sadao Suzuki; Shinkan Tokudome

2008-01-01

163

Fatty acid composition of brown adipose tissue in genetically heat-tolerant FOK rats  

NASA Astrophysics Data System (ADS)

The phospholipid fatty acid composition of brown adipose tissue (BAT) was examined in inbred heat-tolerant FOK rats and compared with that in conventional Wistar rats not previously exposed to heat. The FOK rats showed higher unsaturation states, as indicated by higher levels of polyunsaturated fatty acids and a higher unsaturation index and polyunsaturated fatty acids/saturated fatty acids ratio. This higher level of unsaturation was characterized by the higher amount of polyunsaturated fatty acids such as linoleic acid, arachidonic acid and docosahexaenoic acid. It may be concluded that the increased docosahexaenoic acid level in BAT phospholipids brings about the hyperplasia of BAT, causing an enhancement of its in vivo thermogernic activity as well as the systemic non-shivering thermogenesis observed in heat-tolerant FOK rats.

Ohno, T.; Furuyama, F.; Kuroshima, A.

164

The amino acid composition of estuarine colloidal material  

NASA Astrophysics Data System (ADS)

Amino acids were determined in estuarine colloidal and particulate material from near surface waters ranging from fresh to brackish water (12 g kg -1 salinity). The hydrolizable amino acids and associated ammonia account for an average of 80% of the nitrogen present in colloidal samples, and approximately 75% of the nitrogen from particulate fractions of the same samples. The relative proportions of these amino acids are similar to those of a cultured estuarine diatom. There are no significant amounts of D amino acids, or non-protein amino acids characteristic of bacteria in sediments and soil. A single deep-water sample (25 m) shows some evidence of bottom mud resuspension by the presence of a possible aspartic acid-hydroxyproline dimer.

Sigleo, A. C.; Hare, P. E.; Helz, G. R.

1983-07-01

165

Protonated Dipeptide Losses from b 5 and b 4 Ions of Side Chain Hydroxyl Group Containing Pentapeptides  

NASA Astrophysics Data System (ADS)

In this study, C-terminal protonated dipeptide eliminations were reported for both b 5 and b 4 ions of side chain hydroxyl group (-OH) containing pentapeptides. The study utilized the model C-terminal amidated pentapeptides having sequences of XGGFL and AXVYI, where X represents serine (S), threonine (T), glutamic acid (E), aspartic acid (D), or tyrosine (Y) residue. Upon low-energy collision-induced dissociation (CID) of XGGFL (where X = S, T, E, D, and Y) model peptide series, the ions at m/z 279 and 223 were observed as common fragments in all b 5 and b 4 ion (except b 4 ion of YGGFL) mass spectra, respectively. By contrast, peptides, namely SMeGGFL-NH2 and EOMeGGFL-NH2, did not show either the ion at m/z 279 or the ion at m/z 223. It is shown that the side chain hydroxyl group is required for the possible mechanism to take place that furnishes the protonated dipeptide loss from b 5 and b 4 ions. In addition, the ions at m/z 295 and 281 were detected as common fragments in all b 5 and b 4 ion (except b 4 ion of AYVYI) mass spectra, respectively, for AXVYI model peptide series. The MS4 experiments exhibited that the fragment ions at m/z 279, 223, 295, and 281 entirely reflect the same fragmentation behavior of [M + H]+ ion generated from commercial dipeptides FL-OH, GF-OH, YI-OH, and VY-OH. These novel eliminations reported here for b 5 and b 4 ions can be useful in assigning the correct and reliable peptide sequences for high-throughput proteomic studies.

Atik, A. Emin; Yalcin, Talat

2013-10-01

166

Maximized PUFA measurements improve insight in changes in fatty acid composition in response to temperature.  

PubMed

A general mechanism underlying the response of ectotherms to environmental changes often involves changes in fatty acid composition. Theory predicts that a decrease in temperature causes an increase in unsaturation of fatty acids, with an important role for long-chain poly-unsaturated fatty acids (PUFAs). However, PUFAs are particularly unstable and susceptible to peroxidation, hence subtle differences in fatty acid composition can be challenging to detect. We determined the fatty acid composition in springtail (Collembola) in response to two temperatures (5 degrees C and 25 degrees C). First, we tested different sample preparation methods to maximize PUFAs. Treatments consisted of different solvents for primary lipid extraction, mixing with antioxidant, flushing with inert gas, and using different temperature exposures during saponification. Especially slow saponification at low temperature (90 min at 70 degrees C) in combination with replacement of headspace air with nitrogen during saponification and methylation maximized PUFAs for GC analysis. Applying these methods to measure thermal responses in fatty acid composition, the data showed that the (maximized) proportion of C(20) PUFAs increased at low acclimation temperature. However, C(18) PUFAs increased at high acclimation temperature, which is contrary to expectations. Our study illustrates that PUFA levels in lipids may often be underestimated and this may hamper a correct interpretation of differential responses of fatty acid composition. PMID:19557745

van Dooremalen, Coby; Pel, Roel; Ellers, Jacintha

2009-10-01

167

Selective inhibition of human inducible nitric oxide synthase by S-alkyl-L-isothiocitrulline-containing dipeptides  

PubMed Central

The aim of this study was to investigate the structure-activity relationship of S-alkyl-L-isothiocitrulline-containing dipeptides towards three partially purified recombinant human nitric oxide synthase (NOS) isozymes, as well as the effects of these compounds on cytokine-induced NO production by human DLD-1 cells.In an in vitro assay, S-methyl-L-isothiocitrulline (L-MIT) was slightly selective for human neuronal NOS (nNOS) over the inducible (iNOS) or endothelial (eNOS) isozyme, but the combination of a hydrophobic L-amino acid (L-Phe, L-Leu or L-Trp) with L-MIT dramatically altered the inhibition pattern to give selective iNOS inhibitors. Introduction of a hydroxy, nitro, amino or methoxy group at the para position of the aromatic ring of L-MIT-L-Phe (MILF) decreased the selectivity and inhibitory potency. A longer or larger S-alkyl group also decreased the selectivity and potency. Dixon analysis showed that all of the dipeptides were competitive inhibitors of the three isoforms of human NOS. The enzymatic time course curves indicated that MILF was a slow binding inhibitor of human iNOS.These results suggest that the human NOS isozymes have different-sized cavities in the binding site near the position to which the C-terminal of L-arginine binds, and the cavity of iNOS is hydrophobic. Interestingly, L-MIT-D-Phe (MIDF) showed little inhibitory activity or selectivity, suggesting that the cavity of human iNOS is located in a well-defined direction from the ? carbon atom.NO production in cytokine-stimulated human DLD-1 cells was measured with a fluorescent indicator, DAF-FM. MILF, L-MIT-L-Trp(-CHO) (MILW) and L-MIT-L-Tyr (MILY) showed more potent activity than L-MIT in this whole-cell assay.Thus, S-alkyl-L-isothiocitrulline-containing dipeptides are selective inhibitors of human iNOS, and work efficiently in cell-based assay. PMID:11309260

Park, Jung-Min; Higuchi, Tsunehiko; Kikuchi, Kazuya; Urano, Yasuteru; Hori, Hiroyuki; Nishino, Takeshi; Aoki, Junken; Inoue, Keizo; Nagano, Tetsuo

2001-01-01

168

Selective inhibition of human inducible nitric oxide synthase by S-alkyl-L-isothiocitrulline-containing dipeptides.  

PubMed

The aim of this study was to investigate the structure-activity relationship of S-alkyl-L-isothiocitrulline-containing dipeptides towards three partially purified recombinant human nitric oxide synthase (NOS) isozymes, as well as the effects of these compounds on cytokine-induced NO production by human DLD-1 cells. In an in vitro assay, S-methyl-L-isothiocitrulline (L-MIT) was slightly selective for human neuronal NOS (nNOS) over the inducible (iNOS) or endothelial (eNOS) isozyme, but the combination of a hydrophobic L-amino acid (L-Phe, L-Leu or L-Trp) with L-MIT dramatically altered the inhibition pattern to give selective iNOS inhibitors. Introduction of a hydroxy, nitro, amino or methoxy group at the para position of the aromatic ring of L-MIT-L-Phe (MILF) decreased the selectivity and inhibitory potency. A longer or larger S-alkyl group also decreased the selectivity and potency. Dixon analysis showed that all of the dipeptides were competitive inhibitors of the three isoforms of human NOS. The enzymatic time course curves indicated that MILF was a slow binding inhibitor of human iNOS. These results suggest that the human NOS isozymes have different-sized cavities in the binding site near the position to which the C-terminal of L-arginine binds, and the cavity of iNOS is hydrophobic. Interestingly, L-MIT-D-Phe (MIDF) showed little inhibitory activity or selectivity, suggesting that the cavity of human iNOS is located in a well-defined direction from the alpha carbon atom. NO production in cytokine-stimulated human DLD-1 cells was measured with a fluorescent indicator, DAF-FM. MILF, L-MIT-L-Trp(-CHO) (MILW) and L-MIT-L-Tyr (MILY) showed more potent activity than L-MIT in this whole-cell assay. Thus, S-alkyl-L-isothiocitrulline-containing dipeptides are selective inhibitors of human iNOS, and work efficiently in cell-based assay. PMID:11309260

Park, J M; Higuchi, T; Kikuchi, K; Urano, Y; Hori, H; Nishino, T; Aoki, J; Inoue, K; Nagano, T

2001-04-01

169

THERMAL PROPERTIES OF EXTRUDED-INJECTION MOLDED POLY (LACTIC ACID) AND MILKWEED COMPOSITES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Currently, most polymer composites utilize petroleum-based materials that are non-degradable and difficult to recycle or incur substantial cost for disposal. Green composites can be used in nondurable limited applications. In order to determine the degree of compatibility between Poly (Lactic Acid...

170

Poly(lactic acid) and Osage Orange Wood Fiber Composites for Agricultural Mulch Films  

Technology Transfer Automated Retrieval System (TEKTRAN)

Osage orange wood was combined with poly(lactic acid) to form a polymer composite intendedfor use as an agricultural mulch film. The mechanical properties were comparable to existing products and had the advantage of being completely biodegradable through a single growing season. PLA-OO composites...

171

Proximate, mineral and fatty acid composition of fast foods consumed in Bahrain  

Microsoft Academic Search

Purpose – The purpose of this paper is to evaluate the commonly consumed fast foods in Bahrain with respect to proximate, mineral, sterol composition and their fatty acid profile. Design\\/methodology\\/approach – Foods were purchased from the most frequented fast food outlets in Manama city, the capital of Bahrain. Similar types of foods were pooled into one sample. Proximate composition was

Abdulrahman O. Musaiger; Jassim H. Al-Jedah; Reshma Dsouza

2008-01-01

172

Relation between Fatty Acid Composition and Clinical Status or Genotype in Cystic Fibrosis Patients  

Microsoft Academic Search

Objective: To evaluate the relation of clinical parameters and genotype with the serum phospholipid fatty acid (FA) composition in cystic fibrosis (CF) patients. Methods: A blood sample was taken from CF patients with stable pulmonary disease for the determination of phospholipid FA composition and vitamin E concentration who had been followed for at least 6 months at our Cystic Fibrosis

Stephanie Van Biervliet; Griet Vanbillemont; Jean-Pierre Van Biervliet; Dimitri Declercq; Eddy Robberecht; Armand Christophe

2007-01-01

173

Effect of diet on fatty acid compositions in Sciaenops J. P. TURNER* AND J. R. ROOKER  

E-print Network

Effect of diet on fatty acid compositions in Sciaenops ocellatus J. P. TURNER* AND J. R. ROOKER) were fed three natural diets (Gulf menhaden Brevoortia patronus, brown shrimp Farfantapenaeus aztecus density and PUFA compositions for 40 days. Diets were characterized as containing: high lipid, high

Rooker, Jay R.

174

Fatty acids, protein contents and metal composition of some feed crops from Turkey  

Microsoft Academic Search

In the course of investigations of new sources of higher plant lipids, fatty acid and metal compositions of some feed crops -Vicia ervilia (bitter veitch), Lotus corniculatus, Onobrychis fallax, Trifolium aureum (golden clover), Trifolium repens (white clover) (Fabaceae)- from Turkey were investigated by using GC and ICP-OES system. All the legume crops showed the same pattern of fatty acids. The

Adil Bakoglu; Eyüp Bagci; Harun Ciftci

175

Effect of dietary sources of roasted oilseeds on blood parameters and milk fatty acid composition  

Microsoft Academic Search

The aim of this experiment was to investigate the effect of supplementing the basal diet with oilseeds on blood parameters and composition of milk fatty acids, especially conjugated linoleic acid (CLA). Forty-eight lactating Holstein cows in early lactation were used in a randomized block design. The cows in each group were fed the control basal diet (the control diet) or

Z. L. Liu; D. P. Yang; P. Chen; S. B. Lin; X. Y. Jiang; W. S. Zhao; J. M. Li; W. X. Dong

2008-01-01

176

Genetic regulation of bovine milk fatty acid composition: Improving the healthfulness of milk through selection  

Microsoft Academic Search

The current study was designed to identity polymorphisms in the genes involved in milk lipid biosynthesis to provide animal breeders with tools that allow selection of animals producing milk with healthier fatty acid composition. High concentrations of saturated fatty acids (SFA) in human diets are known to increase plasma cholesterol concentrations and, as a result, increase the risk of developing

Rafael Nafikov

2010-01-01

177

Fetal bovine serum induces changes in fatty acid composition of Trypanosoma cruzi phosphoinositides.  

PubMed

Fetal bovine serum (FBS) is a necessary constituent of the culture media employed to foster the growth of Trypanosoma cruzi epimastigote forms. In different laboratories, the serum is used at final concentrations of 5 or 10%. We have normally supplemented the complex medium with 10% FBS. Under this condition we have described the fatty acid composition of the total lipids and of the phosphoinositide fractions. Additionally, we have reported the increase of polyphosphoinositides and phosphatidic acid after cholinergic stimulation. Since further attempts to reproduce these results with 5% FBS in the culture medium were not successful, the effect of the FBS concentration on the fatty acid composition of phospholipids from the T. cruzi epimastigote forms was thoroughly examined. This work showed that when the FBS concentration supplementing the culture medium was reduced from 10 to 5%, the fatty acid composition of the phosphoinositides was altered while the other major phospholipids were not significantly affected. The most relevant result was the decrease in the content of linoleic acid (18:2) and the increase of palmitoleic acid (16:1) in phosphatidylinositol 4,5-bisphosphate. Phosphatidylinositol (PI) and phosphatidylinositol phosphate also exhibited similar changes in the same fatty acids. The C2 fatty acid composition of the phosphoinositides, under the same conditions, is also reported here for the first time. PMID:8590410

Racagni, G; de Lema, M G; Hernández, G; Machado-Domenech, E E

1995-10-01

178

Mechanistic Consequences of Composition in Acid Catalysis by Polyoxometalate Keggin Clusters  

E-print Network

Mechanistic Consequences of Composition in Acid Catalysis by Polyoxometalate Keggin Clusters Josef based on polyoxometalate (POM) clusters are described in terms of the identity and dynamics catalyzed by Brønsted acids. 1. Introduction Polyoxometalate (POM) clusters with stable Keggin structure

Iglesia, Enrique

179

Effects on milk yield and composition of infusions of volatile fatty acids and caseinate into  

E-print Network

Effects on milk yield and composition of infusions of volatile fatty acids and caseinate isoenergetic infusions of either a low (17 mol/day of 64% acetic, 21% propionic and 15% butyric acids) or high that with infusions, energy and nitrogen needs were met and consisted of 60% maize silage, 10% hay, 21.5% energy

Paris-Sud XI, Université de

180

Determination of fatty acid composition of pork fat by Fourier transform infrared spectroscopy  

Microsoft Academic Search

The fatty acid composition of pork fat determines its processing quality. FTIR spectroscopic methods were evaluated on pork back and breast fat, directly on fat slices and on the fat extracts. Near infrared transmission and middle infrared using an ATR method were developed to determine the fatty acid content in the fat extracts. The results obtained with 80 back and

A Ripoche; A. S Guillard

2001-01-01

181

Using N-terminal targeting sequences, amino acid composition, and sequence motifs for predicting protein  

E-print Network

to the under- lying theory, e.g. classification based on N-terminal targeting sequences, overall amino acidUsing N-terminal targeting sequences, amino acid composition, and sequence motifs for predicting. A key step in this annotation process is the definition of a protein's subcellular lo- calization

Shatkay, Hagit

182

Fatty acid composition of lipids from the vacuolar membranes of the roots of root vegetables  

Microsoft Academic Search

The fatty acid (FA) composition of vacuolar membrane lipids from the storage tissues of parsnip (Pastinaca sativa L.), parsley (Petroselinum crispum L.), and carrot (Daucus carota L.) was studied by gasliquid chromatography, and possible pathways of the biosynthesis of these acids are considered. A high\\u000a level of unsaturated FAs (up to 78% of the total FA amount) was characteristic of

S. P. Makarenko; T. A. Konenkina; S. V. Khotimchenko

2007-01-01

183

The plant geneticist’ contribution toward changing lipid and amino acid composition of safflower  

Microsoft Academic Search

Current research on the fatty acid composition of the seed oil of safflower (Carthamus tinctorius L.) has shown the following: (1) there is a possibility that the oleic acid content can be increased above 80%, though probably\\u000a not above 85%, by use of modifying genes and the major geneol; (2) wild species do not look very promising as a source

P. F. Knowles

1972-01-01

184

Effects of dietary glucogenic amino acid supplementation on growth performance, body composition  

E-print Network

Effects of dietary glucogenic amino acid supplementation on growth performance, body composition libitum) and supplementing diets with alanine (2 g/kg), threonine (2 g/kg), glutamic acid (5 g supplementation slightly improved food to gain ratios but depressed gross energy and protein efficiencies in both

Paris-Sud XI, Université de

185

Impact of potato psyllid (Hemiptera: Triozide) feeding on free amino acid composition in potato  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foliage feeding impacts of potato psyllid (Bactericera cockerelli) on the free amino acids (FAAs) composition in potato leaf and tuber were determined under the greenhouse conditions. The free amino acids in plant extracts were separated by HPLC, and in both leaf and tuber samples, at least, 17 FAAs...

186

Fatty Acid Composition in Tobacco I. Green Tobacco Plants  

PubMed Central

The major fatty acids (16 and 18 carbons) in leaves, flowers, and seeds of Nicotiana tabacum L. cv. Catterton have been analyzed at various intervals during the growth period. From the pattern of their accumulation and relative distribution, it was found that A) the amount of fatty acids in upper young leaves attained a maximum about 75 days after transplanting which is the time of early flowering, while in older leaves the fatty acids continuously declined; B) the relative amount of linolenic acid (18:3) increased progressively with leaf development, from 30% at an early stage to 60% at maturity, while other fatty acids (18:2, 18:1, 18:0, and 16:0) decreased during the same period, indicating a progressive desaturation; and C) a rapid increase of fatty acids was found as flowers developed into seedpods, particularly of linoleic acid (18:2), which comprises 75% of tobacco seed oil. Air-curing resulted in a loss of fatty acids, especially the unsaturated ones. PMID:16656780

Chu, Hilda; Tso, T. C.

1968-01-01

187

Sensitive Amino Acid Composition and Chirality Analysis with the Mars Organic Analyzer (MOA)  

NASA Technical Reports Server (NTRS)

Detection of life on Mars requires definition of a suitable biomarker and development of sensitive yet compact instrumentation capable of performing in situ analyses. Our studies are focused on amino acid analysis because amino acids are more resistant to decomposition than other biomolecules, and because amino acid chirality is a well-defined biomarker. Amino acid composition and chirality analysis has been previously demonstrated in the lab using microfabricated capillary electrophoresis (CE) chips. To analyze amino acids in the field, we have developed the Mars Organic Analyzer (MOA), a portable analysis system that consists of a compact instrument and a novel multi-layer CE microchip.

Skelley, Alison M.; Scherer, James R.; Aubrey, Andrew D.; Grover, William H.; Ivester, Robin H. C.; Ehrenfreund, Pascale; Grunthaner, Frank J.; Bada, Jeffrey L.; Mathies, Richard A.

2005-01-01

188

Application of peanut butter to improve fatty acid composition of biscuits.  

PubMed

Biscuits prepared with different levels of hydrogenated fat (vanaspati) and peanut (Arachis hypogaea L.) butter (PB) (100:00, 75:25, 50;50, 25;75, 00:100) were evaluated for their fatty acid composition and textural property. Saturated fatty acids like myristic, palmitic, stearic acids were higher in control biscuits (100% vanaspati), which decreased with increasing proportion of PB in the experimental biscuits. Oleic acid and linoleic acid were lowest in control biscuits and it gradually increased upon incorporation of PB. The hardness of biscuits also increased with increasing proportion of PB. Overall sensory quality of experimental biscuits improved when 50% vanaspati replaced by PB in the standard biscuits recipe. Biscuits prepared with 50% supplementation of PB had better fatty acid composition with balanced oil quality and also had a greater acceptability by sensory evaluation panel. PMID:23572638

Gajera, H P; Kapopara, M B; Patel, V H

2010-06-01

189

Fatty Acid Composition of Margarines and Cooking Fats Available on the Czech Market  

Microsoft Academic Search

In a series of 20 margarines, nine cooking fats, and butter, the fatty acid composition was determined after the American Oil Chemistry Society (AOCS) standard method using capillary gas chromatography. Margarines contained 15.2–54.1% and cooking fats 16.5–59.1% saturated fatty acids, respectively, which was less than in butter. The content of linoleic fatty acid varied between 3.7 and 52.4% in margarines,

Jir?? Brát; Jan Pokorný

2000-01-01

190

Use of gas liquid chromatography for monitoring the fatty acid composition of canadian rapeseed  

Microsoft Academic Search

Since 1972, Canadian rapeseed has been changing from high erucic acid types to low erucic acid types. In 1970, the Canadian\\u000a Grain Commission instituted a program to monitor the fatty acid composition of rapeseed at the farm level, in railway carlot\\u000a shipments and in export cargo shipments. Initially, in order to process up to 20,000 samples per year, a combined

J. K. Daun; P. B. Mazur; C. J. Marek

1983-01-01

191

Determination of the fatty acid composition of canola, flax, and solin by near-infrared spectroscopy  

Microsoft Academic Search

The ability to rapidly measure key FA in oilseed crops would assist in the administration of identity-preserved systems in\\u000a the grain-handling system or in selection systems in plant-breeding programs. This study shows near-infrared reflectance (NIR)\\u000a spectroscopy to be a reliable method of determining FA composition in canola, flax, and solin (low-linolenic flax), for oleic\\u000a acid, linoleic acid, linolenic acid, and

Bert J. Siemens; James K. Daun

2005-01-01

192

[Relationship between the culture medium and the fatty acid composition of diphtheria and non-pathogenic corynebacteria].  

PubMed

The gasochromatic method was applied to the study of the cellular fatty acids composition in diphtheria and nonpathogenic corynebacteria (diphtheroids and psendo diptheria bacillus). Marked differences in the content of unsaturated fatty acids were revealed in them. Thus, palmito leic acid served the preponderant unsaturated fatty acid in Corynebacteria diphtheriae, and unsaturated fatty acids with 18 carbon atoms (octadeconoic and linoleic)--in nonpathogenic corynebacteria. The mentioned changes permit use this sign as differential. When grown on Loeffler's medium all the corynebacteria under study had a similar fatty acid composition characterized by the prevalence of unsaturated fatty acids with 18 carbon atoms. On the basis of studying the fatty acid spectrum of the nutrient media used it is supposed that one of the factors determining the revealed dependence of the corynebacterial fatty acid composition on the culture medium was the fatty acid composition of the latter. PMID:405825

Vasiurenko, Z P; Siniak, K M

1977-04-01

193

[Taxonomic significance of the fatty acid composition of bacteria of the genera Bordetella and Haemophilus].  

PubMed

Bacteria of the species B. parapertussis and B. bronchiseptica have proved to be identical in their fatty-acid composition with a high level (35.7-39%) of methylene-hexadecanoic acid, found to be absent in B. pertussis in experimental conditions. At the same time the total content of methylene-hexadecanoic acid and its biosynthetic precursor, hexadecenoic acid, in the first two Bordetella species is similar to the content of hexadecenoic acid in B. pertussis, which, along with the presence of common characteristics in the sign under consideration (the low level of C18:1), indicates the close relationship of these three Bordetella species. Bacteria of the species H. influenzae, H. parainfluenzae, H. aegyptius, H. aphrophilus have similar fatty-acid composition with the prevalence of hexadecanoic and hexadecenoic acids and the low level of fatty acids with 18 carbon atoms. The data on fatty-acid composition may suggest the presence of philogenetic links between the genera Bordetella and Haemophilus. PMID:6322484

Vasiurenko, Z P; Kolisnichenko, N I; Khramova, N I

1984-01-01

194

Fatty acid composition and extreme temperature tolerance following exposure to fluctuating temperatures in a soil arthropod.  

PubMed

Ectotherms commonly adjust their lipid composition to ambient temperature to counteract detrimental thermal effects on lipid fluidity. However, the extent of lipid remodeling and the associated fitness consequences under continuous temperature fluctuations are not well-described. The objective of this study was to investigate the effect of repeated temperature fluctuations on fatty acid composition and thermal tolerance. We exposed the springtail Orchesella cincta to two constant temperatures of 5 and 20°C, and a continuously fluctuating treatment between 5 and 20°C every 2 days. Fatty acid composition differed significantly between constant low and high temperatures. As expected, animals were most cold tolerant in the low temperature treatment, while heat tolerance was highest under high temperature. Under fluctuating temperatures, fatty acid composition changed with temperature initially, but later in the experiment fatty acid composition stabilized and closely resembled that found under constant warm temperatures. Consistent with this, heat tolerance in the fluctuating temperature treatment was comparable to the constant warm treatment. Cold tolerance in the fluctuating temperature treatment was intermediate compared to animals acclimated to constant cold or warmth, despite the fact that fatty acid composition was adjusted to warm conditions. This unexpected finding suggests that in animals acclimated to fluctuating temperatures an additional underlying mechanism is involved in the cold shock response. Other aspects of homeoviscous adaptation may protect animals during extreme cold. This paper forms a next step to fully understand the functioning of ectotherms in more thermally variable environments. PMID:21704631

van Dooremalen, Coby; Suring, Wouter; Ellers, Jacintha

2011-09-01

195

Controllable self-assembled laminated nanoribbons from dipeptide-amphiphile bearing azobenzene moiety  

E-print Network

Controllable self-assembled laminated nanoribbons from dipeptide-amphiphile bearing azobenzene nanostructures and biomaterials. In this paper, a dipeptide- amphiphile incorporated with an azobenzene moiety, Stupp has reported pH-induced self-assembly of a peptide-amphiphile to make nanostructured fibrous

Huang, Jianbin

196

[Effect of the exogenous lipids of complex media on the fatty acid composition of mycelial microorganisms].  

PubMed

The effect of exogenous lipid sources on the composition of fatty acids was studied in actinomycetes of the Streptomyces genus and in fungi belonging to the genera Blakeslea, Cunninghamella and Penicillium. The following sources of exogenous lipids were used: soybean and maize flour, sunflower by-products, chicken droppings, maize extract, yeast extract, peptone, sperm whale fat, sunflower and palm oil. The composition of fatty acids in total extracted lipids of the studied mycelial microorganisms was shown to reflect two processes: lipid synthesis de novo and assimilation of exogenous fatty acids. This fact ought to be taken into account both in the chemotaxonomic interpretation of fatty acid composition and in practical recommendations for the utilization of microbial lipids. It is of particular interest to study the physiological role of exogenous lipid metabolism in the cells of microorganisms. PMID:3084926

Konova, I V; Rudakova, L M; Pan'kina, O I; Markvicheva, E A; Bartoshevich, Iu E

1986-01-01

197

Structure-Guided, Single-Point Modifications in the Phosphinic Dipeptide Structure Yield Highly Potent and Selective Inhibitors of Neutral Aminopeptidases  

PubMed Central

Seven crystal structures of alanyl aminopeptidase from Neisseria meningitides (the etiological agent of meningitis, NmAPN) complexed with organophosphorus compounds were resolved to determine the optimal inhibitor–enzyme interactions. The enantiomeric phosphonic acid analogs of Leu and hPhe, which correspond to the P1 amino acid residues of well-processed substrates, were used to assess the impact of the absolute configuration and the stereospecific hydrogen bond network formed between the aminophosphonate polar head and the active site residues on the binding affinity. For the hPhe analog, an imperfect stereochemical complementarity could be overcome by incorporating an appropriate P1 side chain. The constitution of P1?-extended structures was rationally designed and the lead, phosphinic dipeptide hPheP?[CH2]Phe, was modified in a single position. Introducing a heteroatom/heteroatom-based fragment to either the P1 or P1? residue required new synthetic pathways. The compounds in the refined structure were low nanomolar and subnanomolar inhibitors of N. meningitides, porcine and human APNs, and the reference leucine aminopeptidase (LAP). The unnatural phosphinic dipeptide analogs exhibited a high affinity for monozinc APNs associated with a reasonable selectivity versus dizinc LAP. Another set of crystal structures containing the NmAPN dipeptide ligand were used to verify and to confirm the predicted binding modes; furthermore, novel contacts, which were promising for inhibitor development, were identified, including a ?–? stacking interaction between a pyridine ring and Tyr372. PMID:25192493

2014-01-01

198

Crystal structure of the dipeptide binding protein from Escherichia coli involved in active transport and chemotaxis.  

PubMed Central

The Escherichia coli periplasmic dipeptide binding protein functions in both peptide transport and taxis toward peptides. The structure of the dipeptide binding protein in complex with Gly-Leu (glycyl-L-leucine) has been determined at 3.2 A resolution. The binding site for dipeptides is designed to recognize the ligand's backbone while providing space to accommodate a variety of side chains. Some repositioning of protein side chains lining the binding site must occur when the dipeptide's second residue is larger than leucine. The protein's fold is very similar to that of the Salmonella typhimurium oligopeptide binding protein, and a comparison of the structures reveals the structural basis for the dipeptide binding protein's preference for shorter peptides. PMID:8563629

Dunten, P.; Mowbray, S. L.

1995-01-01

199

The fatty acid composition of Octopus vulgaris paralarvae reared with live and inert food: deviation from their natural fatty acid profile  

Microsoft Academic Search

The fatty acids of the mature ovary, late eggs and wild juveniles of Octopus vulgaris were analysed to establish, in accordance with the published data on the fatty acid composition of hatchlings, a theoretical framework of the ideal fatty acid profile, i.e. the “natural” fatty acid profile, during the early life of the species. The time course variation of the

Juan C Navarro; Roger Villanueva

2003-01-01

200

1999 Oxford University Press16421649 Nucleic Acids Research, 1999, Vol. 27, No. 7 Proteome composition and codon usage in  

E-print Network

composition and codon usage in spirochaetes: species-specific and DNA strand-specific mutational biases in codon usage and amino acid composition patterns that are significantly different between genes encoded.pallidum having a much higher G+C content than B.burgdorferi. These changes in amino acid and codon compositions

Paris-Sud XI, Université de

201

Interdpendance entre la composition en acides amins du grain de seigle et son taux d'azote  

E-print Network

content of rye grain. The amino-acid composition of 13 samples of rye grains was determined. The samples plus aspartate and decreasing for all other amino acids. Thus lysine and tryptophan in rye protein were phenotype. Therefore simply knowing N enables one to predict the amino-acid composition of any rye grain

Paris-Sud XI, Université de

202

Phagocytosis of hybrid molecular nanosomal compositions containing oxidized dextrans conjugated with isonicotinic acid hydrazide by macrophages.  

PubMed

We studied phagocytic activity of macrophages towards hybrid molecular nanosomal compositions consisting of 150-800-nm nanoliposomes containing oxidized dextrans with a molecular weight of 35 and 60 kDa obtained by chemical ("permanganate") and radiochemical oxidation of dextran conjugated with isonicotinic acid hydrazide (dextrazides, intracellular prolonged antituberculous drugs). Phagocytic activity of macrophages towards hybrid molecular nanosomal compositions containing dextrazides obtained by chemical oxidation of dextrans is higher than activity towards hybrid molecular nanosomal compositions containing dextrazides prepared by radiochemical oxidation and depends on the size of hybrid molecular nanosomal compositions and molecular weight of oxidized dextrans. PMID:21116494

Shkurupy, V A; Arkhipov, S A; Troitsky, A V; Luzgina, N G; Zaikovskaja, M V; Ufimceva, E G; Iljine, D A; Akhramenko, E S; Gulyaeva, E P; Bistrova, T N

2009-12-01

203

Synthesis and swelling behavior of Protein-g-poly Methacrylic acid/kaolin superabsorbent hydrogel composites  

NASA Astrophysics Data System (ADS)

A novel superabsorbent hydrogel composite based on Collagen have been prepared via graft copolymerization of Methacrylic acid (MAA) in the presence of kaolin powder using methylenebisacrylamide (MBA) as a crosslinking agent and ammonium persulfate (APS) as an initiator. The composite structure was confirmed using FTIR spectroscopy. A new absorption band at 1728 cm-1 in the composite spectrum confirmed kaolin-organic polymer linkage. The effect of kaolin amount and MBA concentration showed that with increasing of these parameters, the water absorbency of the superabsorbent composite was decreased. The swelling measurements of the hydrogels were conducted in aqueous salt solutions.

Sadeghi, Mohammad

2008-08-01

204

Phospholipid fatty acid composition of hepatopancreatic brush-border membrane vesicles from the prawn Penaeus japonicus.  

PubMed

Brush-border membrane vesicles (BBMV) were isolated from prawn hepatopancreas as we previously described (Muriana et al (1993) J Biochem 113, 625-629). The characterization of hepatopancreatic BBMV (hBBMV) by monitoring the activity of marker enzymes indicated a relatively pure apical membrane preparation reduced in basolateral contamination. Phospholipid composition of hBBMV was examined by the Iatroscan TLC/FID technique, whereas the fatty acid profile of phospholipids was examined by capillary gas chromatography. Phosphatidylcholine and phosphatidylethanolamine are the principal phospholipids of these membranes. The major fatty acids of phospholipids are palmitic (16:0), palmitoleic (16:1n-7), stearic (18:0), oleic (18:1n-9), eicosapentaenoic (20:5n-3) and docosapentaenoic (22:5n-3) acids. Individual phospholipids are characterized by distinct fatty acid compositions, but display a similar ratio of unsaturated-to-saturated fatty acids and a similar unsaturation index. PMID:7647111

Muriana, F J; Ruiz-Gutierrez, V; Blaya, J A; Bolufer, J

1995-01-01

205

Isotropic and anisotropic dipeptide films based on gas phase deposition  

NASA Astrophysics Data System (ADS)

We demonstrated the fabrication and application of well-ordered and vertically aligned dipeptide nanostructures based on a simple gas phase deposition. Deposited nanostructures exhibited the superhydrophobic property with a very low sliding angle. Highly reproducible SERS data have also been obtained after combining deposited films with a thin layer of gold. In addition to these, directional peptide films were, for the first time, successfully fabricated based on the oblique angle deposition technique. We believe that such bio-inspired materials would have a great impact in several technological applications involving catalysis, tissue engineering and biosensors.

Demirel, Gokhan; Tamer, Ugur

2012-06-01

206

Dipeptides catalyze rapid peptide exchange on MHC class I molecules.  

PubMed

Peptide ligand selection by MHC class I molecules, which occurs by iterative optimization, is the centerpiece of immunodominance in antiviral and antitumor immune responses. For its understanding, the molecular mechanisms of peptide binding and dissociation by class I molecules must be elucidated. To this end, we have investigated dipeptides that bind to the F pocket of class I molecules. We find that they accelerate the dissociation of prebound peptides of both low and high affinity, suggesting a mechanism of action for the peptide-exchange chaperone tapasin. Peptide exchange on class I molecules also has practical uses in epitope discovery and T-cell monitoring. PMID:25535340

Saini, Sunil Kumar; Schuster, Heiko; Ramnarayan, Venkat Raman; Rammensee, Hans-Georg; Stevanovi?, Stefan; Springer, Sebastian

2015-01-01

207

The Prototype Dipeptide Gly-Gly a Rotational Study  

NASA Astrophysics Data System (ADS)

The simplest dipeptide Gly-Gly has been examined for the first time in the gas phase by laser ablation molecular beam Fourier transform microwave (LA-MB-FTMW) spectroscopy. The nuclear quadrupole hyperfine structure of two ^{14}N nuclei has been totally resolved allowing the conclusive identification of three conformers in the supersonic expansion. Intramolecular hydrogen bonding interactions have been analyzed on the bases of the structure of the observed conformers. Present results indicate that it is possible to face the study larger peptides using LA-MB-FTMW spectroscopy.

Varela, M.; Cabezas, C.; Mata, S.; Alonso, J. L.

2013-06-01

208

Conjugated linoleic acid changes swine performance and carcass composition  

Microsoft Academic Search

ABSTRACT: Conjugated,linoleic acid (CLA) is a col- lective term,for positional,and,geometric,isomers,of linoleic acid. Dietary CLA has been,shown,to improve feed efficiency, decrease body fat, and increase lean tissue in laboratory,animals.,We hypothesized,that CLA would,improve,performance,and carcass,composi- tion and,would,be deposited,in pork,tissues. Diets of 40 crossbred,pigs were,supplemented,with CLA to de- termine,its effects on performance,and carcass composi- tion. Eight replications,of five littermate,barrows,with an initial average,weight,of 26.3 kg

R. L. Thiel-cooper; F. C. Parrish; J. C. Sparks; B. R. Wiegand; R. C. Ewan

209

Explaining longevity of different animals: is membrane fatty acid composition the missing link?  

PubMed Central

Saturated and monounsaturated fatty acids are very resistant to peroxidative damage, while the more polyunsaturated a fatty acid, the more susceptible it is to peroxidation. Furthermore, the products of lipid peroxidation can oxidatively damage other important molecules. Membrane fatty acid composition is correlated with the maximum lifespans of mammals and birds. Exceptionally long-living mammal species and birds have a more peroxidation-resistant membrane composition compared to shorter-living similar-sized mammals. Within species, there are also situations in which extended longevity is associated with peroxidation-resistant membrane composition. For example, caloric restriction is associated more peroxidation-resistant membrane composition; long-living queens have more peroxidation-resistant membranes than shorter-living worker honeybees. In humans, the offspring of nonagenarians have peroxidation-resistant erythrocyte membrane composition compared to controls. Membrane fatty acid composition is a little appreciated but important correlate of the rate of aging of animals and the determination of their longevity. PMID:19424859

2008-01-01

210

Chemical composition of acid rains in the Venezuelan savannah region  

Microsoft Academic Search

The chemical composition of rain events has been determined at 6 sites in the Venezuelan savannah region. The results indicate that precipitations are little affected by anthropogenic emissions and that rain concentrations of anions and cations are similar to those observed at \\

E. Sanhueza; M. C. Arias; L. Donoso; N. Graterol; M. Hermoso; I. Martí; J. Romero; A. Rondón; M. Santana

1992-01-01

211

Effects of dietary n-3 fatty acids on characteristics and lipid composition of ovine sperm.  

PubMed

The fatty acid composition of sperm affects the fertilization rate. The objective was to investigate the effects of dietary fish oil (as a source of n-3 fatty acids) on semen quality and sperm fatty acid composition in sheep. Eight Zandi fat-tailed rams were randomly allocated into two groups and fed either a control diet or a diet supplemented with fish oil. Both diets were isocaloric and isonitrogenous and were fed for 13 weeks, starting in the middle of the breeding season. Semen samples were collected weekly and their characteristics evaluated by standard methods, whereas samples collected at the start and end of the study were assessed (gas chromatography) for sperm lipid composition. Mean (±s.e.m.) sperm concentrations (4.3 × 109 ± 1.3 × 108 v. 3.9 × 109 ± 1.3 × 108 sperm/ml and percentages of motile (77.25 ± 3.34 v. 60.8 ± 3.34) and progressively motile sperm (74.13 ± 1.69 v. 62.69 ± 1.69) were significantly higher in the fish oil group than control. Dietary fish oil increased the proportion of docosahexaenoic acid (DHA, C22:6 n-3) in sperm fatty acid composition. We concluded that feeding fish oil as a source of n-3 fatty acids attenuated seasonal declines in semen quality in rams, perhaps through increased DHA in sperm. PMID:22445376

Samadian, F; Towhidi, A; Rezayazdi, K; Bahreini, M

2010-12-01

212

Dipeptide-based Polyphosphazene and Polyester Blends for Bone Tissue Engineering  

PubMed Central

Polyphosphazene-polyester blends are attractive materials for bone tissue engineering applications due to their controllable degradation pattern with non-toxic and neutral pH degradation products. In our ongoing quest for an ideal completely miscible polyphosphazene-polyester blend system, we report synthesis and characterization of a mixed-substituent biodegradable polyphosphazene poly[(glycine ethyl glycinato)1(phenyl phenoxy)1phosphazene] (PNGEG/PhPh) and its blends with a polyester. Two dipeptide-based blends namely 25:75 (Matrix1) and 50:50 (Matrix2) were produced at two different weight ratios of PNGEG/PhPh to poly(lactic acid-glycolic acid) (PLAGA). Blend miscibility was confirmed by differential scanning calorimetry, Fourier transform infrared spectroscopy, and scanning electron microscopy. Both blends resulted in higher tensile modulus and strength than the polyester. The blends showed a degradation rate in the order of Matrix2 < Matrix1 < PLAGA in phosphate buffered saline at 37°C over 12 weeks. Significantly higher pH values of degradation media were observed for blends compared to PLAGA confirming the neutralization of PLAGA acidic degradation by polyphosphazene hydrolysis products. The blend components PLAGA and polyphosphazene exhibited a similar degradation pattern as characterized by the molecular weight loss. Furthermore, blends demonstrated significantly higher osteoblast growth rates compared to PLAGA while maintaining osteoblast phenotype over a 21-day culture. Both blends demonstrated improved biocompatibility in a rat subcutaneous implantation model compared to PLAGA over 12 weeks. PMID:20334909

Deng, Meng; Nair, Lakshmi S.; Nukavarapu, Syam P.; Jiang, Tao; Kanner, William A.; Li, Xudong; Kumbar, Sangamesh G.; Weikel, Arlin L.; Krogman, Nicholas R.; Allcock, Harry R.; Laurencin, Cato T.

2010-01-01

213

Phenolic acid composition and antioxidant properties of Malaysian honeys.  

PubMed

The phenolic acid and flavonoid contents of Malaysian Tualang, Gelam, and Borneo tropical honeys were compared to those of Manuka honey. Ferric reducing/antioxidant power assay (FRAP) and the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical-scavenging activities were also quantified. All honey extracts exhibited high phenolic contents (15.21 ± 0.51- 42.23 ± 0.64 mg/kg), flavonoid contents (11.52 ± 0.27- 25.31 ± 0.37 mg/kg), FRAP values (892.15 ± 4.97- 363.38 ± 10.57 ?M Fe[II]/kg), and high IC?? of DPPH radical-scavenging activities (5.24 ± 0.40- 17.51 ± 0.51 mg/mL). Total of 6 phenolic acids (gallic, syringic, benzoic, trans-cinnamic, p-coumaric, and caffeic acids) and 5 flavonoids (catechin, kaempferol, naringenin, luteolin, and apigenin) were identified. Among the Malaysian honey samples, Tualang honey had the highest contents of phenolics, and flavonoids, and DPPH radical-scavenging activities. We conclude that among Malaysian honey samples, Tualang honey is the richest in phenolic acids, and flavonoid compounds, which have strong free radical-scavenging activities. PMID:22417491

Khalil, M I; Alam, N; Moniruzzaman, M; Sulaiman, S A; Gan, S H

2011-08-01

214

FATTY ACID COMPOSITION AND TOCOPHEROL CONTENT OF PUMPKIN SEED OIL  

Technology Transfer Automated Retrieval System (TEKTRAN)

Pumpkin seed oil (PSO) has high tocopherol content (TC) and unsaturated fatty acids (UFA) making it well-suited for improving human nutrition. PSO has been implicated in preventing prostate growth, retarding hypertension, mitigating hypercholesterolemia and arthritis, improved bladder compliance, a...

215

Effect of premature weaning on the fatty acid composition of rat adipose tissue.  

PubMed

The authors described the effect of premature weaning on the fatty acid spectrum in the retroperintoneal fat of female rats during ontogenesis. Premature weaning reduced the lower fatty acid content [decanoic acid C 10:0, lauric acid C 12:0, myristic acid C 14:0] in 30- to 90-day-old rats, but in further development no differences between the amount of these fatty acids were observed in suckled and prematurely weaned animals. These changes concurred with the fatty acid composition of the relevant diet (rat milk and a standard laboratory diet). Changes induced in the amount of other acids by premature weaning were not permanent in character, with the exception of stearic acid C 18:0 and linoleic acid C 18:3, which were raised at 720 days in the retroperitoneal fat of prematurely weaned rats. The amount of lower saturated fatty acids fell with advancing age, whereas oleic C 18:1, linolic C 18:2 and linolenic C 18:3 acid rose. PMID:140394

Skottová, N; Palkovic, M; Macho, L

1977-01-01

216

Fatty acid composition of adipose tissue triglycerides after weight loss and weight maintenance: the DIOGENES study.  

PubMed

Fatty acid composition of adipose tissue changes with weight loss. Palmitoleic acid as a possible marker of endogenous lipogenesis or its functions as a lipokine are under debate. Objective was to assess the predictive role of adipose triglycerides fatty acids in weight maintenance in participants of the DIOGENES dietary intervention study. After an 8-week low calorie diet (LCD) subjects with > 8 % weight loss were randomized to 5 ad libitum weight maintenance diets for 6 months: low protein (P)/low glycemic index (GI) (LP/LGI), low P/high GI (LP/HGI), high P/low GI (HP/LGI), high P/high GI (HP/HGI), and a control diet. Fatty acid composition in adipose tissue triglycerides was determined by gas chromatography in 195 subjects before the LCD (baseline), after LCD and weight maintenance. Weight change after the maintenance phase was positively correlated with baseline adipose palmitoleic (16:1n-7), myristoleic (14:1n-5) and trans-palmitoleic acid (16:1n-7t). Negative correlation was found with baseline oleic acid (18:1n-9). Lower baseline monounsaturated fatty acids (14:1n-5, 16:1n-7 and trans 16:1n-7) in adipose tissue triglycerides predict better weight maintenance. Lower oleic acid predicts lower weight decrease. These findings suggest a specific role of monounsaturated fatty acids in weight management and as weight change predictors. PMID:23098653

Kunešová, M; Hlavatý, P; Tvrzická, E; Sta?ková, B; Kalousková, P; Viguerie, N; Larsen, T M; van Baak, M A; Jebb, S A; Martinez, J A; Pfeiffer, A F H; Kafatos, A; Handjieva-Darlenska, T; Hill, M; Langin, D; Zák, A; Astrup, A; Saris, W H M

2012-01-01

217

Fatty Acid Composition of Adipose Tissue Triglycerides After Weight Loss and Weight Maintenance: the DIOGENES Study  

PubMed Central

Summary Fatty acid composition of adipose tissue changes with weight loss. Palmitoleic acid as a possible marker of endogenous lipogenesis or its functions as a lipokine are under debate. Objective was to assess the predictive role of adipose triglycerides fatty acids in weight maintenance in participants of the DIOGENES dietary intervention study. After an 8-week low calorie diet (LCD) subjects with > 8 % weight loss were randomized to 5 ad libitum weight maintenance diets for 6 months: low protein (P)/low glycemic index (GI) (LP/LGI), low P/high GI (LP/HGI), high P/low GI (HP/LGI), high P/high GI (HP/HGI), and a control diet. Fatty acid composition in adipose tissue triglycerides was determined by gas chromatography in 195 subjects before the LCD (baseline), after LCD and weight maintenance. Weight change after the maintenance phase was positively correlated with baseline adipose palmitoleic (16:1n-7), myristoleic (14:1n-5) and trans-palmitoleic acid (16:1n-7t). Negative correlation was found with baseline oleic acid (18:1n-9). Lower baseline monounsaturated fatty acids (14:1n-5, 16:1n-7 and trans 16:1n-7) in adipose tissue triglycerides predict better weight maintenance. Lower oleic acid predicts lower weight decrease. These findings suggest a specific role of monounsaturated fatty acids in weight management and as weight change predictors. PMID:23098653

KUNEŠOVÁ, M.; HLAVATÝ, P.; TVRZICKÁ, E.; STA?KOVÁ, B.; KALOUSKOVÁ, P.; VIGUERIE, N.; LARSEN, T. M.; VAN BAAK, M. A.; JEBB, S. A.; MARTINEZ, J. A.; PFEIFFER, A. F. H.; KAFATOS, A.; HANDJIEVA-DARLENSKA, T.; HILL, M.; LANGIN, D.; ŽÁK, A.; ASTRUP, A.; SARIS, W. H. M.

2013-01-01

218

Composition of mares' colostrum and milk. Protein content, amino acid composition and contents of macro and micro-elements  

Microsoft Academic Search

Changes in the protein content, protein fractions and amino acid composition of mare's colostrum and milk, and the biological value of milk protein during the first 45 days of lactation were studied. Milk samples (averaging 300–800 cm3) from 29 lactating mares were collected daily at the beginning of lactation and weekly from the 5th to 45th days post-partum. Colostrum samples

Zs. Csapó-Kiss; J. Stefler; T. G. Martin; S. Makray; J. Csapó

1995-01-01

219

Photoproducts of carminic acid formed by a composite from Manihot dulcis waste.  

PubMed

Carbon-TiO2 composites were obtained from carbonised Manihot dulcis waste and TiO2 using glycerol as an additive and thermally treating the composites at 800 °C. Furthermore, carbon was obtained from manihot to study the adsorption, desorption and photocatalysis of carminic acid on these materials. Carminic acid, a natural dye extracted from cochineal insects, is a pollutant produced by the food industry and handicrafts. Its photocatalysis was observed under different atmospheres, and kinetic curves were measured by both UV-Vis and HPLC for comparison, yielding interesting differences. The composite was capable of decomposing approximately 50% of the carminic acid under various conditions. The reaction was monitored by UV-Vis spectroscopy and LC-ESI-(Qq)-TOF-MS-DAD, enabling the identification of some intermediate species. The deleterious compound anthracene-9,10-dione was detected both in N2 and air atmospheres. PMID:25466082

Antonio-Cisneros, Cynthia M; Dávila-Jiménez, Martín M; Elizalde-González, María P; García-Díaz, Esmeralda

2015-04-15

220

The composition of coffee oil and its component fatty acids  

Microsoft Academic Search

Summary  A specimen of coffee oil has been examined with the objective of determining its composition in the light of possible uses\\u000a of the oil which is recoverable as a byproduct in the soluble coffee industry. The oil, as obtained by extraction of the coffee\\u000a grounds with solvent, contains over 5% of unique unsaponifiable material which, without preliminary removal, makes the

N. A. Khan; J. B. Brown

1953-01-01

221

The preferred conformation of dipeptides in the context of biosynthesis  

NASA Astrophysics Data System (ADS)

Globular proteins are folded polypeptide structures comprising stretches of secondary structures (helical (?- or 310 helix type), polyproline helix or ?-strands) interspersed by regions of less well-ordered structure ("random coil"). Protein fold prediction is a very active field impacting inte alia on protein engineering and misfolding studies. Apart from the many studies of protein refolding from the denatured state, there has been considerable interest in studying the initial formation of peptides during biosynthesis, when there are at the outset only a few residues in the emerging polypeptide. Although there have been many studies employing quantum chemical methods of the conformation of dipeptides, these have mostly been carried out in the gas phase or simulated water. None of these conditions really apply in the interior confines of the ribosome. In the present work, we are concerned with the conformation of dipeptides in this low dielectric environment. Furthermore, only the residue types glycine and alanine have been studied by previous authors, but we extend this repertoire to include leucine and isoleucine, position isomers which have very different structural propensities.

Bywater, Robert P.; Veryazov, Valera

2013-09-01

222

Determination of fatty acid composition of ?-irradiated hazelnuts, walnuts, almonds, and pistachios  

NASA Astrophysics Data System (ADS)

Hazelnut, walnut, almonds, and pistachio nuts were treated with 1, 3, 5, and 7 kGy of gamma irradiation, respectively. Oil content, free fatty acid, peroxide value, and fatty acid composition of the nuts were investigated immediately after irradiation. The data obtained from the experiments indicated that gamma irradiation did not cause any significant change in the oil content of nuts. In contrast, free fatty acid and peroxide value of the nuts increased proportionally to the dose (p<0.05). Among the fatty acids determined, the concentration of total saturated fatty acids increased while total monounsaturated and total polyunsaturated fatty acids decreased with the irradiation dose (p<0.05 and <0.01).

Gecgel, Umit; Gumus, Tuncay; Tasan, Murat; Daglioglu, Orhan; Arici, Muhammet

2011-04-01

223

The amino acid composition of proteins from anaerobic halophilic bacteria of the order Halanaerobiales.  

PubMed

We performed a comparative analysis of the genome sequences of three anaerobic halophilic fermentative bacteria belonging to the order Halanaerobiales: Halanaerobium praevalens, the alkaliphilic "Halanaerobium hydrogeniformans", and the thermophilic Halothermothrix orenii to assess the amino acid composition of their proteins. Members of the Halanaerobiales were earlier shown to accumulate KCl rather than organic compatible solutes for osmotic balance, and therefore the presence of a dominantly acidic proteome was predicted. Past reports indeed showed a large excess of acidic over basic amino acids in whole-cell hydrolysates of selected members of the order. However, the genomic analysis did not show unusually high contents of acidic amino acids or low contents of basic amino acids. The apparent excess of acidic amino acids in these anaerobic halophiles reported earlier is due to the high content in their proteins of glutamine and asparagine, which yield glutamate and aspartate upon acid hydrolysis. It is thus suggested that the proteins of the Halanaerobiales, which are active in the presence of high intracellular KCl concentrations, do not possess the typical acidic signature of the 'halophilic' proteins of the Archaea of the order Halobacteriales or of the extremely halophilic bacterium Salinibacter. PMID:22527048

Elevi Bardavid, Rahel; Oren, Aharon

2012-05-01

224

Stable carbon isotopic compositions of organic acids in total suspended particles and dusts from Guangzhou, China  

NASA Astrophysics Data System (ADS)

Stable carbon isotopic compositions of individual organic acids were determined in total suspended particles and dusts from Guangzhou. The ? 13C values of high molecular weight n-alkanoic acids (C 20-C 28) varied from -34.1‰ to -32.4‰ and tended to be heavier in summer and lighter in winter. These ? 13C values indicate that high molecular weight n-alkanoic acids were derived mainly from emission by C 3 plants. Reduced biological synthesis of high molecular weight n-alkanoic acids in winter may be the reason for the light carbon isotopic composition. The ? 13C values of low molecular weight n-alkanoic acids (C 10-C 18) changed from -31.7‰ to -30.3‰ and exhibited a reverse seasonal trend, i.e., heavier in winter and lighter in summer. Slightly heavier ? 13C values of low molecular weight n-alkanoic acids than those of high molecular weight n-alkanoic acids suggested that they may be emitted from blended sources, e.g., anthropogenic sources and vegetation waxes. Lighter ? 13C values in summer may be attributed to relatively low anthropogenic sources and high botanic sources in summer. Dicarboxylic acids and aromatic acids have been proposed as secondary products from photochemical degradation. The average ? 13C values of dicarboxylic acids and aromatic acids were heavier, and ranged from -25.2‰ to -22.9‰ and from -30.0‰ to -27.6‰, respectively. Both dicarboxylic acids and aromatic acids displayed the same temporal variations in the ? 13C values, i.e., negative ? 13C in the summer samples and positive in the winter samples, which may be controlled by photochemical reactions; they are generally severe in winter in Guangzhou under the monsoon weather system. The heaviest ? 13C values were observed in dicarboxylic acids, indicating that dicarboxylic acids were formed by fast and more complete oxidation reactions. These results indicate that the stable carbon isotopic composition of organic acids may provide important information about sources and photochemical reactions of organic matter in the atmosphere.

Ma, Shexia; Peng, Ping'an; Song, Jianzhong; Zhao, Jinping; He, Lulu; Sheng, Guoying; Fu, Jiamo

2010-10-01

225

Decreased hepatotoxic bile acid composition and altered synthesis in progressive human nonalcoholic fatty liver disease  

SciTech Connect

Bile acids (BAs) have many physiological roles and exhibit both toxic and protective influences within the liver. Alterations in the BA profile may be the result of disease induced liver injury. Nonalcoholic fatty liver disease (NAFLD) is a prevalent form of chronic liver disease characterized by the pathophysiological progression from simple steatosis to nonalcoholic steatohepatitis (NASH). The hypothesis of this study is that the ‘classical’ (neutral) and ‘alternative’ (acidic) BA synthesis pathways are altered together with hepatic BA composition during progression of human NAFLD. This study employed the use of transcriptomic and metabolomic assays to study the hepatic toxicologic BA profile in progressive human NAFLD. Individual human liver samples diagnosed as normal, steatosis, and NASH were utilized in the assays. The transcriptomic analysis of 70 BA genes revealed an enrichment of downregulated BA metabolism and transcription factor/receptor genes in livers diagnosed as NASH. Increased mRNA expression of BAAT and CYP7B1 was observed in contrast to decreased CYP8B1 expression in NASH samples. The BA metabolomic profile of NASH livers exhibited an increase in taurine together with elevated levels of conjugated BA species, taurocholic acid (TCA) and taurodeoxycholic acid (TDCA). Conversely, cholic acid (CA) and glycodeoxycholic acid (GDCA) were decreased in NASH liver. These findings reveal a potential shift toward the alternative pathway of BA synthesis during NASH, mediated by increased mRNA and protein expression of CYP7B1. Overall, the transcriptomic changes of BA synthesis pathway enzymes together with altered hepatic BA composition signify an attempt by the liver to reduce hepatotoxicity during disease progression to NASH. - Highlights: ? Altered hepatic bile acid composition is observed in progressive NAFLD. ? Bile acid synthesis enzymes are transcriptionally altered in NASH livers. ? Increased levels of taurine and conjugated bile acids are observed in NASH. ? Hepatic bile acid synthesis shifts toward the alternative pathway in NASH.

Lake, April D. [University of Arizona, Department of Pharmacology and Toxicology, Tucson, AZ 85721 (United States); Novak, Petr [Biology Centre ASCR, Institute of Plant Molecular Biology, Ceske Budejovice 37001 (Czech Republic); Shipkova, Petia; Aranibar, Nelly; Robertson, Donald; Reily, Michael D. [Pharmaceutical Candidate Optimization, Bristol-Myers Squibb Co., Princeton, NJ 08543 (United States); Lu, Zhenqiang [The Arizona Statistical Consulting Laboratory, University of Arizona, Tucson, AZ 85721 (United States); Lehman-McKeeman, Lois D. [Pharmaceutical Candidate Optimization, Bristol-Myers Squibb Co., Princeton, NJ 08543 (United States); Cherrington, Nathan J., E-mail: cherrington@pharmacy.arizona.edu [University of Arizona, Department of Pharmacology and Toxicology, Tucson, AZ 85721 (United States)

2013-04-15

226

Dependence of fatty-acid composition of edible oils on their enrichment in olive phenols.  

PubMed

Olive phenol extracts from waste from olive-oil production (alperujo) have been obtained by microwave-assisted extraction and used for edible oil enrichment. The extracts as such or after extractant removal were used to enrich edible oils of different fatty acid composition by liquid-liquid or solid-liquid extraction, respectively. The distribution ratios of the phenols in the different oils [olive-orujo (the waste of milled olives from which low-quality oil is obtained), sunflower, high oleic-acid content sunflower, coconut, and linseed] showed a given order as a function of phenol polarity and molecular weight, with higher distribution factors for more polar and lower molecular-weight phenols. Concerning oil composition, those oils with higher concentration of polyunsaturated fatty acids yielded higher phenol distribution factors; oils with higher concentrations of saturated fatty acids yielded lower distribution factors. PMID:19253972

Girón, María Victoria; Ruiz-Jiménez, José; Luque de Castro, María Dolores

2009-04-01

227

Fatty acid composition and its relationship with physicochemical properties of pecan ( Carya illinoensis ) oil  

Microsoft Academic Search

The composition and physicochemical properties of pecan (Carya illinoensis) kernels and oils from different native trees of the central region of Mexico were investigated. The main compositional characteristic\\u000a of the kernel was the high lipid content (70–79% w\\/w on dry basis) with elevated concentration of oleic acid (55–75% w\\/w).\\u000a The results confirmed the relationship in the biosynthesis of linoleic and

J. F. Toro-Vazquez; M. A. Charó-Alonso; F. Pérez-Briceño

1999-01-01

228

Seasonal distribution and fatty acid composition of littoral microalgae in the Yenisei River  

Microsoft Academic Search

We studied fatty acid (FA) composition of littoral microalgae in the fast-flowing oligotrophic river, the Yenisei, Siberia,\\u000a monthly for 3 years. Seasonal dynamics of species composition had similar patterns in all the studied years. In springs, a\\u000a pronounced dominance of filamentous green algae occurred, in summer and autumn diatoms were abundant, and in late autumn and\\u000a winter epilithic biofilms consisted primarily

Nadezhda N. Sushchik; Michail I. Gladyshev; Elena A. Ivanova; Elena S. Kravchuk

2010-01-01

229

Intra-and interspecific variability of fatty acid composition of soft corals  

Microsoft Academic Search

The intra-and interspecific variability of fatty acid (FA) composition of soft corals was examined in the tropical alcyonarian\\u000a Sarcophyton sp., tropical gorgonian Euplexaura erecta, and boreal alcyonarian Gersemia rubiformis. Characteristic significant differences in the FA composition were found between these species belonging to different taxonomic\\u000a groups and habitats. We assume that the FA groups 14: 0 + 16: 0 +

A. B. Imbs; H. V. Luu; L. Q. Pham

2007-01-01

230

Prediction of milk fatty acid composition by near infrared reflectance spectroscopy  

Microsoft Academic Search

Near-infrared reflectance spectroscopy (NIRS) (700–2500 nm) was used to predict milk fatty acid (FA) composition. Broad FA variability was ensured by using experimental cow milk derived from different feeding regimes (pasture and preserved forages with or without lipid supplements). Detailed FA composition was analyzed by gas chromatography. Predictive equations (354 samples) were developed for liquid and oven-dried milk samples using modified

Mauro Coppa; Anne Ferlay; Christine Leroux; Michel Jestin; Yves Chilliard; Bruno Martin; Donato Andueza

2010-01-01

231

Mutants of Arabidopsis with alterations in seed lipid fatty acid composition  

Microsoft Academic Search

A diverse collection of mutants of Arabidopsis with altered seed lipid compositions was isolated by determining the fatty acid composition of samples of seed from 3,000 mutagenized lines. A series of mutations was identified that caused deficiencies in the elongation of 18:1 to 20:1, desaturation of 18:1 to 18:2, and desaturation of 18:2 to 18:3. In each of these cases

B. Lemieux; M. Miquel; C. Somerville; J. Browse

1990-01-01

232

Influence d'un entranement physique prolong sur la composition en acides gras du tissu adipeux pididymaire  

E-print Network

acid rapeseed oil or low erucic acid rapeseed oil. Dur- ing the same period of time they were subjected in the epididymal fat of trained rats decreased but not those of stearic, linolenic and erucic acids. IntroductionInfluence d'un entraînement physique prolongé sur la composition en acides gras du tissu adipeux

Boyer, Edmond

233

Digestion of milk protein and methanol-grown bacteria protein in the preruminant calf. II. Amino acid composition of  

E-print Network

acid composition of ileal digesta and faeces and blood levels of free amino acids P. GUILLOTEAU, P Beaumont, France. Summary. The aim of this trial was to study the balance of the amino acid digestion-grown bacteria, and the rest by skim-milk powder and synthetic amino acids. Except for methionine, the apparent

Paris-Sud XI, Université de

234

Amino Acid Compositions of 27 Food Fishes and Their Importance in Clinical Nutrition  

PubMed Central

Proteins and amino acids are important biomolecules which regulate key metabolic pathways and serve as precursors for synthesis of biologically important substances; moreover, amino acids are building blocks of proteins. Fish is an important dietary source of quality animal proteins and amino acids and play important role in human nutrition. In the present investigation, crude protein content and amino acid compositions of important food fishes from different habitats have been studied. Crude protein content was determined by Kjeldahl method and amino acid composition was analyzed by high performance liquid chromatography and information on 27 food fishes was generated. The analysis showed that the cold water species are rich in lysine and aspartic acid, marine fishes in leucine, small indigenous fishes in histidine, and the carps and catfishes in glutamic acid and glycine. The enriched nutrition knowledge base would enhance the utility of fish as a source of quality animal proteins and amino acids and aid in their inclusion in dietary counseling and patient guidance for specific nutritional needs. PMID:25379285

Mahanty, Arabinda; Sankar, T. V.; Chakraborty, Kajal; Rangasamy, Anandan; Paul, Baidyanath; Sarma, Debajit; Mathew, Suseela; Asha, Kurukkan Kunnath; Behera, Bijay; Aftabuddin, Md.; Debnath, Dipesh; Vijayagopal, P.; Sridhar, N.; Akhtar, M. S.; Sahi, Neetu; Mitra, Tandrima; Banerjee, Sudeshna; Das, Debajeet; Das, Pushpita; Vijayan, K. K.; Laxmanan, P. T.; Sharma, A. P.

2014-01-01

235

Nanocellulose reinforced PVA composite films: Effects of acid treatment and filler loading  

Microsoft Academic Search

Nanocellulose was prepared by acid hydrolysis of microcrystalline cellulose (MCC) at different hydrobromic acid (HBr) concentrations.\\u000a Polyvinyl alcohol (PVA) composite films were prepared by the reinforcement of nanocellulose into a PVA matrix at different\\u000a filler loading levels and subsequent film casting. Chemical characterization of nanocelluloses was performed for the analysis\\u000a of crystallinity (Xc), degree of polymerization (DP), and molecular weight

Sun-Young Lee; D. Jagan Mohan; In-Aeh Kang; Geum-Hyun Doh; Soo Lee; Seong Ok Han

2009-01-01

236

Tables of critical values for examining compositional non-randomness in proteins and nucleic acids  

NASA Technical Reports Server (NTRS)

A binomially distributed statistic is defined to show whether or not the proportion of a particular amino acid in a protein deviates from random expectation. An analogous statistic is derived for nucleotides in nucleic acids. These new statistics are simply related to the classical chi-squared test. They explicitly account for the compositional fluctuations imposed by the finite length of proteins, and they are more accurate than previous tables.

Laird, M.; Holmquist, R.

1975-01-01

237

Effect of dietary selenium and omega-3 fatty acids on muscle composition and quality in broilers  

Microsoft Academic Search

BACKGROUND: Human health may be improved if dietary intakes of selenium and omega-3 fatty acids are increased. Consumption of broiler meat is increasing, and the meat content of selenium and omega-3 fatty acids are affected by the composition of broiler feed. A two-way analyses of variance was used to study the effect of feed containing omega-3 rich plant oils and

Anna Haug; Susanne Eich-Greatorex; Aksel Bernhoft; Jens P Wold; Harald Hetland; Olav A Christophersen; Trine Sogn

2007-01-01

238

Enzymatically Cross-linked Alginic-Hyaluronic acid Composite Hydrogels As Cell Delivery Vehicles  

PubMed Central

An injectable composite gel was developed from alginic and hyaluronic acid. The ezymatically cross-linked injectable gels were prepared via the oxidative coupling of tyramine modified sodium algiante and sodium hyaluronate in the presence of horse radish peroxidase (HRP) and hydrogen peroxide (H2O2). The composite gels were prepared by mixing equal parts of the two tryaminated polymer solutions in 10U HRP and treating with 1.0% H2O2. The properties of the alginate gels were significanly affected by the addition of hyaluronic acid. The percentage water absorption and storage modulus of the composite gels were found to be lower than the alginate gels. The alginate and composite gels showed lower protein release compared to hyaluronate gels in the absence of hyaluronidase. Even hyaluronate gels showed only approximately 10% protein release after 14 days incubation in phosphate buffer solution. ATDC-5 cells encapsulated in the injectable gels showed high cell viability. The composite gels showed the presence of enlarged spherical cells with significantly higher metabolic activity compared to cells in hyaluronic and alginic acid gels. The results suggest the potential of the composite approach to develop covalently cross-linked hydrogels with tuneable physical, mechanical, and biological properties. PMID:23357799

Ganesh, Nitya; Hanna, Craig; Nair, Shantikumar V.; Nair, Lakshmi S.

2013-01-01

239

One-Pot Synthesis of Diverse dl-Configuration Dipeptides by a Streptomyces d-Stereospecific Amidohydrolase ? †  

PubMed Central

The synthesis of diverse dl-configuration dipeptides in a one-pot reaction was demonstrated by using a function of the aminolysis reaction of a d-stereospecific amidohydrolase from Streptomyces sp., a clan SE, S12 family peptidase categorized as a peptidase with d-stereospecificity. The enzyme was able to use various aminoacyl derivatives, including l-aminoacyl derivatives, as acyl donors and acceptors. Investigations of the specificity of the peptide synthetic activity revealed that the enzyme preferentially used d-aminoacyl derivatives as acyl donors. In contrast, l-amino acids and their derivatives were preferentially used as acyl acceptors. Consequently, the synthesized dipeptides had a dl-configuration when d- and l-aminoacyl derivatives were mixed in a one-pot reaction. This report also describes that the enzyme produced cyclo(d–Pro-l-Arg), a specific inhibitor of family 18 chitinase, with a conversion rate for d-Pro benzyl ester and l-Arg methyl ester to cyclo(d-Pro–l-Arg) of greater than 65%. Furthermore, based on results of cyclo(d-Pro–l-Arg) synthesis, we propose a reaction mechanism for cyclo(d-Pro–l-Arg) production. PMID:21948842

Arima, Jiro; Usuki, Hirokazu; Hatanaka, Tadashi; Mori, Nobuhiro

2011-01-01

240

Neighboring residue effects in terminally blocked dipeptides: implications for residual secondary structures in intrinsically unfolded/disordered proteins.  

PubMed

For nuclear magnetic resonance (NMR)-based protein structure determinations, the random coil chemical shifts are very important because the secondary and tertiary protein structure predictions become possible by examining deviations of measured chemical shifts from those reference chemical shift values. In addition, neighboring residue effects on chemical shifts and J-coupling constants are crucial in understanding the nature of conformational propensities exhibited by unfolded or intrinsically disordered proteins. We recently reported the 1D NMR results for a complete set of terminally blocked dipeptides (Oh KI, Jung YS, Hwang GS, Cho M. J Biomol NMR 2012;53:25-41), but the NMR resonance assignments were not possible so that the average chemical shifts and J-coupling constants were only considered. In the present work, to thoroughly investigate the neighboring residue effects and random coil chemical shifts we extend the previous studies with 2D NMR, and measured all the (3) J(HNH?) values and H(?) and H(N) chemical shifts of the same set of terminally blocked dipeptides that are free from structural effects like secondary structure, hydrogen-bond, long-range backbone, and side-chain interactions. In particular, the preceding and following residue effects on amino-acid backbone conformational propensities are revealed and directly compared with previous works on either short peptides or empirical chemical shift database. PMID:24453185

Jung, Young-Sang; Oh, Kwang-Im; Hwang, Geum-Sook; Cho, Minhaeng

2014-09-01

241

Synthesis, kinetic evaluation, and utilization of a biotinylated dipeptide proline diphenyl phosphonate for the disclosure of dipeptidyl peptidase IV-like serine proteases.  

PubMed

In this study, we report on the synthesis, kinetic characterisation, and application of a novel biotinylated and active site-directed inactivator of dipeptidyl peptidase IV (DPP-IV). Thus, the dipeptide-derived proline diphenyl phosphonate NH(2)-Glu(biotinyl-PEG)-Pro(P)(OPh)(2) has been prepared by a combination of classical solution- and solid-phase methodologies and has been shown to be an irreversible inhibitor of porcine DPP-IV, exhibiting an over all second-order rate constant (k(i)/K(i)) for inhibition of 1.57 x 10(3) M(-1) min(-1). This value compares favourably with previously reported rates of inactivation of DPP-IV by dipeptides containing a P(1) proline diphenyl phosphonate grouping [B. Boduszek, J. Oleksyszyn, C.M. Kam, J. Selzler, R.E. Smith, J.C. Powers, Dipeptide phophonates as inhibitors of dipeptidyl peptidase IV, J. Med. Chem. 37 (1994) 3969-3976; B.F. Gilmore, J.F. Lynas, C.J. Scott, C. McGoohan, L. Martin, B. Walker, Dipeptide proline diphenyl phosphonates are potent, irreversible inhibitors of seprase (FAPalpha), Biochem, Biophys. Res. Commun. 346 (2006) 436-446.], thus demonstrating that the incorporation of the side-chain modified (N-biotinyl-3-(2-(2-(3-aminopropyloxy)-ethoxy)-ethoxy)-propyl) glutamic acid residue at the P(2) position is compatible with inhibitor efficacy. The utilisation of this probe for the detection of both purified dipeptidyl peptidase IV and the disclosure of a dipeptidyl peptidase IV-like activity from a clinical isolate of Porphyromonas gingivalis, using established electrophoretic and Western blotting techniques previously developed by our group, is also demonstrated. PMID:16824486

Gilmore, Brendan F; Carson, Louise; McShane, Laura L; Quinn, Derek; Coulter, Wilson A; Walker, Brian

2006-08-18

242

2-Oxoamide inhibitors of phospholipase A2 activity and cellular arachidonate release based on dipeptides and pseudodipeptides  

PubMed Central

A series of 2-oxoamides based on dipeptides and pseudodipeptides were synthesized and their activities toward two human intracellular phospholipases A2 (GIVA cPLA2 and GVIA iPLA2) and one human secretory phospholipase A2 (GV sPLA2) were evaluated. Derivatives containing a free carboxyl group are selective GIVA cPLA2 inhibitors. A derivative based on the ethyl ester of an ether pseudodipeptide is the first 2-oxoamide, which preferentially inhibits GVIA iPLA2. The effect of 2-oxoamides on the generation of arachidonic acid from RAW 264.7 macrophages was also studied and it was found that selective GIVA cPLA2 inhibitors preferentially inhibited cellular arachidonic acid release; one pseudodipeptide gave an IC50 value of 2 ?M. PMID:19443224

Barbayianni, Efrosini; Stephens, Daren; Grkovich, Andrej; Magrioti, Victoria; Hsu, Yuan-Hao; Cotton, Naomi; Dolatzas, Panagiotis; Kalogiannidis, Dimitrios; Dennis, Edward A.; Kokotos, George

2009-01-01

243

Composition of acid tars from sulfuric acid treatment of petroleum oils  

Microsoft Academic Search

In the production of distillate and residual lube oils, the lube stocks may be treated with concentrated sulfuric acid or oleum. This removes unsaturates, aromatics, sulfur compounds, nitrogen compounds and resinous substances, all of which are materials that lower the stability and have a detrimental effect on the service indexes of commercial petroleum oils. Acid tar is formed as a

A. F. Frolov; T. S. Titova; I. V. Karpova; T. L. Denisova

1985-01-01

244

General characteristics of Pinus spp. Seed fatty acid compositions, and importance of ?5-olefinic acids in the taxonomy and phylogeny of the genus  

Microsoft Academic Search

The ?5-unsaturated polymethylene-interrupted fatty acid (?5-UPIFA) contents and profiles of gymnosperm seeds are useful chemometric\\u000a data for the taxonomy and phylogeny of that division, and these acids may also have some biomedical or nutritional applications.\\u000a We recapitulate here all data available on pine (Pinus; the largest genus in the family Pinaceae) seed fatty acid (SFA) compositions, including 28 unpublished compositions.

Robert L. Wolff; Frédérique Pédrono; Elodie Pasquier; Anne M. Marpeau

2000-01-01

245

Ultrahigh dielectric constant composites based on the oleic acid modified ferroferric oxide nanoparticles and polyvinylidene fluoride  

NASA Astrophysics Data System (ADS)

We studied the dielectric properties of the percolative composites based on polyvinylidene fluoride and oleic acid modified ferroferric oxide nanoparticles. It demonstrates that surface modification not only can prevent the aggregation of the nanoparticles but also can greatly increase the dielectric constant of the composites. The space charge polarization at the interfaces between modified nanoparticles and polymers results in huge enhancement of dielectric constant. The maximum of dielectric constant is up to 24 105 at 100 Hz and the dielectric loss is still controlled in the range of 0-2.5. These composites can be used as the dielectric materials of super-capacitors.

Wang, Tingting; Li, Weiping; Luo, Laihui; Zhu, Yuejin

2013-03-01

246

Influence of oxidation on fulvic acids composition and biodegradability.  

PubMed

Oxidation is well-known process of transforming natural organic matter during the treatment of drinking water. Chlorine, ozone, and chlorine dioxide are common oxidants used in water treatment technologies for this purpose. We studied the influence of different doses of these oxidants on by-products formation and changes in biodegradable dissolved organic carbon (BDOC) and molecular weight distribution (MWD) of fulvic acids (FA) with different BDOC content. Chlorination did not significantly change the MWD of FA and disinfection by-products formation. However, higher molecular weight compounds, than those in the initial FA, were formed. It could be a result of chlorine substitution into the FA structure. Chlorine dioxide oxidized FA stronger than chlorine. During ozonation of FA, we found the highest increase of BDOD due to the formation of a high amount of organic acids and aldehydes. FA molecules were transformed into a more biodegradable form. Ozonation is the most preferable process among those observed for pre-treatment of FA before biofiltration. PMID:23746389

Kozyatnyk, Ivan; ?wietlik, Joanna; Raczyk-Stanis?awiak, Ursula; D?browska, Agata; Klymenko, Nataliya; Nawrocki, Jacek

2013-08-01

247

Poly(L-lactic acid)/vaterite composite coatings on metallic magnesium.  

PubMed

Poly(L-lactic acid)/vaterite composite materials were coated onto metallic magnesium substrates to control rapid degradation and to improve biocompatibility. Two types of composites were prepared by adding 30 and 60 wt% of vaterite to poly(L-lactic acid) (PLLA). The composite coating layer that contained 30 wt% vaterite in the PLLA matrix had almost no pores on the surface and suppressed the initial rapid degradation of the Mg substrate. After immersion in a culture medium for 7 days, pores of 0.5-1.0 ?m in diameter formed on the surface. The composite coating layer that contained 60 wt% vaterite with pores of 1.0-2.0 ?m in diameter on the surface did not suppress the degradation of the Mg substrate. During immersion, the pH of the media near the composite coating surfaces was maintained at 7.4-7.5 because of the degradation of PLLA and because the vaterite particles dissolved in the solution. Proliferation of murine osteoblast-like cells (MC3T3-E1) on the substrates was improved using composite coatings. Cells on the coating that contained 60 wt% vaterite had significantly higher proliferation than those on a bare Mg substrate. Our coating provides the optimum combination to suppress the initial Mg degradation and to promote cell growth on the coating surface by adjusting the vaterite content in the composite. PMID:25096227

Yamada, Shinya; Yamamoto, Akiko; Kasuga, Toshihiro

2014-12-01

248

Fatty acid composition of resynthesized Brassica napus L., B. campestris L. and B. alboglabra Bailey with special reference to the inheritance of erucic acid content  

Microsoft Academic Search

The fatty acid composition of the oil of four resynthesized rapeseed (Brassica napus L.) lines resulting from crosses between B. campestris L. and B. alboglabra Bailey was compared with that of the mid-parent value. Low palmitic acid content was partially epistatic over high. High oleic acid content could be either partially hypostatic to or transgressively epistatic over low content of

B Y Chen; W K Heneen

1989-01-01

249

[Hydrogenated products in Brazil: trans isomers, physico-chemical characteristics and fatty acid composition].  

PubMed

The shortening Brazilian market has wide range of products for specific use, mainly at industrial level. In the present work 19 samples of shortenings, 14 samples of margarines and 9 samples of spreads were studied. Iodine index, softening point, trans fatty acids, solid fat content and fatty acid composition were determined in all samples. High levels of trans fatty acids in most of the samples were observed (30%), varying between 0-62%. Correlations for thermal characteristics of the samples between the fat groups were not found. In Brazil most of shortenings are produced for blends of soy bean oils with different level of hydrogenation. PMID:8984971

Block, J M; Barrera-Arellano, D

1994-12-01

250

The effect of oxytetracycline on the fat content and fatty acid composition of the egg yolk.  

PubMed

The effects of oxytetracycline (OXT) at doses of 0.291, 0.461, 0.922, 1.383 and 1.844 g/l in drinking water on the egg quality and on the fat content and fatty acid composition of egg yolk were studied. OXT had no effect on egg weight, yolk weight or shell thickness. Increasing availability of OXT in water reduced cholesterol and triglyceride in the egg yolk while it had no effect on the phospholipid content. OXT at higher doses favoured unsaturated and polyunsaturated fatty acids relative to saturated fatty acids in the yolk. PMID:2861053

Shaddad, S A; Wasfi, I A; Yassein, O E; Ali, A E; Maglad, M A; Adam, S E

1985-01-01

251

Multifaceted chitin/poly(lactic-co-glycolic) acid composite nanogels.  

PubMed

Cyto-compatible, 80nm sized chitin/PLGA composite nanogels (chit/PLGA-comp NGs) were prepared by regeneration method and characterized. The multifaceted chit/PLGA-comp NGs were surface modified with Au, Fe3O4, CdTe/ZnTe-QDs and umbelliferone, respectively. 185nm sized Au-chit/PLGA-comp NGs, 170nm sized QD-chit/PLGA-comp-NGs and 160nm sized Fe3O4-chit/PLGA-comp-NGs showed RF heating. The QD-chit/PLGA-comp-NGs and 180nm sized umb-chit/PLGA-comp-NGs were well uptaken by Escherichia coli, Staphylococcus aureus and Candida albicans. The chit/PLGA-comp NGs could be useful for microbial monitoring and RF application for cancer therapy. The preliminary data showed that multifaceted chit/PLGA-comp-NGs could be useful for hyperthermia for cancer treatment and microbial labelling and imaging. PMID:24685461

Rejinold, N Sanoj; Biswas, Raja; Chellan, Gopi; Jayakumar, R

2014-06-01

252

3H-L-leucine transport by the promiscuous crustacean dipeptide-like cotransporter.  

PubMed

The crustacean intestine and hepatopancreas display a variety of solute transport mechanisms for transmembrane transfer of dietary contents from lumen to epithelial cytosol. An in vitro intestinal perfusion apparatus was used to characterize mucosal to serosoal (MS) and serosal to mucosal (SM) Zn(2+) -dependent (3)H-L-leucine transport by the intestine of the American lobster, Homarus americanus. Transmural 20?µM MS (3)H-L-leucine fluxes across lobster intestine were a hyperbolic function of luminal zinc concentration (1-50?µM) following Michaelis-Menten kinetics (K(m) = 2.67 ± 0.74?µM; J(max) = 19.56 ± 2.22?pmol/cm(2) ×min). Transmural 20?µM SM (3)H-L-leucine fluxes were not affected by serosal zinc, resulting in a highly significant stimulation of net amino acid transfer to the blood by luminal metal. MS fluxes of 20?µM (3)H-L-leucine were also hyperbolic functions of luminal [Cu(2+)], [Mn(2+)], [Na(+)], and [H(+)]. MS flux of (3)H-L-leucine was a sigmoidal function of luminal [L-leucine] and was stimulated by the addition of 20?µM luminal zinc at both pH 7.0 and 5.5. A greater enhanced amino acid transport occurred at the lower pH 5.5. MS flux of 20?µM (3)H-L-leucine in the presence of 20?µM zinc was significantly inhibited by addition of 100?µM luminal glycylsarcosine, and MS flux of 20?µM (3)H-glycylsarcosine was inhibited by 100?µM L-leucine in the presence of 20?µM zinc. Results suggest that (3)H-L-leucine and metals form a complex (e.g., Leu-Zn-Leu] that may functionally mimic dipeptides and use a dipeptide-like transporter during MS fluxes as suggested for fish and mammals. PMID:21732547

Obi, I; Wells, A L; Ortega, P; Patel, D; Farah, L; Zanotto, F P; Ahearn, G A

2011-10-01

253

Thermochromic Organoaminomodified Silica Composite Films Containing Phosphomolybdic Acid  

NASA Astrophysics Data System (ADS)

A novel thermochromic sol-gel film has been prepared for the first time through entrapping phosphomolybdic acid into a kind of inorganic-organic matrix co-hydrolyzed from tetraethylorthosilicate and 3-aminopropyltriethoxysilane. The thus-obtained amorphous nanocomposite film was characterized by IR spectra, UV-vis absorption spectra, XRD, TG-DTA, and ESR. Results show that phosphomolybdate polyanions interact with R-NH +3 cations strongly and disperse homogeneously in the sol-gel matrix. The sol-gel film exhibits thermochromic properties. Annealed from 120 to 180°C, the transparent film changes from pale-yellow to blue. A possible charge-transfer process has been suggested to explain the thermochromism.

Rui Zhang, Tie; Feng, Wei; Lu, Ran; Yan Bao, Chun; Jin Li, Tie; Ying Zhao, Ying; Nian Yao, Jian

2002-06-01

254

Effects of diets high in saturated fatty acids, canola oil, or safflower oil on platelet function, thromboxane B2 formation, and fatty acid composition of platelet phosphoIipids?3  

Microsoft Academic Search

Platelet function and fatty acid composition were investigated in 30 healthy male subjects who ate a con- trolled-saturated-fatty-acid (baseline) diet far 3 wk and then consumed either safflower oil or canola oil as a major fat source for 8 wk. Fatty acid composition of platelet phospholipids re- flected changes in dietary fatty acid composition. Compared with baseline a 35% decrease

Jong-Sook Kwon; Jean T Snook; Gordon M Wardlaw; Daniel H Hwang

255

Mapping quantitative trait loci (QTLs) for fatty acid composition in an interspecific cross of oil palm  

PubMed Central

Background Marker Assisted Selection (MAS) is well suited to a perennial crop like oil palm, in which the economic products are not produced until several years after planting. The use of DNA markers for selection in such crops can greatly reduce the number of breeding cycles needed. With the use of DNA markers, informed decisions can be made at the nursery stage, regarding which individuals should be retained as breeding stock, which are satisfactory for agricultural production, and which should be culled. The trait associated with oil quality, measured in terms of its fatty acid composition, is an important agronomic trait that can eventually be tracked using molecular markers. This will speed up the production of new and improved oil palm planting materials. Results A map was constructed using AFLP, RFLP and SSR markers for an interspecific cross involving a Colombian Elaeis oleifera (UP1026) and a Nigerian E. guinneensis (T128). A framework map was generated for the male parent, T128, using Joinmap ver. 4.0. In the paternal (E. guineensis) map, 252 markers (199 AFLP, 38 RFLP and 15 SSR) could be ordered in 21 linkage groups (1815 cM). Interval mapping and multiple-QTL model (MQM) mapping (also known as composite interval mapping, CIM) were used to detect quantitative trait loci (QTLs) controlling oil quality (measured in terms of iodine value and fatty acid composition). At a 5% genome-wide significance threshold level, QTLs associated with iodine value (IV), myristic acid (C14:0), palmitic acid (C16:0), palmitoleic acid (C16:1), stearic acid (C18:0), oleic acid (C18:1) and linoleic acid (C18:2) content were detected. One genomic region on Group 1 appears to be influencing IV, C14:0, C16:0, C18:0 and C18:1 content. Significant QTL for C14:0, C16:1, C18:0 and C18:1 content was detected around the same locus on Group 15, thus revealing another major locus influencing fatty acid composition in oil palm. Additional QTL for C18:0 was detected on Group 3. A minor QTL for C18:2 was detected on Group 2. Conclusion This study describes the first successful detection of QTLs for fatty acid composition in oil palm. These QTLs constitute useful tools for application in breeding programmes. PMID:19706196

Singh, Rajinder; Tan, Soon G; Panandam, Jothi M; Rahman, Rahimah Abdul; Ooi, Leslie CL; Low, Eng-Ti L; Sharma, Mukesh; Jansen, Johannes; Cheah, Suan-Choo

2009-01-01

256

Fatty acid composition of liver total lipids in alcoholic patients with and without liver damage.  

PubMed

Alcohol ingestion may promote lipid peroxidation, and the presence of polyunsaturated fatty acids in liver lipids may be essential for the generation of liver damage through this mechanism. The aim of this study is to examine fatty acid composition of liver lipids in chronic alcoholics with and without histological liver damage. A percutaneous liver biopsy was performed to 28 patients hospitalized for treatment of their alcoholism. Liver total lipids were extracted from a portion of the tissue sample and fatty acid composition was measured by gas chromatography. Another piece of the sample was sent for histological study. Six patients had histological cirrhosis or alcoholic hepatitis in their biopsies, the rest of the patients had minimal changes. Patients with liver damage had higher levels of oleic acid and total monoenoic fatty acids, a higher 18:1/18:0 ratio, lower levels of polyunsaturated fatty acids, a lower 20:4/18:2 ratio, and a lower peroxidability index in liver total lipids, than patients without liver damage. Alcoholic patients with asymptomatic liver damage have less unsaturated fatty acids in liver total lipids than their counterparts with normal livers. PMID:8947319

de la Maza, M P; Hirsch, S; Nieto, S; Petermann, M; Bunout, D

1996-11-01

257

Fatty acid composition and volatile compounds of caviar from farmed white sturgeon (Acipenser transmontanus).  

PubMed

The present study was conducted to characterize caviar obtained from farmed white sturgeons (Acipenser transmontanus) subjected to different dietary treatments. Twenty caviar samples from fish fed two experimental diets containing different dietary lipid sources have been analysed for chemical composition, fatty acids and flavour volatile compounds. Fatty acid make up of caviar was only minimally influenced by dietary fatty acid composition. Irrespective of dietary treatments, palmitic acid (16:0) and oleic acid (OA, 18:1 n-9) were the most abundant fatty acid followed by docosahexaenoic acid (DHA, 22:6 n-3) and eicopentaenoic (EPA, 20:5 n-3). Thirty-three volatile compounds were isolated using simultaneous distillation-extraction (SDE) and identified by GC-MS. The largest group of volatiles were represented by aldehydes with 20 compounds, representing the 60% of the total volatiles. n-Alkanals, 2-alkenals and 2,4-alkadienals are largely the main responsible for a wide range of flavours in caviar from farmed white surgeon. PMID:18486649

Caprino, Fabio; Moretti, Vittorio Maria; Bellagamba, Federica; Turchini, Giovanni Mario; Busetto, Maria Letizia; Giani, Ivan; Paleari, Maria Antonietta; Pazzaglia, Mario

2008-06-01

258

Content and composition of fatty acids in marine oil omega-3 supplements.  

PubMed

Marine oil omega-3 supplements are among the most frequently consumed dietary supplements in the United States. However, few studies have evaluated the overall fatty acid composition of these products. We investigated the content and composition of fatty acids in 46 commercially available marine oil omega-3 supplements by gas chromatography with flame ionization detection using the 200 m SLB-IL111 ionic liquid column. Seventy-three fatty acid isomers were quantified, including n-6, n-4, n-3, and n-1 polyunsaturated fatty acids and trans isomers of eicosapentaenoic acid (EPA; C20:5n-3) and docosahexaenoic acid (DHA; C22:6n-3), the chromatographic separations of which we report for the first time on the 200 m SLB-IL111 column. Contents of EPA and DHA met their respective label declarations in more than 80% of the products examined. Eleven of the products (24%) carried the Food and Drug Administration's qualified health claim for EPA and DHA omega-3 fatty acids. PMID:25003526

Srigley, Cynthia Tyburczy; Rader, Jeanne I

2014-07-23

259

Amino acids content and basic chemical composition of roe deer (Capreolus capreolus L.) meat.  

PubMed

The aim of this study was to determine the chemical composition of roe deer meat considering the animals' sex and age and to estimate the content of amino acids in the meat from two selected groups of the animals, i.e. 2-3-year-old males and females. A further goal was to assess the biological value of proteins as compared to the FAO standard. The study has revealed that in proteins from the roe deer muscle tissue the content of exogenous amino acids (in g/100g) is higher by 20-30% on average comparing to the level of amino acids, in the FAO/WHO (1973) standard protein. Among the endogenous amino acids, the highest (in g/100 g of protein) and the lowest concentrations were found for glutamic acid and proline, respectively. The research has also shown that roe deer meat possesses a high content of protein and a relatively low content of fat. PMID:23390753

Cygan-Szczegielniak, D; Janicki, B

2012-01-01

260

The amino acid and sugar composition of diatom cell-walls  

Microsoft Academic Search

The cell walls of diatoms consist of a silica frustule encased in an organic coating. Biochemical characterization of this coating should allow insight into: (1) the mechanism of silicification; (2) taxonomy and evolution of diatoms; (3) preservation of fossil frustules. The amino acid and sugar composition of cell walls from 6 diatom species have been elucidated. When compared to cellular

R. E. Hecky; K. Mopper; P. Kilham; E. T. Degens

1973-01-01

261

Fatty acid composition and change in Collembola fed differing diets: identification of trophic biomarkers  

Microsoft Academic Search

To assess the potential of fatty acid (FA) compositions to act as biomarkers in the soil food web, two species of Collembola, Folsomia candida and Proisotoma minuta, were switched to four possible diets: Cladosporium cladosporioides (a common soil fungus), Panagrellus redivivus (a bacteria feeding nematode), Zea mays (maize) and Alnus glutinosa (alder). The change in FA content of the Collembola

P. M. Chamberlain; I. D. Bull; H. I. J. Black; P. Ineson; R. P. Evershed

2005-01-01

262

Fatty acid composition and change in Collembola fed differing diets: identification of trophic bioma  

Microsoft Academic Search

To assess the potential of fatty acid (FA) compositions to act as biomarkers in the soil food web, two species of Collembola, Folsomia candida and Proisotoma minuta, were switched to four possible diets: Cladosporium cladosporioides (a common soil fungus), Panagrellus redivivus (a bacteria feeding nematode), Zea mays (maize) and Alnus glutinosa (alder). The change in FA content of the Collembola

P. M. Chamberlain; I. D. Bull; H. I. J. Black; P. Ineson; R. P. Evershed

2005-01-01

263

Antimicrobial activity of nisin incorporated in pectin and polylactic acid composite films against Listeria monocytogenes  

Technology Transfer Automated Retrieval System (TEKTRAN)

Extruded composite films from 20% pectin and 80% polylactic acids (PLA) were developed and nisin was loaded into films by a diffusion post extrusion. Inhibitory activities of the films against Listeria monocytogenes were evaluated in brain heart infusion (BHI) broth, liquid egg white and orange juic...

264

Biogeochemistry of the compost bioreactor components of a composite acid mine drainage passive remediation system  

Microsoft Academic Search

The compost bioreactor (“anaerobic cell”) components of three composite passive remediation systems constructed to treat acid mine drainage (AMD) at the former Wheal Jane tin mine, Cornwall, UK were studied over a period of 16 months. While there was some amelioration of the preprocessed AMD in each of the three compost bioreactors, as evidenced by pH increase and decrease in

D. Barrie Johnson; Kevin B. Hallberg

2005-01-01

265

Dietary Fatty Acid Composition and the Hibernation Patterns in Free-Ranging Arctic Ground Squirrels  

E-print Network

486 Dietary Fatty Acid Composition and the Hibernation Patterns in Free-Ranging Arctic Ground of free- ranging populations of hibernating mammals is unknown, however. We conducted a 3-yr study on the diet PUFA contents and subsequent hibernation patterns of free-ranging arctic ground squirrels

Wagner, Diane

266

Carbon isotope composition of low molecular weight hydrocarbons and monocarboxylic acids from Murchison meteorite  

Microsoft Academic Search

Carbon isotopic compositions have been measured for individual hydrocarbons and monocarboxylic acids from the Murchison meteorite, a C2 carbonaceous chondrite which fell in Australia in 1969. With few exceptions, notably benzene, the volatile products are substantially isotopically heavier than their terrestrial counterparts, signifying their extraterrestrial origin. For both classes of compounds, the ratio of C-13 to C-12 decreases with increasing

George Yuen; Neal Blair; D. J. Des Marais; Sherwood Chang

1984-01-01

267

EVALUATION OF POLY(LACTIC ACID) AND AGRICULTURAL COPRODUCTS AS GREEN COMPOSITE MATERIALS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Green composite materials of poly(lactic acid)(PLA) and agricultural coproducts such as sugar beet pulp(SBP), cuphea, lesquerella, and milkweed were compounded using a twin-screw extruder, molded by injection molding and evaluated for structural and mechanical properties using acoustic emission and ...

268

Preparation of poly(lactic acid) and pectin composite films intended for application in antimicrobial packaging  

Technology Transfer Automated Retrieval System (TEKTRAN)

Composite films of pectin and poly(lactic acid) (PLA) were compounded by extrusion. A model antimicrobial polypeptide, nisin, was loaded into the film by diffusion. The incorporation of pectin into PLA resulted in a heterogeneous biphasic structure as revealed by scanning electronic microscopy, co...

269

Water deficit effects on caraway ( Carum carvi L.) growth, essential oil and fatty acid composition  

Microsoft Academic Search

The Mediterranean region suffers of drought which affects plant behaviour regarding biochemical responses. Accordingly, the effects of water deficit on growth, essential oil and fatty acid composition of caraway (Carum carvi L.) seeds were investigated. Plants were treated with different levels of water deficit: control, moderate water deficit and severe water deficit. Plant growth (height, fresh and dry matter weight)

Bochra Laribi; Iness Bettaieb; Karima Kouki; Ali Sahli; Abdelaziz Mougou; Brahim Marzouk

2009-01-01

270

Changes in the fatty acid composition of goat milk fat after a 48-hour fast  

E-print Network

Changes in the fatty acid composition of goat milk fat after a 48-hour fast Anne-Marie MASSART, B-9000 Ghent, Belgium. Summary. Five lactating goats were milked twice daily. After a control period to adipose tissue lipolysis. Introduction. The effect of fasting goats for a period of 24 hr on milk

Paris-Sud XI, Université de

271

Fatty acid composition of goat muscles and fat depots: a review  

Microsoft Academic Search

In addition to the fat content of muscle and adipose depots, the fatty acid composition of lipids affects meat quality. Furthermore, relevant reports are difficult to use for comparisons, in that samples were collected from muscles and fat depots at various anatomical locations and experiments entailed different objectives, designs, procedures and methodologies. Nonetheless, based on currently available publications, according to

V. Banskalieva; T. Sahlu; A. L. Goetsch

2000-01-01

272

Effectof Exerciseon the PlasmaNonesterified FattyAcid Composition of Dogsand Goats:Specieswith Different  

E-print Network

Effectof Exerciseon the PlasmaNonesterified FattyAcid Composition of Dogsand Goats as tracers for turnover studies. Individual NEFA were measured in trained dogs and goats (VO2max dog/VO2max goat = 2.2; where VO2max = max- imal oxygen consumption) during treadmill exercise at 40 and 60% VO2max

McClelland, Grant B.

273

Ingestion rates and dietary lipids affect growth and fatty acid composition of Dendraster excentricus larvae  

Microsoft Academic Search

This study investigated the effect of single and mixed algal diets on growth, fatty acid composition and ingestion rates for Dendraster excentricus larvae. Larvae were assigned to three single algal diet treatments Isochrysis galbana, Dunaliella tertiolecta or Rhodomonas sp. and four mixed algal diet treatments D. tertiolecta and Rhodomonas, I. galbana and D. tertiolecta, I. galbana and Rhodomonas, D. tertiolecta,

Daniela Schiopu; Sophie B. George; John Castell

2006-01-01

274

Ontogenetic change in the lipid and fatty acid composition of scleractinian coral larvae  

E-print Network

REPORT Ontogenetic change in the lipid and fatty acid composition of scleractinian coral larvae J-Verlag 2012 Abstract Some scleractinian coral larvae have an extraordinary capacity to delay metamorphosis. To better understand the role of lipids in the dispersal of broadcast spawning coral larvae, ontogenetic

Cohen, Michael F.

275

Fertilizer effects on yield, nitrogen content and amino acid composition of maize grain  

E-print Network

Fertilizer effects on yield, nitrogen content and amino acid composition of maize grain S. M Bangkok, Thailand SUMMARY In a field experiment with a local variety of maize (Zea mays L.) cultivated in the dry matter. Additional key words : Flint type maize ; SUWAN-1 variety ; yieldlN content curve

Paris-Sud XI, Université de

276

Photoperiod affects daily torpor and tissue fatty acid composition in deer mice  

NASA Astrophysics Data System (ADS)

Photoperiod and dietary lipids both influence thermal physiology and the pattern of torpor of heterothermic mammals. The aim of the present study was to test the hypothesis that photoperiod-induced physiological changes are linked to differences in tissue fatty acid composition of deer mice, Peromyscus maniculatus (˜18-g body mass). Deer mice were acclimated for >8 weeks to one of three photoperiods (LD, light/dark): LD 8:16 (short photoperiod), LD 12:12 (equinox photoperiod), and LD 16:8 (long photoperiod). Deer mice under short and equinox photoperiods showed a greater occurrence of torpor than those under long photoperiods (71, 70, and 14%, respectively). The duration of torpor bouts was longest in deer mice under short photoperiod (9.3 ± 2.6 h), intermediate under equinox photoperiod (5.1 ± 0.3 h), and shortest under long photoperiod (3.7 ± 0.6 h). Physiological differences in torpor use were associated with significant alterations of fatty acid composition in ˜50% of the major fatty acids from leg muscle total lipids, whereas white adipose tissue fatty acid composition showed fewer changes. Our results provide the first evidence that physiological changes due to photoperiod exposure do result in changes in lipid composition in the muscle tissue of deer mice and suggest that these may play a role in survival of low body temperature and metabolic rate during torpor, thus, enhancing favourable energy balance over the course of the winter.

Geiser, Fritz; McAllan, B. M.; Kenagy, G. J.; Hiebert, Sara M.

2007-04-01

277

Composition en acides amins des aliments et des rsidus de fermentation in vitro  

E-print Network

Composition en acides aminés des aliments et des résidus de fermentation in vitro M. ANTONGIOVANNI in vitro fermentation with rumen inoculum, and of the faeces relative to an in vivo digestibility trial run fermentation in vitro comme l'ont fait Dennison et Philips (1983) et des fèces. Pour des raisons de place, nous

Paris-Sud XI, Université de

278

Fatty Acid Composition of Mixed-Rumen Bacteria: Effect of Concentration and Type of Forage  

Microsoft Academic Search

The effects of concentration and type of forage in the diet on lipid content and fatty acid (FA) composition of rumen bacteria were studied in 14 goats fitted with duodenal cannulas. The goats were fed a complete maintenance diet containing 40, 70, or 100% chopped forage (dry matter basis) in two equal meals. Forage was either corn stover or alfalfa

P. Bas; H. Archimède; A. Rouzeau; D. Sauvant

2003-01-01

279

Poly(lactic acid) and Osage Orange Wood Fiber Composites for Agricultural Mulch Films  

Technology Transfer Automated Retrieval System (TEKTRAN)

Osage orange wood(OO)was combined with poly(lactic acid)(PLA)to form a polymer composite intended for use as an agricultural mulch film. The PLA-OO mechanical properties were comparable to existing mulch film products and had the advantage of being completely biodegradable through a single growing ...

280

Genome Size and Deoxyribonucleic Acid Base Composition of .Thermop lasma acidophilurn  

Microsoft Academic Search

The deoxyribonucleic acid base composition of two strains of Thermoplasrna acidophilum including the type strain 122-1B2 was determined by buoyant den- sity and thermal denaturation temperature. The guanine plus cytosine content of the two strains examined was found by both methods to be about 46%. This re- sult is strikingly at variance with the significantly lower values, about 25%, re-

CLAUS CHRISTIANSEN; E. A. FREUNDT; FINN T. BLACK

1975-01-01

281

Proteins in the digesta of the pig: amino acid composition of endogenous, bacterial and fecal fractions.  

PubMed

When studying digestibility, the respective parts of the exogenous, endogenous and bacterial fractions in the digesta or feces must be measured. The proportions of proteins from different sources may be estimated by comparing their amino acid composition with those of reference sources. This study describes the composition of endogenous and microbial proteins, i.e. meconium of piglet small intestine and colon, axenic piglet feces, bacteria isolated in the feces of pigs receiving a standard (cereal-based) or a purified diet, and pure culture of Escherichia coli. The composition of monoxenic piglet feces and of feces of conventional pigs fed the two types of diets have also been studied. The data on 17 amino acids were used to make overall comparisons of compositions, using the method of X2 distances and factorial correspondance analysis. The composition of exclusively endogenous products differed somewhat from that of samples (mucus, mucosa) usually considered as representative of that fraction. In conventional pigs, the major part of fecal proteins was composed of bacterial protein. Accurate estimation of these was difficult: diaminopimelic acid assay gave an estimate of 65% bacterial protein, while in the same experimental conditions X2 distance gave an estimate of 90%. PMID:4095378

Laplace, J P; Darcy-Vrillon, B; Duval-Iflah, Y; Raibaud, P

1985-01-01

282

Effect of tauroursodeoxycholic acid on biliary lipid composition. A dose-response study.  

PubMed

Tauroursodeoxycholic acid has been proposed for the treatment of hepatobiliary disease, but data on the enrichment of biliary tauroursodeoxycholic acid pool and on changes of biliary lipids after administration of the compound are scarce. We studied the composition of biliary lipids in a series of 33 patients with radiolucent stones, before and after treatment with tauroursodeoxycholic acid, 3.5 - 16.6 mg/kg/day for 4 - 6 weeks. Duodenal bile was collected with the Entero-Test after gallbladder contraction. Tauroursodeoxycholic acid administration produced the following dose-dependent effects: a linear decrease of cholesterol saturation (r = 0.59, p < 0.001); a non-linear increase of the percent of ursodeoxycholic acid in bile (r = 0.59, p < 0.001); a non-linear increase of the fraction of ursodeoxycholate conjugated with taurine. At the dose of 11 mg/kg per day, cholesterol saturation was 80%, ursodeoxycholic acid represented about 45% of biliary bile acids, and about half of UDCA was conjugated with taurine. Biliary bile acids were repeatedly measured in 6 patients during long-term treatment with 9.7 - 12.1 mg/kg. The fraction of tauroursodeoxycholic acid decreased progressively from 67.6% +/- 10.5 to 29.1% +/- 5. Tauroursodeoxycholic acid is as effective as ursodeoxycholic acid on a molar basis in reducing biliary cholesterol saturation and in enriching bile with ursodeoxycholate. Moreover, tauroursodeoxycholic acid administration is associated with higher concentrations of tauroconjugates in the bile than those previously reported by feeding the free bile acid. PMID:7582394

Muraca, M; Vilei, M T; Cianci, V; Liu, X T; Garotta, F

1995-07-01

283

Electrical charging changes the composition of sulfuric acid-ammonia/dimethylamine clusters  

NASA Astrophysics Data System (ADS)

Sulfuric acid clusters stabilized by base molecules are likely to have a significant role in atmospheric new particle formation. Recent advances in mass spectrometry techniques have permitted the detection of electrically charged clusters. However, direct measurement of electrically neutral clusters is not possible. Mass spectrometry instruments can be combined with a charger, but the possible effect of charging on the composition of neutral clusters must be addressed before the measured data can be linked to properties of neutral clusters. In the present work we have used formation free energies from quantum chemical methods to calculate the evaporation rates of electrically charged (both positive and negative) sulfuric acid-ammonia/dimethylamine clusters. To understand how charging will affect the composition of these clusters, we have compared the evaporation rates of charged clusters with those of the corresponding neutral clusters. We found that the only cluster studied in this paper which will retain its composition is H2SO4 · NH3 when charged positively; all other clusters will be altered by both positive and negative charging. In the case of charging clusters negatively, base molecules will completely evaporate from clusters with 1 to 3 sulfuric acid molecules in the case of ammonia, and from clusters with 1 or 2 sulfuric acid molecules in the case of dimethylamine. Larger clusters will maintain some base molecules, but the H2SO4 : base ratio will increase. In the case of positive charging, some of the acid molecules will evaporate, decreasing the H2SO4 : base ratio.

Ortega, I. K.; Olenius, T.; Kupiainen-Määttä, O.; Loukonen, V.; Kurtén, T.; Vehkamäki, H.

2014-01-01

284

Composition and textural properties of Mozzarella cheese naturally-enriched in polyunsaturated fatty acids.  

PubMed

The effects of adding flaxseed or fish oil to the diet of dairy cows on the chemical and physical profile of Mozzarella cheese production were studied. The experiment involved 24 Friesian cows, divided into 3 groups accordingly fat supplementation: basal diet (CT), diet supplemented with flaxseed (FS) or fish oil (FO). Mozzarella cheeses were manufactured from bulk milk of each group. Bulk milk was analysed for chemical composition and renneting parameters. Mozzarella cheeses were analysed for chemical composition, fatty acid profile, and textural properties. Results suggest that Mozzarella cheese from cows receiving flaxseed supplementation showed a decrease in saturated fatty acids (SFA), an increase in monounsaturated fatty acids (MUFA), and in polyunsaturated fatty acids (PUFA) compared with control Mozzarella cheese. The increased dietary intake of C18:3 in flaxseed supplemented cows resulted in increased levels of trans-11 C18:1, and of CLA cis-9 trans-11 C18:2, and in low Atherogenic and Trombogenic Indexes. FO Mozzarella cheese showed compositional and textural properties quite similar to CT Mozzarella cheese; however, increased levels of n-3 polyunsaturated fatty acids in FO Mozzarella were found. PMID:23611673

Caroprese, Mariangela; Sevi, Agostino; Marino, Rosaria; Santillo, Antonella; Tateo, Alessandra; Albenzio, Marzia

2013-08-01

285

Relationship between seminal antioxidant enzymes and the phospholipid and fatty acid composition of spermatozoa.  

PubMed

Sperm cell membranes are susceptible to peroxidative damage through an excess of reactive oxygen species. The objective of this study was to determine seminal plasma glutathione peroxidase (GPX) and superoxide dismutase (SOD) activity and relate these to phospholipid profiles and phospholipid-esterified fatty acid composition of spermatozoa. Seminal plasma GPX and SOD activity, phospholipid, phospholipid-esterified fatty acid composition and malondialdehyde (MDA) of spermatozoa were assayed in 10 normozoospermic and 25 asthenozoospermic subjects. Mean seminal GPX and SOD activity in normozoospermic men were not significantly different from asthenozoospermic men. A significant positive correlation was observed between seminal plasma GPX activity and phosphatidylcholine content (r = +0.77, P = 0.037) and there was a significant negative correlation with lysophosphatidylcholine content (r = -0.89, P = 0.02) in normozoospermic sperm samples. Positive correlations were found between SOD activity and polyunsaturated fatty acid composition of spermatozoa. MDA content in the spermatozoa of asthenozoospermic subjects was significantly higher than in normozoospermic males (P < 0.05). Negative correlations were found between MDA content and seminal SOD activity and arachidonic acid content of spermatozoa from normozoospermic samples (r = -0.5; P = 0.046, r = -0.9; P = 0.001 respectively). Seminal plasma GPX and SOD provide protection against lipid peroxidation of phospholipid and phospholipid-bound fatty acids in normozoospermic samples. PMID:18492368

Tavilani, Heidar; Goodarzi, Mohamad Taghi; Doosti, Mahmoud; Vaisi-Raygani, Asad; Hassanzadeh, Taghi; Salimi, Saeedeh; Joshaghani, Hamid Reza

2008-05-01

286

A comparison of the physicochemical properties and fatty acid composition of indaiá (Attalea dubia) and Babassu (Orbignya phalerata) oils.  

PubMed

The physicochemical properties and fatty acid composition of Attalea dubia (Mart.) Burret (indaiá) seed oil were investigated. The oil was extracted in a soxhlet apparatus using petroleum ether and evaluated for iodine, acid, peroxide, ester, and saponification values. The oil was also analyzed using infrared and nuclear magnetic resonance spectroscopy. The fatty acid profile of the oil was determined by GC-MS. For each analysis indaiá oil was compared to Orbignya phalerata (babassu) oil. The two oils appeared to be very similar in their fatty acid composition, in which lauric acid (the most abundant), myristic acid, caprylic acid, and capric acid were the four main fatty acids detected. The unsaturated fatty acids content was lower for indaiá oil (5.8%) than for babassu oil (9.4%). The results suggest that indaiá palm tree could be cultivated as a new source of vegetable oil with potential for food and cosmetic industries. PMID:22593692

Ferreira, Bianca Silva; Faza, Lara Pereira; Le Hyaric, Mireille

2012-01-01

287

A Comparison of the Physicochemical Properties and Fatty Acid Composition of Indaiá (Attalea dubia) and Babassu (Orbignya phalerata) Oils  

PubMed Central

The physicochemical properties and fatty acid composition of Attalea dubia (Mart.) Burret (indaiá) seed oil were investigated. The oil was extracted in a soxhlet apparatus using petroleum ether and evaluated for iodine, acid, peroxide, ester, and saponification values. The oil was also analyzed using infrared and nuclear magnetic resonance spectroscopy. The fatty acid profile of the oil was determined by GC-MS. For each analysis indaiá oil was compared to Orbignya phalerata (babassu) oil. The two oils appeared to be very similar in their fatty acid composition, in which lauric acid (the most abundant), myristic acid, caprylic acid, and capric acid were the four main fatty acids detected. The unsaturated fatty acids content was lower for indaiá oil (5.8%) than for babassu oil (9.4%). The results suggest that indaiá palm tree could be cultivated as a new source of vegetable oil with potential for food and cosmetic industries. PMID:22593692

Silva Ferreira, Bianca; Pereira Faza, Lara; Le Hyaric, Mireille

2012-01-01

288

Fatty acid and hydrocarbon composition in tropical marine Shewanella amazonensis strain SB2B(T).  

PubMed

Shewanella amazonensis strain SB2B(T) is an isolate from shallow-water marine sediments derived from the Amazon River delta. This bacterium contained a long-chain polyunsaturated hydrocarbon, all-cis -3,6,9,12,16,19,22,25,28 hentriacontanonaene (C31:9), constituting 1-2% of the total fatty acid methyl ester and hydrocarbon fraction, which was produced dependently of decreased growth temperature. Analysis of its cellular fatty acid composition demonstrated that isopentadecanoic acid was the major fatty acid component and that all the main monounsaturated fatty acids had straight chains with a cis configuration. However, monoenoic cyclopropyl fatty acids, which were previously reported to be present in this bacterium, were not detected by mass spectrometric analysis. The growth temperature affected the content of ?9-cis -hexadecenoic [16:1(?9c)], palmitic, and heptadecanoic acids. These results suggest that C31:9, as well as 16:1(?9c) might be involved in adaptation to low temperature in S. amazonensis strain SB2B(T) . Our result suggests that polyunsaturated fatty acid synthase protein complex may be involved in synthesis of C31:9 but not in production of eicosapentaenoic acid. PMID:21656813

Motoigi, Taro; Okuyama, Hidetoshi

2011-10-01

289

Fatty acid composition in matrix vesicles and in microvilli from femurs of chicken embryos revealed selective recruitment of fatty acids.  

PubMed

Hypertrophic chondrocytes participate in matrix mineralization by releasing matrix vesicles (MVs). These MVs, by accumulating Ca(2+) and phosphate initiate the formation of hydroxyapatite. To determine the types of lipids essential for mineralization, we analyzed fatty acids (FAs) in MVs, microvilli and in membrane fractions of chondrocytes isolated from femurs of chicken embryos. The FA composition in the MVs was almost identical to that in microvilli, indicating that the MVs originated from microvilli. These fractions contained more monounsaturated FAs especially oleic acid than in membrane homogenates of chondrocytes. They were enriched in 5,8,11-eicosatrienoic acid (20:3n-9), in eicosadienoic acid (20:2n-6), and in arachidonic acid (20:4n-6). In contrast, membrane homogenates from chondrocytes were enriched in 20:1n-9, 18:3n-3, 22:5n-3 and 22:5n-6. Due to their relatively high content in MVs and to their selective recruitment within microvilli from where MV originate, we concluded that 20:2n-6 and 20:3n-9 (pooled values), 18:1n-9 and 20:4n-6 are essential for the biogenesis of MVs and for bone mineralization. PMID:24685481

Abdallah, Dina; Hamade, Eva; Merhi, Raghida Abou; Bassam, Badran; Buchet, René; Mebarek, Saida

2014-04-18

290

Acid-functionalized polysilsesquioxane-nafion composite membranes with high proton conductivity and enhanced selectivity.  

PubMed

A series of new Nafion-based composite membranes have been prepared via an in situ sol-gel reaction of 3-(trihydroxylsilyl)propane-1-sulfonic acid and solution casting method. The morphological structure, ion-exchange capacity, water uptake, proton conductivity, and methanol permeability of the resulting composite membranes have been extensively investigated as functions of the content of sulfopropylated polysilsesquioxane filler, temperature, and relative humidity. Unlike the conventional Nafion/silica composites, the prepared membranes exhibit an increased water uptake and associated enhancement in proton conductivity compared to unmodified Nafion. In particular, considerably high proton conductivities at 80 and 120 degrees C under 30% relative humidity have been demonstrated in the composite membranes, which are over 2 times greater than that of Nafion. In addition to a remarkable improvement in proton conductivity, the composite membranes display lower methanol permeability and superior electrochemical selectivities in comparison to the pure Nafion membrane. These unique properties could be exclusively credited to the presence of pendant sulfonic acid groups in the filler, which provides fairly continuous proton-conducting pathways between filler and matrix in the composite membranes and thus facilitates the proton transport without the anticipated trade-off between conductivity and selectivity. This work opens new opportunities of tailoring the properties of Nafion-the benchmark fuel cell membrane-to obviate its limitations and enhance the conductive properties at high temperature/low humidity and in direct methanol fuel cells. PMID:20356129

Xu, Kui; Chanthad, Chalatorn; Gadinski, Matthew R; Hickner, Michael A; Wang, Qing

2009-11-01

291

Egg fatty acid composition from lake trout fed two Lake Michigan prey fish species.  

PubMed

We previously demonstrated that there were significant differences in the egg thiamine content in lake trout Salvelinus namaycush fed two Lake Michigan prey fish (alewife Alosa pseudoharengus and bloater Coregonus hoyi). Lake trout fed alewives produced eggs low in thiamine, but it was unknown whether the consumption of alewives affected other nutritionally important components. In this study we investigated the fatty acid composition of lake trout eggs when females were fed diets that resulted in different egg thiamine concentrations. For 2 years, adult lake trout were fed diets consisting of four combinations of captured alewives and bloaters (100% alewives; 65% alewives, 35% bloaters; 35% alewives, 65% bloaters; and 100% bloaters). The alewife fatty acid profile had higher concentrations of arachidonic acid and total omega-6 fatty acids than the bloater profile. The concentrations of four fatty acids (cis-13, 16-docosadienoic, eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids) were higher in bloaters than in alewives. Although six fatty acid components were higher in lake trout eggs in 2001 than in 2000 and eight fatty acids were lower, diet had no effect on any fatty acid concentration measured in lake trout eggs in this study. Based on these results, it appears that egg fatty acid concentrations differ between years but that the egg fatty acid profile does not reflect the alewife-bloater mix in the diet of adults. The essential fatty acid content of lake trout eggs from females fed alewives and bloaters appears to be physiologically regulated and adequate to meet the requirements of developing embryos. PMID:20218501

Honeyfield, Dale C; Fitzsimons, John D; Tillitt, Donald E; Brown, Scott B

2009-12-01

292

Lactic acid fermentation by cells immobilised on various porous cellulosic materials and their alginate/poly-lactic acid composites.  

PubMed

Porous delignified cellulose (or tubular cellulose, abbr. TC) from Indian Mango (Mangifera indica) and Sal (Shorea robusta) wood and Rice husk, and TC/Ca-alginate/polylactic acid composites, were used as Lactobacillus bulgaricus immobilisation carriers leading to improvements in lactic acid fermentation of cheese whey and synthetic lactose media, compared to free cells. Specifically, shorter fermentation rates, higher lactic acid yields (g/g sugar utilised) and productivities (g/Ld), and higher amounts of volatile by-products were achieved, while no significant differences were observed on the performance of the different immobilised biocatalysts. The proposed biocatalysts are of food grade purity, cheap and easy to prepare, and they are attractive for bioprocess development based on immobilised cells. Such composite biocatalysts may be used for the co-immobilisation of different microorganisms or enzymes (in separate layers of the biocatalyst), to efficiently conduct different types of fermentations in the same bioreactor, avoiding inhibition problems of chemical or biological (competition) nature. PMID:24690466

Kumar, Mrinal Nishant; Gialleli, Angelika-Ioanna; Masson, Jean Bernard; Kandylis, Panagiotis; Bekatorou, Argyro; Koutinas, Athanasios A; Kanellaki, Maria

2014-08-01

293

A molecular dynamics study of the dielectric properties of aqueous solutions of alanine and alanine dipeptide  

Microsoft Academic Search

Molecular dynamics simulations were used to compute the frequency-dependent dielectric susceptibility of aqueous solutions of alanine and alanine dipeptide. We studied four alanine solutions, ranging in concentration from 0.13-0.55 mol\\/liter, and two solutions of alanine dipeptide (0.13 and 0.27 mol\\/liter). In accord with experiment we find a strong dielectric increment for both solutes, whose molecular origin is shown to be

Stefan Boresch; Martin Willensdorfer; Othmar Steinhauser

2004-01-01

294

Effects of ileal resection on biliary lipids and bile acid composition in patients with Crohn's disease.  

PubMed Central

Biliary lipid composition, cholesterol saturation, and bile acid pattern were determined in fasting duodenal bile of 10 patients (four men and six women, mean age 41 years) with Crohn's disease and a history of ileal resection (mean 64 cm). The data were compared with corresponding values in a group of healthy subjects. None of the patients with Crohn's disease had supersaturated bile. Cholesterol saturation was significantly lower in the patients with Crohn's disease than in the healthy subjects. The molar percentage of cholesterol was also lower among the patients but there was no significant difference. The molar percentages of phospholipids and bile acids were normal. Bile acid composition in the patients with ileal resection was characterised by a significant decrease in the deoxycholic acid fraction and a pronounced increase in the ursodeoxycholic acid fraction compared with the healthy subjects. The surprisingly high percentage of ursodeoxycholic acid may contribute to the low degree of cholesterol saturation in bile. Based on these results patients with Crohn's disease should not have an increased risk of cholesterol gall stone formation. PMID:1773954

Lapidus, A; Einarsson, K

1991-01-01

295

During the first trial, we examined the postprandial amino acid composition of the contents collected during 12 consecutive hours. The samples collected during 3 hours were pooled together.  

E-print Network

During the first trial, we examined the postprandial amino acid composition of the contents were then hydrolyzed by 6 N hydrochloric acid for the amino acid determination. Variations in the amino acid compositions during the day are low, especially as regards the extraction residues. The amino acid

Paris-Sud XI, Université de

296

New insight into the SSC8 genetic determination of fatty acid composition in pigs  

PubMed Central

Background Fat content and fatty acid composition in swine are becoming increasingly studied because of their effect on sensory and nutritional quality of meat. A QTL (quantitative trait locus) for fatty acid composition in backfat was previously detected on porcine chromosome 8 (SSC8) in an Iberian x Landrace F2 intercross. More recently, a genome-wide association study detected the same genomic region for muscle fatty acid composition in an Iberian x Landrace backcross population. ELOVL6, a strong positional candidate gene for this QTL, contains a polymorphism in its promoter region (ELOVL6:c.-533C?acids in muscle and adipose tissues. Here, a combination of single-marker association and the haplotype-based approach was used to analyze backfat fatty acid composition in 470 animals of an Iberian x Landrace F2 intercross genotyped with 144 SNPs (single nucleotide polymorphisms) distributed along SSC8. Results Two trait-associated SNP regions were identified at 93 Mb and 119 Mb on SSC8. The strongest statistical signals of both regions were observed for palmitoleic acid (C16:1(n-7)) content and C18:0/C16:0 and C18:1(n-7)/C16:1(n-7) elongation ratios. MAML3 and SETD7 are positional candidate genes in the 93 Mb region and two novel microsatellites in MAML3 and nine SNPs in SETD7 were identified. No significant association for the MAML3 microsatellite genotypes was detected. The SETD7:c.700G?>?T SNP, although statistically significant, was not the strongest signal in this region. In addition, the expression of MAML3 and SETD7 in liver and adipose tissue varied among animals, but no association was detected with the polymorphisms in these genes. In the 119 Mb region, the ELOVL6:c.-533C?>?T polymorphism showed a strong association with percentage of palmitic and palmitoleic fatty acids and elongation ratios in backfat. Conclusions Our results suggest that the polymorphisms studied in MAML3 and SETD7 are not the causal mutations for the QTL in the 93 Mb region. However, the results for ELOVL6 support the hypothesis that the ELOVL6:c.-533C?>?T polymorphism has a pleiotropic effect on backfat and intramuscular fatty acid composition and that it has a role in the determination of the QTL in the 119 Mb region. PMID:24758572

2014-01-01

297

Determination of the fatty acid composition of the oil in intact-seed mustard by near-infrared reflectance spectroscopy  

Microsoft Academic Search

Near-infrared reflectance spectroscopy (NIRS) was used to estimate the fatty acid composition of the oil in intact-seed samples\\u000a of Ethiopian mustard (Brassica carinata Braun) within a mutation breeding program that produced seeds with variable fatty acid compositions. Five populations, from\\u000a 1992 to 1996 crops, were included in this study; and NIRS calibration equations for major fatty acids (palmitic, stearic,\\u000a oleic,

L. Velasco; J. M. Fernández-Martínez; A. De Haro

1997-01-01

298

Fish protein hydrolysates: proximate composition, amino acid composition, antioxidant activities and applications: a review.  

PubMed

The fish processing industry produces more than 60% by-products as waste, which includes skin, head, viscera, trimmings, liver, frames, bones, and roes. These by-product wastes contain good amount of protein rich material that are normally processed into low market-value products, such as animal feed, fish meal and fertilizer. In view of utilizing these fish industry wastes, and for increasing the value to several underutilised fish species, protein hydrolysates from fish proteins are being prepared by several researchers all over the world. Fish protein hydrolysates are breakdown products of enzymatic conversion of fish proteins into smaller peptides, which normally contain 2-20 amino acids. In recent years, fish protein hydrolysates have attracted much attention of food biotechnologists due to the availability of large quantities of raw material for the process, and presence of high protein content with good amino acid balance and bioactive peptides (antioxidant, antihypertensive, immunomodulatory and antimicrobial peptides). PMID:22980905

Chalamaiah, M; Dinesh Kumar, B; Hemalatha, R; Jyothirmayi, T

2012-12-15

299

Glutamine-containing dipeptides as infusion substrates in the septic state.  

PubMed

Recently a relationship has been postulated between lowered intracellular glutamine concentrations in the skeletal muscle and the rate of protein synthesis. We investigated the effect of 48 hours of parenteral nutrition supplemented with a solution containing glutamine in free or dipeptide form (alanylglutamine or glycylglutamine) on the intracellular glutamine pool in skeletal muscle and on the hind limb exchange of glutamine in dogs with sepsis after surgery. Before surgery, dogs were fasted for 48 hours. We used glutamine dipeptides as sources because they remain stable in an aqueous solution. Nutrition solutions were isocaloric (17.8 kcal/kg body weight/day on day 1 and 35.6 kcal/kg on day 2) and isonitrogenous (0.33 gm nitrogen/kg body weight/day), providing 2.6 mmol/kg body weight/day as glutamine source. During starvation, muscular free glutamine levels decreased by 41% to 10.4 mmol/L (p less than 0.001). On the second postoperative day the dogs had lowered plasma protein levels, a sharp drop in platelet count, an increase in the leukocyte count, and positive blood cultures. None of the solutions investigated in this study was effective in repleting the glutamine pool during 2 days of postoperative nutrition (11 +/- 2.0 mmol/L without glutamine, 10.3 +/- 2.2 mmol/L with glutamine plus alanine, 9.9 +/- 1.6 mmol/L with alanylglutamine, 7.5 +/- 1.1 mmol/L with glutamine plus glycine, and 7.2 +/- 1.2 mmol/L with glycylglutamine, respectively). The release of glutamine from the hindquarter was 631 +/- 38 nmol/kg body weight/min in the control group and decreased significantly in dogs receiving alanylglutamine (13.5 +/- 45 nmol/kg body weight/min; p less than 0.001) or the constituent amino acids (265 +/- 66 nmol/kg body weight/min; p less than 0.01) but was unchanged in dogs receiving glycylglutamine or glutamine plus glycine. We conclude that the duration and dosage of glutamine administration (equivalent to 26 gm glutamine per day in a patient weighing 70 kg) used in this study are not sufficient to restore glutamine deficiency of the skeletal muscle in the depleted state. PMID:2510334

Karner, J; Roth, E; Ollenschläger, G; Fürst, P; Simmel, A; Karner, J

1989-11-01

300

Quantification of the triglyceride fatty acid composition with 3.0?T MRI.  

PubMed

The aim of this work was to validate a sequential method for quantifying the triglyceride fatty acid composition with 3.0?T MRI. The image acquisition was performed with a 3D spoiled gradient multiple echo sequence. A specific phase correction algorithm was implemented to correct the native phase images for wrap, zero- and first-order phase and rebuild the real part images. Then, using a model of a fat (1)H MR spectrum integrating nine components, the number of double bonds (ndb) and the number of methylene-interrupted double bonds (nmidb) were derived. The chain length (CL) was obtained from these parameters using heuristic approximation. Validations were performed on different vegetable oils whose theoretical fatty acid composition was used as reference and in five human subjects. In vivo measurements were made in the liver and in the subcutaneous and visceral adipose tissues. Linear regressions showed strong correlations between ndb and nmidb quantified with MRI and the theoretical values calculated using oil composition. Mean ndb/nmidb/CL were 1.80?±?0.25/0.51?±?0.21/17.43?±?0.07, 2.72?±?0.31/0.94?±?0.16/17.47?±?0.08 and 2.53?±?0.21/0.84?±?0.14/17.43?±?0.07 in the liver, subcutaneous and visceral adipose tissues respectively. The results suggest that the triglyceride fatty acid composition can be assessed in human fatty liver and adipose tissues with a clinically relevant MRI method at 3.0?T. PMID:25125224

Leporq, Benjamin; Lambert, Simon A; Ronot, Maxime; Vilgrain, Valerie; Van Beers, Bernard E

2014-10-01

301

Amino acid composition and ?15N of suspended matter in the Arabian Sea  

NASA Astrophysics Data System (ADS)

Sedimentation in the ocean is fed by large aggregates produced in the surface mixed layer that sink rapidly through the water column. These particles sampled by sediment traps have often been proposed to interact by disaggregation and scavenging with a pool of fine suspended matter with very slow sinking velocities and thus a long residence time. We investigated the amino acid composition and stable nitrogen isotopic ratios of suspended matter sampled during the late SW monsoon season in the Arabian Sea and compared them to those of sinking particles to investigate organic matter degradation/modification during passage through the water column. We found that amino acid (AA) composition of mixed layer suspended matter corresponds more to fresh plankton and their aggregates, whereas AA composition of suspended matter in the sub-thermocline water column deviated progressively from mixed layer composition. We conclude that suspended matter in deep waters and in the mixed layers of oligotrophic stations is dominated by fine material that has a long residence time and organic matter that is resistant to degradation. Whereas SPM in areas of high primary productivity is essentially derived from fresh plankton and thus has a strong imprint of the subsurface nitrate source, SPM at oligotrophic stations and at subthermocline depths appears to exchange amino acids with the DOC pool influencing also the ?15N values.

Gaye, B.; Nagel, B.; Dähnke, K.; Rixen, T.; Lahajnar, N.; Emeis, K.-C.

2013-08-01

302

Preparation and characterization of dry method esterified starch/polylactic acid composite materials.  

PubMed

Corn starch and maleic anhydride were synthesized from a maleic anhydride esterified starch by dry method. Fourier transform infrared spectroscopy (FTIR) was used for the qualitative analysis of the esterified starches. The reaction efficiency of dry method esterified starch reached 92.34%. The dry method esterified starch was blended with polylactic acid (PLA), and the mixture was melted and extruded to produce the esterified starch/polylactic acid (ES/PLA) composites. The degree of crystallinity of the ES/PLA was lower than that of the NS/PLA, indicating that the relative dependence between these two components of starch and polylactic acid was enhanced. Scanning electron microscopy (SEM) indicated that the dry method esterified starch increased the two-phase interface compatibility of the composites, thereby improving the tensile strength, bending strength, and elongation at break of the ES/PLA composite. The introduction of a hydrophobic ester bond and increase in interface compatibility led to an increase in ES/PLA water resistance. Melt index determination results showed that starch esterification modification had improved the melt flow properties of starch/PLA composite material. Strain scanning also showed that the compatibility of ES/PLA was increased. While frequency scanning showed that the storage modulus and complex viscosity of ES/PLA was less than that of NS/PLA. PMID:24315947

Zuo, Yingfeng; Gu, Jiyou; Yang, Long; Qiao, Zhibang; Tan, Haiyan; Zhang, Yanhua

2014-03-01

303

GC constituents and relative codon expressed amino acid composition in cyanobacterial phycobiliproteins.  

PubMed

The genomic as well as structural relationship of phycobiliproteins (PBPs) in different cyanobacterial species are determined by nucleotides as well as amino acid composition. The genomic GC constituents influence the amino acid variability and codon usage of particular subunit of PBPs. We have analyzed 11 cyanobacterial species to explore the variation of amino acids and causal relationship between GC constituents and codon usage. The study at the first, second and third levels of GC content showed relatively more amino acid variability on the levels of G3+C3 position in comparison to the first and second positions. The amino acid encoded GC rich level including G rich and C rich or both correlate the codon variability and amino acid availability. The fluctuation in amino acids such as Arg, Ala, His, Asp, Gly, Leu and Glu in ? and ? subunits was observed at G1C1 position; however, fluctuation in other amino acids such as Ser, Thr, Cys and Trp was observed at G2C2 position. The coding selection pressure of amino acids such as Ala, Thr, Tyr, Asp, Gly, Ile, Leu, Asn, and Ser in ? and ? subunits of PBPs was more elaborated at G3C3 position. In this study, we observed that each subunit of PBPs is codon specific for particular amino acid. These results suggest that genomic constraint linked with GC constituents selects the codon for particular amino acids and furthermore, the codon level study may be a novel approach to explore many problems associated with genomics and proteomics of cyanobacteria. PMID:24933001

Kannaujiya, Vinod K; Rastogi, Rajesh P; Sinha, Rajeshwar P

2014-08-10

304

The degree of dietary fatty acid unsaturation affects torpor patterns and lipid composition of a hibernator.  

PubMed

Diets rich in unsaturated and polyunsaturated fatty acids have a positive effect on mammalian torpor, whereas diets rich in saturated fatty acids have a negative effect. To determine whether the number of double bonds in dietary fatty acids are responsible for these alterations in torpor patterns, we investigated the effect of adding to the normal diet 5% pure fatty acids of identical chain length (C18) but a different number of double bonds (0, 1, or 2) on the pattern of hibernation of the yellow-pine chipmunk, Eutamias amoenus. The response of torpor bouts to a lowering of air temperature and the mean duration of torpor bouts at an air temperature of 0.5 degree C (stearic acid C18:0, 4.5 +/- 0.8 days, oleic acid C18:1, 8.6 +/- 0.5 days; linoleic acid C18:2, 8.5 +/- 0.7 days) differed among animals that were maintained on the three experimental diets. The mean minimum body temperatures (C18:0, +2.3 +/- 0.3 degrees C; C18:1, +0.3 +/- 0.2 degree C; C18:2, -0.2 +/- 0.2 degrees C), which torpid individuals defended by an increase in metabolic rate, and the metabolic rate of torpid animals also differed among diet groups. Moreover, diet-induced differences were observed in the composition of total lipid fatty acids from depot fat and the phospholipid fatty acids of cardiac mitochondria. For depot fat 7 of 13 and for heart mitochondria 7 of 14 of the identified fatty acids differed significantly among the three diet groups. Significant differences among diet groups were also observed for the sum of saturated, unsaturated and polyunsaturated fatty acids.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7962785

Geiser, F; McAllan, B M; Kenagy, G J

1994-01-01

305

The effect of dietary amino acid composition on egg production in blue tits  

PubMed Central

Most studies on the interaction between food supply and reproduction in animals have assumed that energy is likely to be the factor limiting egg number and/or size. In this paper, we investigate whether dietary protein proximately constrains egg production in birds. We provisioned breeding blue tits with two food supplements that differed only in the concentration of five essential amino acids. Birds receiving a supplementary diet containing an amino acid balance close to that required for egg protein formation laid significantly larger clutches (18% greater) than control birds, whereas birds receiving an otherwise identical supplementary diet but without a favourable amino acid balance did not increase egg production. To our knowledge, this is the first demonstration that dietary amino acid composition may limit egg production in free-living birds.

Ramsay, S. L.; Houston, D. C.

1998-01-01

306

Comparison of lipid content and fatty acid composition between Tuber fermentation mycelia and natural fruiting bodies.  

PubMed

A comparison of lipid content and fatty acid (FA) composition between Tuber fermentation mycelia and natural fruiting bodies indicates that the lipid content in Tuber fermentation mycelia is higher than that in fruiting bodies. Unsaturated FAs (particularly linoleic acid and oleic acid) were the predominant constituents in total FAs in both Tuber fermentation mycelia and fruiting bodies. A total of 23 FAs, including arachidonic, eicosapentaenoic, docosahexaenoic, and ?-linolenic acids, were first identified in the Tuber species. A hierarchical clustering analysis showed that the FA profile of fermentation mycelia was quite similar, regardless of Tuber species. However, the FA profile of the fruiting bodies was significantly influenced by its species and habitat environments. Interestingly, the FA profile of the Tuber indicum and Tuber aestivum fruiting bodies was nearly identical to that of the Tuber fermentation mycelia, which partially confirms the similarity between the Tuber fermentation mycelia and the fruiting bodies. PMID:21449542

Tang, Yang; Li, Yuan-Yuan; Li, Hong-Mei; Wan, Duan-Ji; Tang, Ya-Jie

2011-05-11

307

Relationship between cannabinoids content and composition of fatty acids in hempseed oils.  

PubMed

Hempseed oils acquired on the Croatian markets were characterised by cannabinoid content and fatty acid composition. The new method for determination of cannabinoid content was developed and validated in the range of 0.05-60 mg/kg, and the content of tetrahydrocannabinol varied between 3.23 and 69.5 mg/kg. Large differences among the samples were obtained for phenotype ratio suggesting that not all of analysed hempseed oils were produced from industrial hemp. Sample clustering based on cannabinoid content assigned samples to two groups closely related to the phenotype ratios obtained. The results of this study confirm that hempseed oil is a good source of polyunsaturated fatty acids, especially ?-linolenic and stearidonic acid, but the content varies a lot more than the omega-6/omega-3 ratio. The grouping of samples on fatty acid content assigned samples to two groups which were consistent with the groups obtained based on cannabinoid content clustering. PMID:25306338

Petrovi?, Marinko; Debeljak, Željko; Kezi?, Nataša; Džidara, Petra

2015-03-01

308

Fatty acid composition analyses of the DCMU resistant mutants of Nannochloropsis oculata (eustigmatophyceae)  

NASA Astrophysics Data System (ADS)

Ultraviolet mutagenesis was applied to Nannochloropsis oculata and three mutants resistant to 3-(3, 4-dichlorophenyl)-1,1-dimethylurea (DCMU) were isolated. The cellular chlorophyll a and total lipid content of the wild are higher in the medium supplemented with DCMU than in the control without DCMU. Without DCMU, the growth rates and chlorophyll a contents of the mutants are similar to those of the wild. Significant changes of fatty acid content and composition have occurred in DCMU-resistant mutants growing in the medium supplemented with DCMU. The total lipid, palmitic acid (16:0), palmitoleic acid (16:1?9) and oleic (18:1?9) contents decrease significantly, while the vaccenic acid (18:1?11) increases significantly and the EPA content of dried powder increases slightly in the mutants. The study may provide a basis to improve EPA content in Nannochloropsis oculata in the future.

Jimin, Zhang; Shuang, Liu; Xue, Sun; Guanpin, Yang; Xuecheng, Zhang; Zhenhui, Gao

2003-04-01

309

Stratification and intra-and inter-specific differences in fatty acid composition of common dolphin (Delphinus sp.) blubber  

E-print Network

is a biochemically dynamic tissue, in which fatty acid (FA) composition is potentially influenced by diet. Ma- rine of saturated and polyunsaturated fatty acids were greatest in the inner layer. Degree of stratification; Diet; Dolphin; Fatty acid; Feeding habits; Layer; Stratification 1. Introduction Blubber

310

Correlation of erythrocyte fatty acid composition and dietary intakes with markers of atherosclerosis in patients with myocardial infarction  

Microsoft Academic Search

The purpose of this study was to examine the hypothesis that erythrocytes that are low in n-3 fatty acids and high in trans-fatty acids and nutrient intakes are associated with the risk of atherosclerosis. Fifty patients with acute nonfatal myocardial infarction were recruited to measure their dietary intake, erythrocyte fatty acid composition, intima medial thickness (IMT), and the Gensini score,

Yongsoon Park; Jeehyun Lim; Yongju Kwon; Jaeung Lee

2009-01-01

311

Fouling of reverse osmosis and nanofiltration membranes by humic acid—Effects of solution composition and hydrodynamic conditions  

Microsoft Academic Search

Fouling of reverse osmosis (RO) and nanofiltration (NF) membranes by humic acid, a recalcitrant natural organic matter (NOM), was systematically investigated. The membrane flux performance depended on both hydrodynamic conditions (flux and cross-flow velocity) and solution composition (humic acid concentration, pH, ionic strength, and calcium concentration), and was largely independent of virgin membrane properties. While increasing humic acid concentration and

Chuyang Y. Tang; Young-Nam Kwon; James O. Leckie

2007-01-01

312

A quantitative comparison between diet and body fatty acid composition in wild northern pike ( Esox lucius L.)  

Microsoft Academic Search

The fatty acid compositions of wild female northern pike (Esox lucius L.) and their principle prey species were compared to assess the extent to which pike modify the relative abundance of dietary fatty acids during assimilation and to indicate the optimum dietary content of essential fatty acids (EFAs) for pike. Only minor differences existed between the estimated whole body fatty

Karl Schwalmel

1992-01-01

313

Survey of safflower (Carthamus tinctorius L.) germplasm for variants in fatty acid composition and other seed characters  

Microsoft Academic Search

Two hundred safflower accessions, originated in 37 countries, and multiplied in two environments, were evaluated for fatty acid composition of the seed oil and other seed characters. Overall mean values of stearic and palmitic acids were similar in both environments but differed for seed weight and oil content. Oleic and linoleic acids showed also similar overall mean content in both

J. Fernández-Martinez; M. Rio; A. Haro

1993-01-01

314

Muscle fatty acid composition and thiobarbituric acid-reactive substances of broilers fed different cultivars of sorghum.  

PubMed

Two experiments were conducted to evaluate the production parameters, muscle fatty acid composition, and lipid stability of birds fed four different cultivars of sorghum. Experiment 1 used ruby red and valpo red, and Experiment 2 used kinsman and mason cultivars of sorghum. The basal diet was a corn, soy, and flax meal, and sorghum cultivars were substituted at 10 or 5% in Experiments 1 and 2. No significant difference was observed for BW, feed consumption or feed efficiency (P > 0.05). The total lipids were reduced (P < 0.05) in the leg muscle of broilers fed the mason cultivar. The TBA-reactive substances (TBARS) were lower (P < 0.05) in the leg muscle of birds fed the mason cultivar when compared to kinsman or control diet. The content of n-3 polyunsaturated fatty acids were higher (P < 0.05) in the breast and leg muscles of birds fed ruby red, kinsman, and mason cultivars of sorghum. PMID:12269624

Cherian, G; Selvaraj, R K; Goeger, M P; Stitt, P A

2002-09-01

315

A dipeptide transporter from the arbuscular mycorrhizal fungus Rhizophagus irregularis is upregulated in the intraradical phase.  

PubMed

Arbuscular mycorrhizal fungi (AMF), which form an ancient and widespread mutualistic symbiosis with plants, are a crucial but still enigmatic component of the plant micro biome. Nutrient exchange has probably been at the heart of the success of this plant-fungus interaction since the earliest days of plants on land. To characterize genes from the fungal partner involved in nutrient exchange, and presumably important for the functioning of the AM symbiosis, genome-wide transcriptomic data obtained from the AMF Rhizophagus irregularis were exploited. A gene sequence, showing amino acid sequence and transmembrane domains profile similar to members of the PTR2 family of fungal oligopeptide transporters, was identified and called RiPTR2. The functional properties of RiPTR2 were investigated by means of heterologous expression in Saccharomyces cerevisiae mutants defective in either one or both of its di/tripeptide transporter genes PTR2 and DAL5. These assays showed that RiPTR2 can transport dipeptides such as Ala-Leu, Ala-Tyr or Tyr-Ala. From the gene expression analyses it seems that RiPTR2 responds to different environmental clues when the fungus grows inside the root and in the extraradical phase. PMID:25232358

Belmondo, Simone; Fiorilli, Valentina; Pérez-Tienda, Jacob; Ferrol, Nuria; Marmeisse, Roland; Lanfranco, Luisa

2014-01-01

316

A dipeptide transporter from the arbuscular mycorrhizal fungus Rhizophagus irregularis is upregulated in the intraradical phase  

PubMed Central

Arbuscular mycorrhizal fungi (AMF), which form an ancient and widespread mutualistic symbiosis with plants, are a crucial but still enigmatic component of the plant micro biome. Nutrient exchange has probably been at the heart of the success of this plant-fungus interaction since the earliest days of plants on land. To characterize genes from the fungal partner involved in nutrient exchange, and presumably important for the functioning of the AM symbiosis, genome-wide transcriptomic data obtained from the AMF Rhizophagus irregularis were exploited. A gene sequence, showing amino acid sequence and transmembrane domains profile similar to members of the PTR2 family of fungal oligopeptide transporters, was identified and called RiPTR2. The functional properties of RiPTR2 were investigated by means of heterologous expression in Saccharomyces cerevisiae mutants defective in either one or both of its di/tripeptide transporter genes PTR2 and DAL5. These assays showed that RiPTR2 can transport dipeptides such as Ala-Leu, Ala-Tyr or Tyr-Ala. From the gene expression analyses it seems that RiPTR2 responds to different environmental clues when the fungus grows inside the root and in the extraradical phase. PMID:25232358

Belmondo, Simone; Fiorilli, Valentina; Pérez-Tienda, Jacob; Ferrol, Nuria; Marmeisse, Roland; Lanfranco, Luisa

2014-01-01

317

Fatty acid composition of plasma lipids and erythrocyte membranes during simulated extravehicular activity  

NASA Astrophysics Data System (ADS)

Ten subjects (from 27 to 41 years) have been participated in 32 experiments. They were decompressed from ground level to 40-35 kPa in altitude chamber when breathed 100% oxygen by mask and performed repeated cycles of exercises (3.0 Kcal/min). The intervals between decompressions were 3-5 days. Plasma lipid and erythrocyte membrane fatty acid composition was evaluated in the fasting venous blood before and immediately after hypobaric exposure. There were 7 cases decompression sickness (DCS). Venous gas bubbles (GB) were detected in 27 cases (84.4%). Any significant changes in the fatty acid composition of erythrocyte membranes and plasma didn't practically induce after the first decompression. However, by the beginning of the second decompression the total lipid level in erythrocyte membranes decreased from 54.6 mg% to 40.4 mg% in group with DCS symptoms and from 51.2 mg% to 35.2 mg% (p < 0.05) without DCS symptoms. In group with DCS symptoms a tendency to increased level of saturated fatty acids in erythrocyte membranes (16:0, 18:0), the level of the polyunsaturated linoleic fatty acid (18:2) and arachidonic acid (20:4) tended to be decreased by the beginning of the second decompression. Insignificant changes in blood plasma fatty acid composition was observed in both groups. The obtained biochemical data that indicated the simulated extravehicular activity (EVA) condition is accompanied by the certain changes in the blood lipid metabolism, structural and functional state of erythrocyte membranes, which are reversible. The most pronounced changes are found in subjects with DCS symptoms.

Skedina, M. A.; Katuntsev, V. P.; Buravkova, L. B.; Naidina, V. P.

318

Lipid and fatty acid compositions of cod ( Gadus morhua), haddock ( Melanogrammus aeglefinus) and halibut ( Hippoglossus hippoglossus)  

NASA Astrophysics Data System (ADS)

This study was conducted to compare lipid and fatty acid composition of cod, haddock and halibut. Three groups of cod (276 g ± 61 g), haddock (538 g ± 83 g) and halibut (3704 g ± 221 g) were maintained with commercial feeds mainly based on fish meal and marine fish oil for 12 weeks prior to sampling. The fatty acid compositions of muscle and liver were determined by GC/FID after derivatization of extracted lipids into fatty acid methyl esters (FAME). Lipids were also fractionated into neutral and polar lipids using Waters silica Sep-Pak?. The phospholipid fraction was further separated by high-performance thin-layer chromatography (HPTLC) and the FAME profile was obtained. Results of the present study showed that cod and haddock were lean fish and their total muscle lipid contents were 0.8% and 0.7%, respectively, with phospholipid constituting 83.6% and 87.5% of the total muscle lipid, respectively. Halibut was a medium-fat fish and its muscle lipid content was 8%, with 84% of the total muscle lipid being neutral lipid. Total liver lipid contents of cod, haddock and halibut were 36.9%, 67.2% and 30.7%, respectively, of which the neutral lipids accounted for the major fraction (88.1%-97.1%). Polyunsaturated fatty acids were the most abundant in cod and haddock muscle neutral lipid. Monounsaturated fatty acid level was the highest in halibut muscle neutral lipid. Fatty acid compositions of phospholipid were relatively constant. In summary, the liver of cod and haddock as lean fish was the main lipid reserve organ, and structural phospholipid is the major lipid form in flesh. However, as a medium-fat fish, halibut stored lipid in both their liver and muscle.

Zeng, Duan; Mai, Kangsen; Ai, Qinghui; Milley, Joyce E.; Lall, Santosh P.

2010-12-01

319

Fatty acid composition of plasma lipids and erythrocyte membranes during simulated extravehicular activity.  

PubMed

Ten subjects (from 27 to 41 years) have been participated in 32 experiments. They were decompressed from ground level to 40-35 kPa in altitude chamber when breathed 100% oxygen by mask and performed repeated cycles of exercises (3.0 Kcal/min). The intervals between decompressions were 3-5 days. Plasma lipid and erythrocyte membrane fatty acid composition was evaluated in the fasting venous blood before and immediately after hypobaric exposure. There were 7 cases decompression sickness (DCS). Venous gas bubbles (GB) were detected in 27 cases (84.4%). Any significant changes in the fatty acid composition of erythrocyte membranes and plasma didn't practically induce after the first decompression. However, by the beginning of the second decompression the total lipid level in erythrocyte membranes decreased from 54.6 mg% to 40.4 mg% in group with DCS symptoms and from 51.2 mg% to 35.2 mg% (p<0.05) without DCS symptoms. In group with DCS symptoms a tendency to increased level of saturated fatty acids in erythrocyte membranes (16:0, 18:0), the level of the polyunsaturated linoleic fatty acid (18:2) and arachidonic acid (20:4) tended to be decreased by the beginning of the second decompression. Insignificant changes in blood plasma fatty acid composition was observed in both groups. The obtained biochemical data that indicated the simulated extravehicular activity (EVA) condition is accompanied by the certain changes in the blood lipid metabolism, structural and functional state of erythrocyte membranes, which are reversible. The most pronounced changes are found in subjects with DCS symptoms. PMID:11541938

Skedina, M A; Katuntsev, V P; Buravkova, L B; Naidina, V P

1998-01-01

320

Changes in membrane fatty acid composition of Pseudomonas aeruginosa in response to UV-C radiations.  

PubMed

The changes in lipid composition enable the micro-organisms to maintain membrane functions in the face of environmental fluctuations. The relationship between membrane fatty acid composition and UV-C stress was determined for mid-exponential phase and stationary phase Pseudomonas aeruginosa. The total lipids were obtained by dichloromethane/methanol (3:1) and were quantified by GC. The TLC analysis of phospholipids showed the presence of three major fractions phosphatidylethanolamine, phosphatidylglycerol, and cardiolipin. Significant modifications, as manifested by an increase of UFA, were obtained. Interestingly, this microorganism showed a remarkable capacity for recovery from the stressful effects of UV-C. PMID:23463516

Ghorbal, Salma Kloula Ben; Chatti, Abdelwaheb; Sethom, Mohamed Marwan; Maalej, Lobna; Mihoub, Mouadh; Kefacha, Sana; Feki, Moncef; Landoulsi, Ahmed; Hassen, Abdennaceur

2013-07-01

321

Glass microporous fiber/nanoporous polytetrafluoroethene composite membranes for high efficient phosphoric acid fuel cell  

NASA Astrophysics Data System (ADS)

This paper reports a high efficient phosphoric acid fuel cell by employing a micro/nano composite proton exchange membrane incorporating glass microfiber (GMF) sealed by polytetrafluoroethylene (PTFE) nano-porous film. This multilayer membrane not only possesses both thermal and chemical stability at phosphoric acid fuel cell working temperature at 150~220°C but also is cost effective. As a result, the inclusion of the high porosity and proton conductivity from glass microfiber and the prevention of phosphoric acid leakage from PTEF nano film can be achieved at the same time.The composite membrane maximum proton conductivity achieves 0.71 S/cm at 150 °C from AC impedance analysis, much higher than common phosphoric acid porous membranes For single cell test, The GMF fuel cell provides a 63.6mW/cm2 power density at 200mA/cm2 current density while GMF plus methanol treated PTFE (GMF+mPTFE) provides 59.2mW/cm2 power density at 160mA/cm2 current density for hydrogen and oxygen supply at 150 °C. When we change the electrodes that are more suited for phosphoric acid fuel cell, the GMF+mPTFE single cell gets higher performance which achieve 296mW/cm2 power density at 900mA/cm2 current density for hydrogen and oxygen supply at 150 °C.

Lu, Chia-Lien; Lee, Wei-Jia; Chang, Cheng-Ping; Tseng, Fan-Gang

2014-11-01

322

Protein kinase C activation in rat colonic mucosa after diets differing in their fatty acid composition.  

PubMed

We studied the effects of different types of dietary fats on fatty acid composition and activity of protein kinase C (PKC) in rat colonic mucosa. Activation of PKC, a key enzyme in signal transduction and growth regulation, provides a mechanism by which dietary components could be involved in colon carcinogenesis. Male Wistar rats (n = 12/group) were fed a semisynthetic high fat diet (43% of energy) containing either sunflower oil, rapeseed oil, or butter for 4 weeks ad libitum. The control group received a low fat sunflower oil diet (10% of energy). The butter diet increased membrane-associated PKC activity in rat colonic mucosa compared with the low fat control diet (1237 vs. 917 pmol/min per mg prot.; P = 0.028). Mucosal fatty acids reflected dietary fatty acid composition even though there was no clear association between the amount of mucosal fatty acids and PKC activity. More research is needed to elucidate how dietary fatty acids regulate colonic PKC activity. PMID:9103264

Pajari, A M; Rasilo, M L; Mutanen, M

1997-03-19

323

Modulation of membrane phospholipid fatty acid composition by age and food restriction.  

PubMed

Phospholipids from liver mitochondrial and microsomal membrane preparations were analyzed to further assess the effects of age and lifelong calorie restriction on membrane lipid composition. Results showed that the major phospholipid classes, phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol and cardiolipin did not vary significantly with age or diet. The fatty acid composition of the phospholipids was determined in PC and PE and ages of 6, 12 and 24 months. The data revealed characteristic patterns of age-related changes in ad libitum (AL) fed rats: membrane levels of long-chain polyunsaturated fatty acids, 22:4 and 22:5, increased progressively, while membrane linoleic acid (18:2) decreased steadily with age. Levels of 18:2 fell by approximately 40%, and 22:5 content almost doubled making the peroxidizability index increase with age. In addition, levels of 16:1 and 18:1 decreased significantly with age, indicating a possible change in delta 9-desaturase activity coefficient. Food restriction resulted in a significant increase in levels of essential fatty acids while attenuating levels of 22:4, 22:5, 22:6 and peroxidizability. We concluded that the membrane-stabilizing action of long-term calorie restriction relates to the selective modification of membrane long-chain polyunsaturated fatty acids during aging. PMID:8440492

Laganiere, S; Yu, B P

1993-01-01

324

A study on fatty acid composition of fish oil from two marine fish, Eusphyra blochii and Carcharhinus bleekeri.  

PubMed

Two species of marine fish found in coastal waters of Karachi (Pakistan) were studied, Eusphyra blochii (Hammer-headed Shark) and Carcharhinus bleekeri (Shark) for their fatty acid composition. The isolation, identification and characterization of these fatty acids were carried out by gas liquid chromatography (GLC) and a combination of TLC-GLC technique. A large variation was observed between hammer-headed shark liver oil and shark liver oil. Twenty five individual fatty acids from the oil of marine fish were analyzed among those the palmitic acid was a major saturated fatty acid while stearic acid was the other major constituent. Among unsaturated fatty acids monoenoic e.g. oleic and palmitoleic acids were the major constituents and traces of dienoic and trienoic fatty acids were also found. In addition medicinally important polyunsaturated fatty, acid eicosapentaenoic and docosahexaenoic acids were also identified. PMID:16414840

Saify, Z S; Akhtar, S; Hassan, S; Arif, M; Ahmed, F; Siddiqui, S

2000-07-01

325

The Fatty Acid Composition of Phosphatidylglycerol and Sulfoquinovosyldiacylglycerol of Higher Plants in Relation to Chilling Sensitivity  

PubMed Central

The fatty acid composition of phosphatidylglycerol and sulfoquinovosyldiacylglycerol has been measured in the leaves of 27 species of higher plants from six families whose members differed in their degrees of chilling sensitivity. The content of high melting point fatty acids (represented by the sum of hexadecanoic, trans-3-hexadecenoic and octadecanoic acids) in phosphatidylglycerols varied little between members of the same plant family and was not obviously related to the relative chilling sensitivity of members of that family. The saturated fatty acid content (hexadecanoic + octadecanoic acids) of sulfoquinovosyldiacylglycerols also appeared to be characteristic of a plant family, although some exceptions were found. In one case, (Carica papaya) the content of saturated fatty acids in sulfoquinovosyldiacylglycerol was sufficiently high to suggest that this lipid could undergo phase separations above 0°C. It is concluded that the content of high melting point fatty acids in leaf phosphatidylglycerol is not a direct indication of the chilling sensitivity of a plant, but rather may be a reflection of the genetic origin of that plant. PMID:16664962

Kenrick, Janette R.; Bishop, David G.

1986-01-01

326

Abnormalities in the fatty-acid composition of the serum phospholipids of stroke patients.  

PubMed Central

The incidence of cardiovascular diseases, stroke, and myocardial infarction is increasing in sub-Saharan Africa. Since dietary polyunsaturated fatty acids (PUFA) are protective of the cardiovascular system in humans, we were interested in the question of the PUFA status of adults in northern Nigeria who had experienced a recent stroke. We collected blood from 21 consecutive admissions for stroke (15 male patients, mean age 39.3 years and six females, mean age 40.7 years) to the Federal Medical Centre in Gombe, Nigeria and analyzed the fatty-acid composition of the serum phospholipids. Blood was collected from 30 healthy controls for comparison. The contribution palmitic acid made to the fatty-acid total was greatly decreased in the phospholipids of the stroke patients (29.2% versus 37.2 %, p < 0.001). However, the phospholipids of the stroke patients had significantly higher percentages of 20-, 22-, and 24-carbon saturated fatty acids, as well as higher proportions of the omega-6 fatty-acid, arachidonic acid (11.4 versus 8.14%, p < 0.001), and the omega-3 fatty-acid, docosahexaenoic acid (3.21 versus 1.80%, p < 0.001). Using the percentages and melting points of the individual fatty acids, we estimated that the acyl chains of the serum phospholipids of the stroke patients had a lower mean melting point than the controls (27.8 versus 34.6 degrees C, p < 0.001). Assuming that serum phospholipids are surrogates for tissue phospholipids, we conclude that the tissue membranes of the stroke patients may be considerably more fluid than those of the controls. PMID:15233494

Glew, Robert H.; Okolie, Henry; Huang, Yung-Sheng; Chuang, Lu-Te; Suberu, Ojo; Crossey, Michael; VanderJagt, Dorothy J.

2004-01-01

327

[Fatty acids composition of the marine snails Phyllonotus pomum and Chicoreus brevifrons (Muricidae)].  

PubMed

Muricid species of P. pomum and C. brevifrons are of economic importance in the Caribbean. This study includes a comparative evaluation of fatty acid content in the total lipid composition of Phyllonotus pomum and Chicoreus brevifrons. Snail samples were collected during the rainy, dry and transition seasons, in Punta Arena, Sucre (Venezuela). Total lipids were extracted and the specific fatty acid contents were analyzed by gas chromatography. Lipid concentrations varied between 0.87 and 1.85%, with minimum and maximum values corresponding to C. brevifrons collected during rainy and dry seasons, respectively. In the case of total lipids, a high concentration of unsaturated fatty acids (57.21-70.05%) was observed followed by saturated fatty acids (20.33-31.94%), during all seasons. The polyunsaturated occurred in higher proportion among the unsaturated fatty acids, except for P. pomum which showed higher proportion of monounsaturated fatty acids (38.95%) during the transition season. The prevailing fatty acids were: C14:0, C16:0, C18:0, C20:1, C22:1 omega-11, C22:1 omega-9, C18:3 omega-3, C20:5 omega-3 and C22:6 omega-3, among which docosahexaenoic acid was the predominant polyunsaturated fatty acid, showing values between 4.62 and 33.11%. The presence of high concentrations of polyunsaturated fatty acids found in P. Pomum and C. brevifrons allow their recommendation for human consumption with appropriate resource utilization. PMID:20527465

D'Armas, Haydelba; Yáñez, Dayanis; Reyes, Dilia; Salazar, Gabriel

2010-06-01

328

Conjugated linoleic acid alters growth performance, tissue lipid deposition, and fatty acid composition of darkbarbel catfish (Pelteobagrus vachelli).  

PubMed

Fatty liver syndrome is a prevalent problem of farmed fish. Conjugated linoleic acid (CLA) has received increased attention recently as a fat-reducing fatty acid to control fat deposition in mammals. Therefore, the aim of the present study was to determine whether dietary CLA can reduce tissue lipid content of darkbarbel catfish (Pelteobagrus vachelli) and whether decreased lipid content is partially due to alterations in lipid metabolism enzyme activities and fatty acid profiles. A 76-day feeding trial was conducted to investigate the effect of dietary CLA on the growth, tissue lipid deposition, and fatty acid composition of darkbarbel catfish. Five diets containing 0 % (control), 0.5 % (CLA0.5), 1 % (CLA1), 2 % (CLA2), and 3 % (CLA3) CLA levels were evaluated. Results showed that fish fed with 2-3 % CLA diets showed a significantly lower specific growth rate and feed conversion efficiency than those fed with the control diet. Dietary CLA decreased the lipid contents in the liver and intraperitoneal fat with the CLA levels from 1 to 3 %. Fish fed with 2-3 % CLA diets showed significantly higher lipoprotein lipase and hepatic triacylglycerol lipase activities in liver than those of fish fed with the control, and fish fed with 1-3 % CLA diets had significantly higher pancreatic triacylglycerol lipase activities in liver than those of fish fed with the control. Dietary CLA was incorporated into liver, intraperitoneal fat, and muscle lipids, with higher percentages observed in liver compared with other tissues. Liver CLA deposition was at the expense of monounsaturated fatty acids (MUFA). In contrast, CLA deposition appeared to be primarily at the expense of MUFA and n-3 polyunsaturated fatty acids (PUFA) in the intraperitoneal fat, whereas in muscle it was at the expense of n-3 PUFA. Our results suggested that CLA at a 1 % dose can reduce liver lipid content without eliciting any negative effect on growth rate in darkbarbel catfish. This lipid-lowering effect could be in part due to an increment in the activity of lipid metabolism enzymes and an extensive interconversion of fatty acids. Although CLA deposition in muscle (0.66-3.19 % of total fatty acids) are higher than presented in natural sources of CLA, EPA (C20:5n-3) in fish muscle appears simultaneously expendable, when the fish fed with 2-3 % CLA. PMID:25362563

Dong, Gui-Fang; Liu, Wen-Zuo; Wu, Lin-Zhou; Yu, Deng-Hang; Huang, Feng; Li, Peng-Cheng; Yang, Yan-Ou

2015-02-01

329

The identification of QTL that affect the fatty acid composition of milk on sheep chromosome 11.  

PubMed

In this work, we analysed 11 genetic markers localized on OAR11 in a commercial population of Spanish Churra sheep to detect QTL that underlie milk fatty acid (FA) composition traits. Following a daughter design, we analysed 799 ewes distributed in 15 half-sib families. Eight microsatellite markers and three novel SNPs identified in two genes related to fatty acid metabolism, acetyl-CoA carboxylase alpha (ACACA) and fatty acid synthase (FASN), were genotyped in the whole population under study. The phenotypic traits considered in the study included 22 measurements related to the FA composition of the milk and three other milk production traits (milk protein percentage, milk fat percentage and milk yield). Across-family regression analysis revealed four significant QTL at the 5% chromosome-wise level influencing contents of capric acid (C10:0), lauric acid (C12:0), linoleic conjugated acid (CLA) and polyunsaturated fatty acids (PUFA) respectively. The peaks of the QTL affecting C10:0 and PUFA contents in milk map close to the FASN gene, which has been evaluated as a putative positional candidate for these QTL. The QTL influencing C12:0 content reaches its maximum significance at 58 cM, close to the gene coding for the glucose-dependent insulinotropic polypeptide. We were not able to find any candidate genes related to fat metabolism at the QTL influencing CLA content, which is located at the proximal end of the chromosome. Further research efforts will be needed to confirm and refine the QTL locations reported here. PMID:19968648

García-Fernández, M; Gutiérrez-Gil, B; García-Gámez, E; Sánchez, J P; Arranz, J J

2010-06-01

330

Phospholipid fatty acid composition of hepatopancreatic brush-border membrane vesicles from the prawn Penaeus japonicus  

Microsoft Academic Search

Brush-border membrane vesicles (BBMV) were isolated from prawn hepatopancreas as we previously described (Muriana et al (1993) J Biochem 113, 625–629). The characterization of hepatopancreatic BBMV (hBBMV) by monitoring the activity of marker enzymes indicated a relatively pure apical membrane preparation reduced in basolateral contamination. Phospholipid composition of hBBMV was examined by the Iatroscan TLC\\/FID technique, whereas the fatty acid

F. J. G. Muriana; V. Ruiz-Gutierrez; J. A. Blaya; J. Bolufer

1995-01-01

331

Conjugated linoleic acid supplementation in humans: Effects on body composition and energy expenditure  

Microsoft Academic Search

Recent animal studies have demonstrated that dietary conjugated linoleic acid (CLA) reduces body fat and that this decrease\\u000a may be due to a change in energy expenditure. The present study examined the effect of CLA supplementation on body composition\\u000a and energy expenditure in healthy, adult women. Seventeen women were fed either a CLA capsule (3 g\\/d) or a sunflower oil

Kirsten L. Zambell; Nancy L. Keim; Marta D. Van Loan; Barbara Gale; Paloma Benito; Darshan S. Kelley; Gary J. Nelson

2000-01-01

332

Oil concentration and fatty acid composition of achenes of Helianthus species (Asteraceae) from Canada  

Microsoft Academic Search

The cultivated sunflower (Helianthus annuus) is one of the four most important annual crops in the world grown for its edible oil. Species of the genusHelianthus served as the ancestral stock for the present cultivated sunflower. The wild relatives are a valuable genetic reservoir for\\u000a improving the crop species. This study examined oil concentration and fatty acid composition in oil

Gerald J. Seiler; Mary E. Brothers

1999-01-01

333

Fatty acid composition of sunflower ( Helianthus annuus L.) oil as influenced by seed position  

Microsoft Academic Search

The variation in fatty acid composition of the oil from seeds located in different positions within an individual sunflower\\u000a head was determined. Each head was divided into three ring-shaped zones and four samples were taken from each zone. Ten heads\\u000a from an inbred line and ten from an open-pollinated variety were sampled. Position of the seed within the head had

D. C. Zimmerman; G. N. Fick

1973-01-01

334

Phylogenetic Analysis and In Situ Identification of Bacteria Community Composition in an Acidic Sphagnum Peat Bog  

Microsoft Academic Search

The Bacteria community composition in an acidic Sphagnum peat bog (pH 3.9 to 4.5) was characterized by a combination of 16S rRNA gene clone library analysis, rRNA-targeted fluorescence in situ hybridization (FISH), and cultivation. Among 84 environmental 16S rRNA gene clones, a set of only 16 cloned sequences was closely related (>95% similarity) to taxonomically described organisms. Main groups of

Svetlana N. Dedysh; Timofei A. Pankratov; Svetlana E. Belova; Irina S. Kulichevskaya; Werner Liesack

2006-01-01

335

Increased biliary calcium in cholesterol and pigment gallstone disease: The role of altered bile acid composition  

Microsoft Academic Search

The present study was undertaken to define the relationship between calcium metabolism and bile acid composition in animal\\u000a models of diet induced cholesterol and pigment gallstones. Groups of prairie dogs were fed either a control non-lithogenic\\u000a chow (N=12), a 1.2% cholesterol enriched chow (N=6, XOL) for two weeks, or a high carbohydrate diet deficient in iron (N=6,\\u000a CHO-FeD), or a

Mohammad Z. AbedinO; Seth D. Strichadzab; Sarkis Festekdjiana; Joel J. Roslynab

1989-01-01

336

Effects of medium-chain fatty acids on body composition and protien metabolism in overweight rats  

Microsoft Academic Search

The lack of efficiency of classical treatments for obesity has led to propose alternative strategies. In order to obtain information\\u000a about the effects of dietary fatty acid composition on body fat and protein metabolism, overweight female rats were fed on\\u000a isoenergetic diets, using either medium-chain (MCT) or long-chain (LCT) triglycerides as a lipid source. After 23 days, the\\u000a MCT group

E. Simón; A. Fernández-Quintela; M. Del Puy Portillo; A. S. Del Barrio

2000-01-01

337

Preparation and mechanical properties of polylactic acid composites containing hydroxyapatite fibers  

Microsoft Academic Search

Ceramic-polymer composite biomaterials were prepared by hot-pressing a mixture consisting of poly-l-lactic acid (PLA) and hydroxyapatite fibers (HAF) with dimensions of 40–150?m length and 2–10?m diameter, which were converted from ?-Ca(PO3)2 fibers. After PLA dissolved with methylene chloride was mixed with the fibers, the mixture was dried completely and subsequently hot-pressed uniaxially under a pressure of 40MPa at 180°C, resulting

Toshihiro Kasuga; Yoshio Ota; Masayuki Nogami; Yoshihiro Abe

2000-01-01

338

Body Compositional Changes and Growth Alteration in Chicks from Hens Fed Conjugated Linoleic Acid  

Microsoft Academic Search

Effects of feeding conjugated linoleic acid (CLA) to hens on progeny chick development and composition at hatch (NHC) and\\u000a three weeks of age (TWC) were assessed. CLA (0 or 0.5%, composed of mixed isomers of cis-9,trans-11 or trans-10,cis-12-CLA) was fed to hens with either safflower (SO) or olive oil (OO) (3 or 3.5%) to assure successful hatch for 2 weeks

Vanessa A. Leone; Sharon P. Worzalla; Mark E. Cook

2009-01-01

339

Variations in essential oil and fatty acid composition during Myrtus communis var. italica fruit maturation  

Microsoft Academic Search

The essential oil and fatty acid composition of Myrtus communis var. italica fruit during its ripening was determined. The effect of the harvesting time on some physical properties of Myrtus fruits, fruit weight and moisture content, were significant. The increase of fruit weight (from 2.54 to 8.79g% fruits) during ripeness was correlated positively with that of moisture content (from 28%

Wissem Aidi Wannes; Baya Mhamdi; Brahim Marzouk

2009-01-01

340

Fatty acid composition indicates two types of metabolic syndrome independent of clinical and laboratory parameters.  

PubMed

Dietary composition and metabolism of fatty acids (FA) influence insulin resistance, atherogenic dyslipidemia and other components of the metabolic syndrome (MS). It is known that patients with MS exhibit a heterogeneous phenotype; however, the relationships of individual FA to MS components have not yet been consistently studied. We examined the plasma phosphatidylcholine FA composition of 166 individuals (68F/98M) with MS and of 188 (87F/101M) controls. Cluster analysis of FA divided the groups into two clusters. In cluster 1, there were 65.7 % of MS patients and 37.8 % of controls, cluster 2 contained 34.3 % of patients and 62.2 % of controls (P<0.001). Those with MS within cluster 1 (MS1) differed from individuals with MS in cluster 2 (MS2) by concentrations of glucose (P<0.05), NEFA (P<0.001), HOMA-IR (P<0.05), and levels of conjugated dienes in LDL (P<0.05). The FA composition in MS1 group differed from MS2 by higher contents of palmitoleic (+30 %), gamma-linolenic (+22 %), dihomo-gamma-linolenic (+9 %) acids and by a lower content of linoleic acid (-25 %) (all P<0.01). These FA patterns are supposed to be connected with the progression and/or impaired biochemical measures of MS (lipolysis, oxidative stress, dysglycidemia, and insulin resistance). PMID:25428743

Zák, A; Burda, M; Vecka, M; Zeman, M; Tvrzická, E; Sta?ková, B

2014-11-26

341

Electrical charging changes the composition of sulfuric acid-ammonia/dimethylamine clusters  

NASA Astrophysics Data System (ADS)

Sulfuric acid clusters stabilized by base molecules are likely to have a significant role in atmospheric new-particle formation. Recent advances in mass spectrometry techniques have permitted the detection of electrically charged clusters. However, direct measurement of electrically neutral clusters is not possible. Mass spectrometry instruments can be combined with a charger, but the possible effect of charging on the composition of neutral clusters must be addressed in order to interpret and understand the measured data. In the present work we have used formation free energies from quantum chemical methods to calculate the evaporation rates of electrically charged (both positive and negative) sulfuric acid-ammonia/dimethylamine clusters. To understand how charging will affect the composition of electrically neutral clusters, we have compared the evaporation rates of the most stable neutral clusters with those of the corresponding charged clusters. Based on the evaporation rates of different molecules from the charged clusters, we determined the most likely resulting cluster composition when a stable neutral cluster is charged and the molecules with the highest evaporation rates are lost from it. We found that all of the most stable neutral clusters will be altered by both positive and negative charging. In the case of charging clusters negatively, base molecules will completely evaporate from clusters with 1 to 3 sulfuric acid molecules in the case of ammonia, and from clusters with 1 or 2 sulfuric acid molecules in the case of dimethylamine. Larger clusters will maintain some base molecules, but the H2SO4 : base ratio will increase. In the case of positive charging, some of the acid molecules will evaporate, decreasing the H2SO4 : base ratio.

Ortega, I. K.; Olenius, T.; Kupiainen-Määttä, O.; Loukonen, V.; Kurtén, T.; Vehkamäki, H.

2014-08-01

342

Volatile compound content and fatty acid composition of pork as influenced by linoleic acid content of the diet.  

PubMed

Eighty pigs (average weight of 60 kg) were allotted by weight and sex to pens and treatments. There were four dietary treatments, five pens per treatment, and four pigs per pen. Diets consisted of a typical corn-soybean mix containing 9% total fat, 3% from the corn-soybean mix and 6% added. The four dietary treatments included 1) 6% safflower oil, 2) 4% safflower oil and 2% tallow, 3) 2% safflower oil and 4% tallow, and 4) 6% tallow, resulting in 6.1, 4.6, 3.2, and 1.76% linoleic acid, respectively, in the diet. Pigs were slaughtered at an average weight of 100 kg. Proximate composition, tristimulus color coordinates (L, a, and b values), pH, and flavor difference of the longissimus muscle (LM) were evaluated. Fatty acid content (milligrams per 100 grams of tissue) of the subcutaneous fat and LM and headspace volatile content of the LM were determined by capillary gas liquid chromatography. Proximate composition, color, pH, and flavor of the LM were not influenced by diet. Fatty acid content of the subcutaneous fat and LM and volatile content of the LM were influenced by diet. Increased levels of safflower oil in the diet resulted in less C16:0 and C18:1 and more C18:2, C20:2, and C20:3 in the subcutaneous fat. The LM contained more C18:2 and less C18:3 and C24:0 due to increased levels of safflower oil in the diet. Compared with the 6% tallow diet, LM from pigs fed the 4 or 6% safflower diets contained more pentanal, hexanal, 2-heptanone, trans-2-heptenal, 2-pentyl furan, 2-ethyl-1-hexanol, decanal, and undecanal.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1526908

Larick, D K; Turner, B E; Schoenherr, W D; Coffey, M T; Pilkington, D H

1992-05-01

343

Detailed Dimethylacetal and Fatty Acid Composition of Rumen Content from Lambs Fed Lucerne or Concentrate Supplemented with Soybean Oil  

PubMed Central

Lipid metabolism in the rumen is responsible for the complex fatty acid profile of rumen outflow compared with the dietary fatty acid composition, contributing to the lipid profile of ruminant products. A method for the detailed dimethylacetal and fatty acid analysis of rumen contents was developed and applied to rumen content collected from lambs fed lucerne or concentrate based diets supplemented with soybean oil. The methodological approach developed consisted on a basic/acid direct transesterification followed by thin-layer chromatography to isolate fatty acid methyl esters from dimethylacetal, oxo- fatty acid and fatty acid dimethylesters. The dimethylacetal composition was quite similar to the fatty acid composition, presenting even-, odd- and branched-chain structures. Total and individual odd- and branched-chain dimethylacetals were mostly affected by basal diet. The presence of 18?1 dimethylacetals indicates that biohydrogenation intermediates might be incorporated in structural microbial lipids. Moreover, medium-chain fatty acid dimethylesters were identified for the first time in the rumen content despite their concentration being relatively low. The fatty acids containing 18 carbon-chain lengths comprise the majority of the fatty acids present in the rumen content, most of them being biohydrogenation intermediates of 18?2n?6 and 18?3n?3. Additionally, three oxo- fatty acids were identified in rumen samples, and 16-O-18?0 might be produced during biohydrogenation of the 18?3n?3. PMID:23484024

Alves, Susana P.; Santos-Silva, José; Cabrita, Ana R. J.; Fonseca, António J. M.; Bessa, Rui J. B.

2013-01-01

344

Feeding feedlot steers fish oil alters the fatty acid composition of adipose and muscle tissue.  

PubMed

Sixteen steers (441±31.7kg initial body weight) consumed two high concentrate diets with either 0 or 3% fish oil to determine the impact of fish oil, an omega-3 fatty acid source, on the fatty acid composition of beef carcasses. Collected tissue samples included the Longissimus thoracis from the 6th to 7th rib section, ground 10th to 12th rib, liver, subcutaneous adipose tissue adjacent to the 12th rib, intramuscular adipose tissue in the 6th to 7th rib sections, perirenal adipose tissue, and brisket adipose tissue. Including fish oil in the diet increased most of the saturated fatty acids (P<0.01) and proportions of polyunsaturated fatty acids (P<0.06), and decreased (P<0.01) proportions of monounsaturated fatty acids. Dietary fish oil increased (P<0.01) levels of omega-3 fatty acids in sampled tissues, resulting in lower (P<0.01) omega-6:omega-3 ratios. The weight percentages of C20:5 and C22:6 in tissue may provide the recommended daily allowance for humans. Fish oil may have a role in beef niche marketing if there are no deleterious effects on consumer satisfaction. PMID:22061591

Wistuba, T J; Kegley, E B; Apple, J K; Rule, D C

2007-10-01

345

Dietary inclusion of tea catechins changes fatty acid composition of muscle in goats.  

PubMed

This study was conducted to examine dietary tea catechins (TC) supplementation on the fatty acid composition of muscle and ruminal bacteria in goats fed a maize stover-based diet. Forty goats, 8 months old (16.2 ± 1.2 kg), were randomly divided into four equal groups (10 animals in each group) and assigned to four experiment diets with TC supplementation at four levels (0, 2,000, 3,000 and 4,000 mg TC/kg feed, namely TC0, TC2000, TC3000 and TC4000, respectively). After a 60-day feeding period, all the goats were slaughtered and sampled. The results showed that dietary TC inclusion increased the average daily gain (ADG), protein content in the semimembranosus muscle and dry matter in the longissimus dorsi muscle (LD). Dietary TC supplementation increased the ratio of n-6 to n-3 fatty acid, the ratio of polyunsaturated fatty acids to saturated fatty acids was higher in TC3000 and TC4000 than in TC0 and TC2000 for LD. The current results implied that dietary inclusion of a suitable TC dose could improve the growth performance and increase the proportions of unsaturated fatty acids in muscle, and the biohydrogenation of ruminal microorganisms might change the profiles of fatty acids in the muscle of growing goats. PMID:20938752

Tan, C Y; Zhong, R Z; Tan, Z L; Han, X F; Tang, S X; Xiao, W J; Sun, Z H; Wang, M

2011-03-01

346

Soft glass rheology in liquid crystalline gels formed by a monodisperse dipeptide.  

PubMed

Thermal and extensive rheological characterization of a nematic liquid crystal gelated with a novel monodisperse dipeptide, also a liquid crystal, has been carried out. For certain concentrations, the calorimetric scans display a two-peak profile across the chiral nematic-isotropic (N*-I) transition, a feature reminiscent of the random-dilution to random-field crossover observed in liquid crystal gels formed with aerosil particles. All samples show shear thinning behavior without a Newtonian plateau region at lower shear rates. Small deformation oscillatory data at lower frequencies exhibit a frequency dependence of the storage (G') and loss (G'') moduli that can be described by a weak power-law, characteristic of soft glassy rheological systems. At higher frequencies, while lower concentration composites have a strong frequency dependence with a trend for possible crossover from viscoelastic solid to viscoelastic liquid behavior, the higher-concentration gels show frequency-independent rheograms of entirely elastic nature G' > G''. The plateau modulus of G' is described by a power-law with an exponent again common to soft materials, such as foams, slurries, etc. Other features which are a hallmark of such materials observed in the present study are: (i) above a critical strain, a strain softening of the moduli with a peak in the loss modulus, (ii) power-law variation of the storage modulus in the nonlinear viscoelastic regime, and (iii) absence of Cox-Merz superposition for the complex viscosity. An attractive feature of these gels is the fast recovery upon removal of large strain and qualitatively different temporal behavior of the recovery between the low and high concentration composites, with the latter indicating the presence of two characteristic time scales. PMID:20028007

Nair, Geetha G; Krishna Prasad, S; Bhargavi, R; Jayalakshmi, V; Shanker, G; Yelamaggad, C V

2010-01-21

347

Electrochemical Oxidation and Determination of Oxalic Acid at an Exfoliated Graphite-Polystyrene Composite Electrode  

PubMed Central

An exfoliated graphite-polystyrene composite electrode was evaluated as an alternative electrode in the oxidation and the determination of oxalic acid in 0.1 M Na2SO4 supporting electrolyte. Using CV, LSV, CA procedures, linear dependences I vs. C were obtained in the concentrations range of oxalic acid between 0.5 to 3 mM, with LOD =0.05 mM, and recovery degree of 98%, without need of surface renewing between successive runs. The accuracy of the methods was evaluated as excellent comparing the detection results with that obtained using conventional KMnO4 titration method. In addition, the apparent diffusion coefficient of oxalic acid D was found to be around 2.89 · 10-8 cm2·s-1 by CA and CV.

Manea, Florica; Radovan, Ciprian; Corb, Ioana; Pop, Aniela; Burtica, Georgeta; Malchev, Plamen; Picken, Stephen; Schoonman, Joop

2007-01-01

348

Isotope composition of sulphate in acid mine drainage as measure of bacterial oxidation  

USGS Publications Warehouse

The formation of acid waters by oxidation of pyrite-bearing ore deposits, mine tailing piles, and coal measures is a complex biogeochemical process and is a serious environmental problem. We have studied the oxygen and sulphur isotope geochemistry of sulphides, sulphur, sulphate and water in the field and in experiments to identify sources of oxygen and reaction mechanisms of sulphate formation. Here we report that the oxygen isotope composition of sulphate in acid mine drainage shows a large variation due to differing proportions of atmospheric- and water-derived oxygen from both chemical and bacterially-mediated oxidation. 18O-enrichment of sulphate results from pyrite oxidation facilitated by Thiobacillus ferrooxidans in aerated environments. Oxygen isotope analysis may therefore be useful in monitoring the effectiveness of abatement programmes designed to inhibit bacterial oxidation. Sulphur isotopes show no significant fractionation between pyrite and sulphate, indicating the quantitative insignificance of intermediate oxidation states of sulphur under acid conditions. ?? 1984 Nature Publishing Group.

Taylor, B.E.; Wheeler, M.C.; Nordstrom, D.K.

1984-01-01

349

Influence of harvest date and crop yield on the fatty acid composition of virgin olive oils from cv. Picual.  

PubMed

In this study was analyzed the effect of crop year and harvesting time on the fatty acid composition of cv. Picual virgin olive oil. The study was carried out during the fruit ripening period for three crop seasons. The mean fatty acid composition of Picual oils was determined. The oils contained palmitic acid (11.9%), oleic acid (79.3%), and linoleic acid (2.95%). The content of palmitic acid and saturated fatty acids decreased during fruit ripening while oleic and linoleic acids increased. The amount of stearic and linolenic acids decreased. The amount of saturated acids, palmitic and stearic, and the polyunsaturated acids linoleic and linolenic was dependent on the time of harvest, whereas the amount of oleic acid varied with the crop year. The differences observed between crop years for both palmitic and linoleic acid may be explained by the differences in the temperature during oil biosynthesis and by the amount of summer rainfall for oleic acid content. A significant relationship was observed between the MUFA/PUFA ratio and the oxidative stability measured by the Rancimat method. PMID:15161211

Beltrán, Gabriel; Del Rio, Carmen; Sánchez, Sebastián; Martínez, Leopoldo

2004-06-01

350

Influence of acetic, citric, and lactic acids on Escherichia coli O157:H7 membrane lipid composition, verotoxin secretion, and acid resistance in simulated gastric fluid.  

PubMed

The effect of organic acid (acetic, citric, and lactic acids) adaptation at equivalent initial pH values (6.4 and 5.4) on changes in membrane lipid composition, verotoxin concentration, and acid resistance in simulated gastric fluid (pH 1.5, 37 degrees C) was determined for Escherichia coli O157:H7 ATCC 43895 (HEC) and an rpoS mutant of E. coli O157:H7 ATCC 43895 (RM, FRIK 816-3). For HEC, lactic acid-adapted (pH 5.4) cells had the greatest D-value (32.2 min) and acetic acid-adapted (pH 5.4) cells had the smallest D-value (16.6 min) in simulated gastric fluid. For RM, D-values of citric and acetic acid-adapted cells were similar to those for nonadapted cells grown at pH 7.3, but D-values increased from 13.1 to 27.9 min in lactic acid-adapted cells (from pH 7.3 to pH 5.4). For both strains, the ratio of cis-vaccenic to palmitic acids decreased for citric and lactic acid-adapted cells, but the ratio increased for acetic acid-adapted cells at pH 5.4. Organic acid-adapted cells produced less total verotoxin than did nonadapted cells at approximately 10(8) CFU/ml. Extracellular verotoxin concentration proportionally decreased with decreasing pH for both HEC and RM. Changes in membrane lipid composition, verotoxin concentration, and acid resistance in HEC and RM were dependent on both pH and organic acid. Deletion of the rpoS gene did not affect these changes but did decrease acid resistance in citric acid-adapted cells. Results indicate that decreased membrane fluidity may have caused increased acid resistance and decreased verotoxin secretion. PMID:15830655

Yuk, Hyun-Gyun; Marshall, Douglas L

2005-04-01

351

A Functional Nexus between Photoperiod Acclimation, Torpor Expression and Somatic Fatty Acid Composition in a Heterothermic Mammal  

PubMed Central

The seasonal changes in thermal physiology and torpor expression of many heterothermic mammals are controlled by photoperiod. As function at low body temperatures during torpor requires changes of tissue lipid composition, we tested for the first time whether and how fatty acids are affected by photoperiod acclimation in hamsters, Phodopus sungorus, a strongly photoperiodic species. We also examined changes in fatty acid composition in relation to those in morphology and thermal biology. Hamsters in short photoperiod had smaller reproductive organs and most had a reduced body mass in comparison to those in long photoperiod. Pelage colour of hamsters under short photoperiod was almost white while that of long photoperiod hamsters was grey-brown and black. Short photoperiod acclimation resulted in regular (28% of days) torpor use, whereas all hamsters in long photoperiod remained normothermic. The composition of total fatty acids differed between acclimation groups for brown adipose tissue (5 of 8 fatty acids), heart muscle (4 of 7 fatty acids) and leg muscle (3 of 11 fatty acids). Importantly, 54% of all fatty acids detected were correlated (r2?=?0.60 to 0.87) with the minimum surface temperature of individuals, but the responses of tissues differed. While some of the compositional changes of fatty acids were consistent with a ‘homeoviscous’ response, this was not the case for all, including the sums of saturated and unsaturated fatty acids, which did not differ between acclimation groups. Our data identify a possible nexus between photoperiod acclimation, morphology, reproductive biology, thermal biology and fatty acid composition. They suggest that some of the changes in thermal physiology are linked to the composition of tissue and organ fatty acids. PMID:23717487

Geiser, Fritz; Klingenspor, Martin; McAllan, Bronwyn M.

2013-01-01

352

Poultry fat decreased fatty acid transporter protein mRNA expression and affected fatty acid composition in chickens  

PubMed Central

Background A study was undertaken to examine the effects of poultry fat (PF) compared with those of soybean oil (SBO) on intestinal development, fatty acid transporter protein (FATP) mRNA expression, and fatty acid composition in broiler chickens. A total of 144?day-old male commercial broilers were randomly allocated to 2 treatment groups (6 replicates of 12 chicks for each treatment) and fed isocaloric diets containing 3.0% PF or 2.7% SBO at 0 to 3 wk and 3.8% PF or 3.5% SBO at 4 to 6 wk, respectively. Results PF had no influence on intestinal morphology, weight, or DNA, RNA, or protein concentrations at 2, 4, and 6?wk of age. However, compared with SBO, PF significantly decreased FATP mRNA abundance at 4?wk (P?=?0.009) and 6?wk of age (P?acid-binding protein (L-FABP) mRNA abundance at 6?wk of age (P?=?0.039); and decreased C18:2 (P?=?0.015), C18:3 (P?acids (?-PUFA) (P?=?0.020), and the proportion of PUFA (P?

2012-01-01

353

Adamantylamide dipeptide as effective immunoadjuvant in rabbits and mice.  

PubMed

In the search for more potent and less toxic immunomodulators, adamantylamide dipeptide (AdDP) was synthesized by the covalent union of amantadine with the L-alanyl-D-isoglutamine residue of muramyldipeptide (MDP). The present experiments demonstrate the ability of AdDP, co-administered with a protein immunogen, to raise or enhance a humoral response in immunized animals. BALB/c mice were immunized either by the intraperitoneal (ip) or oral route with ovalbumin (Ova) alone or combined with either AdDP or CpG oligonucleotide (ODN-CpG), a proved adjuvant. A clear adjuvant dose-response relationship was observed on the increment of Ova-specific serum antibody titers when AdDP was used as adjuvant, irrespectively of the administration route. The IgG isotype analysis showed that AdDP promotes a consistent increment in IgG1 antibodies associated with a dominant Th2 response pattern. When administered by the oral route, AdDP was at least as efficient as ODN-CpG as adjuvant. Similar results were obtained in rabbits immunized by the oral route, suggesting that the adjuvanticity of AdDP is not restricted to the murine system. In conclusion, AdDP was shown to be a powerful and non-toxic adjuvant at both systemic and mucosal levels, which makes it a promising tool for vaccine development. PMID:11535307

Becker, P D; Corral, R S; Guzmán, C A; Grinstein, S

2001-09-14

354

ANALYTICAL VARIATION IN THE DETERMINATION OF THE FATTY ACID COMPOSITION OF STANDARD PREPARATIONS OF BRINE SHRIMP ARTEMIA: AN INTERLABORATORY EXERCISE  

EPA Science Inventory

An international interlaboratory exercise was conducted to investigate the variability associated with the preparation and analysis of samples and the reporting of fatty acid composition data for tvo samples of Artemia supplied to the laboratories by the Artemia Reference Center ...

355

Molecular dynamics investigation of dipeptide-transition metal salts in aqueous solutions.  

PubMed

Molecular dynamics (MD) simulations of glycylglycine dipeptide with transition metal ions (Mn(2+), Fe(2+), Co(2+), Ni(2+), Cu(2+), and Zn(2+)) in aqueous solutions have been carried out to get an insight into the solvation structure, intermolecular interactions, and salt effects in these systems. The solvation structure and hydrogen bonding were described in terms of radial distribution function (RDF) and spatial distribution function (SDF). The dynamical properties of the solvation structure were also analyzed in terms of diffusion and residence times. The simulation results show the presence of a well-defined first hydration shell around the dipeptide, with water molecules forming hydrogen bonds to the polar groups of the dipeptide. This shell is, however, affected by the strong electric field of divalent metal ions, which at higher ion concentrations lead to the shift in the dipeptide-water RDFs. Higher salt concentrations lead also to increased residence times and slower diffusion rates. In general, smaller ions (Cu(2+), Zn(2+)) demonstrate stronger binding to dipeptide than the larger ones (Fe(2+), Mn(2+)). Simulations do not show any stronger association of peptide molecules indicating their dissolution in water. The above results may be of potential interest to future researchers on these molecular interactions. PMID:21086976

Santosh, M S; Lyubartsev, Alexander P; Mirzoev, Alexander A; Bhat, D Krishna

2010-12-16

356

Phospholipid fatty acid composition, vitamin E content and susceptibility to lipid peroxidation of duck spermatozoa.  

PubMed

Recent studies on chicken semen have suggested that the lipid and fatty acid composition of spermatozoa may be important determinants of fertility. Phospholipid fatty acid composition, vitamin E content and in vitro susceptibility to lipid peroxidation of duck spermatozoa were investigated using GC-MS and HPLC based methods. The total phospholipid fraction of duck spermatozoa was characterized by high proportions of the n-6 polyunsaturated fatty acids arachidonic (20:4n-6), docosatetraenoic (22:4n-6) and docosapentaenoic (22:5n-6) acids but a substantial proportion of the n-3 fatty acid docosahexaenoic (22:6n-3) acid was also present. Palmitic (16:0) and stearic (18:0) fatty acids were the major saturates in sperm phospholipids. Among the phospholipid classes, phosphatidylserine (PS) had the highest degree of unsaturation due to very high proportions of 22:6n-3, 22:5n-6, 22:4n-6 and 20:4n-6, comprising together more than 75% of total fatty acids in this fraction. Phosphatidylethanolamine (PE) also contained high proportions of these four C(20-22) polyunsaturates, which together formed 60% of total fatty acids in this phospholipid. Spermatozoa and seminal plasma of duck semen were characterized by unexpectedly low content of vitamin E, being more than 4-fold lower than in chicken semen. In duck semen the major proportion of the vitamin E (>70%) was located in the spermatozoa. The very high proportion of 22:6n-3 in PS and PE fractions of duck sperm lipids and the comparatively low levels of vitamin E could predispose semen to lipid peroxidation. Nevertheless the in vitro susceptibilities to Fe2+-stimulated lipid peroxidation of duck and chicken spermatozoa were very similar. The results of the study suggest that increased superoxide dismutase and glutathione peroxidase activity and increased antioxidant activity of seminal plasma may compensate for the low levels of vitamin E to help protect the membranes of duck spermatozoa, which exhibit a high degree of unsaturation from oxidative stress. PMID:10798481

Surai, P F; Brillard, J P; Speake, B K; Blesbois, E; Seigneurin, F; Sparks, N H

2000-03-15

357

Adaptive modification of membrane phospholipid fatty acid composition and metabolic thermosuppression of brown adipose tissue in heat-acclimated rats  

NASA Astrophysics Data System (ADS)

Thermogenesis, especially facultative thermogenesis by brown adipose tissue (BAT), is less important in high ambient temperature and the heat-acclimated animals show a lower metabolic rate. Adaptive changes in the metabolic activity of BAT are generally found to be associated with a modification of membrane phospholipid fatty acid composition. However, the effect of heat acclimation on membrane phospholipid fatty acid composition is as yet unknown. In this study, we examined the thermogenic activity and phospholipid fatty acid composition of interscapular BAT from heat-acclimated rats (control: 25+/-1°C, 50% relative humidity and heat acclimation: 32+/-0.5°C, 50% relative humidity). Basal thermogenesis and the total thermogenic capacity after noradrenaline stimulation, as estimated by in vitro oxygen consumption of BAT (measured polarographically using about 1-mm3 tissue blocks), were smaller in the heat-acclimated group than in the control group. There was no difference in the tissue content of phospholipids between the groups when expressed per microgram of DNA. The phospholipid fatty acid composition was analyzed by a capillary gas chromatograph. The state of phospholipid unsaturation, as estimated by the number of double bonds per fatty acid molecule, was similar between the groups. The saturated fatty acid level was higher in the heat-acclimated group. Among the unsaturated fatty acids, heat acclimation decreased docosahexaenoic acid and oleic acid levels, and increased the arachidonic acid level. The tissue level of docosahexaenoic acid correlated with the basal oxygen consumption of BAT (r=0.6, P<0.01) and noradrenaline-stimulated maximum values of oxygen consumption (r=0.5, P<0.05). Our results show that heat acclimation modifies the BAT phospholipid fatty acids, especially the n-3 polyunsaturated fatty acid docosahexaenoic acid, which is possibly involved in the metabolic thermosuppression.

Saha, S. K.; Ohno, T.; Tsuchiya, K.; Kuroshima, A.

358

Genetic parameters for fatty acid composition and feed efficiency traits in Japanese Black cattle.  

PubMed

We estimated the genetic parameters related to feed intake (FI), feed efficiency traits (including feed conversion ratio (FCR) and residual feed intake (RFI) of digestible crude protein (DCP) and total digestible nutrients (TDN)), beef marbling score (BMS), melting point of fat (MP) and fatty acid composition. Fat and meat (Musculus trapezius) samples were taken from the carcasses of 863 Japanese Black steers derived from 65 sires, for determination of the MP and fatty acid composition of the total lipid in intramuscular adipose tissue. Genetic parameters were estimated using uni- and bivariate animal models. In addition, pedigree information for 4841 animals was used. Heritability estimates for BMS, MP, individual fatty acids, monounsaturated fatty acids (MUFA), the ratio of saturated fatty acids to MUFA (MUS) and the ratio of elongation (ELONG) were generally high. The FI values of TDN and DCP were also high, but FCRs and RFIs of those were low (0.09 to 0.22). Genetic correlation of BMS with MP was -0.34 (favorable) and with C18:1, MUFA, MUS and ELONG values were 0.40, 0.28, 0.29 and 0.37, respectively (favorable). Genetic correlations of MP with C18:1, MUFA, MUS and ELONG were negative (also favorable) and high (-0.85, -0.98, -1.00 (-0.996) and -0.66, respectively). The correlation estimates for feed efficiency traits of DCP were quite similar to those of TDN. Genetic correlations of BMS with FCRs and RFIs of TDN and DCP were all positive (unfavorable; 0.21 to 0.51), and in particular, the correlations with RFIs of those were high. The correlations of C18:1, MUFA, MUS and ELONG with RFIs of TDN and DCP were positive (unfavorable) but low (0.06 to 0.17), whereas the corresponding correlations with FCRs of those were all negative (favorable; -0.38 to -0.10). These results suggest that the quantity and quality of beef fat can be simultaneously improved and that the quality of beef fat (fatty acid composition) can be improved directly or indirectly with MP. Furthermore, selecting MP or fatty acid traits does not significantly affect feed efficiency. PMID:22440094

Inoue, K; Kobayashi, M; Shoji, N; Kato, K

2011-05-01

359

Recovery of uranium from phosphoric acid medium by polymeric composite beads encapsulating organophosphorus extractants  

SciTech Connect

The present study deals with the preparation and evaluation of the poly-ethersulfone (PES) based composite beads encapsulating synergistic mixture of D2EHPA and Cyanex 923 (at 4:1 mole ratio) for the separation of uranium from phosphoric acid medium. SEM was used for the characterization of the composite materials. Addition of 1% PVA (polyvinyl alcohol) improved the internal morphology and porosity of the beads. Additionally, microscopic examination of the composite bead confirmed central coconut type cavity surrounded by porous polymer layer of the beads through which exchange of metal ions take place. Effect of various experimental variables including aqueous acidity, metal ion concentration in aqueous feed, concentration of organic extractant inside the beads, extractant to polymer ratio, liquid to solid (L/S) ratio and temperature on the extraction of uranium was studied. Increase in acidity (1-6 M), L/S ratio (1- 10), metal ion concentration (0.2-3 g/L U{sub 3}O{sub 8}) and polymer to extractant ratio (1:4 -1:10) led to decrease in extraction of uranium. At 5.5 M (comparable to wet process phosphoric acid concentration) the extraction of uranium was about 85% at L/S ratio 5. Increase in extractant concentration inside the bead resulted in enhanced extraction of metal ion. Increase in temperature in the range of 30 to 50 Celsius degrees increased the extraction, whereas further increase to 70 C degrees led to the decrease in extraction of uranium. Amongst various reagents tested, stripping of uranium was quantitative by 12% Na{sub 2}CO{sub 3} solution. Polymeric beads were found to be stable and reusable up-to 10 cycles of extraction/stripping. (authors)

Singh, D.K.; Yadav, K.K.; Varshney, L.; Singh, H. [Bhabha Atomic Research Centre, Mumbai 400 085 (India)

2013-07-01

360

Cellular fatty acid composition of Haemophilus species, Pasteurella multocida, Actinobacillus Actinomycetemcomitans and Haemophilus vaginalis (Corynebacterium vaginale).  

PubMed

The fatty acid composition of 35 Haemophilus influenzae strains was found to be grossly similar and characterized by relatively large amounts of 14:0, 3-OH-14:0, 16:1 and 16:0. The three C18 fatty acids 18:2, 18:1 and 18:0 were also present, but in much lower concentrations. This general pattern was also found for most of the other species of Haemophilus examined (H. aegyptius, H. aphrophilus, H. canis, H. gallinarum, H. haemolyticus, and H. parainfluenzae). Small but distinct quantitative discrepancies were detected for H. ducreyi and the haemin-independent species H. paraphrohaemolyticus, H. paraphrophilus and H. suis. Actinobacillus actinomycetemcomitans was found to be indistinguishable from H. influenzae. Pasteurella multocida also exhibited a fatty acid pattern closely related to that of Haemophilus, but could be distinguished by its higher concentration levels of the C18 fatty acids. The fatty acid pattern of H. vaginalis was considerably different from those of the other species examined. This species lacked 3-OH-14:0 and 18:2 and contained small amounts of 14:0 and 16:0, whereas 18:1 and 18:0 were the major constituents. PMID:6990689

Jantzen, E; Berdal, B P; Omland, T

1980-04-01

361

Proximate Composition, Amino Acid, Mineral, and Heavy Metal Content of Dried Laver  

PubMed Central

Laver, a red algae belonging to the genus Porphyra, is one of the most widely consumed edible seaweeds. The most popular commercial dried laver species, P. tenera and P. haitanensis, were collected from Korea and China, respectively, and evaluated for proximate composition, amino acids, minerals, trace heavy metals, and color. The moisture and ash contents of P. tenera and P. haitanensis ranged from 3.66~6.74% and 8.78~9.07%, respectively; crude lipid and protein contents were 1.96~2.25% and 32.16~36.88%, respectively. Dried lavers were found to be a good source of amino acids, such as asparagine, isoleucine, leucine, and taurine, and ?-aminobutyric acid. K, Ca, Mg, Na, P, I, Fe, and Se minerals were selected for analysis. A clear regional variation existed in the amino acid, mineral, and trace metal contents of lavers. Regular consumption of lavers may have heath benefits because they are relatively low in fat and high in protein, and contain functional amino acids and minerals. PMID:24471123

Hwang, Eun-Sun; Ki, Kyung-Nam; Chung, Ha-Yull

2013-01-01

362

Diffusion dialysis. Effect of membrane composition on acid/salt separation  

SciTech Connect

Diffusion dialysis is an energy-saving separation technique. In order to highlight the relationship between membrane composition and ability to separate acid/salt mixtures by diffusion dialysis, a few anion-exchange membranes were examined. Experiments on solubility/diffusivity phenomena were carried out in contact with hydrochloric acid and sodium chloride solutions (single- and two-solute experiments). Computations using Glueckauf and Tye models have indicated high nonuniformity in the distribution of fixed charged within the membranes and different accessibilities of the internal membrane volumes for the acid and salt. The Neosepta AFN-7 membrane (Tokuymam Soda Co.) has proved effective in differentiating the permeants by sorption (k{sub HCl}/k{sub NaCl} {approx} 2) and diffusivity ({bar D}{sub HCl}/{bar D}{sub NaCl} up to 10). This membrane is also the only one which, when in contact with two-solutes solutions, absorbs the acid preferentially to the salt. For this membrane the preferential sorption and transport of the acid depends not only on the physical structure of the membrane but also on the chemical nature of the polymer which contains pyridine moieties.

Narebska, A.; Warszawski, A. (Nicolaus Copernicus Univ., Torun (Poland))

1992-05-01

363

Characterization of the bovine gene LIPE and possible influence on fatty acid composition of meat  

PubMed Central

LIPE is an intracellular neutral lipase, which is capable of hydrolyzing a variety of esters and plays a key role in the mobilization of fatty acids from diacylglycerols. The objectives of this study were to characterize the genetic polymorphism of bovine LIPE gene and to evaluate the possible association between three SNPs in the coding regions of this gene with the fatty acid composition of meat in a cattle population. Forty-three unrelated animals from different cattle breeds were re-sequenced and 21 SNPs were detected over approximately 2600 bp, five of these SNPs were novel. Three SNPs were selected, on the basis of evolutionary conservation, to perform validation and association studies in a crossbred cattle population. Our results may suggest a possible association of SNP1 with contents of oleic acid and total monounsaturated fatty acids (p < 0.01), and SNP2 and SNP3 with Heneicosylic acid content (p < 0.01), may be helpful to improve the quality of meat and improve health. PMID:25606458

Goszczynski, Daniel Estanislao; Mazzucco, Juliana Papaleo; Ripoli, María Verónica; Villarreal, Edgardo Leopoldo; Rogberg-Muñoz, Andrés; Mezzadra, Carlos Alberto; Melucci, Lilia Magdalena; Giovambattista, Guillermo

2014-01-01

364

Determination of the base composition of deoxyribonucleic acid by measurement of the adenine/guanine ratio  

PubMed Central

A method is described for determination of the base composition (as guanine+cytosine or adenine+thymine content) of DNA by accurate measurement of the adenine/guanine ratio. The DNA is hydrolysed with 0·03n-hydrochloric acid for 40min. to release the purines. The hydrolysate is subjected to ion-exchange chromatography on Zeo-Karb 225. Apurinic acids are eluted with 0·03n-hydrochloric acid and then guanine and adenine are eluted separately with 2n-hydrochloric acid. Guanine and adenine are each collected as a single fraction, and the amount of base in each case is determined by measuring the volume and the extinction at suitable wavelengths. For use in the calculations, millimolar extinction coefficients in 2n-hydrochloric acid of 12·09 for adenine at 262m?, and 10·77 for guanine at 248m?, were determined with authentic samples of bases. The method gives extremely reproducible results: from 12 determinations with calf thymus DNA the adenine/guanine molar ratio had a standard deviation of 0·011; this corresponds to a standard deviation in guanine+cytosine content of 0·2% guanine+cytosine. PMID:5626094

Kirk, J. T. O.

1967-01-01

365

The effects of season on fatty acid composition and ?3/?6 ratios of northern pike ( Esox lucius L., 1758) muscle lipids  

NASA Astrophysics Data System (ADS)

In the present study, the effects of season on fatty acid composition, total lipids, and ?3/?6 ratios of northern pike muscle lipids in Kizilirmak River (Kirikkale, Turkey) were investigated. A total of 35 different fatty acids were determined in gas chromatography. Among these, palmitic, oleic, and palmitoleic acids had the highest proportion. The main polyunsaturated fatty acids (PUFAs) were found to be docosahexaenoic acid, eicosapentaenoic acid, and arachidonic acid. There were more PUFAs than monounsaturated fatty acids (MUFA) in all seasons. Similarly, the percentages of ?3 fatty acids were higher than those of total ?6 fatty acids in the fatty acid composition. ?3/?6 ratios were calculated as 1.53, 1.32, 1.97, and 1.71 in spring, summer, autumn and winter, respectively. Overall, we found that the fatty acid composition and ?3/?6 fatty acid ratio in the muscle of northern pike were significantly influenced by season.

Mert, Ramazan; Bulut, Sait; Konuk, Muhsin

2015-01-01

366

Effect of dietary fatty acid supplements, varying in fatty acid composition, on milk fat secretion in dairy cattle fed diets supplemented to less than 3% total fatty acids.  

PubMed

Dietary fatty acids can affect both milk fat yield and fatty acid (FA) composition. This relationship is well established when the dietary level of FA exceeds 3% of diet dry matter (DM). We could find no reports directly examining the effects of dietary FA profile on milk fat at levels below 3%. Twenty-four primiparous and 36 multiparous lactating cows were paired by production (1 high with 1 low, within parity) to form 30 experimental units. Pairs were fed 6 diets in five 6×6 balanced Latin squares with 21-d periods, and data were collected during the last 5d of each period. Two control diets were fed: a corn control diet (CC; 29% corn silage, 16% alfalfa silage, 19% corn grain, and 8% distillers grain on a DM basis) containing 1.8% FA; and a low-oil control diet (LOC; 9% corn silage, 35% alfalfa silage, 20% food-grade corn starch, and 8% corn gluten feed on a DM basis) containing 1.2% FA. A portion of the food-grade corn starch in LOC was replaced with 4 different FA supplements to create the 4 treatment diets. Treatments were 1.7% (DM basis) of a 50:50 blend of corn oil and high-linoleic safflower oil (LO), 1.7% high-oleic sunflower oil (OO), 1.7% palm oil (PO), or 1.8% calcium salts of palm fatty acids (PFA). The resultant diets were thus enriched in linoleic (LO), oleic (OO), or palmitic acid (PO and PFA). Dietary treatments did not affect dry matter intake. Addition of any of the fat sources to LOC resulted in increased milk yield, but milk fat yields and milk FA composition were variable for the different treatments. The LO treatment resulted in lower milk fat yield, fat concentration, and C16:0 yield but increased both trans-10 C18:1 and trans-10,cis-12 C18:2 yields compared with the other added FA treatments. Diets PO and PFA resulted in increased milk C16:0 yield and decreased total milk C18 yield compared with OO. Regression analysis revealed a negative coefficient for dietary linoleic acid content over basal (LOC) for both milk short-chain FA yield and C16:0 yield. Dietary linoleic acid content also had a positive coefficient for milk trans-10 C18:1 and trans-10,cis-12 conjugated linoleic acid yield. These results demonstrate that even when total dietary FA are below 3%, free oils rich in linoleic acid can reduce milk fat yield by reducing secretion of milk FA with fewer than 18 carbons. Fatty acid composition of fat supplements is important even at this low level of total dietary fat. PMID:25468700

Stoffel, C M; Crump, P M; Armentano, L E

2015-01-01

367

Temporal dynamics of amino and fatty acid composition in the razor clam Ensis siliqua (Mollusca: Bivalvia)  

NASA Astrophysics Data System (ADS)

Few studies have been conducted on the temporal dynamics of both amino acid (AA) and fatty acid (FA) profiles in marine bivalves. We investigated the seasonal variation of these compounds in the pod razor clam Ensis siliqua in relation to food availability, salinity, water temperature and reproductive cycle. AA content varied between 46.94 and 54.67 % dry weight (DW), and the AAs found in greater quantity were glutamic acid, glycine and aspartic acid. FA content varied between 34.02 and 87.94 mg g-1 DW and the FAs found in greater quantity were 16:0 and 22:6 n-3. Seasonal trends were observed for AAs and FAs. FAs increased with gametogenesis and decreased with spawning while AA content increased throughout spawning. The effect of increasing temperature and high food availability during the spawning season masked the loss of AAs resulting from gamete release. Still, a comparatively greater increase in the contents of glutamic acid and leucine with spawning indicate their possible involvement in a post-spawning gonad recovery mechanism. A post-spawning decrease in 14:0, 16:0, 16:1 n-7, 18:1 n-7 and 18:1 n-9 is indicative of the importance of these FAs in bivalve eggs. An increase in 18:3 n-3, 18:4 n-3, 20:1 n-9 and 20:2 n-6 during gametogenesis suggests their involvement in oocyte maturation. The FA 22:4 n-6, while increasing with spawning, appears to play a role in post-spawning gonad recovery. Salinity did not have an effect on the AA composition. None of the environmental parameters measured had an effect on FA composition.

Baptista, Miguel; Repolho, Tiago; Maulvault, Ana Luísa; Lopes, Vanessa M.; Narciso, Luis; Marques, António; Bandarra, Narcisa; Rosa, Rui

2014-12-01

368

Fatty acid composition of subcutaneous adipose tissue from male calves at different stages of growth.  

PubMed

The objective of this investigation was to compare fatty acid composition of calves from Bos taurus and Bos indicus cows across different stages of growth. Hereford (H) and Brahman (B) embryos were transferred to H or B cows (n = 58) to produce purebred Brahman (BB), purebred Hereford (HH), Hereford x Brahman (HB), and Brahman x Hereford (BH) offspring. Calves were castrated at 2 to 3 wk of age. Before weaning (210 d of age), calves were fed native grasses. After weaning, calves were fed a concentrate diet in dry-lot pens. Adipose tissue was obtained by biopsy at two times: at weaning during forage feeding and 3 mo after weaning when placed on feed. A third sample was collected from the fed steers at slaughter (approximately 430 d of age). Samples obtained by biopsy and after death were collected from the perianal region. Fatty acid composition for each sample was determined as the normalized percentage area means from the duplicate measures. Generally, BB calves grew slowest and BH steers grew fastest (P < .05). The BH steers exhibited 15 and 20% heavier (P < .05) carcasses per day of age than H-sired steers and BB steers, respectively. Adipose tissue samples from calves from Brahman sires or dams were less saturated (P < .05) than samples from calves from Hereford sires or dams. Differences in degree of unsaturation primarily were due to the percentages of monounsaturated fatty acids (MUFA). As calves became older, MUFA increased markedly, polyunsaturated fatty acids increased slightly (due to inverse, nearly proportional changes in 18:2 and 18:3), and saturated fatty acids decreased by 10 percentage units (P < .001). Thus, adipose tissue from Brahman and Hereford purebred and crossbred calves became markedly more unsaturated early postweaning; this change was less dramatic in the purebred Hereford calves. PMID:8791197

Huerta-Leidenz, N O; Cross, H R; Savell, J W; Lunt, D K; Baker, J F; Smith, S B

1996-06-01

369

Regulation of fatty acid composition and lipid storage by thyroid hormone in mouse liver  

PubMed Central

Background Thyroid hormones (THs) are potent hormones modulating liver lipid homeostasis. The perturbation of lipid homeostasis is a hallmark of non-alcoholic fatty liver disease (NAFLD), a very common liver disorder. It was reported that NAFLD patients were associated with higher incidence of hypothyroidism. However, whether abnormal thyroid function contributes to the pathogenesis of NAFLD remains unclear. Results We used in vivo models to investigate the influence of hypothyroidism and TH on hepatic lipid homeostasis. We did not observe hepatic triglyceride accumulation in the liver of hypothyroid mice, although the liver was enlarged. We then characterized the hepatic fatty acid composition with gas chromatography–mass spectrometry in mice under different thyroid states. We found that hypothyroidism decreased saturated fatty acid (SFA) content while TH treatment restored the level of SFA. In agreement with this finding, we observed that the expression of acetyl-CoA carboxylase 1 and fatty acid synthase, the rate-limit enzymes for de novo lipogenesis (DNL), decreased in hypothyroid mice while increased after TH treatment. We also found that the ratio of C18:1n-9/C18:0 and C16:1n-7/C16:0 was decreased by TH treatment, suggesting the activity of stearoyl-CoA desaturase-1 was suppressed. This finding indicated that TH is able to suppress triglyceride accumulation by reducing fatty acid desaturation. Additionally, we found that hepatic glycogen content was substantially influenced by TH status, which was associated with glycogen synthase expression. The increased glycogen storage might explain the enlarged liver we observed in hypothyroid mice. Conclusions Taken together, our study here suggested that hypothyroidism in mice might not lead to the development of NAFLD although the liver became enlarged. However, disturbed TH levels led to altered hepatic fatty acid composition and glycogen accumulation. PMID:25105012

2014-01-01

370

The composition of the free fatty acids from Dendrolimus pini exuviae.  

PubMed

The pine moth Dendrolimus pini effectively resists many insecticides, but it can be controlled by the use of bioinsecticides such as entomopathogenic fungi. In the use of microbial agents for the biocontrol of D. pini, it is important to identify the cuticular lipids of this pest if we are to understand the factors responsible for the preferential adhesion or selective repulsion of entomopathogenic fungi that are potentially useful in biocontrol. In this work the qualitative and quantitative analyses of free fatty acids in two exuviae extracts (petroleum ether and dichloromethane) and two developmental stages (larval-larval and larval-pupal molts) were studied. The free fatty acid composition of the epicuticular lipids from exuviae of D. pini was characterized chemically using gas chromatography (GC) and gas chromatography-electron impact mass spectrometry (GC-MS). Structural analyses of the dichloromethane extracts from larval-larval exuviae (LLE) and larval-pupal exuviae (LPE) revealed that the carbon numbers for the major acid moieties ranged from C(8:0) to C(34:0). Only C(23:0) was not identified in the LPE extract. The relative contents of fatty acids in the extracts varied from trace amounts to 34%. The fatty acids extracted by dichloromethane were essentially the same as those in the petroleum ether extract. We also identified dehydroabietic acid in the exuviae of D. pini. The respective quantities of dehydroabietic acid obtained from D. pini LLE and LPE were 1763+/-103 microg/g exuviae and 11521+/-1198 microg/g of exuviae. PMID:19932114

Go?ebiowski, Marek; Bogu?, Mieczys?awa I; Paszkiewicz, Monika; Stepnowski, Piotr

2010-04-01

371

Effects of ensiling processes and antioxidants on fatty acid concentrations and compositions in corn silages  

PubMed Central

Background Corn silage is the main dietary component used for ruminant breeding in China and is an important dietary source of fatty acids for these animals. However, little is known regarding effective means to protect the fatty acid (FA) contents in silages. In this study, we examined the changes in FA contents and compositions during corn ensiling and screened several antioxidants for their inhibition of lipid oxidation during corn ensiling. Methods We conducted two different experiments. In Experiment 1, corn was ensiled in 30 polyethylene bottles (bottle volume: 1 L, silage density: 600 g/dm3) and three bottles were opened at 0.5 d, 1 d, 1.5 d, 2 d, 2.5 d, 3 d, 5 d, 7 d, 14 d, and 28 d after ensiling. In Experiment 2, corn was treated with various antioxidants: (1) No additives (CK); (2) BHA (Butylated hydroxyanisole); (3) TBHQ (Tertiary butyl hydroquinone); (4) TPP (Tea polyphenols); and (5) VE (Vitamin E). These treatments were applied at 50 mg/kg and 100 mg/kg of fresh weight with each treatment replicated 3 times. Results During ensiling in Experiment 1, saturated fatty acids (SFA; C16:0 and C18:0) and malondialdehyde (MDA) contents tended to increase, whereas unsaturated fatty acids (UFA; C18:1, C18:2 and C18:3) tended to decrease. However, these changes were only significant on the first 2 days of ensiling. In Experiment 2, all of the antioxidants tested affected the total FA contents and those of unsaturated fatty acids (C18:1, C18:2 and C18:3) and MDA. The effects of TBHQ and TPP were greater than those of the other antioxidants. Conclusions The reduced total FA contents in corn silages were due to unsaturated fatty acids’ oxidation during the early stages of ensiling. Adding an antioxidant could prevent fatty acids’ oxidation in corn silages. PMID:24304647

2013-01-01

372

Fatty acid composition of spruce needle lipids after exposure to air pollutants  

SciTech Connect

Alterations in the fatty acid composition of membrane lipids have been observed in long-term experiments using realistic exposures of air pollutants. Monogalactosyl diglyceride (MGDG), from red spruce, showed a 12% reduction in linolenic acid (18:3) compared with controls, after a 21 week winter fumigation with SO{sub 2} NO{sub 2} (20 ppb each). The composition of phosphatidyl choline from the same trees was unaffected. In Norway spruce exposed to 70 ppb O{sub 3} for 3 consecutive summers there was no treatment effect on 18:3 content of MGDG, which ranged from 70 to 80%, with highest values in November. The percentage of octadecatetranoic acid (18:4) also varied seasonally. Compared with controls, polluted plants had proportionally less 18:4 during autumn, perhaps indicating some effect of O{sub 3} on the winter hardening process. Our observations emphasize the need for long-term experiments to investigate subtle disturbances to seasonal metabolic cycles.

Wolfenden, J.; Wellburn, A.R. (Univ. of Lancaster (England))

1990-05-01

373

Prediction of Aptamer-Target Interacting Pairs with Pseudo-Amino Acid Composition  

PubMed Central

Aptamers are oligonucleic acid or peptide molecules that bind to specific target molecules. As a novel and powerful class of ligands, aptamers are thought to have excellent potential for applications in the fields of biosensing, diagnostics and therapeutics. In this study, a new method for predicting aptamer-target interacting pairs was proposed by integrating features derived from both aptamers and their targets. Features of nucleotide composition and traditional amino acid composition as well as pseudo amino acid were utilized to represent aptamers and targets, respectively. The predictor was constructed based on Random Forest and the optimal features were selected by using the maximum relevance minimum redundancy (mRMR) method and the incremental feature selection (IFS) method. As a result, 81.34% accuracy and 0.4612 MCC were obtained for the training dataset, and 77.41% accuracy and 0.3717 MCC were achieved for the testing dataset. An optimal feature set of 220 features were selected, which were considered as the ones that contributed significantly to the interacting aptamer-target pair predictions. Analysis of the optimal feature set indicated several important factors in determining aptamer-target interactions. It is anticipated that our prediction method may become a useful tool for identifying aptamer-target pairs and the features selected and analyzed in this study may provide useful insights into the mechanism of interactions between aptamers and targets. PMID:24466214

Huang, Guo-Hua; Cui, Wei-Ren; Zhang, Ning; Cai, Yu-Dong

2014-01-01

374

Comparison of fatty acid composition in major lipid classes of the dominant benthic invertebrates of the Yenisei river  

Microsoft Academic Search

The composition and content of fatty acids (FAs) in total lipids, triacylglycerols (TAG) and polar lipids (PL) in dominant groups of benthic invertebrates: gammarids (Gammaridae, Amphipoda), chironomid larvae (Chironomidae, Diptera), caddisfly larvae (Trichoptera) and mayfly larvae (Ephemeroptera) were studied in the Yenisei river. For the first time data on the FA composition of species belonging to Trichoptera (Insecta) are presented.

N. N. Sushchik; M. I. Gladyshev; A. V. Moskvichova; O. N. Makhutova; G. S. Kalachova

2003-01-01

375

Case Study: A snapshot of fatty acids composition of grass herbage as affected by time of day  

Technology Transfer Automated Retrieval System (TEKTRAN)

Manipulation of functional poly unsaturated fatty acid (PUFA) in ruminant products depends on rumen biohydrogenation and the net amount and composition of fatty acid ingested. Total non-structural carbohydrates and DM concentrations of herbage increase during the day; however, it is not known if fat...

376

Efficacy of a Novel Whey Protein Gel Complex to Increase the Unsaturated Fatty Acid Composition of Bovine Milk Fat  

Microsoft Academic Search

A novel whey protein emulsion gel (WPEG) complex was developed to protect dietary unsaturated fatty acids from rumen biohydrogenation with the goal of modifying the fatty acid composition of milk fat. Three experiments were conducted with WPEG complexes made from either whey protein concentrate containing 80% crude protein, whey protein isolate, or whey pro- tein concentrate high-gel capacity. Each experiment

S. M. Carroll; E. J. DePeters; M. Rosenberg

2006-01-01

377

Fatty acid and sterol oil composition of four Tunisian ecotypes of Ziziphus zizyphus (L.) H.Karst  

Microsoft Academic Search

Oils isolated from seeds of Ziziphus zizyphus (L.) H. Karst. were investigated by capillary gas chromatography. A comparison of four Tunisian ecotypes (Sfax, Choutrana, Mahres and Mahdia) shows that they differ only in the quantitative composition, while the qualitative profiles are similar. Ten fatty acids are identified from seed oils. The qualitative study shows that oleic acid is the major

Meriem El Aloui; Khaled Mguis; Abdelwahed Laamouri; Ali Albouchi; Murielle Cerny; Céline Mathieu; Gérard Vilarem; Brahim Hasnaoui

2012-01-01

378

Optimisation of ozone treatment for colour and COD removal of acid dye effluent using central composite design experiment  

Microsoft Academic Search

Central composite design experiment is used to study the effect of ozone treatment for acid dye effluents and to optimise the variables such as salt concentration, pH and time, which influence the efficiency of colour and COD removal of dye effluents. Acid Red 88 dye is used for this study and the salt additive sodium sulphate is varied between 5

M. Muthukumar; D. Sargunamani; N. Selvakumar; J. Venkata Rao

2004-01-01

379

Correlation of erythrocyte fatty acid composition and dietary intakes with markers of atherosclerosis in patients with myocardial infarction.  

PubMed

The purpose of this study was to examine the hypothesis that erythrocytes that are low in n-3 fatty acids and high in trans-fatty acids and nutrient intakes are associated with the risk of atherosclerosis. Fifty patients with acute nonfatal myocardial infarction were recruited to measure their dietary intake, erythrocyte fatty acid composition, intima medial thickness (IMT), and the Gensini score, which are markers of atherosclerosis. Trans-oleic acid of erythrocytes was positively (P = .05) correlated with the carotid IMT. After adjusting for age, sex, and energy intake, the IMT was negatively associated with the intake of protein, fat, phosphate, zinc, vitamin B(1), vitamin B(2), vitamin B(6), niacin, linoleic acid, linolenic acid, total fatty acids, total n-3 fatty acids, and total n-6 fatty acids. The Gensini score was also negatively associated with the intake of protein, fat, phosphate, sodium, zinc, vitamin E, vitamin B(1), vitamin B(2), vitamin B(6), niacin, linolenic acid, total fatty acids, and total n-3 fatty acids. In conclusion, lower levels of trans-oleic acid (elaidic acid) in erythrocytes and higher intakes of vitamins, minerals, and n-3 fatty acids were associated with the decreased risk of atherosclerosis. However, these findings need further investigation in randomized controlled clinical trials before public health recommendations for atherosclerosis prevention can be made. PMID:19628105

Park, Yongsoon; Lim, Jeehyun; Kwon, Yongju; Lee, Jaeung

2009-06-01

380

Dietary conjugated linoleic acids as free fatty acids and triacylglycerols similarly affect body composition and energy balance in mice.  

PubMed

The objective of this study was to compare the effects of conjugated linoleic acid (CLA) as triacylglycerols (TAG) or free fatty acids (FFA) on body composition and energy balance in mice. We fed four groups of 5-wk-old Balb-C mice (n = 9) semipurified diets containing either CLA (0.5 g CLA/100 g of diet) or high oleic sunflower oil (HOSF) in the form of FFA or TAG for 42 d. Body composition was determined and the energy in the carcasses, excreta and food was measured in a bomb calorimeter. The amount of body fat was 4.72 +/- 0.95 g (17.9 +/- 2.8%) in the HOSF-FFA group, 2.36 +/- 0.29 g (9.4 +/- 1.0%) in the CLA-FFA mice (mean +/- SD, P < 0.05), 4.76 +/- 0.74 g (18.2 +/- 2.2%) in the HOSF-TAG group and 2.32 +/- 0.38 g (9.3 +/- 1.1%) in the CLA-TAG mice (P < 0.05). The percentage of energy intake that was stored in the body was 3.5 +/- 1.2% in the HOSF-FFA group, 0.6 +/- 0.3% in the CLA-FFA group (P < 0.05), 3.5 +/- 1.1% in the HOSF-TAG group and 0.5 +/- 0.4 in the CLA-TAG mice (P < 0.05). Conversely, the percentage of energy intake that was expended as heat was 89.4 +/- 1.2% in the HOSF-FFA group, 92.4 +/- 0.8% in the CLA-FFA mice (P < 0.05), 89.47 +/- 1.23% in the HOSF-TAG group and 92.2 +/- 0.4% in the CLA-TAG group (P < 0.05). Thus, CLA in the form of FFA or TAG had similar effects on body composition and energy balance. PMID:14519807

Terpstra, A H M; Javadi, M; Beynen, A C; Kocsis, S; Lankhorst, A E; Lemmens, A G; Mohede, I C M

2003-10-01

381

Self-assembled dipeptide-gold nanoparticle hybrid spheres for highly sensitive amperometric hydrogen peroxide biosensors.  

PubMed

Novel self-assembled dipeptide-gold nanoparticle (DP-AuNP) hybrid microspheres with a hollow structure have been prepared in aqueous solution by a simple one-step method. Diphenylalanine (FF) dipeptide was used as a precursor to form simultaneously peptide spheres and a reducing agent to reduce gold ions to gold nanoparticles in water at 60°C. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that formed AuNPs were localized both inside and on the surface of the dipeptide spheres. Horseradish peroxidase (HRP) as a model enzyme was further immobilized on the dipeptide-AuNP hybrid spheres to construct a mediate H2O2 amperometric biosensor. UV-vis spectroscopy showed that the immobilized HRP retained its original structure. Cyclic voltammetry characterization demonstrated that the HRP/dipeptide-AuNP hybrid spheres modified glassy carbon electrode showed high electrocatalytic activity to H2O2. The proposed biosensor exhibited a wide linear response in the range from 5.0×10(-7) to 9.7×10(-4)M with a high sensitivity of 28.3µAmM(-1). A low detection limit of 1.0×10(-7)M was estimated at S/N=3. In addition, the biosensor possessed satisfactory reproducibility and long-term stability. These results indicated that the dipeptide-AuNP hybrid sphere is a promising matrix for application in the fabrication of electrochemical biosensors due to its excellent biocompatibility and good charge-transfer ability. PMID:25483915

Gong, Yufei; Chen, Xu; Lu, Yanluo; Yang, Wensheng

2015-04-15

382

The acid-base properties and chemical composition of the surface of the InSb-ZnTe system  

Microsoft Academic Search

The acid-base properties and chemical composition of the surface of solid solutions and binary components of the InSb-ZnTe\\u000a system were studied by the hydrolytic adsorption, nonaqueous conductometric titration, mechanochemistry, IR spectroscopy,\\u000a and mass spectrometry methods. The strength, nature, and concentration of acid centers were determined. Changes in the concentration\\u000a of acid centers caused by surface exposure to CO and changes

I. A. Kirovskaya; E. G. Shubenkova; O. T. Timoshenko; T. N. Filatova

2008-01-01

383

The acid-base properties and chemical composition of the surface of the InSb-ZnTe system  

Microsoft Academic Search

The acid-base properties and chemical composition of the surface of solid solutions and binary components of the InSb-ZnTe system were studied by the hydrolytic adsorption, nonaqueous conductometric titration, mechanochemistry, IR spectroscopy, and mass spectrometry methods. The strength, nature, and concentration of acid centers were determined. Changes in the concentration of acid centers caused by surface exposure to CO and changes

I. A. Kirovskaya; E. G. Shubenkova; O. T. Timoshenko; T. N. Filatova

2008-01-01

384

Effect of maturity on the fatty acid composition of eight varieties of peanuts grown at perkins, Oklahoma in 1968  

Microsoft Academic Search

Eight varieties of peanuts were grown under measured field conditions. Seed obtained at five successive harvest dates and\\u000a separated into three maturity levels were analyzed for fatty acid composition of oil. Mature peanuts were mostly higher in\\u000a stearic (18:0) and oleic (18:1) acids, and lower in linoleic (18:2), arachidic (20:0) and behenic (22:0) acids. Oleic-linoleic\\u000a ratios, which are correlated with

C. T. Young; M. E. Mason; R. S. Matlock; G. R. Waller

1972-01-01

385

A central composite rotatable design analysis of lipase catalyzed synthesis of lauroyl lactic acid at bench-scale level  

Microsoft Academic Search

Porcine Pancreas lipase (PPL) was employed for the reaction between lactic acid and lauric acid at bench-scale level. A Response Surface Methodological (RSM) study was conducted by employing a five-level, five variable, central composite rotatable design (CCRD) in order to understand the esterification behavior of PPL in the lauroyl lactic acid synthesis. Five important variables were considered, namely, enzyme\\/substrate (E\\/S)

K. R. Kiran; B. Manohar; S. Divakar

2001-01-01

386

Low pressure process for continuous fiber reinforced polyamic acid resin matrix composite laminates  

NASA Technical Reports Server (NTRS)

A low pressure processor was developed for preparing a well-consolidated polyimide composite laminate. Prepreg plies were formed from unidirectional fibers and a polyamic acid resin solution. Molding stops were placed at the sides of a matched metal die mold. The prepreg plies were cut shorter than the length of the mold in the in-plane lateral direction and were stacked between the molding stops to a height which was higher than the molding stops. The plies were then compressed to the height of the stops and heated to allow the volatiles to escape and to start the imidization reaction. After removing the stops from the mold, the heat was increased and 0 - 500 psi was applied to complete the imidization reaction. The heat and pressure were further increased to form a consolidated polyimide composite laminate.

Druyun, Darleen A. (inventor); Hou, Tan-Hung (inventor); Kidder, Paul W. (inventor); Reddy, Rakasi M. (inventor); Baucom, Robert M. (inventor)

1994-01-01

387

Impedance Spectroscopy and DSC Studies of Poly(vinyl Alcohol)/silicotungstic Acid Crosslinked Composite Membranes  

NASA Astrophysics Data System (ADS)

Chemically crosslinked composite membranes consisting of poly(vinyl alcohol) (PVA) and silicotungstic acid (STA) have been prepared by solution casting method and evaluated as proton conducting polymer electrolytes. The proton conductivity of the membranes were investigated as a function of blending composition, crosslinking density and temperature. The conductivity mechanism was investigated by using Impedance spectroscopy in the region between 40 Hz and 10 MHz. Membranes were also characterized by FTIR spectroscopy to confirm the crosslinking reaction and differential scanning calorimetry (DSC) to assess the thermal stability. Membrane swelling decreased with increase in crosslinking density accompanied by improvement in mechanical properties. The proton conductivity of the membranes were of the order of 10-3 S/cm and showed similar resistance to methanol permeability than Nafion 112 under the same measurement conditions.

Anis, Arfat; Banthia, A. K.

2006-06-01

388

Activation of the jasmonic acid plant defence pathway alters the composition of rhizosphere bacterial communities.  

PubMed

Jasmonic acid (JA) signalling plays a central role in plant defences against necrotrophic pathogens and herbivorous insects, which afflict both roots and shoots. This pathway is also activated following the interaction with beneficial microbes that may lead to induced systemic resistance. Activation of the JA signalling pathway via application of methyl jasmonate (MeJA) alters the composition of carbon containing compounds released by roots, which are implicated as key determinants of rhizosphere microbial community structure. In this study, we investigated the influence of the JA defence signalling pathway activation in Arabidopsis thaliana on the structure of associated rhizosphere bacterial communities using 16S rRNA gene amplicon pyrosequencing. Application of MeJA did not directly influence bulk soil microbial communities but significant changes in rhizosphere community composition were observed upon activation of the jasmonate signalling pathway. Our results suggest that JA signalling may mediate plant-bacteria interactions in the soil upon necrotrophic pathogen and herbivorous insect attacks. PMID:23424661

Carvalhais, Lilia C; Dennis, Paul G; Badri, Dayakar V; Tyson, Gene W; Vivanco, Jorge M; Schenk, Peer M

2013-01-01

389

Activation of the Jasmonic Acid Plant Defence Pathway Alters the Composition of Rhizosphere Bacterial Communities  

PubMed Central

Jasmonic acid (JA) signalling plays a central role in plant defences against necrotrophic pathogens and herbivorous insects, which afflict both roots and shoots. This pathway is also activated following the interaction with beneficial microbes that may lead to induced systemic resistance. Activation of the JA signalling pathway via application of methyl jasmonate (MeJA) alters the composition of carbon containing compounds released by roots, which are implicated as key determinants of rhizosphere microbial community structure. In this study, we investigated the influence of the JA defence signalling pathway activation in Arabidopsis thaliana on the structure of associated rhizosphere bacterial communities using 16S rRNA gene amplicon pyrosequencing. Application of MeJA did not directly influence bulk soil microbial communities but significant changes in rhizosphere community composition were observed upon activation of the jasmonate signalling pathway. Our results suggest that JA signalling may mediate plant-bacteria interactions in the soil upon necrotrophic pathogen and herbivorous insect attacks. PMID:23424661

Carvalhais, Lilia C.; Dennis, Paul G.; Badri, Dayakar V.; Tyson, Gene W.; Vivanco, Jorge M.; Schenk, Peer M.

2013-01-01

390

Correlated Strontium and Barium Isotopic Compositions of Acid-Cleaned Single Silicon Carbides from Murchison  

E-print Network

We present strontium, barium, carbon, and silicon isotopic compositions of 61 acid-cleaned presolar SiC grains from Murchison. Comparison with previous data shows that acid washing is highly effective in removing both strontium and barium contamination. For the first time, by using correlated $^{88}Sr$/$^{86}Sr$ and $^{138}Ba$/$^{136}Ba$ ratios in mainstream SiC grains, we are able to resolve the effect of $^{13}C$ concentration from that of $^{13}C$-pocket mass on s-process nucleosynthesis, which points towards the existence of large $^{13}C$-pockets with low $^{13}C$ concentration in AGB stars. The presence of such large $^{13}$R-pockets with a variety of relatively low $^{13}C$ concentrations seems to require multiple mixing processes in parent AGB stars of mainstream SiC grains.

Liu, Nan; Gallino, Roberto; Davis, Andrew M; Bisterzo, Sara; Gyngard, Frank; Kaeppeler, Franz; Cristallo, Sergio; Dauphas, Nicolas; Pellin, Michael J; Dillmann, Iris

2015-01-01

391

Novel composite material polyoxovanadate@MIL-101(Cr): a highly efficient electrocatalyst for ascorbic acid oxidation.  

PubMed

A novel hybrid composite material, PMo10V2@MIL-101 was prepared by the encapsulation of the tetra-butylammonium (TBA) salt of the vanadium-substituted phosphomolybdate [PMo10V2O40](5-) (PMo10V2) into the porous metal-organic framework (MOF) MIL-101(Cr). The materials characterization by powder X-ray diffraction, Fourier transform infrared spectra and scanning electron microscopy confirmed the preparation of the composite material without disruption of the MOF porous structure. Pyrolytic graphite electrodes modified with the original components (MIL-101(Cr), PMo10V2), and the composite material PMo10V2@MIL-101 were prepared and their electrochemical responses were studied by cyclic voltammetry. Surface confined redox processes were observed for all the immobilized materials. MIL-101(Cr) showed one-electron reduction process due to chromium centers (Cr(III) ? Cr(II)), while PMo10V2 presented five reduction processes: the peak at more positive potentials is attributed to two superimposed 1-electron vanadium reduction processes (V(V) ? V(IV)) and the other four peaks to Mo-centred two-electron reduction processes (Mo(VI) ? Mo(V)). The electrochemical behavior of the composite material PMo10V2@MIL-101 showed both MIL-101(Cr) and PMo10V2 redox features, although with the splitting of the two vanadium processes and the shift of the Mo- and Cr- centered processes to more negative potentials. Finally, PMo10V2@MIL-101 modified electrode showed outstanding enhanced vanadium-based electrocatalytic properties towards ascorbic acid oxidation, in comparison with the free PMo10V2, as a result of its immobilization into the porous structure of the MOF. Furthermore, PMo10V2@MIL-101 modified electrode showed successful simultaneous detection of ascorbic acid and dopamine. PMID:24308331

Fernandes, Diana M; Barbosa, André D S; Pires, João; Balula, Salete S; Cunha-Silva, Luís; Freire, Cristina

2013-12-26

392

Fatty acid composition and sensory characteristics of lamb carcasses from Britain and Spain.  

PubMed

Fatty acid composition of intramuscular fat in M. Longissimus was measured in four groups of lambs representing two Spanish breeds: Rasa Aragonesa (RA) and Merino (ME) and two British lamb types: the Welsh Mountain breed (WM), whose carcasses were purchased in Spain and typical early lambs (EL) purchased in Britain. The lambs grown in Spain were concentrate fed and slaughtered at a lighter weight and lower age than those grown in Britain. The British lamb carcasses purchased in Spain were of a similar weight to the Spanish lambs but were lighter than the lamb carcasses purchased in Britain. The British lambs were grass fed. Relationships between fatty acid (FA) composition and sensory attributes were examined following sensory testing of all lambs by both British and Spanish taste panels. The production system was shown to be more important than breed in determining FA composition. British lambs had higher percentages, within total fatty acids, of 18:0, 18:3 (n-3) and long chain polyunsaturated n-3 FA and lower percentages of 18:2 (n-6) and long chain polyunsaturated n-6 FA than Spanish lambs. These differences were due to the different feeding systems used. The amounts of these FA in muscle (mg/100 g) were also different between the British and Spanish groups, not only because the British lambs had more total fat. For both taste panels, odour and flavour intensity were positively correlated with the amounts and percentages of 18:0 and 18:3 and negatively correlated with those of 18:2. This was explained by the fact that both panels gave higher odour and flavour intensity scores to the grass-fed British lamb with high 18:3 levels and lower scores to the concentrate-fed Spanish lamb with high 18:2 levels. However, 18:0 and 18:3 were positively correlated with flavour quality and overall appraisal for the British panel and negatively for the Spanish panel. Conversely, 18:2 was a positive contributor to flavour and overall preference for the Spanish panel and was negative for the British panel. The results show that the production system affects muscle fatty acid composition and the flavour of lamb. However, people's preference is determined to a large extent by their past experience. PMID:22060790

Sañudo, C; Enser, M E; Campo, M M; Nute, G R; María, G; Sierra, I; Wood, J D

2000-04-01

393

Changes in body composition in mice during feeding and withdrawal of conjugated linoleic acid  

Microsoft Academic Search

Two experiments were conducted. In Experiment 1, 8-wk-old mice were fed control diet or diet supplemented with 0.5% conjugated\\u000a linoleic acid (CLA) to study the effect of CLA on body composition (CLA: 40.8–41.1% c-9,t-11 isomer, 43.5–44.9% t-10,c-12 isomer). The data for CLA-fed mice vs. controls described parallel but significantly distinct responses for both absolute\\u000a and relative changes in body fat

Karen J. Albright; Jayne M. Storkson; Wei Liu; Mark E. Cook; Michael W. Pariza

1999-01-01

394

Effect of different types of forages, animal fat or marine oils in cow’s diet on milk fat secretion and composition, especially conjugated linoleic acid (CLA) and polyunsaturated fatty acids  

Microsoft Academic Search

This review summarises the known effects of forages, animal fats or marine oils on bovine milk fat secretion and composition. Special attention is given to fatty acids that could play a positive role for human health, such as butyric acid, oleic acid, C18 to C22 polyunsaturated fatty acids and conjugated linoleic acid (CLA). The efficiency of the transfer of n-3

Yves Chilliard; Anne Ferlay; Michel Doreau

2001-01-01

395

Pressurized hot water extraction of benzoic acid and phthalic anhydride from petrochemical wastes using a modified supercritical fluid extractor and a central composite design for optimization  

Microsoft Academic Search

Using the pressurized hot water extraction technique, benzoic acid and phthalic anhydride were selectively removed from solid petrochemical wastes (called molten phthalic anhydride). A statistical experimental design based on “central composite design” was applied for obtaining optimized conditions for the semi-continuous extraction of phthalic anhydride and benzoic acid from their mixture with benzoic acid, maleic acid, phthalic acid, phthalic anhydride,

H. Kamali; H. S. Ghaziaskar

2010-01-01

396

Effect of the polyunsaturated fatty acid composition of beef muscle on the profile of aroma volatiles.  

PubMed

The effect of n-3 polyunsaturated fatty acids (PUFAs) in beef muscle on the composition of the aroma volatiles produced during cooking was measured. The meat was obtained from groups of steers fed different supplementary fats: (i) a palm-oil-based control; (ii) bruised whole linseed, which increased muscle levels of alpha-linolenic (C18:3 n-3) and eicosapentaenoic acid (EPA, C20:5 n-3); (iii) fish oil, which increased EPA and docosahexaenoic acid (C22:6 n-3); (iv) equal quantities of linseed and fish oil. Higher levels of lipid oxidation products were found in the aroma extracts of all of the steaks with increased PUFA content, after cooking. In particular, n-alkanals, 2-alkenals, 1-alkanols, and alkylfurans were increased up to 4-fold. Most of these compounds were derived from the autoxidation of the more abundant mono- and di-unsaturated fatty acids during cooking, and such autoxidation appeared to be promoted by increased levels of PUFAs. PMID:10564028

Elmore, J S; Mottram, D S; Enser, M; Wood, J D

1999-04-01

397

Influence of the composition of monoacyl phosphatidylcholine based microemulsions on the dermal delivery of flufenamic acid.  

PubMed

Although microemulsions are one of the most promising dermal carrier systems, their clinical use is limited due to their skin irritation potential. Therefore, microemulsions based on naturally derived monoacyl phosphatidylcholine (MAPL) were developed. The influence of the water, oil and surfactant content on dermal delivery of flufenamic acid was systematically investigated for the first time. A water-rich microemulsion led to significantly higher in vitro skin penetration of flufenamic acid compared to other microemulsions. The superiority of the water-rich microemulsion over a marketed flufenamic acid containing formulation was additionally confirmed. Differences in drug delivery could be explained by alterations of the microemulsions after application. Evaporation of isopropanol led to crystal-like structures of MAPL on the skin surface from the surfactant- or oleic acid-rich microemulsions. In contrast, the formation of this additional barrier was hindered in case of the water-rich microemulsion. The skin penetration of MAPL was additionally analyzed by combined ATR-FTIR and tape stripping experiments, where MAPL itself penetrated only into the initial layers of the stratum corneum, independent of the microemulsion composition. Since a surfactant must penetrate the skin to cause irritation, MAPL can be presumed as a skin-friendly emulsifier with the ability to stabilize pharmaceutically acceptable microemulsions. PMID:25178824

Hoppel, Magdalena; Ettl, Hanna; Holper, Evelyn; Valenta, Claudia

2014-11-20

398

Fatty Acid Composition of Egg Yolk from Chickens Fed a Diet including Marigold (Tagetes erecta L.)  

PubMed Central

The objective of this study was to determine the effects of diet supplemented with marigold on egg yolk fatty acid composition and egg quality parameters. Sixty hens were assigned into three groups and fed diets supplemented with 0 (control), 10?g?kg?1, or 20?g?kg?1 marigold for 42 days. Eggs collected at the 6th week of the study were analyzed for fatty acid analysis. Laying performance, egg quality parameters, and feed intake were also evaluated. Yolk color scores in the group fed the 20?g?kg?1 marigold-supplemented diet were found greater than control (10.77 versus 9.77). Inclusion of 20?g?kg?1 marigold in diet influenced egg weights adversely compared to the control. Diet supplemented with 10?g?kg?1 or 20?g?kg?1 marigold increased the levels of C16:0 and C18:0 and decreased levels of C16:1 (n-7) and C18:1 (n-9) in the egg yolk. Also, diet including marigold increased total saturated fatty acids (SFA) and decreased monounsaturated fatty acids (MUFA) in the egg yolk. PMID:25587451

Altunta?, A.; Aydin, R.

2014-01-01

399

Oxygen Consumption Constrains Food Intake in Fish Fed Diets Varying in Essential Amino Acid Composition  

PubMed Central

Compromisation of food intake when confronted with diets deficient in essential amino acids is a common response of fish and other animals, but the underlying physiological factors are poorly understood. We hypothesize that oxygen consumption of fish is a possible physiological factor constraining food intake. To verify, we assessed the food intake and oxygen consumption of rainbow trout fed to satiation with diets which differed in essential amino acid (methionine and lysine) compositions: a balanced vs. an imbalanced amino acid diet. Both diets were tested at two water oxygen levels: hypoxia vs. normoxia. Trout consumed 29% less food under hypoxia compared to normoxia (p<0.001). Under both hypoxia and normoxia trout significantly reduced food intake by 11% and 16% respectively when fed the imbalanced compared to the balanced amino acid diet. Oxygen consumption of the trout per unit body mass remained identical for both diet groups not only under hypoxia but also under normoxia (p>0.05). This difference in food intake between diets under normoxia together with the identical oxygen consumption supports the hypothesis that food intake in fish can be constrained by a set-point value of oxygen consumption, as seen here on a six-week time scale. PMID:23991148

Saravanan, Subramanian; Geurden, Inge; Figueiredo-Silva, A. Cláudia; Nusantoro, Suluh; Kaushik, Sadasivam; Verreth, Johan; Schrama, Johan W.

2013-01-01

400

Ontogenetic change in the lipid and fatty acid composition of scleractinian coral larvae  

NASA Astrophysics Data System (ADS)

Some scleractinian coral larvae have an extraordinary capacity to delay metamorphosis, and this is reflected in the large geographic range of many species. Coral eggs typically contain a high proportion of wax esters, which have been hypothesized to provide a source of energy for long-distance dispersal. To better understand the role of lipids in the dispersal of broadcast spawning coral larvae, ontogenetic changes in the lipid and fatty acid composition of Goniastrea retiformis were measured from the eggs until larvae were 30 days old. Egg biomass was 78.8 ± 0.5% lipids, 86.3 ± 0.2% of which were wax esters, 9.3 ± 0.0% polar lipids, 4.1 ± 0.2% sterols, and 0.3 ± 0.1% triacylglycerols. The biomass of wax esters declined significantly through time, while polar lipids, sterols and triacylglycerols remained relatively constant, suggesting that wax esters are the prime source of energy for development. The most prevalent fatty acid in the eggs was palmitic acid, a marker of the dinoflagellate Symbiodinium, highlighting the importance of symbiosis in coral reproductive ecology. The proportion of polyunsaturated fatty acids declined through time, suggesting that they are essential for larval development. Interestingly, triacylglycerols are only abundant in the propagules that contain Symbiodinium, suggesting important differences in the energetic of dispersal among species with vertical and horizontal transmission of symbionts.

Figueiredo, J.; Baird, A. H.; Cohen, M. F.; Flot, J.-F.; Kamiki, T.; Meziane, T.; Tsuchiya, M.; Yamasaki, H.

2012-06-01

401

Changes of amino acid composition and lysinoalanine formation in alkali-pickled duck eggs.  

PubMed

Duck eggs were pickled in alkali for 20 days to prepare Pidan. The extent of the degradation of compositional amino acids, the formation of lysinoalanine (LAL) in Pidan, and the relationship between the formation of LAL and the racemization values of D-serine and D-aspartic acid in Pidan albumen during the pickling period were investigated. Results showed that the remaining percentages of Cys, Arg, Lys, Ser, and Thr in albumen were much lower than that of the corresponding amino acid in yolk. The formation of LAL in albumen in the first stage was due to the speedy increase in the pH and the abundant formation of dehydroalanine (DHA) from cysteine. However, the formation of LAL in the later pickling period was related much more to the alkali-treating time than to the pH factor. Among the amino acids, cysteine was observed to be the most sensitive to alkaline and contributed mostly to the formation of LAL throughout the pickling period. PMID:10564005

Chang, H M; Tsai, C F; Li, C F

1999-04-01

402

Effect of changes in the composition of cellular fatty acids on membrane fluidity of Rhodobacter sphaeroides.  

PubMed

Cellular fatty acid composition is important for metabolic plasticity in Rhodobacter sphaeroides. We explored the effects of changing the cellular ratio of unsaturated fatty acids (UFA) to saturated fatty acids (SFA) in R. sphaeroides by overexpressing several key fatty acid biosynthetic enzymes through the use of expression plasmid pRK415. Bacteria containing the plasmid pRKfabI1 with the fabI1 gene that encodes enoyl-acyl carrier protein (ACP) reductase showed a reduction in the cellular UFA to SFA ratio from 4 (80% UFA) to 2 (65% UFA) and had decreased membrane fluidity and reduced cell growth. Additionally, the ratio of UFA to SFA of the chromatophore vesicles from pRKfabI1-containing cells was similarly lowered, and the cell had decreased levels of light harvesting complexes, but no change in intracytoplasmic membrane content (ICM) or photosynthetic (PS) gene expression. Both inhibition of enoyl-ACP reductase with diazaborine and addition of exogenous UFA restored membrane fluidity, cell growth and a UFA to SFA ratio to wild-type levels in this strain. R. sphaeroides containing the pRKfabB plasmid with the fabB gene that encodes the enzyme ?-ketoacyl-ACP synthase I exhibited an increased UFA to SFA ratio from 4 (80% UFA) to 9 (90% UFA), but showed no change in membrane fluidity or growth rate relative to control cells. Thus, membrane fluidity in R. sphaeroides remains fairly unchanged when membrane UFA levels are between 80% and 90%, whereas membrane fluidity, cell growth and cellular composition are affected when UFA levels are below 80%. PMID:25418478

Kim, Eui-Jin; Lee, Jeong K

2014-11-24

403

Molecular composition of dicarboxylic acids, ketocarboxylic acids, ?-dicarbonyls and fatty acids in atmospheric aerosols from Tanzania, East Africa during wet and dry seasons  

NASA Astrophysics Data System (ADS)

Atmospheric aerosol samples of PM2.5 and PM10 were collected during the wet and dry seasons in 2011 from a rural site in Tanzania and analysed for water-soluble dicarboxylic acids, ketocarboxylic acids, ?-dicarbonyls, and fatty acids using a gas chromatography/flame ionization detector (GC/FID) and GC/mass spectrometry. Here we report the molecular composition and sources of diacids and related compounds for wet and dry seasons. Oxalic acid (C2) was found as the most abundant diacid species followed by succinic and/or malonic acids whereas glyoxylic acid and glyoxal were the dominant ketoacid and ?-dicarbonyl, respectively in both seasons in PM2.5 and PM10. Mean concentration of C2 in PM2.5 (121 ± 47 ng m-3) was lower in wet season than dry season (258 ± 69 ng m-3). Similarly, PM10 samples showed lower concentration of C2 (169 ± 42 ng m-3) in wet season than dry season (292 ± 165 ng m-3). Relative abundances of C2 in total diacids were 65% and 67% in PM2.5 and 65% and 64% in PM10 in the wet and dry seasons, respectively. Total concentrations of diacids (289-362 ng m-3), ketoacids (37.8-53.7 ng m-3), and ?-dicarbonyls (5.7-7.8 ng m-3) in Tanzania are higher than those reported at a rural background site in Nylsvley (South Africa) but comparable or lower than those reported from sites in Asia and Europe. Diacids and ketoacids were found to be present mainly in PM2.5 in both seasons (total ?-dicarbonyls in the dry season), suggesting a production of organic acids from pyrogenic sources and photochemical oxidations. Averaged contributions of total diacids to aerosol total carbon were 1.4% in PM2.5 and 2.1% in PM10 during wet season and 3.3% in PM2.5 and 3.9% in PM10 during dry season whereas those to water-soluble organic carbon were 2.2% and 4.7% in PM2.5 during wet season and 3.1% and 5.8% in PM10 during dry season. The higher ratios in dry season suggest an enhanced photochemical oxidation of organic precursors probably via heterogeneous reactions on aerosols under strong solar radiation. Strong positive correlations were found among diacids and related compounds as well as good relations to source tracers in both seasons, suggesting a mixed source from natural biogenic emissions, biomass burning, biofuel combustion, and photochemical production.

Mkoma, S. L.; Kawamura, K.

2013-02-01

404

Effects of dietary ?-linolenic acid deficiency during pregnancy and lactation on lipid fatty acid composition of liver  

E-print Network

amount of linoleic acid (18 : 2 n-6), i.e. 940 mg/100 g of diet, but the sunflower diet supplied 43 times was compensated by an increase in the level of n-6 polyunsaturated fatty acids (n-6 PUFA), and particularly acids= n-6 PUFA ; polyunsaturated n-3 fatty acids = n-3 PUFA. #12;These fatty acids, mostly composed

Paris-Sud XI, Université de

405

Interspecific variability of RAPD and fatty acid composition of some pomegranate cultivars ( Punica granatum L.) growing in Southern Anatolia Region in Turkey  

Microsoft Academic Search

The interspecific variability of fatty acid (FA) composition and RAPD profiles was used to examine biochemical and genetic relationships among six pomegranate cultivars, which dominate pomegranate production in Southern Anatolia Region of Turkey. Fatty acid composition of pomegranate leaves was determined by using gas chromatography. Differences in the FA composition were found among cultivars. In particular, cv. kirli hanim had

Sezai Ercisli; Guleray Agar; Emine Orhan; Nalan Yildirim; Yasemin Hizarci

2007-01-01

406

Fatty acid composition, including conjugated linoleic acid, of intramuscular fat from steers offered grazed grass, grass silage, or concentrate-based diets1  

Microsoft Academic Search

The effects of grazed grass, grass silage, or concentrates on fatty acid composition and conju- gated linoleic acid (cis-9, trans-11-18:2; CLA) concentra- tions of i.m. fat of steers fed to achieve similar carcass growth rates were investigated. Fifty steers were di- vided into 10 blocks based on body weight and assigned at random from within blocks to one of five

C. Stanton; F. Lawless; E. G. O'Riordan; F. J. Monahan; P. J. Caffrey; A. P. Moloney

407

Inuence of conjugated linoleic acid on body composition and target gene expression in peroxisome proliferator-activated receptor K-null mice  

E-print Network

In£uence of conjugated linoleic acid on body composition and target gene expression in peroxisome the beneficial effects of conjugated linoleic acid (CLA) are unknown, but one hypothesis.V. All rights reserved. Keywords: Body composition; Gene expression; Conjugated linoleic acid; Peroxisome

Omiecinski, Curtis

408

Amino acid composition and microbial contamination of Spirulina maxima , a blue-green alga, grown on the effluent of different fermented animal wastes  

Microsoft Academic Search

The nutrient compositions of various fermented manures were compared. Large differences in the mineral concentration were observed. There were no important differences among the amino acid composition of S. spirulina grown on the different nutrient media. All were low in methionine, but were rich in glutamic acid, aspartic acid, arginine, and leucine. The crude protein content was 71.8-60.1%. Considerable contamination

Jung F. Wu; Wilson G. Pond

1981-01-01

409

The role of lipid composition for insertion and stabilization of amino acids in membranes  

NASA Astrophysics Data System (ADS)

While most membrane protein helices are clearly hydrophobic, recent experiments have indicated that it is possible to insert marginally hydrophobic helices into bilayers and have suggested apparent in vivo free energies of insertion for charged residues that are low, e.g., a few kcals for arginine. In contrast, a number of biophysical simulation studies have predicted that the bilayer interior is close to a pure hydrophobic environment with large penalties for hydrophilic amino acids—and yet the experimental scales do significantly better at predicting actual membrane proteins from sequence. Here, we have systematically studied the dependence of the free energy profiles on lipid properties, including tail length, saturation, headgroup hydrogen bond strength, and charge, both to see to whether the in vivo insertion can be explained in whole or part from lipid composition of the endoplasmic reticulum (ER) membranes, and if the solvation properties can help interpret how protein function depends on the lipids. We find that lipid charge is important to stabilize charged amino acids inside the bilayer (with implications, e.g., for ion channels), that thicker bilayers have higher solvation costs for hydrophilic side chains, and that headgroup hydrogen bond strength determines how adaptive the lipids are as a hydrophobic/hydrophilic solvent. None of the different free energy profiles are even close to the low apparent in vivo insertion cost, which suggests that regardless of the specific ER membrane composition the current experimental results cannot be explained by normal lipid-type variation.

Johansson, Anna C. V.; Lindahl, Erik

2009-05-01

410

Surface roughness of flowable resin composites eroded by acidic and alcoholic drinks  

PubMed Central

Aim: The aim of this study is to evaluate the surface roughness of four flowable resin composites following exposure to acidic and alcoholic drinks. Materials and Methods: SureFil SDR flow, TetricEvoFlow, Esthet-X Flow and Amaris Flow HT samples were immersed in artificial saliva, Coca Cola and Chivas Regal Whisky. Each specimen was examined using a Leica DCM 3D microscope: Arithmetical mean height of the surface profiles was measured (Sa). Results: Kruskal-Wallis test showed significant differences among various groups (P<0,001). Mann Whitney test was applied and control groups showed significantly lower Sa values than other groups (P=0,008). Coca Cola groups showed highest Sa values (P<0,021). No significant differences (P=0,14) in surface texture were found among the specimens of the different materials. No significant differences were found among TetricEvoFlow, Esthet-X Flow and Amaris Flow under control conditions nor after Coca Cola application. Under control condition and after Coca Cola application SureFil SDR flow showed significantly higher Sa values. Moreover, after whisky application Amaris Flow showed significantly lower Sa values then the other three groups that showed no significant differences among them. Conclusions: Acidic and alcoholic drinks eroded the surface roughness of all evaluated flowable resin composites. PMID:22557811

Poggio, Claudio; Dagna, Alberto; Chiesa, Marco; Colombo, Marco; Scribante, Andrea

2012-01-01

411

High-resolution food webs based on nitrogen isotopic composition of amino acids  

PubMed Central

Food webs are known to have myriad trophic links between resource and consumer species. While herbivores have well-understood trophic tendencies, the difficulties associated with characterizing the trophic positions of higher-order consumers have remained a major problem in food web ecology. To better understand trophic linkages in food webs, analysis of the stable nitrogen isotopic composition of amino acids has been introduced as a potential means of providing accurate trophic position estimates. In the present study, we employ this method to estimate the trophic positions of 200 free-roaming organisms, representing 39 species in coastal marine (a stony shore) and 38 species in terrestrial (a fruit farm) environments. Based on the trophic positions from the isotopic composition of amino acids, we are able to resolve the trophic structure of these complex food webs. Our approach reveals a high degree of trophic omnivory (i.e., noninteger trophic positions) among carnivorous species such as marine fish and terrestrial hornets.This information not only clarifies the trophic tendencies of species within their respective communities, but also suggests that trophic omnivory may be common in these webs. PMID:25360278

Chikaraishi, Yoshito; Steffan, Shawn A; Ogawa, Nanako O; Ishikawa, Naoto F; Sasaki, Yoko; Tsuchiya, Masashi; Ohkouchi, Naohiko

2014-01-01

412

High-resolution food webs based on nitrogen isotopic composition of amino acids.  

PubMed

Food webs are known to have myriad trophic links between resource and consumer species. While herbivores have well-understood trophic tendencies, the difficulties associated with characterizing the trophic positions of higher-order consumers have remained a major problem in food web ecology. To better understand trophic linkages in food webs, analysis of the stable nitrogen isotopic composition of amino acids has been introduced as a potential means of providing accurate trophic position estimates. In the present study, we employ this method to estimate the trophic positions of 200 free-roaming organisms, representing 39 species in coastal marine (a stony shore) and 38 species in terrestrial (a fruit farm) environments. Based on the trophic positions from the isotopic composition of amino acids, we are able to resolve the trophic structure of these complex food webs. Our approach reveals a high degree of trophic omnivory (i.e., noninteger trophic positions) among carnivorous species such as marine fish and terrestrial hornets.This information not only clarifies the trophic tendencies of species within their respective communities, but also suggests that trophic omnivory may be common in these webs. PMID:25360278

Chikaraishi, Yoshito; Steffan, Shawn A; Ogawa, Nanako O; Ishikawa, Naoto F; Sasaki, Yoko; Tsuchiya, Masashi; Ohkouchi, Naohiko

2014-06-01

413

Fatty Acid Composition of the Muscle Lipids of Five Fish Species in I??kl? and Karacaören Dam Lake, Turkey  

PubMed Central

Total fatty acid composition of muscle lipids in some fish species (Cyprinus carpio (I??kl? Dam Lake), Tinca tinca (I??kl? Dam Lake), Scardinius erythrophthalmus (I??kl? Dam Lake), Cyprinus carpio (Karacaören Dam Lake), and Carassius carassius (Karacaören Dam Lake)) was determined by gas chromatography. Polyunsaturated fatty acids (PUFAs) of Cyprinus carpio (I??kl? Dam Lake) were found higher than PUFA of other species. Palmitic acid was the highest saturated fatty acid (SFA) in Tinca tinca (24.64%). Oleic acid was the highest monounsaturated fatty acid (MUFAs) in Cyprinus carpio (I??kl? Dam Lake) (19.25%). The most abundant polyunsaturated fatty acid in Scardinius erythrophthalmus was docosahexaenoic acid (DHA) (17.94%). Total ?3 fatty acid composition was higher than the total ?6 fatty acids of Cyprinus carpio in both dam lakes. ?3/?6 rates in Cyprinus carpio (I??kl? Dam Lake), Tinca tinca, Scardinius erythrophthalmus, Cyprinus carpio (Karacaören), and Carassius carassius were 2.12, 1.19, 2.15, 2.87, and 2.82, respectively. PMID:25143856

Kalyoncu, Leyla; Kahraman, Oguzhan

2014-01-01

414

Distinctive lipid composition of the copepod Limnocalanus macrurus with a high abundance of polyunsaturated fatty acids.  

PubMed

We studied the copepod Limnocalanus macrurus for seasonal variation in the composition of fatty acids, wax esters and sterols in large boreal lakes, where it occurs as a glacial-relict. Vast wax ester reserves of Limnocalanus were accumulated in a period of only two months, and comprised mono- and polyunsaturated fatty acids (PUFA) and saturated fatty alcohols. In winter, the mobilization of wax esters was selective, and the proportion of long-chain polyunsaturated wax esters declined first. PUFA accounted for >50% of all fatty acids throughout the year reaching up to ca. 65% during late summer and fall. Long-chain PUFA 20:5n-3 and 22:6n-3 together comprised 17-40% of all fatty acids. The rarely reported C24 and C26 very-long-chain PUFA (VLC-PUFA) comprised 6.2 ± 3.4 % of all fatty acids in August and 2.1 ± 1.7% in September. The VLC-PUFA are presumably synthesized by Limnocalanus from shorter chain-length precursors because they were not found in the potential food sources. We hypothesize that these VLC-PUFA help Limnocalanus to maximize lipid reserves when food is abundant. Sterol content of Limnocalanus, consisting ca. 90% of cholesterol, did not show great seasonal variation. As a lipid-rich copepod with high abundance of PUFA, Limnocalanus is excellent quality food for fish. The VLC-PUFA were also detected in planktivorous fish, suggesting that these compounds can be used as a trophic marker indicating feeding on Limnocalanus. PMID:25092258

Hiltunen, Minna; Strandberg, Ursula; Keinänen, Markku; Taipale, Sami; Kankaala, Paula

2014-09-01

415

Genetic determination of fatty acid composition in Spanish Churra sheep milk.  

PubMed

The objective of this study was to estimate the genetic variation of ovine milk fatty acid (FA) composition. We collected 4,100 milk samples in 14 herds from 976 Churra ewes sired mostly by 15 AI rams and analyzed them by gas-liquid chromatography for milk fatty acid composition. The studied traits were 12 individual FA contents (proportion in relation to the total amount of FA), 3 groups of fatty acids [saturated fatty acids (SFA), monounsaturated FA (MUFA), and polyunsaturated FA (PUFA)], and 2 FA ratios (n-6:n-3 and C18:2 cis-9,trans-11:C18:1 trans-11). In addition, percentages of fat and protein and daily milk yield were studied. For the analysis, repeatability animal models were implemented using Bayesian methods. In an initial step, univariate methods were conducted to test the hypothesis of the traits showing additive genetic determination. Deviance information criterion and Bayes factor were employed as model choice criteria. All the studied SFA showed additive genetic variance, but the estimated heritabilities were low. Among unsaturated FA (UFA), only C18:1 trans-11 and C18:2 cis-9,cis-12 showed additive genetic variation, their estimated heritabilities being [marginal posterior mean (marginal posterior SD)] 0.02(0.01) and 0.11(0.04), respectively. For the FA groups, only PUFA showed significant additive genetic variation. None of the studied ratios of FA showed additive genetic variation. In second multitrait analyses, genetic correlations between individual FA and production traits, and between groups of FA and ratios of FA and production traits, were investigated. Positive genetic correlations were estimated among medium-chain SFA, ranging from 0 to 0.85, but this parameter was close to zero between long-chain SFA (C16:0 and C18:0). Between long- and medium-chain SFA, estimated genetic correlations were negative, around -0.6. Among those UFA showing significant additive genetic variance, genetic correlations were close to zero. The estimated genetic correlations among all the investigated FA, milk yield, and fat and protein percentages were not different from zero. Our results suggest that low additive genetic variation is involved in the determination of the FA composition of milk fat in Churra sheep under current production conditions, which results in low values of heritabilities. PMID:20059931

Sánchez, J P; San Primitivo, F; Barbosa, E; Varona, L; de la Fuente, L F

2010-01-01

416

Liquid Chromatography/Mass Spectrometry Methods for Measuring Dipeptide Abundance in Non-Small Cell Lung Cancer  

PubMed Central

RATIONALE Metabolomic profiling is a promising methodology of identifying candidate biomarkers for disease detection and monitoring. Although lung cancer is among the leading causes of cancer-related mortality worldwide, the lung tumor metabolome has not been fully characterized. METHODS We utilized a targeted metabolomic approach to analyze discrete groups of related metabolites. We adopted a dansyl [5-(dimethylamino)-1-napthalene sulfonamide] derivatization with liquid chromatography/ mass spectrometry (LC/MS) to analyze changes of metabolites from paired tumor and normal lung tissues. Identification of dansylated dipeptides was confirmed with synthetic standards. A systematic analysis of retention times (RT) was required to reliably identify isobaric dipeptides. We validated our findings in a separate sample cohort. RESULTS We produced a database of the LC retention time and MS/MS spectra of 361 dansyl dipeptides. Interpretation of the spectra is presented. Using this standard data, we identified a total of 279 dipeptides in lung tumor tissue. The abundance of 90 dipeptides was selectively increased in lung tumor tissue compared to normal tissue. In a second set of validation tissues, 12 dipeptides were selectively increased. CONCLUSIONS A systematic evaluation of certain metabolite classes in lung tumors may identify promising disease-specific metabolites. Our database of all possible dipeptides will facilitate ongoing translational applications of metabolomic profiling as it relates to lung cancer. PMID:23943330

Fitch, William L.; Zheng, Ming; Merritt, Robert E.; Shrager, Joseph B.; Zhang, Weiruo; Dill, David L.; Peltz, Gary; Hoang, Chuong D.

2013-01-01

417

Milk production and composition, milk fatty acid profile, and blood composition of dairy cows fed whole or ground flaxseed in the first half of lactation  

Microsoft Academic Search

A total of 27 multiparous Holstein cows averaging 634kg body weight (BW) were allotted at calving to six groups of four cows and one group of three cows blocked for similar calving dates to determine effects of feeding whole or ground flaxseed on dry matter (DM) intake, milk production, milk composition, milk fatty acid profile and concentration of some blood

H. V. Petit; C. Côrtes

2010-01-01

418

Changes in lipid content, lipid class composition and fatty acid composition of developing eggs and unfed larvae of cod ( Gadus morhua )  

Microsoft Academic Search

Changes in the lipid class and fatty acid composition of developing eggs and unfed larvae of cod (Gadus morhua L.) were studied with the objective of determining probable requirements of cod larvae for dietary lipid. The eggs were collected on 24 March 1985 from holding tanks containing cod which had been caught off the northwest coast of Scotland. Phosphatidylcholine (PC)

A. J. Fraser; J. C. Gamble; J. R. Sargent

1988-01-01

419

Distinct Amino Acid Compositional Requirements for Formation and Maintenance of the [PSI+] Prion in Yeast.  

PubMed

Multiple yeast prions have been identified that result from the structural conversion of proteins into a self-propagating amyloid form. Amyloid-based prion activity in yeast requires a series of discrete steps. First, the prion protein must form an amyloid nucleus that can recruit and structurally convert additional soluble proteins. Subsequently, maintenance of the prion during cell division requires fragmentation of these aggregates to create new heritable propagons. For the Saccharomyces cerevisiae prion protein Sup35, these different activities are encoded by different regions of the Sup35 prion domain. An N-terminal glutamine/asparagine-rich nucleation domain is required for nucleation and fiber growth, while an adjacent oligopeptide repeat domain is largely dispensable for prion nucleation and fiber growth but is required for chaperone-dependent prion maintenance. Although prion activity of glutamine/asparagine-rich proteins is predominantly determined by amino acid composition, the nucleation and oligopeptide repeat domains of Sup35 have distinct compositional requirements. Here, we quantitatively define these compositional requirements in vivo. We show that aromatic residues strongly promote both prion formation and chaperone-dependent prion maintenance. In contrast, nonaromatic hydrophobic residues strongly promote prion formation but inhibit prion propagation. These results provide insight into why some aggregation-prone proteins are unable to propagate as prions. PMID:25547291

MacLea, Kyle S; Paul, Kacy R; Ben-Musa, Zobaida; Waechter, Aubrey; Shattuck, Jenifer E; Gruca, Margaret; Ross, Eric D

2015-03-01

420

Modifications in membrane fatty acid composition of Salmonella typhimurium in response to growth conditions and their effect on heat resistance.  

PubMed

The effects of growth temperature (in the range 10-45 degrees C) and acidification up to pH 4.5 of the culture medium (Brain Heart Infusion, BHI) with different organic acids (acetic, citric and lactic) and hydrochloric acid on membrane fatty acid composition and heat resistance of Salmonella typhimurium CECT 443 were studied. The heat resistance was maximal in cells grown at 45 degrees C (cells grown in non-acidified BHI showed a D58-value of 0.90 min) and decreased with decreasing growth temperature up to 10 degrees C (D58-value of 0.09 min). The growth of cells in acidified media caused an increase in their heat resistance. In general, acid adapted cells showed D-values of between 1.5 and 2 times higher than the corresponding for non-acid adapted control cells. This cross-protection response, which has important implications in food processing, was not dependent on the pH value and the acid used to acidify the growth medium. A membrane adaptation corresponding to an increase in the unsaturated to saturated fatty acids ratio (UFA/SFA) and membrane fluidity was observed at low growth temperature. Moreover, the acidification of the growth medium caused a decrease in UFA/SFA ratio and in the C18:1 relative concentration, and an increase in cyclopropane fatty acids (CFA) content mainly due to the increase in cyc19 relative concentration. Thus, acid adapted cells showed CFA levels 1.5 times higher than non-acid adapted control cells. A significant proportion of unsaturated fatty acids were converted to their cyclopropane derivatives during acid adaptation. These changes in membrane fatty acid composition result in cells with decreased membrane fluidity. A clear relation between membrane fatty acid composition and heat resistance was observed. In general, D-values were maximum for cells with low UFA/SFA ratio, and, consequently, with low membrane fluidity. Moreover, CFA formation played a major role in protecting acid adapted cells from heat inactivation. However, changes observed in membrane fatty acid composition are not enough to explain the great thermotolerance of cells grown at 45 degrees C. Thus, other mechanisms, such as the synthesis of Heat Shock Proteins, could be responsible for this increase in the bacterial heat resistance. PMID:18313782

Alvarez-Ordóñez, Avelino; Fernández, Ana; López, Mercedes; Arenas, Ricardo; Bernardo, Ana

2008-04-30

421

Analysis of the correlation between dipeptides and taste differences among soy sauces by using metabolomics-based component profiling.  

PubMed

Characterizing the relationships between the components and taste differences among soy sauces can help evaluate and improve the quality of soy sauces. Although previous studies have reported that certain taste-active dipeptides, the relationships between taste differences and dipeptides of soy sauces are unknown. Therefore, our objective in this study was to investigate the correlations between the dipeptides and the taste differences among soy sauces. To analyze the dipeptides, we constructed an analytical method using liquid chromatography/tandem mass spectrometry (LC/MS/MS) in multiple reaction monitoring mode. Based on this method, we detected 237 dipeptides, the largest number ever detected in soy sauce research. Next, orthogonal projections to latent structures regressions were performed. The data matrix of components, including dipeptides and other low-molecular-weight hydrophilic components obtained from gas chromatography/mass spectrometry (GC/MS), served as explanatory variables (366 in total), whereas a sensory data matrix obtained using quantitative descriptive analysis served as the response variable. The accuracy of models for the sweetness and saltiness differences constructed using the LC/MS/MS and GC/MS data matrix were higher than did models constructed using only the GC/MS data matrix. As a result of investigation of the correlation between the dipeptides and taste differences among soy sauces by using variable importance in the projection (VIP) score, many dipeptides showed the high correlation with taste differences. Specifically, Ile-Gln, Pro-Lys, Ile-Glu, Thr-Phe, and Leu-Gln showed the high VIP score on sweet differences. This study is the first report that reveals the correlations between the dipeptides and taste differences among soy sauces. PMID:24491915

Yamamoto, Shinya; Shiga, Kazuki; Kodama, Yukako; Imamura, Miho; Uchida, Riichiro; Obata, Akio; Bamba, Takeshi; Fukusaki, Eiichiro

2014-07-01

422

Chromatographic retention and thermodynamics of adsorption of dipeptides on a chiral crown ether stationary phase.  

PubMed

The enantioselective adsorption of several dipeptides on the crown ether-based stationary phase ChiroSil RCA(+) was studied by means of the linear chromatography method. The retention of analytes was measured with acidified water-methanol mobile phases with varied concentration of methanol (from 60 to 90%, v/v) at different temperatures. Thermodynamic characteristics of adsorption were determined and analyzed applying extrathermodynamic relationships. A considerable difference in adsorption mechanisms of dipeptides with a chiral and achiral N-terminal fragment was proved. An explanation to this fact was proposed assuming that the enantiorecognition of the dipeptides of the first type occurred through the interaction of side groups of the N-terminus with the chiral cavity formed by the crown ether ring. The enantiorecognition of the dipeptides of the second type occurs through the interaction of the C-terminal residue with the side groups of the crown ether moiety. The study also demonstrates how extrathermodynamic concepts can be used for obtaining additional information about retention mechanisms from a limited amount of chromatographic data. PMID:21993964

Asnin, Leonid; Sharma, Kavita; Park, Se Won

2011-11-01

423