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  • 1985-1989  (41,782)
  • 1925-1929  (10,411)
  • 1890-1899  (12,616)
  • Chemistry  (64,809)
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  • 1
    Electronic Resource
    Electronic Resource
    Chemistry of high mountain lakes in siliceous chatchments of the Central Eastern Alps (1989)
    Springer
    Aquatic sciences 51 (1989), S. 108-128 
    Details
    ISSN: 1420-9055
    Keywords: Chemistry ; mountain lakes ; silica ; acidity ; sediment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Alpine lakes in siliceous catchments of Tyrol and Carinthia (Austria) show signs of acidification. About 9% of the studied lakes have no alkalinity, more than 20% are below pH 6. About two thirds of all lakes have acid neutralizing capacities below 100 μeq 1−1. In spite of moderate precipitation acidity, some lakes show considerable concentrations of dissolved reactive aluminum during or shortly after snowmelt. High altitude lakes of the Alps are definitely more acidic than high mountain lakes in remote areas. Large differences in water and soil chemistry of nearby situated lakes were attributed to heterogeneities of bedrock geology. Paleolimnological investigations on former pH values of five lakes, based on diatom assemblages in the sediment, showed different developments: recent and past acidification, stable conditions, and alkalinization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00879298
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  • 2
    Electronic Resource
    Electronic Resource
    Structural basis of hierarchical multiple substates of a protein. IV: Rearrangements in atom packing and local deformations (1989)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 5 (1989), S. 125-131 
    Details
    ISSN: 0887-3585
    Keywords: protein conformation ; dynamics ; Monte Carlo simulation ; conformational energy ; minimization ; plastic deformation ; conformational heterogeneity ; hierarchy in dynamics ; trypsin inhibitor ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Differences in atom packing are studied in the minimum energy conformations derived from the record of the Monte Carlo simulation of conformational fluctuation in the native state of a globular protein, bovine pancreatic trypsin inhibitor. It is found that local deformations observed among the minima which are found in the previous paper are accompanied by rearrangement of atom packing. Spatial locations of the local deformations in the three-dimensional folded structure are also studied. It is foundthat the local deformations are distributed in space in several clusters inthe folded structure. The size and location of the clusters characterize the respective fluctuations of the first and the second levels observed in the simulation. In the fluctuations of the first level local deformations, each of which usually involves a few side chains and one main chain local segment, are thermally exited independently of each other near thesurface of the molecule. The observed fluctuation of the second level involves a cooperative deformation involving many side chains and local main chain segments all in one cluster, which goes though the core of the molecule. The collective local deformations observed both in the first and second levels are plastic in the sense that they are accompanied with rearrangement of atom packing.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340050206
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  • 3
    Electronic Resource
    Electronic Resource
    Structural principles of α/β barrel proteins: The packing of the interior of the sheet (1989)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 5 (1989), S. 139-148 
    Details
    ISSN: 0887-3585
    Keywords: protein architecture ; packing ; evolutionary relationships ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: α/β barrel structures very similar to that first observed in triose phosphate isomerase are now known to occur in 14 enzymes. To understand the origin of this fold, we analyzed in three of these proteins the geometry of the eight-stranded β-sheets and the packing of the residues at the center of the barrel. The Packingin thisregion is seen in its simplest form in glycolate oxidase. It consists of 12 residues arranged in three layers. Each layer contains four side chains. The packing of RubisCO and TIM can be understood in terms of distortions of this simple pattern, caused by residues with small side chains at someof the positions inside the barrel. Two classes of packing are found. In one class, to which RubisCO and TIM belong, the central layer is formed by a residue from the first, third, fifth, and seventh strands; the upper and lower layers are formed by residues fromthe second, fourth, sixth, and eighth strands. In the second class, to which GAO belongs, this is reversed: it is side chains from the even-numbered strands that form the central layer, and side chains from the oddnumbered strands that form the outer layers. Our results suggest that not all proteins with this fold are related by evolution, but that they represent a common favorable solution to the structural problems involved in the creation of a closed β barrel.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340050208
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  • 4
    Electronic Resource
    Electronic Resource
    Rebuilding flavodoxin from Cα coordinates: A test study (1989)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 5 (1989), S. 170-182 
    Details
    ISSN: 0887-3585
    Keywords: modeling ; flavodoxin ; structure prediction ; side chains ; database ; structure analysis ; protein ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The tertiary structure of flavodoxin has been model build from only the X-ray crystallographic α-carbon coordinates. Main-Chain atoms were generated from a dictionary of backbone structures. Side-chain conformations were initially set according to observed statistical distributions, clashes were resolved with reference to other knowledge-based parameters, and finally, energy minimization was applied. The RMSD of the model was 1.7 Å across all atoms to the native structure. Regular secondary structural elements were modeledmore accurately than other regions. About 40%of the ξ1 torsional angles were modeled correctly. Packing of side chains in the core was energetically stable but diverged significantly from the native structure in some regions.The modeling of protein structures is increasing in popularity but relatively few checks have been applied to determine the accuracy of the approach. In this work a variety of parameters have been examined. It was found that close contact, and hydrogen-bonding patterns could identifypoorly packed residues. These tests, however, did not indicate which residues had a conformation different from the native structure or how to move such residues to bring them into agreement. To assist in the modeling of interacting side chains a database of known interactions has been prepared.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340050212
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  • 5
    Electronic Resource
    Electronic Resource
    The 15 N-terminal amino acids of hexokinase II are not required for in vivo function: Analysis of a truncated form of hexokinase II in Saccharomyces cerevisiae (1989)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 5 (1989), S. 218-223 
    Details
    ISSN: 0887-3585
    Keywords: yeast hexokinase II ; dimerization ; in vivo functions ; glucose repression ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The function of the N-terminal amino acids of Saccharomyces cerevisiae hexokinase II was studied in vivo using strains producing a form of hexokinase II lacking its first 15 amino acids (short form).This short form of hexokinase II was produced from a fusion between the promoter region of the PGK1 gene and the HXK2 coding sequence except the first 15 codons. As expected, the in vitro analysis of the short from protein by gel filtration chromatography indicates that the short protein does not form dimers under conditions where the wild-type protein dimerizes. Kinetic studies show that the enzymatic activities are very similarto wild-type behavior. The physiological experiments performed on the strains containing the fusion allele demonstrate that the short form ofthe enzyme is similar to the wild-type both in terms of phosphorylation of hexoses and glucose repression. We conclude that the N-terminalamino acids of hexokinase II are not required in vivo either for phosporylation of hexoses or for glucose repression.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340050305
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  • 6
    Electronic Resource
    Electronic Resource
    The structure of aconitase (1989)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 5 (1989), S. 289-312 
    Details
    ISSN: 0887-3585
    Keywords: aconitase ; iron-sulfur enzyme ; crystal structure ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The crystal structure of the 80,000 Da Fe—S enzyme aconitase has been solved and refined at 2.1 Å resolution. The protein contains four domains; the first three from the N-terminus are closely associated around the [3Fe-4S] cluster with all three cysteine ligands to the cluster being provided by the third domain. Associationof the larger C-terminal domain with the first three domains createsan extensive cleft leading to the Fe—S cluster. Residues from all four domains contribute to the active site region, which is defined by the Fe—S cluster and a bound SO42-ion. This region of the structure contains 4 Arg, 3 His, 3 Ser, 2 Asp, 1 Glu, 3 Asn, and 1 Gln residues, as well asseveral bound water molecules. Three of these side chains reside on a threeturn 310 helix in the first domain. The SO42-ion is bound 9.3 Å from the center of the [3Fe-4S] cluster by the side chains of 2 Arg and 1 Gln rsidues. Each of 3 His side chains in the putative active site is paired with Asp or Glu side chains.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340050406
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  • 7
    Electronic Resource
    Electronic Resource
    Three-dimensional structure of a fluorescein-Fab complex crystallized in 2-methyl-2,4-pentanediol (1989)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 5 (1989), S. 271-280 
    Details
    ISSN: 0887-3585
    Keywords: antifluorescyl monoclonal antibody ; high-affinity binding site ; effects of MPD on hapten binding ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The crystal structure of a fluorescein-Fab (4-4-20) complex was determined at 2.7 Å resolution by molecularreplacement methods. The starting model was the refined 2.7 Å structure of unliganded Fab from an autoantibody (BV04-01) with specificity for single-stranded DNA. In the 4-4-20 complex fluorescein fits tightly into a relatively deep slot formed by a network of tryptophan and tyrosine side chains. The planar xanthonyl ring of the hapten is accommodated at the bottom of the slot while the phenylcarboxyl group interfaces with solvent. Tyrosine 37 (light chain) and tryptophan 33 (heavy chain) flank the xanthonyl group and tryptophan 101 (light chain) provides the floor of the combining site. Tyrosine 103 (heavy chain) is situated near the phenyl ring of the hapten and tyrosine 102 (heavy chain) forms part of the boundary of the slot. Histidine 31 and arginine 39 of the light chain are located in positions adjacent to the two enolic groups at opposite ends of the xanthonyl ring, and thus account for neutralization of one of two negative charges in the haptenic dianion. Formation of an enol-arginine ion pair in a region of low dielectric constant may account for an incremental increase in affinity of 2-3 orders of magnitude in the 4-4-20 molecules relative to other members of an idiotypic family of monoclonalantifluorescyl antibodies. The phenyl carboxyl group of fluorescein appearsto be hydrogen bonded to the phenolic hydroxyl group of tyrosine 37 of the light chain. A molecule of 2-methyl-2,4-pentanediol (MPD), trapped in the interface of the variable domainsjust below the fluorescein binding site, may be partly responsible for the decrease in affinity for the hapten in MPD.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340050404
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  • 8
    Electronic Resource
    Electronic Resource
    A 3D building blocks approach to analyzing and predicting structure of proteins (1989)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 5 (1989), S. 355-373 
    Details
    ISSN: 0887-3585
    Keywords: protein ; structure ; prediction ; primary ; secondary ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A new approach is introduced for analyzing and ultimately predicting protein structures, defined at the level of Cα coordinates. We analyze hexamers (oligopeptides of six amino acid residues) and show that their structure tends to concentrate in specific clusters rather than vary continuously. Thus, we can use a limited set ofstandard structural building blocks taken from these clusters as representatives of the repertoire of observed hexamers. We demonstrate that protein structures can be approximated by concatenating such building blocks. We have identified about 100 building blocks by applying clustering algorithms, and have shown that they can “replace” about 76% ofall hexamers in well-refined known proteins with an error of less than 1 Å, and can be joined together to cover 99% of the residues. After replacing each hexamer by a standard building block with similar conformation, we can approximately reconstruct the actual structure by smoothly joining the overlapping building blocks into a full protein. The reconstructed structures show, in most cases, high resemblance to the original structure, although using a limited number of building blocks and local criteria of concatenating them is not likely to produce a very precise global match. Since these building blocks reflect, in many cases, some sequence dependency, it may be possible to use the results of this study as a basis for a protein structure prediction procedure.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340050410
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  • 9
    Electronic Resource
    Electronic Resource
    Molecular dynamics simulations of ribonuclease T1: Comparison of the free enzyme and 2′ GMP-enzyme complex (1989)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 6 (1989), S. 20-31 
    Details
    ISSN: 0887-3585
    Keywords: ribonuclease ; active site ; conformational change ; protein-nucleic ; acid interactions ; fluorescence depolarization ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Molecular dynamics simulations were performed on free RNase T1 and the 2′GMP-RNase T1 complex in vacuum and with water in the active site along with crystallographically identified waters, allowing analysis of both active site and overall structural and dynamics changes due to the presence of 2′GMP. Difference in the active site include a closing in the presence of 2′GMP, which is accompanied by a decrease in mobility of active site residues. The functional relevance of the active site fluctuations is discussed. 2′GMP alters the motion of Tyr-45, suggesting a role for that residue in providing a hydrophobic environment for the protein-nucleic acid interactions responsible for the specificity of RNase T1. The presence of 2′GMP causes a structural change of the C-terminus of the α-helix, indicating the transmission of structural changes from the active site through the protein matrix. Overall fluctuations of both the free and 2′GMP enzyme forms are in good agreement with X-ray temperature factors. The motion of Trp-59 is influenced by 2′GMP, indicating difference in enzyme dynamics away from the active site, with the calculated changes following those previously seen in time-resolved fluorescence experiments.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340060103
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  • 10
    Electronic Resource
    Electronic Resource
    Recombinant HIV1 protease secreted by Saccharomyces cerevisiae correctly processes myristylated gag polyprotein (1989)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 6 (1989), S. 324-337 
    Details
    ISSN: 0887-3585
    Keywords: aspartyl protease ; HIV/AIDS ; yeast expression ; polyprotein processing ; α-factor ; secretion ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The protease of the human immunodeficiency virus type I (HIV1) was expressed both intracellularly and extracellularly in Saccharomyces cerevisiae. Intracellular expression of the protease was achieved by fusing a 179 amino acid precursor form of the protease to human superoxide dismutase (hSOD). Self-processing of the viral enzyme from the hybrid precursor was demonstrated to ocur within the yeast host. Secretion of the protease was achieved by fusing the leader sequence of yeast α-factor to the precursor form of the protrease or to the 99 amino acid mature form of the protease. Authentic and active forms of the retroviral enzyme were detected in yeast supernatants of cells expressing the precursor or the mature form of the protease. A D25E active site variant of the retroviral enzyme exhibited diminished autocatalytic activity when expressed intracellularly or secreted from yeast. The wild-type protease was active in an in vitro assay on the natural substrate, myristylated gag precursor, Pr53gag. Correct processing of Pr53gag at the Tyr 138-Pro 139 junction was confirmed by amino terminal sequence analysis of the resulting capsid protein (CA, p24). The secreted protease was purified to homogeneity from yeast media using preparative isoelectric focusing and reverse-phase HPLC. Amino terminal sequence analysis showed a sequence beginning at amino acid 1 of the mature enzyme (Pro) and another sequence beginning at amino acid 6 (Trp). This shorter sequence may represent a natural autolytic product of the proteaseaspartyl protease.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340060315
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  • 11
    Electronic Resource
    Electronic Resource
    Use of restrained molecular dynamics in water to determine three-dimensional protein structure: Prediction of the three-dimensional structure of Ecballium elaterium trypsin inhibitor II (1989)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 6 (1989), S. 405-417 
    Details
    ISSN: 0887-3585
    Keywords: protein tertiary structure ; incorrect and correct folding ; molecular surfaces ; solvation free energy ; solution and crystal structure ; disulfide connectivity determination ; squash inhibitor family ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Refinement of distance geometry (DG) structures of EETI-II (Heitz et al.:Biochemistry 28:2392-2398, 1989), a member of the squash family trypsin inhibitor, have been carried out by restrained molecular dynamics (RMD) in water. The resulting models show better side chain apolar/polar surface ratio and estimated solvation free energy than structures refined “in cacuo.” The consistent lower values of residual NMR constraint violations, apolar/polar surface ration and solvation free energy of one of these refined structures allowed prediction of the 3D folding and disulfide connectivity of EETI-II. Except for the few first residues for which no NMR constraints were available, this computer model fully agree with X-ray structures of CMTI-I (Boe et al.: FEBS Lett. 242:285-292, 1989) and EETI-II complexed with trypsin that appeared after the RMD simulation was completed. Restrained molecular dynamics n water is thus proved to highly valuable for refinement of DG structures Also, the successful use of apolar/polar surface ratio and solvation free energy reinforce the analysis of Novotny et al. (Proteins 4: 19-30, 1988) and shows that these criteria are useful indicators of correct versus misfolded models.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340060407
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  • 12
    Electronic Resource
    Electronic Resource
    Masthead (1989)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 5 (1989) 
    Details
    ISSN: 0887-3585
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340050101
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  • 13
    Electronic Resource
    Electronic Resource
    Comparing short protein substructures by a method based on backbone torsion angles (1989)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 6 (1989), S. 155-167 
    Details
    ISSN: 0887-3585
    Keywords: protein structure comparison ; dihedral angles ; protein conformation ; hemoglobin structure ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: An efficient algorithm was characterized that determines the similarity in main chain conformation between short protein substructures. The algorithm computes Δt, the root mean square difference in φ and ψ torsion angles over a small number of amino acids (typically 3-5). Using this algorithm, large number of protein substrates comparisons were feasible. The parameter Δt was sensitive to variations in local protein conformation, and it correlates with Δr, the root mean square deviation in atomic coordinates. Values for Δt were obtained that define similarity thresholds, which determine whether two substructure are considered structurally similar. To set a lower bound on the similarity threshold, we estimated the component of Δt due to measurement noise fromcomparisons of independently refined coordinates of the same protein. A sample distribution of Δt from nonhomologous protein comparisons identified an upper bound on the similarity threshold, one that refrains from incorporating large numbers of nonmatching comparisons large numbers of nonmatching comparisons. Unlike methods based on Cα atoms alone, Δt was sensitive to rotations in the peptide plane, shown to occur in several proteins. Comparisons of homologus proteins by Δt showed that the active site torsion angles are highly conserved. The Δt method was applied to the α-chain of human hemoglobin, where it readily demonstrated the local differences in the structures of different ligation states.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340060206
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  • 14
    Electronic Resource
    Electronic Resource
    A computer model to dynamically simulate protein folding: Studies with crambin (1989)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 6 (1989), S. 193-209 
    Details
    ISSN: 0887-3585
    Keywords: protein folding ; simulated annealing ; empirical potentials ; Monte Carlo dynamics ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The current work describes a simplified representation of protein structure with uses in the simulation of protein folding. The model assumes that a protein can be represented by a freely rotating rigid chain with a single atom approximately the effect of each side chains. Potentials describing the attraction or repulsion between different types of amino acids are determined directly from the distribution of amino acids in the database of known protein structures. The optimization technique of simulated annealinghas been used to dynamically sample the conformations available to this sample model, allowing the protein to evolve from an extended, random coil into a compact globular structure. Many characteristics expected of true proteins, such as the sequence-dependent formation of secondary structure, the partitioning of hydrophobic residues, and specific disulfide, suggestion the model may accurately simulate the folding process.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340060208
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  • 15
    Electronic Resource
    Electronic Resource
    The carboxyl terminal domain of Escherichia coli DNA topoisomerase I confers higher affinity to DNA (1989)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 6 (1989), S. 249-258 
    Details
    ISSN: 0887-3585
    Keywords: DNA binding domain ; etheno-M13 DNA ; single-stranded DNA affinity chromatography ; proteolytic fragments ; truncated topoisomerase ; protein-DNA interaction ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Limited digestion of E. coli DNA topoisomerase I with trypsin or papain generated a DNA-binding domain of MW 14,000 corresponding to the carboxyl terminal of the enzyme. This fragment binds to single-stranded DNA agarose as tightly as the intact enzyme. It required around 400 mM NaCl for elution. A truncated topoisomerase that lacks this C-terminal domain was purified. It was eluted from the single-stranded DNA agarose column at around 150 mM NaCl. Although the truncated enzyme could relax negatively supercoiled DNA as efficiently as the intact enzyme at low ionic strength, its processivity was more sensitive to increasing salt concentration. Measurement of binding to fluorescent etheno-M13 DNA also demonstrated that the presence of the C-terminal domain confers higher affinity to DNA for the enzyme.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340060307
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  • 16
    Electronic Resource
    Electronic Resource
    Substrate specificities in class A β-lactamases: Preference for penams vs. cephams. The role of residues 237 (1989)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 6 (1989), S. 275-283 
    Details
    ISSN: 0887-3585
    Keywords: mutagenesis ; structure-function relationships ; enzymatic catalysis ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Site saturation mutagenesis has been carried out at Ala-237 in RTEM-1 β-lactamase to assess the role of this site in modulating differences in specificity of β-lactamases for penams vs. cephams as substrates. (An Ala-237 Thr mutation had previously been shown to increase activity on cephems by about 30-80%.1,2) Screening of all 19 possibles mutants on penams and cephems revealed the even more active Ala-237 Asn mutant. Detailed kinnetic analysis showns that this mutant has about four times the activity toward cephalothin and cephalosporin C as the wild-type enzyme. Both mutations reduce the activity toward penams to about 10% that of RETM-1 β-lactamase and lower by about 5°C the tempreature at which the enzyme denatures. Functional properties of the other mutants have also been surveyed. The most intresting aspect of these results is that two quite disparate amino acids, theronine and asparagine, when intorduced for Ala-237, cause such similar changes in enzyme specificity while more similar residues do not alter the catalytic properties of the enzyme to such a significant degree.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340060310
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  • 17
    Electronic Resource
    Electronic Resource
    Axial ligand replacement in horse heart cytochrome c by semisynthesis (1989)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 6 (1989), S. 338-340 
    Details
    ISSN: 0887-3585
    Keywords: cytochrome c ; axial ligand ; semisynthesis ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Semisynthesis has been employed to replace the axial methionine in horse heart cytochrome c with histidine. The reduction potential of the His-80 protein (cyt c-His-80) is 41 mV vs NHE (0.1 M phosphate; pH 7.0; 25°C). The absorption spectra of oxidized and reduced cyt c-His-80 are very similar to those of the native protein in the porphyrin region, but the 695 nm band is absent in the oxidized His-80 protein.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340060316
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  • 18
    Electronic Resource
    Electronic Resource
    Masthead (1989)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 6 (1989) 
    Details
    ISSN: 0887-3585
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340060401
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  • 19
    Electronic Resource
    Electronic Resource
    Deletions and replacements of omega loops in yeast iso-1-cytochrome c (1989)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 6 (1989), S. 372-381 
    Details
    ISSN: 0887-3585
    Keywords: cytochromec ; Saccharomyces cerevisiae ; protein secondary structures ; protein design ; protein engineering ; protein folding ; protein evolution ; modular exchange ; loop swap ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Ω(Omega)-loops are protein secondary structural elements having small distance between segment termini. It should be possible to delete or replace certain of these Ω-loops without greatly distorting the overall structure of the remaining portion of the molecule. Functional requirements of regions of iso-1-cytochrome c from the yeast Saccharomyces cerevisiae were in investigated by determining the biosynthesis and activity in vivo of mutant forms in which four different Ω-loops were individually deleted, or in which one Ω-loop was replaced with five different segments. Deletion encompassing amino acid positions 27-33 and79-83 either prevented synthesis of the holoprotein, or produced highly labile iso-1-cytochromes c, whereas deletions encompassing position 42-45 and 48-55 allowed partial synthesis and activity. These two latter regions, therefore, are not absolutely required for any biosynthetic process such as heme attachment, mitochondrial import, or for enzymatic interactions. All replacements in Loop A (residue position 24-33) with the same size (10 amino acid residues), longer (13 and 15 amino acid residues), or shorter segments (6 amino acid residues), resulted in strains having at least partial levels of iso-1-cytochrome c; however, the relative activities ranged from zero to almost the normal level. Thus, Loop A does not appear to be essential for such biosynthetic steps as heme attachment and mitochondrial import. In contrast, the full range of relative activities suggest that this region interacts with physiological partners to carry out efficient electron transport.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340060404
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    Electronic Resource
    Electronic Resource
    The surface area of monomeric proteins: Significance of power law behavior (1989)
    New York, NY : Wiley-Blackwell
    Proteins: Structure, Function, and Genetics 6 (1989), S. 418-423 
    Details
    ISSN: 0887-3585
    Keywords: accessible area ; power law fit ; bootstrap analyses ; fractal structure ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The coefficients in a power low fit of accessible area versus molecular weight for high-reslution monomeric protein structures are assessed with respect to statistical accuracy using bootstrap analyses, and with respect to physical significance using model systems and the concept of roughness or fractal structure of the protein surface.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prot.340060408
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  • 21
    Electronic Resource
    Electronic Resource
    Effect of collision gas pressure and collision energy on reactions between ammonia and protonated trichothecenes in the collision cell of a triple-quadrupole mass spectrometer (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 116-121 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Low-energy reactive collisions between the protonated molecule of a trichothecene and ammonia inside the collision cell of a triple-stage quadrupole mass spectrometer produce an adduct ion, solvated ions and ions formed by substitution reactions and collisionally activated dissociation (CAD). The collision conditions have an important effect on the relative abundances. Energy- and pressure-resolved curves show that the formation of the adduct ion, substitution ions and solvated ions is favoured by high pressure of ammonia (5-9 mTorr) and low collision energy (0.1-10 eV), while the formation of CAD ions is favoured by high pressure and high energy.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180206
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  • 22
    Electronic Resource
    Electronic Resource
    Characterization of monosaccharide mixtures by low-energy electron impact mass spectrometry (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 145-146 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Qualitative and semi-quantitative analysis of monosaccharide mixtures is explored through low-energy (15 eV) electron impact mass spectrometry of their per-O-acetylated N-(p-nitrophenyl) derivatives with distinctive features on its mass spectra.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180210
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  • 23
    Electronic Resource
    Electronic Resource
    The determination of sulfonated azo dyes in municipal wastewater by ion spray liquid chromatography tandem mass spectrometry (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 233-240 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A liquid-solid extraction method suitable for rapid screening of sulfonated azo dyes in municipal wastewater has been developed. The dyes (Color Index Acid Yellow 23, Red 14 and Yellow 49) were separated on a short, reversedphase liquid chromatographic column with a water-methanol gradient containing 2 mM sulfuric acid. The column effluent was directed via a split-valve to an ion spray liquid chromatography/mass spectrometry (LC/MS) interface to an atmospheric pressure ionization mass spectrometer. The ion spray LC/MS system produced abundant [M - Na]- and [M - 2Na]2- ions according to the number of sulfonic acid substituents. Collision-induced dissociation of the parent ions for the dyes studied gave the SO3-. fragment common to sulfonated compounds plus additional daughter ion fragments characteristic of each dye. The dyes were quantified by monitoring from four to six different daughter ions of each dye. The relative abundances and the sum of the daughter ion current counts were used for confirmation and quantification with external standards. Recoveries of the dyes were in the range of 70-122%, and the relative standard deviation of replicate determinations was 5.4-12%. The method detection limit was three times higher for Acid Yellow 23 compared with the other two dyes, which could be detected down to 50 ppb in municipal wastewater.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180405
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    Electronic Resource
    Electronic Resource
    Forthcoming events (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 279-279 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180411
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  • 25
    Electronic Resource
    Electronic Resource
    Masthead (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989) 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180801
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  • 26
    Electronic Resource
    Electronic Resource
    Strategy for the analysis of cuticular hydrocarbon waxes from insects using gas chromatography/mass spectrometry with electron impact and chemical ionization (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 787-800 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Gas chromatographic/mass spectrometric methods have been developed for the analysis of cuticular hydrocarbon waxes from termites, ants and house flies. A combination of electron impact, chemical ionization with ethylene oxide, methane and ammonia together with methoxy mercuration followed by reductive demercuration, enabled alkane and alkene components of waxes from Reticulitermes termites, Hypoponera eduardi, Camponotus Vagus, and Cataglyphis cursor ants and Calliphora Vomitora house flies to be characterized.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180924
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  • 27
    Electronic Resource
    Electronic Resource
    FAB and tandem mass spectrometry of synthetic neuropeptides and their 2H-labelled analoguesPresented in a preliminary form on the Third International Symposium on The Synthesis and Applications of Isotopically Labelled Compounds, Innsbruck, 1988. (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 836-840 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Fast atom bombardment (FAB) combined with tandem mass spectrometry has been used to verify the amino acid sequence in Org 2766 [H-Met(O2)-Glu-His-Phe-D-Lys-(Phe-OH)] and its deuterated analogues. It is shown that FAB mass spectrometry in addition to the [M + H]+ ion yields dominantly N-terminal sequence ions and some C-terminal sequence ions. These results together permit determination of the amount of deuterium incorporated and the position of the denterated amino acids in the peptide.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180930
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  • 28
    Electronic Resource
    Electronic Resource
    Masthead (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989) 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200181001
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  • 29
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    Packed capillary liquid chromatography/mass spectrometry using a moving belt interfacePresented in part at the American Society for Mass Spectrometry 35th Annual Conference, Denver, 1987 and at the 17th Annual Symposium on the Analytical Chemistry of Pollutants, Jekyll Island, 1987. (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 77-82 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Packed capillary liquid chromatography/mass spectrometry using a moving belt interface is a practical, versatile technique for the identification of unknowns. The low flow rates (1-2 μl min-1) improve the operation of the moving belt and allow direct deposition of eluates from reversed-phase liquid chromatographic columns containing large proportions of water. Column performance and durability is equivalent to that obtained with conventional or microbore liquid chromatographic columns. Techniques have been developed for analyzing dilute solutions with no loss in column performance and for the detection of radiolabeled metabolites. Applications to analyses of polar, thermally labile compounds and environmental samples are presented.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180111
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    Charge-exchange reactions with water in the detection of perfluorocarbons by thermospray liquid chromatography/mass spectrometry (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 106-109 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Perfluorocarbons (PFCs) can be detected by thermospray liquid chromatography/mass spectrometry (LC/MS) only when the system is operated in the negative ion mode with filament on and some water entering the thermospray source. A new mechanism for PFC ionization is proposed, based on studies of LC/MS detection of the perfluorinated forms of cyclohexane, methyl and dimethyl cyclohexane, decalin, 1-methyl decalin and toluene. The ion evaporation mechanism of Dodd, involving pre-ionization of PFCs in the presence of aqueous NH4OAc, is not operative, nor is chemical ionization of PFCs by the reagent ions as in true thermospray LC/MS. Instead, PFC ionization is attributable to the negative ions formed from the water in the source; these ions undergo prompt charge-exchange reactions with the more electronegative PFCs to form structure-retaining PFC ions.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180204
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    Electronic Resource
    Electronic Resource
    Suppression effects in peptide mapping by plasma desorption mass spectrometry (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 131-137 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Suppression effects observed in plasma desorption (PD) mass spectrometry have been studied and compared to those found in fast atom bombardment mass spectrometry. A basic difference in the mechanism of suppression in the two techniques is demonstrated. In positive ion mode PD mass spectrometry, peptides carrying net positive charges are preferentially detected when analysed together with peptides carrying net negative charges, and in negative ion mode PD mass spectrometry, the situation is generally reversed. Based on this complementarity, PD mapping carried out by enzymatic digestion of a nitrocellulose-bound sample can in many cases yield almost complete coverage of smaller proteins.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180208
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  • 32
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    Fast atom bombardment and fast atom bombardment collision-activated dissociation/mass-analysed ion kinetic energy analysis of C-glycosidic flavonoids (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 122-130 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Fast atom bombardment (FAB) mass spectrometry and FAB tandem mass spectrometry in negative mode can provide molecular weight and very useful structural prior information for C-glycosyl flavonoids without derivatization. Diethanolamine or thioglycerol matrix gave an abundant deprotonated molecular ion for all the studied compounds. Mass-analysed ion kinetic energy (MIKE) and collision-activated dissociation/MIKE spectra provide characteristic fragment ions which permit differentiation of the 6- and/or 8-location, and the position of O-glycosylation.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180207
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    Electronic Resource
    Electronic Resource
    Application of megabore capillary gas chromatography/mass spectrometry in the analysis of samples generated by the volatile organic sampling train (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 138-144 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method of analyzing volatile organic sampling train (VOST) samples by megabore capillary gas chromatography/mass spectrometry has been developed to enhance compound resolution and to improve the characterization of products of incomplete combustion in stack emissions. Several analytical systems were evaluated. The combination of components which gave the best overall performance consisted of a clamshell oven used to desorb the Tenax® and/or Tenax®/charcoal VOST cartridges onto an analytical trap in a commercial purge and trap unit. The purge and trap unit thermally desorbed the contents of the analytical trap onto a megabore capillary column installed in a gas chromatograph where the VOST target compounds were characterized and quantified by a computerized mass spectrometer. All VOST target compounds showed response factors with coefficients of variation of less than 25% for triplicate analyses at four concentrations. The time of analysis using the capillary column was 30% faster than the present VOST protocol that requires packed-column gas chromatography.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180209
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    Metabolic studies of explosives 6. Electron impact and chemical ionization mass spectrometry of metabolites of 2,4-dinitrotoluene (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 149-156 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of metabolites of 2,4-dinitrotoluene have been synthesized and analysed by electron impact and chemical ionization mass spectrometry. Identification characteristics of these metabolites by their mass spectra have been determined. Differentiation of isomers is made possible by electron impact ions which are characteristic to the position of the methyl group with regard to the nitro group and to the position of the carboxylic acid group with regard to the nitro group. Metabolites containing an acetyl amino group are characterized by an [M - COCH2]+. electron impact ion.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180302
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    Characterization of seven antihistamines, their N-oxides and related metabolites by fast atom bombardment mass spectrometry and fast atom bombardment tandem mass spectrometry (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 157-167 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We have examined the synthetic N-oxides of five ethylenediamine-type antihistamines using fast atom bombardment (FAB) mass spectrometry and FAB tandem mass spectrometry (MS/MS). Fragmentation of the protonated molecule in the normal and collisionally activated spectra appeared to be characteristic for this class of antihistamine N-oxide. Spectra were also acquired from an ethanolamine and a propylamine antihistamine N-oxide for comparison. These results were very similar to those obtained from biologically produced antihistamine N-oxides, as well as isomeric metabolites, which were readily distinguished from the N-oxides by characteristic fragmentation. In addition, a prominent ion 16 daltons lower in mass, which has been attributed to loss of elemental oxygen from the protonated N-oxide in chemical ionization mass spectral studies, was shown to be a matrix-dependent product of the solution-phase reduction of the antihistamine N-oxide to the parent antihistamine during FAB ionization. These results demonstrate that with a non-reducing matrix such as glycerol, FAB mass spectrometry and FAB MS/MS are excellent methods for the characterization of the non-conjugated antihistamine metabolites such as the N-oxides.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180303
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  • 36
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    Biotransformation of aliphatic formamides: Metabolites of (±)-N-methyl-N-(1-methyl-3,3-diphenylpropyl) formamide in ratsPresented in part at the 35th ASMS Meeting, Denver, Colorado, May 1987. (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 690-701 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The in vivo biliary and urinary metabolites of (±)-N-methyl-N-(1-methyl-3,3-diphenylpropyl) formamide (1) from male Wistar rats have been characterized by gas chromatography/mass spectrometry. In urine, non-conjugated metabolites included 1,1-diphenyl-3-butanone (4) and 3-methylamino-1,1, diphenylbutane (7). β-Glucuronidase liberated 4, 1,1-diphenyl-3-butanol (5), 1,1-diphenyl-3-butanone oxime (6), N-hydroxymethyl-N-(1-methyl-3, 3-diphenylpropyl) formamide (3), 1-(4-hydroxyphenyl)-1-phenyl-3-butanone (11), 1-(4-hydroxyphenyl)-1-phenyl-3-butanone oxime (12), N-methyl-N-(1-methyl-3-(4-hydroxyphenyl)-3-phenylpropyl) formamide (8), 1-(4-hydroxy-3-methoxyphenyl)-1-phenyl-3-butanone (16), 1-(4-hydroxy-3-methoxyphenyl)-1-phenyl-3-butanol (17), 1-(4-hydroxy-3-methoxyphenyl)-1-phenyl-3-butanone oxime (18), N-(1-methyl-3-(4-hydroxy-3-methoxyphenyl)-3-phenylpropyl) formamide (14) and N-methyl-N-(1-methyl-3-(4-hydroxy-3-methoxyphenyl)-3-phenylpropyl) formamide (13). Most of the carbinolamide (3) decomposed in the gas chromatograph inlet to N-(1-methyl-3,3-diphenylpropyl) formamide (2) unless stabilized as a trimethylsilyl (TMS) derivative. In bile, compounds 1, 2, 3, 5, 6, 11, 12 and 16 were present as non-conjugated metabolites. β-Glucuronidase also liberated N-(1-methyl-3-(4-hydroxyphenyl)-3-phenylpropyl) formamide (9), and all of the previously listed compounds except 7. Trimethylsilylation of the conjugated bile fraction revealed the presence of an additional two compunds: N-hydroxymethyl-N-(1-methyl-3-(4-hydroxyphenyl)-3-phenylpropyl) formamide (10) and N-hydroxymethyl-N-(1-methyl-3-(4-hydroxy-3-methoxyphenyl)-3-phenylpropyl) formamide (15). A stable carbinolamide metabolite standard was synthesized and the mass spectral fragmentations of its TMS derivative studied by tandem mass spectroscopy. This is the first report on stable carbinolamide metabolites of high-molecular-weight formamides.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200180908
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    Parent ion spectroscopy in the identification of advanced glycation products (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 713-718 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Advanced glycation products have been investigated by parent ion spectroscopy, employing B2/E = constant linked scans of furoyl ions obtained from hydrolysed glycated albumin and polylysine mixtures, without any extraction procedures. Using such an instrumental approach, together with exact mass measurements and collision spectroscopy, the identification of 2-(2-furoyl)-4-hydroxyl-1H-imidazole and 2-(2-furoyl)-4-carboxy-1H-imidazole among the advanced glycation products has been achieved.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180911
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    Identification of long-chain fatty acids and alcohols from human cerumen by the use of picolinyl and nicotinate esters (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 719-723 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Human cerumen was hydrolysed with base and the constituents were examined as trimethylsilyl (TMS), methyl ester/TMS, picolinyl/TMS and nicotinate/TMS derivatives by gas chromatography and gas chromatography/mass spectrometry. A sample was also reacted with osmium tetroxide for double bond location. The major constituents were cholesterol, squalene and several series of long-chain fatty acids and alcohols. These latter compounds had chain lengths of 12-26 carbon atoms and were predominantly either straight-chain saturated or straight-chain unsaturated compounds. Saturated branched-chain acids with methyl groups predominantly on even-numbered carbon atoms were present but were less abundant. Unsaturated, branched-chain acids were also present. The major unsaturated acids contained unsaturation at the delta-6-position or were derived from these acids by chain elongation. The compounds were similar to those found in vernix caseosa. The mass spectra of picolinyl esters were, for the first time, shown to be capable of determining both the position of unsaturation and methyl branching in the same molecule.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200180912
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    Tandem mass spectrometry of leucine enkephalin and physalaemin using a hybrid instrument (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 727-732 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Daughter ion mass spectral data of [M + H]+ ions of leucine enkephalin and physalaemin, which were formed by fast atom bombardment, were obtained using an instrument of EBQQ configuration. In the case of leucine enkephalin, experiments were carried out in which the collision energy was varied and the collision gas pressure kept constant and vice versa. The results show that conditions can be established under which seuqence-relevant ions above m/z 200 are formed, as well as under which mainly immonium and acylium type ions are generated. Of possible interest for characterization of unknown peptides, when using hybrid instruments, are the mid-chain cleavage ions, which, at a constant argon gas pressure of 5 × 10-6 mbat, were found to maximize at around 30 eV collision energy. Daughter ion mass spectral data are also presented for [M + H]+ ions of physalaemin (mol. wt 1264). Compared to data obtained for physalaemin on multisector instruments, our results indicate that the formation of mid-chain cleavage ions is clearly enhanced.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200180914
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    Characterization of virus infected cell cultures by pyrolysis/direct chemical ionization mass spectrometry (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 757-760 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The supernatants of Vero cell cultures after infection with a herpes simplex virus or a poliomyelitis virus as well as a blank were analysed by pyrolysis/direct chemical ionization mass spectrometry (Py/DCI MS). Informative pyrogrammes were obtained and used for characterization of viral proteins by applying pattern recognition methods. Differentiation of viral proteins was evaluated by analysing ‘blind’ samples. Herpes viruses could be classified correctly but the observed differences between the blank and the polio virus supernatants were too small for reliable classification of the polio viruses. Purification of the samples seems to be a prerequisite for further studies. The potential value of Py/DCI MS as a rapid non-invasive diagnostic method for viral meningoencephalitis is stressed.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180919
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    Fast atom bombardment combined with tandem mass spectrometry for analysis of a complex mixture of lipo-oligopeptides from Nocardia rubra cell wallskeletonPart of the results in this paper have been presented at the 36th ASMS Conference on Mass Spectrometry and Allied Topics, San Francisco, USA, p. 1285 (1988). (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 761-766 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Experimental variables in fast atom bombardment combined with tandem mass spectrometry based on low-energy collision-induced dissociation have been systematically invetigated in order to optimize parameters for analysis of synthetic lipo-oligopeptides. The parameters studied were matrix, ion polarity, collision gas, collision gas pressure and collision energy. The optimal parameters recommended in this study have been applied to the N-terminal amino acid seuquence determination of lipopeptide obtained from Nocardia rubra cell wall skeleton. Daughter and parent ion experiments with negative ion fast atom bombardment combined with tandem mass spectrometry have proven to be very useful for structure elucidation of a complex mixture of lipo-oligopeptides.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200180920
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    The determination of atmospheric bis (chloromethyl) ether by gas chromatography/tandem mass spectrometry (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 775-779 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The technique of gas chromatography/tandem mass spectrometry is applied to the analysis of bis(chloromethyl) ether in laboratory and production environments. A selected reaction monitoring method is shown to yield superior sensitivity and selectivity to previous methods. A detection limit of ∼1 ppt is established even for chemically complex atmospheres which have proved intractable by previous techniques.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200180922
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    Capillary gas-liquid chromatographic/mass spectrometric measurement of plasma acetate content and (2-13C) acetate enrichment (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 816-819 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In studies where (2-13C)acetate is employed as isotopic tracer in vivo, we have reported a selected ion monitoring gas-liquid chromatographic/mass spectrometric method which allows plasma tracer enrichment as well as plasma acetate content to be determined in the same 200-500 μl sample through the use of methacrylic acid as the assay internal standard. For standard solutions in the range equivalent to plasma acetic acid concentrations of 10-200 μM, assay precision was ±4.3%. For plasma samples in the physiological range (approximately 20-300 μM acetate) assay precision averaged better than ±5%. The use of the method is illustrated by measuring acetate turnover in a young adult.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200180927
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    Announcement (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. i 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180402
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  • 45
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    Fast atom bombardment mass spectrometry of some aminoglucoses and glucosamine phosphates and sulphates (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 241-246 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Fast atom bombardment mass spectrometry in combination with collisional activation has been used to investigate a number os amino- and phosphate-substituted glucoses and of phosphate- and sulphate-substituted glucosamines. The collisional activation spectra of the [M - H]- ions readily reveal the presence of sulphate or phosphate substituents, whereas specific fragmentation reactions can be used to distinguish among the various positional isomers. The fragmentation of the pseudomolecular cations depends on the number of Na atoms incorporated. By selecting the appropriate pseudomolecular ion it is possible to get information on the nature and/or position of the substituents.
    Additional Material: 8 Tab.
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    URL: http://dx.doi.org/10.1002/bms.1200180406
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  • 46
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    Capillary zone electrophoresis/tandem mass spectrometry for the determination of sulfonated azo dyes (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 253-257 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Full-scan capillary zone electrophoresis/mass spectrometry and capillary zone electrophoresis/tandem mass spectrometry (CZE/MS/MS) are demonstrated for the determination of monosulfonated and polysulfonated azo dyes at the low picomole levels. Under selected ion monitoring conditions femtomole levels of the dyes are detectable. Ion evaporation via the ion spray liquid chromatography/mass spectrometry interface is a mild form of ionization exhibiting only deprotonated singly charged or poly-deprotonated multiply charged negative molecular ions for sulfonated azo dyes. CZE/MS/MS daughter ion scanning after collision-induced dissociation of the molecular species for all sulfonated azo dyes contained the sulfonate ion (m/z 80). The presence of three sulfonated azo dyes in a wastewater extract was confirmed by parent ion scanning for the sulfonate daughter ion (m/z 80).
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200180408
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  • 47
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    Analysis of platelet activating factor in human saliva by gas chromatography/mass spectrometry (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 258-264 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Platelet activating factor (PAF) bioactivity has been demonstrated in saliva from normal volunteers. We sought structural confirmation and evidence of heterogeneity in the 1-O-alkyl chain of the acetyl glyceryl ether phosphoryl choline (AGEPC) extracted from saliva by employing stable isotope dilution techniques in conjunction with gas chromatography/mass spectrometry. The method described involves removal of the polar phosphocholine moiety, accounts for acetyl group migration, and allows for acylation of the resultant free hydroxyl with pentafluorobenzoyl chloride. Thin-layer chromatography (TLC) purification is undertaken after phospholipase C cleavage and again after pentafluorobenzoyl chloride derivatization. The majority of the ion current is represented in the molecular anion, allowing measurement of 50 pg in biological fluid with a signal-to-noise ratio of ≥9. In one subject with markedly increased salivary PAF levels, we found evidence for molecular heterogeneity of AGEPC with production of not only C16:0 but also C18:0 and C18:1 in the alkyl chain. This technique, by using TLC in lieu of high-performance liquid chromatography, avoids potentially confounding trace contamination effects, produces spectra with few interfering signals and increases sample throughput.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200180409
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    Masthead (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989) 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180501
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  • 49
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    Mass spectral investigations on trichothecene mycotoxins. VIII - thermospray ionization and collisionally activated dissociation of macrocyclic trichothecenes (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 287-300 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Several structurally similar, biologically active macrocyclic trichothecenes were ionized under thermospray conditions followed by collisionally activated dissociation of the ammonium adducts. Most of the observed daughter ions were formed by bond cleavage at the exocyclic ester bridges. Compounds with similar ester bridges formed several common daughter ions and underwent similar neutral losses. Fragmentation pathways proposed for the dissociation of the adducts were confirmed from the corresponding neutral loss spectra. Simple experiments designed for the sequential monitoring of the characteristic daughter ions were used for the rapid, direct and accurate analysis of macrocyclic trichothecenes in real samples. The primary drawback of the method is its inability to distinguish between isomers.
    Additional Material: 11 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200180503
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  • 50
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    Fast atom bombardment mass spectrometry and selective acid hydrolysis for the analysis of partially modified retro-inverso peptide analogues (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 867-871 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Fast atom bombardment (FAB) mass spectrometry has been successfully applied to the analysis of partially modified retro-inverso peptide isomers. The spectra are characterized by abundant protonated molecular ions and also by sequence ions due to fragmentation of the inverted bonds. Unambiguous information, as to the nature and the position in the backbone of the amino acids involved in the partial modification of the structure, are given by using a combination of FAB mass spectrometry and partial, selective acid hydrolysis, without separation of the resulting peptide mixtures.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200181005
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    Practical considerations in the use of stable isotope labelled compounds as tracers in clinical studies (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 321-327 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Increasingly widespread usage of stable isotope tracers to aid clinical diagnosis and support basic research has stemmed from both advances in mass spectrometry and the availability of competitively priced labelled compounds. Stable isotopes have been used generally to investigate normal and abnormal metabolic pathways, to estimate energy expenditure and body composition and to quantitate substrate flux and oxidation rates. Despite the fact that the underlying principles relating to the use of stable isotopes for in vivo studies are straightforward, careful consideration must be given to all aspects of human studies. This review highlights some of these, including choice of label and tracer molecule, mode of tracer administration and sampling site, analytical instrumentation, interpretation of data and ethical constraints.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200180507
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    Masthead (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989) 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180601
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    Forthcoming events (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 358-358 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180512
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    Direct liquid inlet liquid chromatographic/mass spectrometric identification and high-performance liquid chromatographic analysis of a benzodiazepine glucuronide (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 359-362 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The glucuronide of N-1-hydroxy-ethyl flurazepam has been analysed by a direct liquid inlet liquid chromatographic/mass spectrometric system using MeOH/H2O (70:30 v/v) as mobile phase, at a flow rate of 0.7 ml min-1. Urine samples were purified by amberlite XAD-2 chromatography; the glucuronide was quantified by highperformance liquid chromatography using a counterion (tetrabutyl ammonium nitrate in methanol). Chromatographic results were validated by an enzymatic method: treatment of the samples with β-glucuronidase and extraction of the parent drug with ethyl ether at pH 9. The biological application of this method was demonstrated by determination of this glucuronide in the urine of healthy human volunteers following a single intravenous administration of 50 mg of N-1-hydroxy-ethyl flurazepam.
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    URL: http://dx.doi.org/10.1002/bms.1200180602
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    Mass spectrometry of domoic acid, a marine neurotoxinNRCC No. 29369. (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 373-386 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Domoic acid is a naturally occurring amino acid, formerly available in limited amounts as a natural product of some algae of the family Rhodomelaceae. As the result of a recent incidence of toxicity in cultured blue mussels (Mytilus edulis) from a highly localized region of Atlantic Canada, useful amounts of this substance are likely to become available in the near future. Domoic acid is an important substance for fundamental studies in neurobiology as it possesses the highest affinity amongst known substances for the kainate receptors of the central nervous system. The present work describes fast atom bombardment (FAB) mass spectra of domoic acid, and of some of its isomers present in minor quantities in contaminated mussel extracts. These FAB spectra are subject to interferences from beam-inducced reduction reactions associated with matrices such as glycerol, but not with others such as 3-nitrobenzyl alcohol. Tandem mass spectrometry of the MH+ ions from these compounds is also reported. As a more feasible approach to quantitative analysis at trace levels, formation of the volatile tert-butyldimethylsilyl derivatives has been investigated and shown to be highly promising.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200180604
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    Collisional activation mass spectra of M-. ions of azo dyes containing 2-naphthol (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 394-400 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Collisionally activated decomposition mass spectra of M-. ions of azo dyes are presented. The compounds are of general structure Ar(1)—N=N—Ar(2), where Ar(1) is substituted phenyl and Ar(2) is 2-naphthol. Characteristic fragment ions observed include m/z 157, which corresponds to the 2-naphthol substituent with cleavage of the —N=N— bond represented as [Ar(2) - N]-.. Ion of general structure [Ar(1)- NH]- are also observed. Parent ion scans of m/z 157 provide a potential screening technique for 2-naphthol-containing axo dyes. Specific results are reported for the chloroform extract of FD&C Red #8, and capillary gas chromatographic introduction is compared with direct exposure probe introduction for the identification of dyes.
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    URL: http://dx.doi.org/10.1002/bms.1200180606
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    Studies on the biotransformation of ketamine. II - quantitative significance of the N-demethylation pathway in rats in vivo determined by a novel stable isotope technique (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 401-404 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In order to determine the fraction of an intravenous bolus dose of ketamine which is metabolized in vivo to the corresponding N-desmethyl compound, norketamine, a novel stable isotope technique was developed and applied to a study in rats. Co-injection of equimoiar amounts of deuterium-labeled ketamine and unlabeled norketamine to four animals, followed by gas chromatographic/mass spectrometric analysis of both the administered compounds and deuterium-labeled norketamine in plasma yielded pharmacokinetic data from which the fraction of the parent drug subjected to N-demethylation (fm) was calculated from AUC data to be 36.8 ± 2.4%. It is concluded that this stable isotope co-administration technique represents a powerful approach to the determination of fm, in that the pharmacokinetics of the metabolite of interest, given as the preformed compound and generated in vivo, are determined simultaneously. This experimental design thus obviates the influence of time-dependent changes in metabolite clearance which may complicate the interpretation of studies performed using the classical cross-over design.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200180607
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    Profiles in altered metabolism. IV - induction of acute dicarboxylic aciduria following 2-octynoic acid administration to the ratPrevious paper in this series: ‘Profiles in Altered Metabolism III - (Ω-1)-Hydroxyacid Excretion in a Case of Episodic Hypoglycemia’, O. A. Mamer, J. A. Montgomery and E. Colle, Biomed. Mass Spectrom., 7, 53 (1980). (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 416-423 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Rats given 2-octynoic acid by intraperitoneal injection excrete elevated amounts of medium-chain dicarboxylic acids and other acidic metabolites usually associated with human medium-chain acyl-CoA dehydrogenase deficiency. Onset of this organic acid profile is immediate and lasts for approximately 24 h. The induced acidosis in this animal model closely, acutely and transiently resembles the human disorder. The 2-octynoate load is also extensively Ω- and Ψ-oxidized, and evidence is presented for the enzymic hydration of 2-octynoate to 3-ketooctanoic acid.
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    High-sensitivity thermospray ionization mass spectrometry of dyes (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 445-449 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of dyes belonging to different chemical classes have been analyzed by thermospray (TSP) ionization mass spectrometry using a modified source containing a wire-repeller. Detection limits were determined and found to be in the range 0.05-20 ng, which are lower by a factor of 10-400 than previously published results. Positive-ion TSP mass spectra of some sulfonated dyes could be recorded for the first time owing to the increased sensitivity. Losses of SO3Na and 2SO3Na as well as losses of Na and 2Na were observed. The losses of each one of these groups involved replacement by a hydrogen atom.
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    URL: http://dx.doi.org/10.1002/bms.1200180614
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    Masthead (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989) 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180701
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    Identification of point of specific enzymic cleavage of P1,P4-bis(5′-adenosy) tetraphosphate by negative ion FAB mass spectrometry (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 450-452 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200180615
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    Determination of the new aromatic retinoic acid Ro 13-7410 in plasma by two-dimensional gas chromatography negative ion chemical ionization mass spectrometry with selected-ion monitoringDedicated to Professor Dr. Gerhard Spiteller on the occasion of his 60th birthday. (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 453-463 
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    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A highly sensitive and specific method for the determination of the aromatic retinoic acid Ro 13-7410 in plasma at the picogram per millilitre level is described. The method involves extraction of plasma using Extrelut-1 columns, purification of the extract with Bond Elut-NH2 cartridges, derivatization with pentafluorobenzyl bromide, and subsequent analysis by two-dimensional capillary gas chromatography using the zone-cutting technique, stable isotope dilution and selective negative ion monitoring chemical ionization mass spectrometry. A tetradeuterated analogue is used as internal standard. Quantification is possible down to 25 pg/ml using 1 ml of plasma. The coefficients of variation of the method as calculated from quality control samples are 8.5 and 4.2% at the 100 and 400 pg/ml levels. The method has been applied to the analysis of plasma of volunteers following an oral dose of 40 μg Ro 13-7410 and plasma of dogs following an intravenous and oral dose of 25 and 50 μg, respectively.
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    URL: http://dx.doi.org/10.1002/bms.1200180703
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    Identification and determination of tert-alkylphenols in carp from the trenton channel of the Detroit River, Michigan, USA (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 478-483 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Whole carp from the Detroit River were analyzed by gas chromatographic mass spectrometry. Seven tertiary alkyl phenols (tert-pentylphenols, tert-butyl-tert-pentylphenols, a di-tert-pentylphenol and a tri-tert-pentylphenol) and eight chlorinated derivatives of these compounds were identified from their mass spectra and confirmed with synthesized authentic standards. 2,4-Di-tert-pentylphenol was the most abundant of these compounds; in one fish sample, its concentration was about 140 ppm. The same alkyl phenols were also found in technical-grade 2,4-di-tert-pentylphenol, which is manufactured at a chemical plant located near the Detroit River. Comparison of the alkyl phenol levels in carp with those in nearby sediments showed that many of these compounds are taken up by carp and that carp can be used to roughly track local sediment contamination.
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    URL: http://dx.doi.org/10.1002/bms.1200180706
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    Identification of mustard related compounds in aqueous samples by gas chromatography/mass spectrometry (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 484-491 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Capillary column gas chromatography/mass spectrometry, under electron impact and chemical ionization conditions, was used for the detection and identification of mustard and other sulfur vesicant-related decomposition products in a number of aqueous sample extracts. Interpretation of the mass spectral, infrared, chromatographic and trimethylsilyl derivatization data acquired during this study enabled the identification of nineteen sulfur vesicant-related hydrolysis products. Many of the compounds characterized during these analyses, including a number of ether/thioether macrocycles and vinyl alcohols, have either not been previously reported or have not been previously associated with the decomposition of munitions-grade mustard.
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    URL: http://dx.doi.org/10.1002/bms.1200180707
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    Collisional activation mass spectrometry of doubly charged ions from hexachlorobiphenyl isomers (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 507-509 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180711
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  • 66
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    Facile connection of aluminium clad capillary GC columns to a magnetic sector mass spectrometer (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 503-506 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180710
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  • 67
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    Guest editorial (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. ii 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180802
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  • 68
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    Electron impact mass spectrometry of substituted 1,3,8-triazaspiro[4,5]decan-4-ones (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 1000-1004 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The neuroleptic butyrophenone drug spiroperidol (8-[4-fluorophenyl)-(4-oxobutyl]-1-phenyl-1,3,8-triazaspiro[4,5]decan-4-one) and related compounds are valuable tools for mapping the dopamine receptors in the brain. During the development of the radiochemical synthesis of these compounds with very short-lived isotopes suitable for positron emission tomography studies, positive electron impact mass spectrometric information was obtained. Ion series are present in the spectra of all 12 compounds studied, which unambiguously allow recognition of type and site of substitution on the spiro system.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200181108
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  • 69
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    Analysis by fast atom bombardment mass spectrometry of 4,4-dicarboxy-5-(pyridoxyl-5′-phosphate)-proline, of 4-carboxy-5-(pyridoxyl-5′-phosphate)-proline and 4,4-dicarboxy-5-pyridoxylproline (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 995-999 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: γ-Carboxyglutamic acid (Gla) reacts easily and quantitatively with piridoxal-5′-phosphate in H2O at room temperature, to give the 4,4-dicarboxy-5-(pyridoxyl-5′-phosphate)-proline (1). This product has been characterized by fast atom bombardment (FAB) mass spectrometry, including the B/E linked scan technique, ultraviolet and 1H nuclear magnetic resonance (NMR) analysis. In order to support further on the structure of 1, the 4-monodecarboxyderivative (2), obtained by heating compound 1 at 100°C for 30 min and the 5′-dephosphoderivative (3), obtained by enzymatic hydrolysis of 1 with alkaline phosphatase, were also analysed by FAB and 1H NMR techniques. FAB was shown to be the only adequate ionization technique to deal with such thermolabile and non-volatile compounds and could provide an elegant and fast method to detect Gla in biological matrices.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200181107
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  • 70
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    Quantitative determination of arecoline in plasma by gas chromatography chemical ionization mass spectrometry (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 1005-1009 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A capillary gas chromatography/mass spectrometry (GC/MS) method for the quantitative analysis of arecoline in plasma has been developed for concentrations in the range 1-50 ng ml-1. Hexadeuterated arecoline was utilized as the internal standard. The removal of drug from plasma was accomplished by a two-step liquid/liquid extraction procedure involving a wash step followed by extraction with 5% triethyl amine in ethyl acetate. The GC/MS determinations were carried out with temperature-programmed capillary GC and ammonia chemical ionization mass spectrometry. The [M + H]+ ions of both analyte and internal standard were monitored at m/z 156 and 162, respectively. The method is linear and has sufficient sensitivity, precision, accuracy and selectivity for analysis of drug levels in human plasma.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200181109
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  • 71
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    Determination of the new aromatase inhibitor CGS 16 949 in biological fluids by capillary gas chromatography/mass spectrometry (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 558-562 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A specific and sensitive gas chromatographic/mass spectrometric method was developed and validated for the quantitative determination of the aromatase inhibitor CGS 16 949 in plasma and urine. A deuterium-labelled analogue of CGS 16 949 was used as internal standard. The analysis of spiked samples demonstrated the good accuracy and precision of the method. For both plasma and urine, the limit of quantification (LOQ: coefficient of variation (CV) = 10%) and the limit of detection (LOD: CV = 100%) were estimated to be 5 and 1 nmol l-1, respectively. The method was applied to the determination of unchanged CGS 16 949 in plasma and urine of a healthy volunteer orally dosed with 1 mg of CGS 16 949 A.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180808
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  • 72
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    Determination of pipecolic acid in serum or plasma by solid-phase extraction and isotope dilution mass spectrometry (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 566-571 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The determination of pipecolic acid in serum or plasma by positive chemical ionization gas chromatography/mass spectrometry is assessed. This quantitative method involves stable isotope dilution and cation-exchange solid-phase extraction. Several derivatives of pipecolic acid and its octadeuterated analogue were investigated for their mass spectrometric characteristics. The beptafluorobutyric methyl ester derivatives afford optimal resolution on gas chromatography of biological extracts. Moreover, the derivatizing reagent (methanolic HCl) allows a combined elution and derivatization. Selected ion monitoring is performed on the [M + H]+ ions of both analyte and internal standard, at m/z 340 and 348, respectively. Serum or plasma samples from healthy subjects and patients suspected of peroxisomal diseases have been examined.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180810
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  • 73
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    On the use of laser microprobe mass spectrometry for the analysis of organic biomolecules (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 581-591 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Laser microprobe mass spectrometry has been applied to a variety of organic polyfunctional molecules, covering a wide range of polarity and mass spectrometric behaviour. The technique apparently combines desorption under relatively soft conditions with extensive fragmentation and hence allows much structural information from intactly released thermolabiles to be obtained. The mass spectra appear unfamiliar in comparison to conventional techniques. Interpretation is attempted in a purely empirical way by means of the evidence from our database and tentative hypotheses to rationalize the desorption and ionization by laser microbeam irradiation of organic solids. Selected examples are presented to illustrate the potential and limitations of the method in the field of biomolecules, such as pyridoxine and pyridoxal phosphate, nucleosides, nucleotides and related analogues, drugs and the corresponding N-oxides.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180813
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  • 74
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    Differentiation of spruce needles by integrated mass spectra and principal component analysisCharacterization of Plant Materials by Pyrolysis-Field Ionization Mass Spectrometry Part IV; for part I see ref. 11, part II ref. 14 and part III ref. 15. (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 1023-1029 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Spruce needles differing in age and from different trees were analysed by temperature-programmed pyrolysis (Py) field ionization (FI) mass spectrometry. The integrated Py-FI mass spectra are highly reproducible and characteristic. Their information can be used to distinguish the needle samples. The chemical differences between the samples are explained by interpreting the most relevant principal components of the mass spectral data set. The results suggest that Py-FI mass spectra can be used to detect slight changes in plant materials which are due to natural ageing and chemical effects of environmental pollution such as acid rain. It is shown that Py-FI mass spectrometry in combination with pattern recognition techniques is well suited for environmental monitoring.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200181112
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  • 75
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    Forthcoming events (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 1035-1035 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200181114
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  • 76
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    Announcement (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 1036-1036 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200181115
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  • 77
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    Masthead (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989) 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200181201
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  • 78
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    Desorption of ions from rat membranes: Selectivity of different ionization techniques (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 1037-1045 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Complex lipid biomarkers, including phosphatidylcholines, cerebrosides and sulfatides, are shown to be desorbed intact from rat brain myelin and rat liver microsomes by liquid secondary ion mass spectrometry, by plasma desorption and by laser desorption. Different polar lipids are favored by the different desorption techniques and as negative or positive ions. These selectivities support current theories about ionization for the different techniques.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/bms.1200181202
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  • 79
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    Analysis of glycolipids by fast atom bombardment mass spectrometry (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 1046-1050 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The positive and negative ion fast atom bombardment (FAB) mass spectra of four glycolipids obtained from microbial cultures are reported. The spectra of the glycolipids in the positive ion mode are characterized by abundant [M + Na]+, [M + Na + matrix]+ and [M + 2Na - H]+ species. In negative FAB conditions the molecules yield [M - H]-. Our understanding of the FAB behaviour of glycolipids in both positive and negative modes has been considerably aided in the structure elucidation, without any derivatization or degradation reaction of the compounds studied. The technique allows unambiguous molecular weight determination of low-microgram amounts of these glycolipids purified from biological sources and provides useful fragmentation information.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200181203
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  • 80
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    Molecular species analysis of phospholipids by negative ion fast atom bombardment mass spectrometry: Application of surface precipitation technique (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 1051-1056 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Eight phospholipidic classes from bovine brain cortex and soybean were prepared and purified by preparative high-performance and liquid chromatography, and their molecular species were identified by negative ion fast atom bombardment mass spectrometry using the ‘surface precipitation’ method. Its main advantages are: (i) clear-cut and abundant diagnostic ions for structural elucidation of the species; (ii) fragments characteristic of the main fatty acids, the polar head-group and the molecule frame in phospholipids; (iii) less background caused by the liquid matrix.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200181204
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  • 81
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    Metabolism of a thromboxane A2 antagonist in isolated rat hepatocytes (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 1057-1062 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Metabolism of a thromboxane A2 antagonist (±)-5-(Z)-7-(3-endo-phenylsulphonylaminobicyclo[2.2.1]hept-2-exoyl)-heptenoic acid (S-145) in isolated rat hepatocytes was examined by high-performance liquid chromatography and gas chromatography/mass spectrometry. As the hydrophobic metabolites, bis-nor S-145, tetra-nor S-145 and bis-nordihydro S-145 were identified, and two other products were estimated to be monohydroxylated S-145 and dehydrogenated S-145. On the basis of kinetics of S-145 metabolism, a metabolic pathway of S-145 in isolated hepatocytes is tentatively proposed.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200181205
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  • 82
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    Direct detection of organic compounds in water at parts-per-billion levels using a simple membrane probe and a quadrupole ion trap (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 1063-1070 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organic compounds present in aqueous solutions can be analyzed directly using a quadrupole ion trap detector (ITD) when the solution is introduced via a hollow fiber membrane probe. The flow-through configuration used for sample introduction allows the aqueous solution to flow through the capillary membrane tubing while the organic compounds which selectively permeate the membrane are ionized in the ion source. In this mode of operation, the instrument shows high sensitivity. Chemical ionization mass spectra for a set of ten organic compounds of environmental interest were recorded and the ITD/membrane system was found to consistently allow detection of part-per-billion (ppb) levels of these compounds directly from water without any preconcentration. Analysis of well water samples containing ppb to part-per-million levels of organics was demonstrated using the ITD/membrane system. The combination of the membrane probe and ion trap produces a compact, inexpensive, rapid and sensitive system for environmental analysis. The flow-through membrane configuration was also used with a direct insertion probe in a triple quadrupole. Detection limits in the ppb range for organic compounds in water were measured. Detection of particular compounds in complex matrices was demonstrated by detection of 10 ppb 2-methoxypyridine in a fermentation medium using a triple-quadrupole mass spectrometer.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200181206
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  • 83
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    Analysis of cyclodextrins using fast atom bombardment/mass spectrometry and tandem mass spectrometry (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 1071-1078 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The combination of fast atom bombardment/mass spectrometry (FAB/MS) and FAB with tandem mass spectrometry (FAB/MS/MS) was used for the characterization of nearly 30 chemically modified cyclodextrins. Optimum FAB/MS analysis conditions as well as both positive and negative ion FAB data are presented. In addition, FAB/MS and FAB/MS/MS were used to characterize the in vitro reaction products of β-cyclodextrin (βCD) with soman, an organophosphorous nerve agent. The main product identified from the reaction was a covalently bound soman-βCD conjugate.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200181207
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  • 84
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    Collision-induced dissociation mass spectrum of polyamino alcohol derivative of a bacterial lipopeptide (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 1099-1101 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200181211
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  • 85
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    Enhancing the stability of disulfide - bond containing peptides under fast-atom bombardment conditions (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 1102-1104 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200181212
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  • 86
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    Polymerization photoinitiated by carbonyl compounds. VIII. Solvent and photoinitiator concentration effects (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 139-145 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The interaction of benzil and thioxanthone triplets with triethylamine leads to the production of free radicals that are able to initiate the polymerization of methylmethacrylate and vinyl acetate. The process is mediated by a charge transfer complex. The initiation efficiency is higher in benzene than in acetonitrile, a result explained in terms of competition between back electron transfer, production of free ions and ketyl radical formation. The initiation efficiency decreases when the carbonyl concentration increases, because of the occurrence of a radical molecule reaction such as The α-hydroxy radicals produced in this reaction are unable to initiate the polymerization chain.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080270112
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    Poly(enamine-ketones) from hydrogen-terminated aromatic dipropynones and aromatic diamines (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 171-183 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Poly(enamine-ketones) were prepared by the nucleophilic (Michael-type) addition of various aromatic diamines to 1,1′-(1,3- or 1,4-phenylene)bis(2-propyn-1-one)(1,3 or 1,4-PPO) in m-cresol at 5-23°C. The low molecular weight polymers (inherent viscosity of 0.25 dL/g) exhibited limited solubility in organic solvents. Glass transition temperatures were generally undetectable by differential scanning calorimetry while polymer decomposition temperatures (10% weight loss), as measured by thermogravimetric analysis, were observed from 355 to 419°C. Polymers prepared from 1,4-PPO were semi-crystalline as shown by wide-angle X-ray diffraction. The poly(enamine-ketone) structure was confirmed by matching infrared spectral characteristics of the polymers with those of well-characterized model enamine ketones.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080270115
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  • 88
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    Dithiafulvene (1,3-dithiole): Monomers and polymers (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 971-977 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Monomers and polymers of 2-benzylidene-1,3-dithioles (dithiafulvenes) were synthesized. Polymerization of substituted dithiafulvenes with diacid chlorides, p-phenylene diisocyanate, or terephthalaldehyde yielded yellow polymers with inherent viscosities ranging from 0.10 to 0.21 dL/g.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080270320
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  • 89
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    Synthesis of regiospecifically meta-substituted poly(phenylacetylene)s and some of their electrical properties (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 989-997 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The syntheses, characterizations, and electrical properties of four regiospecifically substituted poly(phenylacetylene)s are described. Tungsten(VI) chloride/tetra-n-butyltin (WCl6/n-Bu4Sn) catalyst system (Higashimura-Masuda, H.-M. catalyst) was used to polymerize 3-bromo-, 3-chloro-, 3-trimethylsilyl-, and 3-trimethylstannylphenylacetylenes in order to obtain high-molecular-weight and soluble materials. Characterizations of these polymers were done by IR and UV spectroscopic methods, GPC, DSC, and elemental analysis. The electrical conductivities of the polymers were measured on the surface of pressed pellets by a four-point probe.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080270322
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  • 90
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    Synthesis and characterization of liquid crystalline polymethacrylates, polyacrylates, and polysiloxanes containing 4-methoxy-4′-hydroxy-α-methylstilbene-based mesogenic groups (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 999-1015 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis and characterization of polymethacrylates and polyacrylates containing 4-methoxy-4′-hydroxy-α-methylstilbene side groups attached either directly or through flexible spacers containing eleven, eight, six, three, and respectively two methylenic units, and of the polysiloxanes containing the same mesogenic group connected through flexible spacers containing eleven, eight, six, and respectively three methylenic units are described. All polymers exhibit thermotropic liquid crystallinity. The nature of the mesophase is determined by the spacer length. However, the nature of the polymer backbone determines the thermal stability of the mesophase. That is, for the same spacer length and similar polymer molecular weight, the most flexible polymer backbone leads to the highest isotropization temperature.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080270323
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  • 91
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    Preparation and properties of polyarylates and copolyarylates from phenylindanedicarbonyl chloride and bisphenols (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 979-988 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of polyarylates having inherent viscosities of 0.4-1.1 dL/g was prepared by the two phase polycondensation of 1,1,3-trimethyl-3-(4-chloroformylphenyl)indanecarbonyl chloride with various bisphenols in an organic solvent-aqueous alkaline solution system in the presence of a phase transfer catalyst. Similarly, copolyarylates of high molecular weights were prepared from a mixture of the phenylindanedicarbonyl chloride, terephthaloyl chloride, and 2,2-bis(4-hydroxy-phenyl)propane. All the polyarylates were characterized by their amorphous nature and high solubility in organic solvents. They gave transparent and tough films by the solution casting. The films had tensile strength of 33-46 MPa, elongation at break of 3-16%, and tensile modulus of 1.2-1.6 GPa. These polyarylates had glass transition temperatures in the range of 205-310°C, and began to decompose at ca. 350°C in air.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080270321
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  • 92
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    Binding of butyl orange by poly(2-dimethylaminoethyl methacrylate) and copolymers of 2-dimethylaminoethyl methacrylate and N-vinyl-2-pyrrolidone: Peculiar temperature dependence of the binding (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 555-563 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The temperature dependence of the binding of butyl orange by a homopolymer of 2-dimethylaminoethyl methacrylate (DMAEMA) and copolymers of DMAEMA and N-vinyl-2-pyrrolidone (VPy) has been examined at various pH's. The binding is very much dependent upon the temperature of the system, the pH of the binding medium, and the DMAEMA content in the polymer. In this case maximal binding is obtained at approximately 15-25° in the temperature range measured, although in most cases which have been examined, the degree of binding increases steadily with increasing temperature. This peculiar temperature dependence of the binding becomes more pronounced as the pH and the DMAEMA content are increased. The appearance of the peculiarity is discussed in terms of the pH-induced conformational changes of the polymer and the hydrophobicity of the polymer.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080270215
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  • 93
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    Electronic Resource
    Aspects of degradation and stability of ABS copolymers. I. Effect of β-carotene as antioxidant (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 343-355 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The oxidative degradation of polybutadiene-styrene-acrylonitrile (ABS) copolymer was extensively investigated. Three factors were studied: the influence of ageing temperature on the rate of the oxidation of the copolymer; the efficiency of β-carotene as chain breaking antioxidant; and the effect of butadiene content on the rate of the oxidative degradation of the ABS copolymer.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080270129
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  • 94
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    Electronic Resource
    Interaction of N-partially alkylated poly(4-vinylpyridine) with methyl orange (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 389-392 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080270133
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  • 95
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    Electronic Resource
    Synthesis and characterization of polystyrene-poly(ethylene oxide)-heparin block copolymers (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 397-397 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080270135
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  • 96
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    Catalyzed degradation of poly(vinylchloride). III. Zinc(II) chloride catalysis (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 399-408 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: When PVC films containing zinc(II) chloride were heated in the temperature range 65-95°C, broad absorptions developed in the 250-900 nm region with maxima around 610 nm. The development of the color, the rate of which was proportional to the ZnCl2 content, was preceded by an induction period, the length of which depended on the temperature. The activation energy of the process decreased as the ZnCl2 content of the film increased. Color developments in air and in vacuum were compared.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080270201
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  • 97
    Electronic Resource
    Electronic Resource
    Copolyamides of nylon-4,6 and nylon-4,T (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 423-430 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Copolyamides of nylon-4,6 and nylon-4,T were prepared by a two-step method: (1) a prepolymerization in an autoclave (40 min at 210°C) and (2) a postcondensation in the solid state (4 h, 260°C). On these materials was studied the melting behavior with DSC, the crystalline structure with WAXS, the water absorption, and the mechanical properties with a torsion pendulum. In these copolyamides the order was found to remain high, but the crystalline structures of -4,6 and -4,T were not isomorphous. The torsion moduli increased with -4,T content both at RT and at 140°C.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080270203
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  • 98
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    Electronic Resource
    New polymer syntheses 22. LC-poly(esterimide)s derived from trimellitic acid, ω-amino acids and hydroquinone or 4,4′-dihydroxybiphenyl (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 431-446 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Diacids with variable spacer length were prepared by condensation of trimellitic anhydride and ω-amino acids. From these diacids, homopolyesters were prepared by thermal condensation with the acetates of hydroquinone or 4,4′-dihydroxy biphenyl and a series of copolyesters containing 4-hydroxy benzoic acid. The same LC poly(ester imide)s could also be prepared in a “one-pot procedure” from trimellitic anhydrid, lactams, and bisphenol acetates. The differential scanning calorimetry (DSC) traces of most poly(ester imide)s exhibit two endotherms representing the solid → LC phase transition (Tm1) and the LC phase → isotropic melt transition (Tm2). Observation under the polarizing microscope and wide-angle X-ray scattering (WAXS) measurements suggest that the LC phase formed immediately above the melting points (Tm1) have a smectic character. Poly(ester imide)s of 4,4′-dihydroxybiphenyl possess higher melting points and a broader temperature range of the LC phase than those of hydroquinone. The copolyesters possess a nematic melt over a broad temperature range. Thermomechanical analyses under low pressure (0.05 kg/mm2) gave heat distortion temperatures close to the melting points (Tm1), and under high pressure (1 kg/mm2), values between Tm1 and the glass transition temperatures (Tg). Thermogravimetric measurements indicate that processing from the melt is feasible up to temperatures around 340°C.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080270204
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  • 99
    Electronic Resource
    Electronic Resource
    Water-soluble graft copolymers from macromonomer method (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 1099-1114 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Water-soluble graft copolymers of well-defined structure having hydrophobic polymethacrylate branches with different ester groups were prepared by the macromonomer method. Methacrylate macromonomers of controlled molecular weights having a methacryloyloxyl end group were synthesized by radical polymerization of the corresponding monomer in the presence of thioglycolic acid followed by the reaction of glycidyl methacrylate with the terminal carboxyl group. These macromonomers were copolymerized with methacrylic acid and methyl methacrylate to prepare tailor-made graft copolymers composed of a hydrophlic backbone and different kinds of hydrophobic branches, which were characterized by elemental analysis, NMR, and GPC. The viscosities of the aqueous solutions of the sodium salts of these graft copolymers were measured. It was found that the viscosity of the dilute solution of the graft copolymer was remarkably high compared with the corresponding random copolymer irrespective of the ester group in branch segments. Solubilizing behavior of Orange-OT in aqueous solutions of the graft copolymers and the random copolymer were also investigated to study the nature of the hydrophobic domain of the graft copolymers.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080270401
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  • 100
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    Electronic Resource
    Synthesis and characterization of bigraft copolymers based on grafted type peracid polymer (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 3451-3463 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In this study, a radiation-induced copolymer, namely, polyethylene-g-acrylic acid and EVA-g-acrylic acid, in the form of a membrane, particulate, or tube was used as a substrate. The carboxyl groups of the grafted acrylic chains were oxidized into peracids. Optimal conditions for the oxidation, including the catalyst, reaction time, and temperature were investigated. Novel bigraft copolymers were then synthesized from the grafted polymeric peracid. A third component (e.g., 2-hydroxyethyl methacrylate) was grafted through the decomposition of peracid groups. Abnormality in morphology of the acrylic acid grafted and HEMA bigraft membrane was investigated by SEM and TEM observation, which showed the levelling effect of the third component and manifested a third circular domain generated inside the membrane at high degree of grafting.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080271023
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