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  • 1
    ISSN: 1615-6102
    Keywords: Floral binding protein ; Flower development ; Immunocytochemistry ; MADS-box genes ; Ovule ; Transcription factors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary DuringPetunia hybrida seed development, the MADS-box genes encoding the floral binding proteins (FBP) 7 and 11 are expressed in the seed coat and not in the endosperm or embryo. These proteins are thought to function as transcription factors and are essential for ovule formation inPetunia spp. Immunocytochemical methods were used to analyze the distribution of FBP7 and FBP11 after fertilization in wild type and ectopic and cosuppression mutants. During the first nine days of seed development the protein was found in the nuclei of seed coat cells, of both wild-type plants and plants which ectopically expressedFBP11. The signal for FBP7 and -11 proteins diminished during seed development, was first lost in the outer epidermis of the seed coat, then in the endothelium, and finally, at 9 days after pollination (DAP), the protein could not be detected anymore in the parenchyma cells of the seed coat. Although the distribution patterns in wild-type andFBP11 ectopically expressing plants are similar, the latter exhibited higher protein levels. A mild-cosuppression mutant ofFBP7 andFBP11, having only a total of 5%FBP7 and -11 mRNA, showed hardly any FBP7 and -11 proteins. The lack of FBP7 and -11 caused endosperm degeneration in the mutant at a moment when the protein had already decreased to an undetectable level in the wild type and ectopic expression mutant (i.e., at 13 DAP). It is suggested that till about 9 DAP a minimal amount of FBP7 and -11 is needed for the normal functioning of the seed coat during later stages, i.e., for transfer of nutrients to endosperm and embryo. Besides the immunocytochemical data on theFBP7 andFBP11 MADS-box gene products, the morphological analysis of wild type and mutants contributes details on early seed development inPetunia hybrida.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: GE2270A is a novel antibiotic active against Gram-positive bacteria and anaerobes. Its structure originates from a peptidic backbone, the amino acids of which have been modified to produce a macrocycle and a side-chain. It contains a heterocyclic chrornophonc system, a number of thiazoleamino acids and three unmodified natural amino acids. The structure [relative molecular mass (RMM) 1289] was determined using various spectroscopic techniques, of which fast atom bombardment mess spectrometry, gas chromatography/mass spectrometry, desorption chemical ionization mass spectrometry and fast atom bombardment tandem mass spectrometry played an important role. The mass spectrometric approach was applied to the intact molecule and to the various hydrolysis products, including the chromophoric part (RMM 634).
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0951-4198
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: The GE2270 complex consists mainly of GE2270 A (MW 1289), a thiazolyl peptide antibiotic whose structure originates from the modification of a chain of 14 amino acids in a process which creates six thiazole rings and one pyridine. Together with the main component, a number of structurally related molecules are co-produced in small quantities by fermentation. A preparative high-performance liquid chromatrography method was developed to isolate GE2270 factors B1, B2, C1, Ca, C2a, C2b, D1, D2, E and T. Their structures, preliminarily determined by 1H-nuclear magnetic resonance spectroscopy in comparison with GE2270 A, were confirmed by low and high resolution fast-atom bombardment mass spectrometry and studies on the intact molecules and on their main hydrolysis products. Their molecular weights range from 1246 to 1306 Da. The structural differences between the factors lie in the extent of methylation and/or oxidation of thiazole rings (D and E) and asparagine, and in the aromatization of the oxazoline ring.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 17 (1986), S. 23-27 
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The medium-resolution Raman spectrum of benzoic acid vapour has been recorded. Comparison of the high-frequency spectrum with the internal spectra of substituted and similar molecules indicates that previous assignments of the spectra should be revised. Three possible explanations are proposed for the broad feature observed at very low frequencies. Two of them lead to the conclusion that there is a very low barrier for hindered rotation around the C—C bond connecting the carboxylic group with the phenyl ring.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 19 (1988), S. 9-11 
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Low-frequency polarized Raman spectra of an oriented single-crystal sample of phthalic anhydride have been recorded and an assignment of observed frequencies has been made on the basis of lattice normal mode calculation performed in the ‘rigid body’ approximation.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 6 (1977), S. 277-281 
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Raman and infrared spectroscopic studies of benzoic acid dimers and crystals have been made. Molecular and crystal normal modes have been calculated. An assignment of the observed spectra has been proposed and some specific modes discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 11 (1981), S. 143-149 
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The vibrational spectrum of the benzophenone molecule has been studied using Raman spectroscopic techniques. The assignment of the observed bands has been supported by a normal mode calculation. Special attention has been paid to the interpretation of the low-frequency modes.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 21 (1990), S. 169-175 
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Solid terephthalic acid exists in two polymorphic forms with both structures being triclinic. Raman spectroscopic studies have been made in order to recognize the presence of form I and/or form II in the sample.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 7 (1978), S. 31-34 
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The lattice vibrational spectrum of p-nitrotoluene (PNT) single crystals has been studied by Raman and IR spectroscopic techniques. Twenty-one lines have been recorded in the Raman spectrum and nine lines in the far IR spectrum. Calculations of vibrational frequencies have been performed using the rigid molecule approximation. Intermolecular interactions have been described by atom-pair intermolecular potential functions for interatomic distances up to 4.0 Å. An assignment of the observed to the calculated frequencies has been proposed.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 15 (1984), S. 252-256 
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Raman and infrared vibrational spectra have been recorded for o-phthalic acid as a single crystal, as a powder and in solution. The proposed assignment of the observed frequencies was made on the basis of a normal coordinate analysis and symmetry considerations of the crystal spectrum, which allowed the separation of internal vibrations of the A and B species.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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