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  • Articles: DFG German National Licenses  (6)
  • Synthesis  (4)
  • Key words Bat  (2)
  • 1
    ISSN: 1434-4475
    Keywords: 1-(Dipyrrinon-9-yl)-3-(dipyrrinon-9-ylidene)-propenes ; b-Vinylogous verdin ; Synthesis ; Spectroscopy ; Protonation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung 1-(Dipyrrinon-9-yl)-3-(dipyrrinon-9-yliden)-propen, einb-vinyloges Verdin, wurde durch Kondensation von 3-(Dipyrrinon-9-yl)-propenal mit einem in Position 9 unsubstituierten Dipyrrinon dargestellt. Kondensation des Letzteren mit Dimedon oder Quadratsäure lieferte vinyloge Pigmente, welche in ihren konfigurationellen und konformationellen Freiheiten eingeschränkt sind. Die chemischen und spektroskopischen Eigenschaften dieser neuen Systeme werden diskutiert.
    Notes: Summary 1-(Dipyrrinon-9-yl)-3-(dipyrrinon-9-ylidene)-propene, ab-vinylogous verdin, was synthesized by condensation of 3-(dipyrrinon-9-yl)-propenal with a dipyrrinone unsubstituted in position 9. By condensing the latter with dimedone or squaric acid,b-vinylogous verdin pigments with restricted configurational and conformational degrees of freedom were obtained. The chemical and spectroscopic properties of these novel systems are discussed.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Monatshefte für Chemie 126 (1995), S. 1323-1329 
    ISSN: 1434-4475
    Keywords: 1,4-bis-(Dipyrrinone-9-ylidene)-1,3-butene ; Dipyrrinone ; b-homo-Verdin ; Synthesis ; Spectroscopy ; Protonation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung 1,4-bis-(Dipyrrinon-9-yliden)-buten-2, ein verdinoides, in Position 10 extendiertes System, wurde durch Kondensation eines in Position 9 unsubstituierten Dipyrrinons mit 2,5-Dihydro-2,5-dimethoxy-furan oder 2,5-Dimethoxy-tetrahydrofuran synthetisiert. Die chemischen und spektroskopischen Eigenschaften dieses neuen chromophoren Systems werden diskutiert.
    Notes: Summary 1,4-bis-(Dipyrrinone-9-ylidene)-butene-2, a verdinoid system extended at C-10, was synthesized by condensing a dipyrrinone unsubstituted in position 9 with 2,5-dihydro-2,5-dimethoxyfuran or 2,5-dimethoxy-tetrahydrofuran. The chemical and spectroscopic properties of this novel chromophoric system are discussed.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Monatshefte für Chemie 127 (1996), S. 69-75 
    ISSN: 1434-4475
    Keywords: 1,2-bis-(1-Iodo-dipyrrin)-ethane ; Porphyrin ; Corrphycene ; Synthesis ; Ullmann coupling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Durch Kupfer katalysierte intramolekulare Kupplung der leicht zugänglichen 1,2-bis-(1-Iod-dipyrrin-9-yl)-ethane und anschließende Demetallierung der gebildeten Kupferkomplexe ergibt Corrphycene in Gesamtausbeuten von fast 40%.
    Notes: Summary By means of copper catalyzed intramolecular coupling of the easily accessible 1,2-bis-(1-iodo-dipyrrin-9-yl)-ethanes and subsequent demetallation of the intermediate copper complexes corrphycenes could be prepared in nearly 40% overall yields.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1434-4475
    Keywords: 1-(Dipyrrinon-9-yl)-3-(dipyrrinon-9-ylidene)-propene ; b-Vinylogous verdin ; Synthesis ; Spectroscopy ; Protonation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Durch Kondensation eines Dipyrrinon-9-yl-acroleins mit einem in Position 9 unsubstituierten Dipyrrinon wurde ein unsymmetrischesb-vinyloges verdinoides Pigment dargestellt. Die Konfiguration dieses Moleküls wurde mit Hilfe von 2D-1H-NMR-Experimenten in Lösungen von und Dimethylsulfoxid als (4Z,10E,12Z,17Z) abgeleitet; seine Konformation konnte zu 5syn,9syn,11anti,16syn festgelegt werden. Die ausgeprägte Solvatochromie dieses Moleküls mit cyclisch helikaler Geometrie konnte auf solvensinduzierte konformative Veränderungen zurückgeführt werden.
    Notes: Summary By condensing a dipyrrinon-9-yl-acrolein with a dipyrrinone unsubstituted in position 9, an unsymmetricb-vinylogous verdinoid pigment was prepared. The configuration of this molecule was elucidated by means of 2D1H NMR experiments to be (4Z,10E,12Z,17Z) in solutions of chloroform and dimethylsulfoxide, and its conformation was derived to be 5syn,9syn,11anti,16syn. The pronounced solvatochromic effect of this molecule with a cyclic helical geometry could be explained by solvent induced conformational changes.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 181 (1997), S. 591-597 
    ISSN: 1432-1351
    Keywords: Key words Bat ; Columnar organization ; Binaural representation ; Frequency representation ; Primary auditory cortex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract This study examines the binaural and frequency representation in the primary auditory cortex (AC) of the big brown bat, Eptesicus fuscus, by using an ear-phone stimulation system. All 306 cortical neurons studied were excited by contralateral sound stimulation but they were either excited, inhibited or not affected by ipsilateral sound stimulation. These cortical neurons were columnarly organized according to their binaural and frequency-tuning properties. The excitation-excitation columns which occupy about 15% of the AC are mainly aggregated within an oval-shaped area of the central AC. The excitation-inhibition neurons and binaural neurons with mixed properties are distributed in the remaining 85% of the surrounding primary AC. Although the best frequency (BF) of these neurons shows a tendency to decrease from high to low along the anteroposterior axis of the primary AC, systematic variation in BF is not always consistent across the entire mapping area. In particular, BFs of cortical neurons isolated in the anterior AC vary quite unsystematically such that neurons with similar BFs are aggregated in isolated patches. Isofrequency and binaural columns are segregated into bands that intersect each other.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 183 (1998), S. 683-697 
    ISSN: 1432-1351
    Keywords: Key words Bat ; Central auditory sensitivity ; Corticofugal facilitation and inhibition ; Inferior colliculus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Under free-field stimulation conditions, corticofugal regulation of auditory sensitivity of neurons in the central nucleus of the inferior colliculus of the big brown bat, Eptesicus fuscus, was studied by blocking activities of auditory cortical neurons with Lidocaine or by electrical stimulation in auditory cortical neuron recording sites. The corticocollicular pathway regulated the number of impulses, the auditory spatial response areas and the frequency-tuning curves of inferior colliculus neurons through facilitation or inhibition. Corticofugal regulation was most effective at low sound intensity and was dependent upon the time interval between acoustic and electrical stimuli. At optimal interstimulus intervals, inferior colliculus neurons had the smallest number of impulses and the longest response latency during corticofugal inhibition. The opposite effects were observed during corticofugal facilitation. Corticofugal inhibitory latency was longer than corticofugal facilitatory latency. Iontophoretic application of γ-aminobutyric acid and bicuculline to inferior colliculus recording sites produced effects similar to what were observed during corticofugal inhibition and facilitation. We suggest that corticofugal regulation of central auditory sensitivity can provide an animal with a mechanism to regulate acoustic signal processing in the ascending auditory pathway.
    Type of Medium: Electronic Resource
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