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  • Photoinduced electron transfer  (5)
  • Intramolecular electron transfer  (3)
  • Basicity  (2)
  • Depression  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Medikamentenindizierter Kopfschmerz (1999)
    Springer
    Der Schmerz 13 (1999), S. 304-314 
    Details
    ISSN: 1432-2129
    Keywords: Schlüsselwörter Medikamenteninduzierter Kopfschmerz ; Serotonin ; Migräne ; Depression ; Angsterkrankungen ; Key words Drug-induced headache ; Serotonin ; Migraine ; Depression ; Anxiety
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The pathogenesis of drug abuse in patients suffering from drug-induced headache is not known in detail. It is unclear whether drug abuse in chronic daily headache should be classified as a form of drug dependence. Current findings concerning the neurobiological correlates of addictive behavior and affective disorders point to the importance of monoaminergic dysregulation, especially a dysfunction of central serotonergic neurotransmission. We reviewed the literature on drug-induced headache and examined hypothetical pathomechanisms of addiction. Drugs causing drug-induced headache such as paracetamol, coffein and ergotamine interfere with behavior patterns or neurotransmitter systems that are also affected by drugs of abuse. Several drugs that ameliorate acute headache interact with central serotonergic neurotransmission and may affect anxiety and depression in patients with chronic daily headache. Non human primate and human studies revealed mechanisms of serotonergic dysfunction in drug dependence, which may also be relevant for drug-abuse in medication-induced headache. Medication-induced dysfunction of monoaminergic, especially serotonergic neurotransmission, may affect drug dependence by exacerbating mood disorders. Further studies are necessary to assess serotonergic neurotransmission in patients with drug-induced headache and abuse of medication.
    Notes: Zusammenfassung Die Pathogenese des Medikamentenmißbrauchs bei chronischen Kopfschmerzen ist weitgehend unbekannt. Es ist unklar, ob es sich um eine typische Abhängigkeitserkrankung handelt und ob sich monoaminerge neurobiologische Störungen nachweisen lassen, die in vergleichbarer Form auch bei anderen Abhängigkeitssyndromen auftreten. Wir analysierten die vorliegende Literatur zu medikamenteninduzierten Kopfschmerzen im Hinblick auf Befunde zu möglichen neurobiologischen Mechanismen der Abhängigkeitsentwicklung. Schmerzmittel, Koffein und Ergotamine verursachen ähnliche Verhaltensauffälligkeiten oder wirken in vergleichbarer Weise auf monoaminerge Neurotransmittersysteme ein wie Suchtsubstanzen. Eigene bildgebende Untersuchungen zeigten eine Assoziation zwischen einer serotonergen Dysfunktion, affektiven Störungen und der Entwicklung abhängigen Verhaltens, die auch für die Entstehung der medikamenteninduzierten Kopfschmerzen relevant sein könnte. Medikamentös induzierte Störungen der monoaminergen, insbesondere der serotonergen Neurotransmission führen möglicherweise deshalb zur Abhängigkeitsentwicklung, weil sie affektive Störungen verstärken. Weitere Studien sind notwendig, um serotonerge Mechanismen der Entstehung und Aufrechterhaltung des Medikamentenmißbrauchs bei medikamenteninduzierten Kopfschmerzen zu überprüfen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004820050237
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  • 2
    Electronic Resource
    Electronic Resource
    Serotonerge Dysfunktion als Folge sozialer Isolation Bedeutung für die Entstehung von Aggression und Alkoholabhängigkeit (1999)
    Springer
    Der Nervenarzt 70 (1999), S. 780-789 
    Details
    ISSN: 1433-0407
    Keywords: Schlüsselwörter Serotonin ; Verhaltensinhibierendes System ; Impulsivität ; Aggression ; Depression ; Key words Serotonin ; Behavior inhibition system ; impulsivity ; Aggression ; Depression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Dysfunction of serotonergic neurotransmission has been associated with two different psychopathological syndromes – impulsive aggressivity resulting form a lack of stimulation of the “behavior inhibition system” on the one hand and the manifestation of clinical depression and compulsive syndromes on the other. The examination of primate behavior provides a model which may reconciliate these seemingly contradictory hypotheses. According to primate experiments, monoaminergic depletion results in anxious and desperate behavior only if the individual has previously been exposed to social isolation stress, which in turn induces a decrease in the central serotonin turnover rate. Young non-human primates who experience early social separation stress are anxious and fearful, while as adults they tend to be aggressive, consume excessive amounts of alcohol and are less intoxicated by alcohol intake. These observation indicate the importance of social separation stress in the pathogenesis of alcoholism and antisocial behavior and may point to prophylactic and pharmacological treatment strategies.
    Notes: Zusammenfassung Eine Dysfunktion serotonerger Transmission wurde mit zwei verschiedenen psychopathologischen Syndromen in Verbindung gebracht. Einerseits wurde der serotonergen Neurotransmission eine wesentliche Rolle in der Stimulation des “verhaltensinhibierenden Systems” zuerkannt und postuliert, daß ein verminderter Serotoninumsatz zur Enthemmung impulsiver und aggressiver Verhaltensweisen führt. Andererseits gibt es Hinweise auf die Bedeutung einer verminderten serotonergen Transmission in der Pathogenese der Depression und der Angsterkrankungen. Eine mögliche Deutung der vordergründig widersprüchlichen Befunde ergibt sich aus der Untersuchung serotonerger Transmission bei Primaten. Eine pharmakogen induzierte Verarmung an monoaminergen Neurotransmittern führt demnach nur dann zu depressionsanalogen Verhaltensweisen, wenn in der individuellen Entwicklung mehrfach Phasen sozialer Isolation durchlebt wurden. Umgekehrt ist soziale Isolation bei jungen Primaten mit einem verminderten Serotoninumsatz, verstärkter Ängstlichkeit und sozialer Inkompetenz assoziiert, während sich bei diesen Primaten im Erwachsenenalter eine erhöhte Aggressivität und Alkoholtoleranz und ein erhöhter freiwilliger Alkoholkonsum nachweisen lassen. Diese Befunde unterstreichen die Bedeutung von Streß- und Lernfaktoren in der Ausgestaltung der psychopathologischen Korrelate einer serotonergen Dysfunktion und verweisen auf mögliche prophylaktische und pharmakologische Behandlungsoptionen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001150050512
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  • 3
    Electronic Resource
    Electronic Resource
    Intramolecular Electron Transfer between 2,5-Dimethoxy-1,4-phenylene Units in [n.n]Paracyclophane Radical Cations (1998)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 139-148 
    Details
    ISSN: 1434-193X
    Keywords: Paracyclophanes ; Cyclic voltammetry ; Radical cations ; ESR/ENDOR spectroscopy ; Intramolecular electron transfer ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A range of [n.n]paracyclophane radical cations (4·+-12·+), in which two 2,5-dimethoxy-1,4-phenylene units are connected by alkano bridges of varying length, have been studied by ESR and ENDOR spectroscopy. In the [2.2]- and [3.3]paracyclophane radical cations 4·+-6·+, 10·+ and 11·+ the delocalization of the unpaired electron over both π-moieties and the distinct difference between the first and second oxidation potentials, ΔE = E20 - E10, are evidence for a strong intramolecular electronic interaction between the two electrophores. The [5.5] and [7.7] species (8·+ and 9·+) are localized radical cations at low temperature (ca. 220 K). At room temperature, the higher molecular flexibility leads to a significant increase in the number of internal collisions between the electrophores, resulting in a fast (ESR time scale) intramolecular electron transfer. The intermediate [4.4]paracyclophane radical cations 7·+ and 12·+ are apparently also localized radical cations. The close interplanar distance between the two π-moieties, however, facilitates their mutual contacts. In 7·+, the intramolecular electron transfer becomes fast on the ESR time scale at room temperature; in 12·+ the transfer is fast over the temperature range 200-300 K.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Isomeric Tetrakis(dimethylamino)naphthalenes: Syntheses, Structure-Dependence of Basicities, Crystal Structures, and Physical Properties (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 1617-1622 
    Details
    ISSN: 1434-193X
    Keywords: Tetrakis(dimethylamino)naphthalenes ; Basicity ; Hydrogen bonds ; Cyclicvoltammetry ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---For comparison to the recently described 2,3,6,7-tetrakis(dimethylamino)naphthalene (1) the three isomers 2,3, and 4 were synthesized. The basicities of this group of isomers are strongly dependent upon the different mutual orientations of the pairs of dimethylamino substituents: only the isomers 3 and, partially, 4, both with dimethylamino groups in adjacent peri-positions of the naphthalene, are strong “proton sponges”. For the isomers 1 and 2 with the same number and kind of twofold dimethylamino substituents in neighbouring ortho-positions, however, no significant basicity increase is observed. To explain this difference between the two groups of isomers it is suggested that in the ortho-pairs of 1 and 2 the C-N bonds diverge considerably, leading to an increased N···N distance and consequently to less stable [N···H···N]+ hydrogen bonds in contrast to the parallel C-N bonds in the peri-substituted isomers 3 and 4. X-ray crystal structure analyses of the bases and of some of the salts derived therefrom were solved and are discussed. Cyclic voltammetry indicates that 1 to 4 are strong electron donors, reacting easily to radical cations or dications which with suitable acids have been obtained as salts.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    [2.2]Paracyclophane-4,7,12,15-tetrone, [2.2](1,4)Naphthalenophane-4,7,14,17-tetrone, and 1,4,8,11-Pentacenetetrone Radical Anions - A Comparative ESR Study (1998)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 221-227 
    Details
    ISSN: 1434-193X
    Keywords: 1,4-Benzoquinones ; [2.2]Paracyclophanes ; 1,4,8,11-Pentacenetetrones ; Cyclic voltammetry ; Radical anions ; ESR/ENDOR spectroscopy ; Intramolecular electron transfer ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Three types of tetrone radical anions in which two 1,4-benzoquinone units are connected by ethano (1·-, 2·-), [2.2]paracyclophane (3·-, 4·-), and anthracene bridges (5·-, 6·-) have been studied by ESR and ENDOR spectroscopy. The displacement of the unpaired electron over the two π moieties in the [2.2]cyclophane radical anions 1·--4·- and the marked difference between the first and second reduction potentials, ΔE = |E20 - E10| ≥ 0.20 V, are evidence for a substantial intramolecular electronic interaction between the two electrophores. Similar ΔE data for the syn- (3) and anti-naphthalenophanes (4) indicate that most of the intramolecular electronic interaction takes place through the [2.2]paracyclophane bridge. When ion pairing is inhibited by complexation of the cation, the unpaired electron in 5·- and 6·- is also delocalized over the whole pentacenetetrone system at temperatures as low as 160 K.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Intramolecular Electron Transfer between Terminal 1,4-Dimethoxybenzene Units in Radical Cations with a [2.2](1,4)Naphthalenophane, [2.2](1,4)Anthracenophane, and Pentacene Skeleton (1998)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 1161-1170 
    Details
    ISSN: 1434-193X
    Keywords: [2.2](1,4)Naphthalenophanes ; [2.2](1,4)Anthracenophane ; Pentacene ; Cyclic voltammetry ; Radical cations ; ESR/ENDOR spectroscopy ; Intramolecular electron transfer ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Various radical cations, in which two terminal 1,4-dimethoxybenzene units are anellated to [2.2]paracyclophane (2b•+, 3b•+), [2.2](1,4)naphthalenophane (4d•+), and anthracene bridges (5•+), have been studied by ESR and ENDOR spectroscopy. In the syn- and anti-naphthalenophane radical cations 2b•+ and 3b•+ the delocalization of the unpaired electron over both π-moieties and the distinct difference between the first and second oxidation potentials, ΔE = E20 - E10, are evidence for a substantial intramolecular electronic interaction between the two electrophores. Extension of the bridge in 4d•+ and 5 by benzo anellation results in a localized radical cation. Strong intramolecular electronic interaction between the two electrophores is found in the 1,4,8,11-tetramethoxy-pentacene radical cation (5•+). The syntheses of 4d are described.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Photoinduced electron transfer in porphyrin-quinone cyclophanes, 5. Quinone-porphyrin-quinone and quinone-porphyrin-donor cyclophanes: Syntheses, structures and electron-transfer-related properties (1992)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 125 (1992), S. 2275-2283 
    Details
    ISSN: 0009-2940
    Keywords: Photosynthesis models ; Photoinduced electron transfer ; Porphyrin-quinone cyclophanes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: To study the structure dependence of photoinduced electron transfer between porphyrins and quinones the concept of a new family of porphyrin-quinone cyclophanes with vertical arrangements of porphyrin and quinone units is presented. The syntheses of the quinone-porphyrin-quinone cyclophane 1, the prototype of this series, and of the quinone-porphyrindonor cyclophanes 12 and 14 are described. Spectroscopic data are discussed with regard to the structures involved and in relation to electron-transfer reactions occurring in these systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19921251016
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  • 8
    Electronic Resource
    Electronic Resource
    Zinc Complexes of Porphyrin-Quinone Cyclophanes: Syntheses, Structures and Electron-Transfer-Related Properties (1994)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 127 (1994), S. 231-236 
    Details
    ISSN: 0009-2940
    Keywords: Zinc porphyrin complexes ; Porphyrin-quinone cyclophanes ; Photoinduced electron transfer ; Electron-transfer mechanism in metalloporphyrin-quinone cyclophanes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In order to increase the driving force for photoinduced electron-transfer reactions of porphyrin-quinone cyclophanes, the zinc complexes 3a-e and 4a-e were prepared from the corresponding cyclophanes of the 1 and 2 series. Electron-transfer-related properties like redox potentials and fluorescence spectra were determined for 3a-e and 4a-e. The X-ray structure analysis of 4a indicates that for the very fast and solvent-independent electron transfer in these systems a specific mechanism involving an interaction of a quinone carbonyl group with the zinc might be considered as an alternative to through-space electron-transfer.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19941270133
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  • 9
    Electronic Resource
    Electronic Resource
    Photoinduced electron transfer in porphyrin-quinone cyclophanes, 6. Porphyrin-quinone cyclophanes with gradually varied acceptor strength: Syntheses and characterizations (1992)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 125 (1992), S. 2285-2301 
    Details
    ISSN: 0009-2940
    Keywords: Porphyrin-quinone cyclophanes ; Photoinduced electron transfer ; Porphyrin cyclophane syntheses ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: For studying intramolecular electron-transfer reactions, three groups of double- and single-bridged porphyrin-quinone cyclophanes 1-4, 5-9, and 11-14, resp., with gradual variation of quinone acceptor strengths were synthesized. As key intermediates for building up the porphyrin-cyclophane skeleton the correspondingly 3,6-substituted 1,4-bis[4-(2-formylphenyl)-butyl]-2,5-dimethoxybenzenes 15-20 were synthesized. Condensation with pyrrole yielded the doubly bridged porphyrin cyclophanes 42-45; via the bis(dipyrrolylmethyl) derivatives 46-51 and 64-67 the single-bridged porphyrin cyclophanes 58-63 and 72-75 were obtained by acidic condensation with triethyl formate. Cleavage of the methoxy groups and oxidation yielded the corresponding porphyrin-quinone systems. Some magnesium and zinc complexes of these cyclophanes are described. Spectroscopic data (MS, 1H NMR) are reported in support of the proposed structures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19921251017
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  • 10
    Electronic Resource
    Electronic Resource
    Syntheses and Properties of New Quinone-Bridged Diphenyl- and Tetraphenylporphyrins (1994)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 127 (1994), S. 223-229 
    Details
    ISSN: 0009-2940
    Keywords: Porphyrin-quinone cyclophanes ; Photoinduced electron transfer ; Absorption and emission spectra of porphyrin-quinone cyclophanes ; Photosynthesis models ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Syntheses and spectroscopic properties of the porphyrin-quinone cyclophanes 1, 2 and 3 of which structural and/or conformational studies have recently reported[1] are described. Physical properties related to photoinduced electron-transfer reactions like redox potentials, absorption and emission spectra were determined for these compounds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19941270132
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