Results 161 to 170 of about 1,271 (193)

Proton Transfer Dynamics of Norharman in Organic Solvents

The Journal of Physical Chemistry A, 1997
Excited-state reactions involved in the fluorescence of norharman have been investigated in different binary mixtures of acetic acid with dichloromethane, dioxane, and benzene. Time-resolved fluorescence measurements have revealed the existence of a new species which has not been observed from the steady-state spectra.
D. Reyman, M. H. Viñas, J. M. L. Poyato, A. Pardo   +3 more
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Factors Influencing the Norharman and Harman Contents in Espresso Coffee

Journal of Agricultural and Food Chemistry, 2007
Espresso coffee (EC) brews were analyzed for beta-carboline [norharman (NH) and harman (H)] contents, by RP-HPLC with fluorescence detection. The influence of the coffee species (arabica or robusta), the roast degree, and the brew length was studied.
Rita C, Alves, Susana, Casal, Beatriz P P, Oliveira   +2 more
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Isolation and Characterization of Norharmane from Reticulitermes Termites (Isoptera: Rhinotermitidae)

Journal of Economic Entomology, 2005
The fluorescent alkaloid norharmane has been isolated from Reticulitermes termites and characterized by 1H NMR, UV/Vis, mass spectrometry, and gas chromatography/mass spectrometry. Microcoil 1H NMR spectroscopy allowed spectra to be obtained from mass-limited material, facilitating the identification of norharmane, which is the major component in ...
Matthew S, Siderhurst, David M, James, Christopher D, Rithner, Donald L, Dick, Louis B, Bjostad   +4 more
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Plasma harman and norharman in Parkinson's disease.

Journal of neural transmission. Supplementum, 1996
Several lines of evidence suggest that endogenous and exogenous toxins may play a major role in the pathogenesis of Parkinson's disease (PD). In the brain aromatic beta-carbolines, like harman or norharman, may be formed by cyclization of indoleamines. Because of the structural similarity to MPTP, beta-carbolines have been proposed as endogenous toxins.
W, Kuhn, T, Müller, H, Grosse, H, Rommelspacher   +3 more
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Excited-state acid-base kinetics and equilibria in norharman

The Journal of Physical Chemistry, 1993
Absorption and CW and time-resolved fluorescence measurements were performed to investigate the excited-state acid-base kinetics and equilibria of norharman in aqueous solutions of different pH. Four different excited-state species, namely cation, neutral molecule, anion, and zwitterion, can be distinguished.
Sonja Draxler, Max E. Lippitsch
openaire   +1 more source

Tryptophan: a precursor for the endogenous synthesis of norharman in man

Neuroscience Letters, 2001
We investigated whether in healthy subjects L-tryptophan may serve as a precursor for the endogenous synthesis of the beta-carboline norharman. For this purpose subjects, smokers as well as non-smokers, received 0 or 1.2 g of an oral dose of tryptophan. Smokers started the experiment 2 h after cessation of smoking.
Fekkes, Durk, Tuiten, A, Bom, I, Pepplinkhuizen, L (Lolke)   +3 more
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Light-stable bis(norharmane)silver(I) compounds: Synthesis, characterization and antiproliferative effects in cancer cells

Journal of Inorganic Biochemistry, 2014
Four different-anion Ag(I) compounds with the ligand norharmane (9H-Pyrido[3,4-b]indole; Hnor) and having the general formula [Ag(Hnor)2](anion) (anion=ClO4(-), NO3(-) and BF4(-)) [Ag(Hnor)2(MeCN)](PF6) are reported, and studied in detail regarding their coordination mode and in vitro antiproliferative effects.
Rais Ahmad Khan, Khalid Al-Farhan, Andreia de Almeida, Ali Alsalme, Angela Casini, Mohamed Ghazzali, Jan Reedijk   +6 more
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Harman and norharman induce SOS responses and frameshift mutations in bacteria

Mutation Research Letters, 1988
Norharman and harman, beta-carboline derivatives with comutagenic activity in Salmonella typhimurium, were examined for their activity to induce SOS responses in S. typhimurium using the umu-test and mutations in Escherichia coli. The inducibility of the umuC gene by norharman and harman was assayed by measuring the levels of beta-galactosidase ...
Y, Oda, S, Nakamura, I, Oki
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Neuroactive β-Carbolines Norharman and Harman in Coffee

2015
Coffee is among the highest sources of norharman and harman in the human diet. Their presence in coffee has increased the conflictive and inconclusive list of compounds with possible biological activity in this popular beverage. Because regular coffee consumption has been epidemiologically associated with a reduced risk for Parkinson disease and ...
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Neutral N-Donor Ligands Derived From Norharman

2011
Metal complexes of nitrogen-donor ligands exhibit some of the most interesting stoichiometric and useful catalytic transformations described in the chemical literature. 1H-pyridin-(2E)-ylidene and related N- donor ligands (Figure 1) have been described recently and their coordination chemistry and catalytic chemistry investigated.
R. J. Thatcher, SOLINAS, GAVINO, R. E. Douthwaite   +2 more
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