Showing 1-30 of 34 results for "A2355"
R A Wevers et al.
Clinical chemistry, 41(5), 744-751 (1995-05-01)
This study describes a standardized method for recording single-pulse 1H-nuclear magnetic resonance (1H-NMR) spectra from cerebrospinal fluid (CSF). Quantitative data for alanine, valine, threonine, and lactic acid correlated well with data obtained with conventional techniques. The pH of the samples...
Kailash Manda et al.
Journal of pineal research, 42(4), 386-393 (2007-04-19)
Antioxidant function of melatonin is well established. However, N(1)-acetyl-N(2)-formyl-5-methoxykynuramine (AFMK), a melatonin metabolite is a sparingly investigated biogenic amine, especially in relation to its in vivo antioxidant function. We have evaluated the oxidative damage to biomolecules (DNA, protein and lipid)...
Alexandre Budu et al.
Journal of pineal research, 42(3), 261-266 (2007-03-14)
We previously reported that intraerythrocytic malaria parasites have their development synchronized by melatonin and other products of tryptophan catabolism (i.e. serotonin, N-acetylserotonin and tryptamine). Here, we show that N(1)-acetyl-N(2)-formyl-5-methoxykynuramine (AFMK), a product of melatonin degradation, synchronizes Plasmodium chabaudi and Plasmodium...
S Kastenbauer et al.
Neurology, 58(2), 186-191 (2002-01-24)
To study reactive nitrogen species-mediated oxidative brain damage and antioxidant defenses in patients with acute bacterial meningitis. Nitrotyrosine (a widely used marker for the formation of reactive nitrogen species, such as peroxynitrite) and the lipid peroxidation product 4-hydroxynonenal were detected...
Valdecir F Ximenes et al.
Journal of pineal research, 44(2), 115-120 (2008-02-22)
Accumulating evidence points to relationships between increased production of reactive oxygen or decreased antioxidant protection in schizophrenic patients. Chlorpromazine (CPZ), which remains a benchmark treatment for people with schizophrenia, has been described as a pro-oxidant compound. Because the antioxidant compound...
Valerio Leoni et al.
Clinical chemistry and laboratory medicine, 42(2), 186-191 (2004-04-06)
24S-Hydroxycholesterol (24OHC) and 27-hydroxycholesterol (27OHC) are two structurally similar oxysterols of different origins--the former almost exclusively formed in the brain and the latter formed to a lesser extent in the brain than in most other organs. HYPOTHESIS TO BE TESTED:...
Natalia Fagali et al.
Life sciences, 81(4), 299-305 (2007-07-03)
The lipid peroxidation of triglycerides enriched in polyunsaturated fatty acids was investigated by photoemission techniques and the TBARS assay. Butylated hydroxytoluene, 5-OH-tryptophan and N-acetylserotonin inhibited light emission and TBARS formation in a concentration dependent manner. However, it was enhanced in...
Katinka Seever et al.
Journal of pineal research, 44(4), 450-455 (2008-01-16)
Irradiation of the melatonin metabolite N(1)-acetyl-N(2)-formyl-5-methoxykynuramine (AFMK) with UV light of 254 nm causes the release of carbon monoxide (CO) and, thus, deformylation to N(1)-acetyl-5-methoxykynuramine (AMK). Liberation of CO was demonstrated by reduction of PdCl(2) to metallic palladium, under avoidance...
A Lerche et al.
Acta neurologica Scandinavica, 69(3), 168-175 (1984-03-01)
Cyclic adenosine 3',5'-monophosphate (cAMP) and cyclic guanosine 3',5'-monophosphate (cGMP) were measured in cerebrospinal fluid (CSF) and plasma from 7 patients with bacterial meningitis, 9 patients with serous meningitis, 5 patients with idiopathic polyneuritis and 15 reference patients. A significantly (P...
Márcio Alberto Geihs et al.
General and comparative endocrinology, 166(1), 72-82 (2009-10-13)
In vertebrates, many studies verified different effects of melatonin in the antioxidant defense system (ADS). In crustaceans, few studies have been conducted to verify this possibility. We verified the melatonin effects in the crab Neohelice granulata using low (0.002 and...
Fabrice Collin et al.
Journal of mass spectrometry : JMS, 44(3), 318-329 (2008-11-19)
The hydrogen-deuterium exchange of protonated melatonin and its in vitro oxidation end-products have been examined by liquid chromatography coupled with ion-trap mass spectrometry. Specific H/D scrambling of protons in the C2 and C4 positions of the indole ring during gas-phase...
Igor Semak et al.
Journal of pineal research, 45(4), 515-523 (2008-08-23)
In the present study we provide direct evidence for the involvement of rat microsomal cytochrome P450s in melatonin O-demethylation and hydroxylation at two different positions: 2 and 6, as well as generation of N(1)-acetyl-N(2)-formyl-5-methoxy-kynuramine (AFMK) and two unknown products. Moreover...
Sida Niu et al.
Journal of pineal research, 49(2), 106-114 (2010-06-16)
The interactions of melatonin, a potent endogenous antioxidant, with reactive oxygen species generate several products that include N(1)-acetyl-N(2)-formyl-5-methoxykynuramine (AFMK) and N(1)-acetyl-5-methoxy-kynuramine (AMK). The physiological or pathological significance of AFMK/AMK formation during the process of melatonin metabolism in mammals has not...
Dun-Xian Tan et al.
Journal of pineal research, 42(1), 28-42 (2007-01-03)
Melatonin is a highly conserved molecule. Its presence can be traced back to ancient photosynthetic prokaryotes. A primitive and primary function of melatonin is that it acts as a receptor-independent free radical scavenger and a broad-spectrum antioxidant. The receptor-dependent functions...
Arunachalam Subramanian et al.
NMR in biomedicine, 18(4), 213-225 (2005-01-01)
This article describes proton MR spectroscopic analysis of cerebrospinal fluid of 167 children suffering from meningitis and 24 control cases. Quantification of 12 well-separated and commonly observed cerebrospinal fluid metabolites viz., beta-hydroxybutyrate, lactate, alanine, acetate, acetone, acetoacetate, pyruvate, glutamine, citrate...
Jean A Boutin et al.
Journal of pineal research, 45(4), 524-531 (2008-10-02)
Quinone reductase 2 (QR2, E.C. 1.10.99.2) is implicated in cell reactive oxygen species production. The catalytic activity of this enzyme is inhibited by 1 microM of melatonin. QR2 was identified as the third melatonin binding site (MT3). It is of...
Sueli de Oliveira Silva et al.
Journal of pineal research, 39(3), 302-306 (2005-09-10)
We evaluated the presence of the melatonin metabolite N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK), in cerebrospinal fluid (CSF) of patients with viral meningitis (n = 20) and control samples (n = 8) and correlate AFMK levels with inflammatory markers such as cellularity, protein, tumor...
Ni Ni Than et al.
Redox report : communications in free radical research, 11(1), 15-24 (2006-03-31)
The melatonin metabolite N1-acetyl-5-methoxykynuramine (AMK; 1), which was previously shown to be a potent radical scavenger, was oxidized using the ABTS cation radical [ABTS = 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid)]. Several new oxidation products were obtained, which were separated by repeated chromatography and...
Kailash Manda et al.
Journal of pineal research, 45(4), 430-438 (2008-07-18)
Evaluation of potential health effects from high energy charged particle radiation exposure during long duration space travel is important for the future of manned missions. Cognitive health of an organism is considered to be maintained by the capacity of hippocampal...
Antonio Rodríguez-Núñez et al.
Brain & development, 25(2), 102-106 (2003-02-13)
To determine the effects of meningitis on cerebral energy metabolism, cerebrospinal fluid concentrations of adenosine monophosphate, inosine monophosphate, inosine, adenosine, guanosine, adenine, guanine, hypoxanthine, xanthine and urate were determined by high-performance liquid chromatography, and neuron-specific enolase by an enzyme immunoassay...
Valdecir F Ximenes et al.
Journal of pineal research, 42(3), 291-296 (2007-03-14)
There is a growing body of evidence that melatonin and its oxidation product, N(1)-acetyl-N(2)-formyl-5-methoxykynuramine (AFMK), have anti-inflammatory properties. From a nutritional point of view, the discovery of melatonin in plant tissues emphasizes the importance of its relationship with plant peroxidases....
Glaucia R Martinez et al.
Endocrine, 27(2), 111-118 (2005-10-12)
Many physiologic changes related to light-dark cycles and antioxidant effects have been related to melatonin (N-acetyl-5-methoxytryptamine) and its metabolites, N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK) and N1-acetyl-5-methoxykynuramine (AMK). In this review, we discuss some methodologies, in particular, those employing high-performance liquid chromatography tandem mass...
Deepa S Maharaj et al.
Bioscience reports, 27(6), 299-320 (2007-09-11)
The fact that the full extent of the function of the pineal gland has not yet been elucidated, has stimulated melatonin research worldwide. This review introduces melatonin's mechanism of action, direct and indirect antioxidant actions as well as the antioxidant...
Dun-Xian Tan et al.
FASEB journal : official publication of the Federation of American Societies for Experimental Biology, 21(8), 1724-1729 (2007-02-23)
N1-acetyl-N2-formyl-5-methoxykynuramine (AMFK) is a major metabolite of melatonin in mammals. To investigate whether AFMK exists in plants, an aquatic plant, water hyacinth, was used. To achieve this, LC/MS/MS with a deuterated standard was employed. AFMK was identified in any plant...
Natasa Dragicevic et al.
Journal of pineal research, 51(1), 75-86 (2011-03-02)
Mitochondrial dysfunction is a hallmark of Alzheimer's disease (AD) and is observed in mutant amyloid precursor protein (APP) transgenic mouse models of familial AD. Melatonin is a potent antioxidant, can prevent toxic aggregation of Alzheimer's beta-amyloid (Aβ) peptide and, when...
Valdecir F Ximenes et al.
Journal of pineal research, 49(2), 115-122 (2010-06-16)
Melatonin is widely known for its antioxidant, immunomodulatory, and anti-inflammatory effects. Hypochlorous acid (HOCl) is one example of an endogenous oxidant that is promptly neutralized by melatonin. Melatonin also inhibits myeloperoxidase, the enzyme that catalyzes the oxidation of chloride to...
S O Silva et al.
Journal of neuroimmunology, 156(1-2), 146-152 (2004-10-07)
A growing body of evidence suggests that the pineal hormone, melatonin, has immunomodulatory properties, although very little is known about its effect on leukocytes. Therefore, we aimed to investigate the effect of melatonin and its oxidation product N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK) on...
Sueli de Oliveira Silva et al.
Microbes and infection, 8(2), 420-425 (2005-10-26)
Activated phagocytes oxidize the hormone melatonin to N1-acethyl-N2-formyl-5-methoxykynuramine (AFMK) in a superoxide anion- and myeloperoxidase-dependent reaction. We examined the effect of melatonin, AFMK and its deformylated-product N-acetyl-5-methoxykynuramine (AMK) on the phagocytosis, the microbicidal activity and the production of hypochlorous acid...
Valdecir F Ximenes
Journal of pineal research, 45(3), 297-301 (2008-04-01)
N(1)-acetyl-N(2)-formyl-5-methoxykynuramine (AFMK) is the product of oxidative pyrrole ring cleavage of melatonin. AFMK and its deformylated derivative N(1)-acetyl-5-methoxykynuramine (AMK) are compounds for which there are increasing demands because of their antioxidant, immunomodulatory and anti-inflammatory properties. Here, we sought to determine...
Rüdiger Hardeland et al.
Journal of pineal research, 47(2), 109-126 (2009-07-04)
Kynuramines represent their own class of biogenic amines. They are formed either by decarboxylation of kynurenines or pyrrole ring cleavage of indoleamines. N(2)-formylated compounds formed in this last reaction can be deformylated either enzymatically by arylamine formamidases or hemoperoxidases, or...

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