Abstract：
:N-[2-(6-methoxyquinazolin-4-yl)-ethyl] acetamide (MQA) is a compound formed from the melatonin metabolite N(1)-acetyl-5-methoxykynuramine (AMK). We followed MQA production in reaction systems containing various putative reaction partners, in the absence and presence of hydrogen peroxide and/or copper(II). Although MQA may be formally described as a condensation product of either N(1)-acetyl-N(2)-formyl-5-methoxykynuramine (AFMK) with ammonia, or AMK with formamide, none of these combinations led to substantial quantities of MQA. However, MQA formation was observed in mixtures containing AMK, hydrogen peroxide, hydrogen carbonate and ammonia, or AMK, hydrogen peroxide, copper(II) and potentially carbamoylating agents, such as potassium cyanate or, more efficiently, carbamoyl phosphate. In the presence of hydrogen peroxide, copper(II) and carbamoyl phosphate, MQA was the major product obtained from AMK, but the omission of copper(II) mainly led to another metabolite, 3-acetamidomethyl-6-methoxycinnolinone (AMMC). This was caused by nitric oxide (NO) generated under oxidative conditions from carbamoyl phosphate, as shown by an NO spin trap. MQA formation with carbamoyl phosphate was not due to the possible decomposition product, formamide. The reaction of AMK with carbamoyl phosphate under oxidative conditions, in which inorganic phosphate and water are released and which differs from the typical process of carbamoylation via isocyanate, may be considered as a new physiological route of MQA formation.
journal_name
J Pineal Resjournal_title
Journal of pineal researchauthors
Kuesel JT,Hardeland R,Pfoertner H,Aeckerle Ndoi
10.1111/j.1600-079X.2009.00723.xsubject
Has Abstractpub_date
2010-01-01 00:00:00pages
47-54issue
1eissn
0742-3098issn
1600-079Xpii
JPI723journal_volume
48pub_type
杂志文章abstract：:To examine the role of melatonin in pathological hyperprolactinemia we compared untreated young females (N = 5) with hyperprolactinemic amenorrhea owing to pituitary microadenoma to healthy female controls (N = 6). Serum samples for melatonin, prolactin, and luteinizing hormone (LH) concentrations were obtained every ...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079x.1996.tb00242.x
更新日期：1996-03-01 00:00:00
abstract：:Melatonin is a powerful antioxidant and free radical scavenger. A large body of in vivo and in vitro evidence shows that melatonin effectively inhibits membrane lipid peroxidation; this damage was based on the measurement of malondialdehyde and/or 4-hydroxynonenal levels. In the current study, for the first time using...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079X.2005.00311.x
更新日期：2006-05-01 00:00:00
abstract：:Light and electron microscopic demonstrations for acid phosphatase (AcPase) activity in the chicken pineal gland were studied with special reference to the changes induced by the light-dark cycle. AcPase-positive lysosomes and Golgi cisternae and vesicles located in the pinealocyte in the light period are well develop...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079x.1989.tb00407.x
更新日期：1989-01-01 00:00:00
abstract：:This study examined plasma melatonin levels and the suppressant effect of light on melatonin production in the squirrel monkey. Monkeys were maintained on a 12:12 light-dark cycle (LD 12:12) with lights on from 07:00 to 19:00. Plasma levels of melatonin were determined by gas chromatography negative chemical ionizatio...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079x.1990.tb00689.x
更新日期：1990-01-01 00:00:00
abstract：:The aim of this study was to determine, in the rat, the interaction between melatonin and cholecystokinin in the regulation of the ileal interdigestive motility. This was analyzed by the chronic electromyography technique. Ileal motility was defined by the presence of intermittent spike bursts corresponding to the con...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079x.1994.tb00117.x
更新日期：1994-09-01 00:00:00
abstract：:The effect on nocturnal melatonin secretion of acute administration of the indirectly acting serotonin (5-HT) receptor agonists d-fenfluramine (30 mg) and paroxetine (20 mg) and a partial 5-HT1A receptor agonist ipsapirone (20 mg) was investigated in healthy male volunteers and compared to a placebo condition. Each su...
journal_title：Journal of pineal research
pub_type： 临床试验,杂志文章,随机对照试验
doi：10.1111/j.1600-079x.1996.tb00271.x
更新日期：1996-09-01 00:00:00
abstract：:The distribution of nerve fibers immunoreactive (IR) to catecholamine-synthesizing enzymes, tyrosine hydroxylase (TH), dopamine-beta-hydroxylase (D beta H), and phenylethanolamine-N-methyltransferase (PNMT) as well as neuropeptide Y (NPY), in the pineal gland of adult sows was investigated by the use of double-labelin...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079x.1994.tb00109.x
更新日期：1994-08-01 00:00:00
abstract：:Ischemia/reperfusion injury (IRI) is harmful to the cardiovascular system and causes mitochondrial oxidative stress. Numerous data indicate that the JAK2/STAT3 signaling pathway is specifically involved in preventing myocardial IRI. Melatonin has potent activity against IRI and may regulate JAK2/STAT3 signaling. This ...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/jpi.12070
更新日期：2013-10-01 00:00:00
abstract：:Hepatocellular carcinoma (HCC) is one of the most common cancers and its incidence is increasing worldwide. Melatonin, an indoleamine hormone, exerts anti-oxidant, immunomodulatory, anti-aging, and antitumor effects. Previous studies have shown that melatonin can act through specific receptors, including MT(1), MT(2),...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079X.2009.00719.x
更新日期：2009-11-01 00:00:00
abstract：:The pineal hormone melatonin has been reported to have in vitro antiproliferative effects on estrogen receptor-positive human breast cancer cell lines at concentrations near to plasma physiological concentrations (1 x 10(-11) to 1 x 10(-9) M). Its growth inhibitory actions have been thought to be linked to the estroge...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079x.1998.tb00390.x
更新日期：1998-12-01 00:00:00
abstract：:Preterm delivery is the leading cause of neonatal mortality and contributes to delayed physical and cognitive development in children. At present, there is no efficient therapy to prevent preterm labor. A large body of evidence suggests that intra-amniotic infections may be a significant and potentially preventable ca...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/jpi.12108
更新日期：2014-03-01 00:00:00
abstract：:Melatonin, a major pineal secretory product, exerts a range of physiological and neuroprotective effects. However, the functional significance of melatonin in determining neural identity, and the mechanisms by which this may occur, is unknown. In this study, P19 cells were used as a model system and cell behavior was ...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/jpi.12153
更新日期：2014-09-01 00:00:00
abstract：:In the present research, we studied the effect of the administration of melatonin or S-adenosyl-L-methionine (S-AMe) on oxidative stress and hepatic cholestasis produced by double ligature of the extra-hepatic biliary duct (LBD) in adult male Wistar rats. Hepatic oxidative stress was evaluated by the changes in the am...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1034/j.1600-079x.2001.280303.x
更新日期：2000-04-01 00:00:00
abstract：:Hypochlorous acid (HOCl) is a potent cytotoxic oxidant generated by the enzyme myeloperoxidase (MPO) in the presence of hydrogen peroxide (H2 O2 ) and chloride (Cl- ). Elevated levels of HOCl play an important role in various pathological conditions through oxidative modification of several biomolecules. Recently, we ...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/jpi.12463
更新日期：2018-04-01 00:00:00
abstract：:A link between endotoxemia and nonalcoholic fatty liver disease (NAFLD) has been demonstrated in human and rodent animals. Nevertheless, the molecular mechanisms of endotoxin-evoked NAFLD remain poorly understood. We hypothesize that reactive oxygen species (ROS) mediate lipopolysaccharide (LPS)-evoked hepatic lipid a...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079X.2011.00905.x
更新日期：2011-11-01 00:00:00
abstract：:Previous studies proved that melatonin protected against secondary brain damage by modulating oxidative stress after experimental subarachnoid hemorrhage (SAH), but it has not been evaluated yet about its effects on inflammatory pathway and secondary cognitive dysfunction in SAH model. This study was undertaken to eva...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/jpi.12087
更新日期：2013-11-01 00:00:00
abstract：:Oxidative stress is involved in ischemia-reperfusion injury and allograft rejection after transplantation. We studied two well-known antioxidants, melatonin and ascorbic acid (AA), in relation to the survival of a pancreas transplantation model without immunosuppression. Forty-eight Landrace pigs were divided into thr...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079X.2011.00908.x
更新日期：2011-11-01 00:00:00
abstract：:While ectopic overexpression of serotonin N-acetyltransferase (SNAT) in plants has been accomplished using animal SNAT genes, ectopic overexpression of plant SNAT genes in plants has not been investigated. Because the plant SNAT protein differs from that of animals in its subcellular localization and enzyme kinetics, ...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/jpi.12392
更新日期：2017-04-01 00:00:00
abstract：:Studies on farm animals have contributed significantly to our increased understanding of basic melatonin-related physiological mechanisms, as well as to the regulation of reproduction and pelage in individual domestic species. This review concentrates on recent work on the role of melatonin in the regulation of porcin...
journal_title：Journal of pineal research
pub_type： 杂志文章,评审
doi：10.1111/j.1600-079x.1994.tb00097.x
更新日期：1994-05-01 00:00:00
abstract：:Melatonin biosynthesis was examined in Sekiguchi mutant rice lacking functional tryptamine 5-hydroxylase (T5H) activity, which is the terminal enzyme for serotonin biosynthesis in rice. During senescence process, the leaves of Sekiguchi mutant rice produced more tryptamine and N-acetyltryptamine compared with the wild...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079X.2011.00930.x
更新日期：2012-03-01 00:00:00
abstract：:Recently, a species-dependent distribution of melatonin binding sites have been found in lamina I-V and lamina X of the spinal cord. In order to learn more about the function of spinal melatonin receptors, we investigated (i) the gene expression for melatonin receptor subtypes in lumbar and thoracal spinal cord tissue...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1034/j.1600-079x.2003.00047.x
更新日期：2003-08-01 00:00:00
abstract：:Retinopathy of prematurity is a vision-threatening disease associated with retinal hypoxia-ischemia, leading to the death of retinal neurons and chronic neuronal degeneration. During this study, we used the oxygen-induced retinopathy mice model to mimic retinal hypoxia-ischemia phenotypes to investigate further the ne...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/jpi.12716
更新日期：2021-01-11 00:00:00
abstract：:The objective of this study was to apply the radioimmunoassay for 6-sulphatoxymelatonin (aMT6s) to rat urine, and use it to study the source of aMT6s. The radioimmunoassay was found to have acceptable within- and between-assay variation, excellent specificity, and good parallelism between the standard and unknown. Bec...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079x.1991.tb00831.x
更新日期：1991-04-01 00:00:00
abstract：:Despite high in-hospital mortality associated with acute respiratory distress syndrome (ARDS), there is no effective therapeutic strategy. We tested the hypothesis that combined melatonin-mitochondria treatment ameliorates 100% oxygen-induced ARDS in rats. Adult male Sprague-Dawley rats (n = 40) were equally categoriz...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/jpi.12199
更新日期：2015-03-01 00:00:00
abstract：:Melatonin is an endogenous indoleamine, produced mainly by the pineal gland. Melatonin has been proven to have chronobiotic, antioxidant, antihypertensive, anxiolytic and sedative properties. There are also experimental and clinical data supporting an analgesic role of melatonin. In experimental studies, melatonin sho...
journal_title：Journal of pineal research
pub_type： 杂志文章,评审
doi：10.1111/j.1600-079X.2011.00895.x
更新日期：2011-10-01 00:00:00
abstract：:Melatonin regulates mitogen-activated protein kinase (MAPK) and Akt signaling pathways. The MAPK family mainly includes extracellular signal-regulated kinase (ERK), p38, and c-Jun N-terminal kinase (JNK). Our previous study documented that melatonin delays osteoblast proliferation; however, the mechanism of action of ...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079X.2011.00971.x
更新日期：2012-08-01 00:00:00
abstract：:Melatonin is a highly effective treatment in different animal models of excitotoxicity or ischemia/reperfusion injury. Due to a lack of patentability, commercial sponsors are not interested in funding clinical evaluations of melatonin. Investigators may initiate small-scale clinical evaluation, and intravenous (i.v.) ...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079X.2006.00372.x
更新日期：2006-11-01 00:00:00
abstract：:Improved survival because of advances in neonatal care has resulted in an increased number of infants at risk for chronic lung disease. Even though the etiology of lung injury is multifactorial, recent animal and clinical data indicate that pulmonary damage depends in large part on the ventilatory strategies used. Ven...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/j.1600-079X.2005.00251.x
更新日期：2005-10-01 00:00:00
abstract：:The circadian clock plays a vital role in physiology and behavior such as the sleep-wake cycle and blood pressure and hormone levels. Immune responses also display circadian rhythmicity and particularly pineal melatonin contributes to immunological processes. Little attention, however, is given to mechanisms underlyin...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/jpi.12230
更新日期：2015-05-01 00:00:00
abstract：:Melatonin is part of the evolutionary conserved highly functional network in vertebrates. It plays a central role in the adaptative behavior of the animal to the environment, including entrainment of daily and annual physiological rhythms, reproductive behavior, food intake, locomotor activity, growth, and breeding pe...
journal_title：Journal of pineal research
pub_type： 杂志文章
doi：10.1111/jpi.12149
更新日期：2014-08-01 00:00:00
