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1.
Angew Chem Int Ed Engl ; 58(46): 16651-16659, 2019 Nov 11.
Article in English | MEDLINE | ID: mdl-31509309

ABSTRACT

Methyl-selective α-oxygenation of tertiary amines is a highly attractive approach for synthesizing formamides while preserving the amine substrate skeletons. Therefore, the development of efficient catalysts that can advance regioselective α-oxygenation at the N-methyl positions using molecular oxygen (O2 ) as the terminal oxidant is an important subject. In this study, we successfully developed a highly regioselective and efficient aerobic methyl-selective α-oxygenation of tertiary amines by employing a Cu/nitroxyl radical catalyst system. The use of moderately hindered nitroxyl radicals, such as 1,5-dimethyl-9-azanoradamantane N-oxyl (DMN-AZADO) and 1-methyl-2-azaadamanane N-oxyl (1-Me-AZADO), was very important to promote the oxygenation effectively mainly because these N-oxyls have longer life-times than less hindered N-oxyls. Various types of tertiary N-methylamines were selectively converted to the corresponding formamides. A plausible reaction mechanism is also discussed on the basis of experimental evidence, together with DFT calculations. The high regioselectivity of this catalyst system stems from steric restriction of the amine-N-oxyl interactions.

2.
Int J Neurosci ; 118(1): 39-57, 2008 Jan.
Article in English | MEDLINE | ID: mdl-18041605

ABSTRACT

This study compared the D(2) partial agonists, aripiprazole, (R(+)-terguride; S(-)-3-(3-hydroxyphenyl)-N-n-propylpiperidine [S(-)-3-PPP]; 7-[3-[4-(2,3-dimethylphenyl)piperazinyl]propoxy]-2(1H)-quinolinone [OPC-4392]) and D(2) antagonists (haloperidol, olanzapine, clozapine, risperidone, and quetiapine) on prepulse inhibition (PPI) of the startle response, and the ability to reverse apomorphine-induced deficits in the PPI response. Aripiprazole did not essentially affect PPI in naïve rats but dose-dependently restored apomorphine-induced PPI disruption. R(+)-terguride restored PPI disruption but suppressed PPI significantly in naïve rats, S(-)-3-PPP partially restored whereas OPC-4392 did not restore PPI disruption. Haloperidol and risperidone restored PPI disruption whereas olanzapine and quetiapine partially restored PPI disruption and clozapine had no restorative effect. In conclusion, aripiprazole, unlike other antipsychotic agents, failed to suppress PPI significantly and restored PPI disruption.


Subject(s)
Dopamine Agents/pharmacology , Neural Inhibition/drug effects , Piperazines/pharmacology , Quinolones/pharmacology , Reaction Time/drug effects , Receptors, Dopamine D2/drug effects , Reflex, Startle/drug effects , Acoustic Stimulation , Animals , Antipsychotic Agents/pharmacology , Apomorphine/pharmacology , Aripiprazole , Conditioning, Classical/drug effects , Dopamine Agents/classification , Drug Interactions , Inhibition, Psychological , Ion Channel Gating/drug effects , Male , Rats , Rats, Wistar
3.
Virchows Arch ; 444(1): 66-73, 2004 Jan.
Article in English | MEDLINE | ID: mdl-14648220

ABSTRACT

Mucus overproduction from goblet cells, a characteristic feature of the allergic asthmatic inflammation induced by ovalbumin (OVA) in mice, was examined morphologically. In OVA-untreated (normal) mice, there were no goblet cells in intrapulmonary bronchus and bronchiole. However, goblet cells with or without hyperplasia in the mucosa of inflamed bronchus-bronchiole were recognized in the allergic asthmatic mice. The non-ciliated epithelium containing electron lucent granules (mucus) showed many similarities to Clara cells, which have characteristic secretory granules and many mitochondria, except for the less-developed smooth endoplasmic reticulum seen in normal mice. Ciliated Clara cells with or without mucus were rarely recognized. In addition, mucus was found in neither ciliated nor basal epithelium. The present study suggests that goblet-cell metaplasia in the bronchus and bronchiole of inflamed mucosa may be derived, at least in part, from Clara cells.


Subject(s)
Asthma/pathology , Goblet Cells/pathology , Animals , Asthma/immunology , Bronchi/pathology , Disease Models, Animal , Endoplasmic Reticulum, Smooth/pathology , Female , Metaplasia , Mice , Mice, Inbred DBA , Microscopy, Electron , Mitochondria/pathology , Mucous Membrane/pathology , Ovalbumin/immunology , Secretory Vesicles/pathology
4.
Eur J Pharmacol ; 472(1-2): 89-97, 2003 Jul 04.
Article in English | MEDLINE | ID: mdl-12860477

ABSTRACT

Catalepsy and changes in striatal and limbic dopamine metabolism were investigated in mice after oral administration of aripiprazole, haloperidol, and risperidone. Catalepsy duration decreased with chronic (21 day) aripiprazole compared with acute (single dose) treatment across a wide dose range, whereas catalepsy duration persisted with chronic haloperidol treatment. At the time of maximal catalepsy, acute aripiprazole did not alter neostriatal dopamine metabolite/dopamine ratios or homovanillic acid (HVA) levels, and produced small increases in dihydroxyphenylacetic acid (DOPAC). Effects were similar in the olfactory tubercle. Dopamine metabolism was essentially unchanged in both regions after chronic aripiprazole. Acute treatments with haloperidol or risperidone elevated DOPAC, HVA, and metabolite/dopamine ratios in both brain areas and these remained elevated with chronic treatment. The subtle effects of aripiprazole on striatal and limbic dopamine metabolism, and the decrease in catalepsy with chronic administration, illustrate fundamental differences in dopamine neurochemical actions and behavioral sequelae of aripiprazole compared to haloperidol or risperidone.


Subject(s)
Antipsychotic Agents/toxicity , Catalepsy/metabolism , Dopamine/metabolism , Administration, Oral , Animals , Aripiprazole , Catalepsy/chemically induced , Corpus Striatum/drug effects , Corpus Striatum/metabolism , Haloperidol/toxicity , Limbic System/drug effects , Limbic System/metabolism , Male , Mice , Mice, Inbred ICR , Piperazines/toxicity , Quinolones/toxicity , Risperidone/toxicity , Time Factors
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