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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
3
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pubmed:dateCreated |
1988-4-11
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pubmed:abstractText |
A series of 4-amino-6,7-dimethoxy-2-[4-(substituted oxyethoxy)piperidino] quinazoline derivatives (2) was synthesized and evaluated for alpha-adrenoceptor affinity and antihypertensive activity. Most compounds showed binding affinities within the nanomolar range for alpha 1-receptors, although 25 and 26 showed enhanced potency (Ki, ca. 1.5 X 10(-10) M), equivalent to that of prazosin. Series 2 also displaced [3H]clonidine from alpha 2-adrenoceptors, but at relatively high doses of 10(-6) M, and selectivity for alpha 1 sites still predominated. In a rabbit pulmonary artery preparation, 12, 16, and 25 were potent antagonists of the alpha 1-mediated, postjunctional vasoconstrictor activity of norepinephrine with no effect at the prejunctional alpha 2 sites which modulate transmitter release. Physicochemical measurements gave a pKa of 7.63 +/- 0.10 for 12, and N-1 protonation will be favored (60%) at physiological pH to provide the alpha 1-adrenoceptor pharmacophore, 28. Antihypertensive activity of series 2 was evaluated following oral administration to spontaneously hypertensive rats, and blood pressure was measured after 1 and 6 h. Compounds 12, 13, 16, 23, and 37 displayed moderate efficacy and duration of action in lowering blood pressure, but the plasma half-life (ca. 2 h) of 16 in dogs was not compatible with potential once-daily administration in humans.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Adrenergic alpha-Antagonists,
http://linkedlifedata.com/resource/pubmed/chemical/Antihypertensive Agents,
http://linkedlifedata.com/resource/pubmed/chemical/Clonidine,
http://linkedlifedata.com/resource/pubmed/chemical/Prazosin,
http://linkedlifedata.com/resource/pubmed/chemical/Quinazolines
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pubmed:status |
MEDLINE
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pubmed:month |
Mar
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pubmed:issn |
0022-2623
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
31
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
516-20
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pubmed:dateRevised |
2003-11-14
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pubmed:meshHeading |
pubmed-meshheading:2894465-Adrenergic alpha-Antagonists,
pubmed-meshheading:2894465-Animals,
pubmed-meshheading:2894465-Antihypertensive Agents,
pubmed-meshheading:2894465-Blood Pressure,
pubmed-meshheading:2894465-Clonidine,
pubmed-meshheading:2894465-Half-Life,
pubmed-meshheading:2894465-Hydrogen-Ion Concentration,
pubmed-meshheading:2894465-Prazosin,
pubmed-meshheading:2894465-Quinazolines,
pubmed-meshheading:2894465-Rabbits
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pubmed:year |
1988
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pubmed:articleTitle |
2,4-Diamino-6,7-dimethoxyquinazolines. 4. 2-[4-(substituted oxyethoxy) piperidino] derivatives as alpha 1-adrenoceptor antagonists and antihypertensive agents.
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pubmed:affiliation |
Department of Discovery Chemistry, Pfizer Central Research, Sandwich, Kent, United Kingdom.
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pubmed:publicationType |
Journal Article
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