Linked Life Data

14613326

Source:http://linkedlifedata.com/resource/pubmed/id/14613326

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
24
pubmed:dateCreated
2003-11-17
pubmed:abstractText
Optically active mexiletine analogues were synthesized and evaluated in vitro as use-dependent blockers of skeletal muscle sodium channels. The mexiletine analogues were obtained by replacing either the methyl group on the stereogenic center of mexiletine [1-(2,6-dimethylphenoxy)propan-2-amine] with a phenyl group or modifying the phenoxy moiety (by removal of one or both of the methyl groups, or introducing a chlorine atom), or both. The voltage clamp recordings showed that, regardless of the substitution pattern of the aryloxy moiety, all the compounds bearing a phenyl group on the stereogenic center (3a-f) were more active than mexiletine both in tonic and phasic block. This observation was in contrast with what was observed for mexiletine, where the removal of both methyls from the aryloxy moiety caused a dramatic reduction of potency. The most potent congener, (R)-2-(2-methylphenoxy)-1-phenylethanamine [(R)-3b], was 27-fold more potent than (R)-mexiletine in producing a tonic block, i.e., the reduction of peak sodium current in resting conditions after application of the compound. (R)-3b maintained a use-dependent behavior, being 23-fold more potent in condition of high frequency of stimulation (phasic block). Despite what was observed with mexiletine, the stereoselectivity held in phasic block conditions. Stereoselectivity indexes were generally low, ranging from 1 to 4, but except for that of the 2,6-xylyloxy congener 3c, they were higher for the congeners bearing a phenyl ring on the stereogenic center than for mexiletine and its strictly related analogue 1-methyl-2-phenoxyethanamine (1). This finding was in agreement with Pfeiffer's rule. The introduction of a chlorine atom in the 4-position of the aryloxy moiety caused a reduction of potency and a reversal of stereoselectivity as well. On the basis of the model to date accepted for the sodium channel local anesthetic-like molecule receptor, some possible explanations of our observations will be proposed.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-2623
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
46
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5238-48
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Optically active mexiletine analogues as stereoselective blockers of voltage-gated Na(+) channels.
pubmed:affiliation
Dipartimento Farmaco-Chimico and Farmaco-Biologico, Università degli Studi di Bari - Via E Orabona 4, 70125 Bari, Italy. cfranc@farmchim.uniba.it
pubmed:publicationType
Journal Article, In Vitro