title: Enantioselective syntheses and calcium channel modulating effects of (+)- and (-)-3-isopropyl 5-(4-methylphenethyll) 1,4-dihydro-2,6-dimethyl-4-(2-pyridyl)-3,5-pyridinedicarboxylates.
abstract: The (+)- and (-)-enantiomers of 3-isopropyl 5-(4-methylphenethyl) 1,4-dihydro-2,6-dimethyl-4-(2-pyridyl)-3,5-pyridinedicarboxylate were synthesized using an efficient highly enantioselective (ee > or = to 96%) variant of the Hantzsch dihydropyridine synthesis. The key step in this procedure involved the asymmetric Michael addition of a metalated chiral aminocrotonate, derived from D-valine or L-valine, respectively, to the Knoevenagel acceptor (Z)-2-isopropoxycarbonyl-1-(2-pyridyl)-but-1-en-3-one. Both enantiomers exhibited a dual cardioselective partial calcium channel agonist (positive inotropic)/smooth muscle selective calcium channel antagonist effect. The relative in vitro smooth muscle calcium channel antagonist activities of the (-):(+) enantiomers was 26:1. In contrast, the (+)-enantiomer exhibited a greater in vitro positive inotropic effect on guinea pig left atrium where the contractile force was maximally increased by 14.8% at a concentration of 1.63 x 10(-8)M.
authors.affiliation: University of Alberta, Edmonton, Canada.
authors.forename: N
authors.initials: N
authors.lastname: Iqbal
authors.forename: D
authors.initials: D
authors.lastname: Vo
authors.forename: C A
authors.initials: CA
authors.lastname: McEwen
authors.forename: M W
authors.initials: MW
authors.lastname: Wolowyk
authors.forename: E E
authors.initials: EE
authors.lastname: Knaus
mesh_terms: D000818:Animals; D002120:Calcium Channel Agonists / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D006325:Heart Atria; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009200:Myocardial Contraction / Q000187:drug effects*; D009543:Nifedipine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: D002120:Calcium Channel Agonists; D002121:Calcium Channel Blockers; D009543:Nifedipine