Synthesis and calcium antagonistic activity of 8-[N-[2-(3,4-dimethoxy- phenyl)ethyl]-beta-alanyl]-5,6,7,8-tetrahydrothieno[3,2-b][1,4]thiazepi ne fumarate.
KT-362 is an antiarrhythmic and antihypertensive agent with vasodilating activity. Since it carries a homoveratryl group in the side chain, an obvious relation exists to the verapamil-type calcium antagonists. Replacement of the fused aromatic moiety in KT-362 with thiophene provided 8-[N-[2-(3,4-dimethoxyphenyl) ethyl]-beta-alanyl]-5,6,7,8-tetrahydrothieno[3,2-b][1,4] thiazepine (1). Compound 1 shows a negative chronotropic activity in spontaneously beating right atria (IC50 = 23 microM, n = 7), and a negative inotropic effect in papillary muscles (IC50 = 2.7 microM, n = 7) and left atria (IC50 = 4 microM, n = 6) of the guinea-pig heart. The decrease of contractility in papillary muscles could be antagonized by increasing the extracellular calcium concentration. Compound 1 was found to affect high (IC50: 70 +/- 5 microM) and low (IC50: 129 +/- 34 microM) voltage-activated calcium channel currents as well as voltage-activated sodium channel currents (IC50: 80 +/- 13 microM) in chick dorsal root ganglion neurons. In addition nicotine-induced currents were potently inhibited (IC50: 6 +/- 0.7 microM) in bovine chromaffin cells.
Erker
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Institute of Pharmaceutical Chemistry, University of Vienna, Austria.
Laimer
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Huck
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Boehm
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Studenik
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Heistracher
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D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D015220:Calcium Channels / Q000378:metabolism; D002417:Cattle; D002642:Chick Embryo; D005727:Ganglia, Spinal / Q000187:drug effects / Q000378:metabolism; D006168:Guinea Pigs; D066298:In Vitro Techniques; D015640:Ion Channel Gating; D009200:Myocardial Contraction / Q000187:drug effects; D015222:Sodium Channels / Q000378:metabolism; D013841:Thiazepines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*
D000889:Anti-Arrhythmia Agents; D002121:Calcium Channel Blockers; D015220:Calcium Channels; D015222:Sodium Channels; D013841:Thiazepines; C051271:KT 362