title: [Synthesis and vasorelaxant activities of benzopyran-4-one hydrazone derivatives].
abstract: OBJECTIVE
  In search of more potent, less toxic and selective potassium channel openers.
  
  
  METHODS
  According to the structure-activity relationships of benzopyran compounds and the features of structures of aprikalim, dofetilide and nifekalant, twenty benzopyran-4-one hydrazone derivatives have been designed and synthesized from 4-cyanophenos through acetylation, Fries rearrangment, cyclization, hydrazone, substitution reaction and so on. The compounds were tested for their vasorelaxant activity in low (30 mmol.L-1) and high (80 mmol.L-1) KCl-induced contraction of rat aorta to identify potential potassium channel openers in vitro.
  
  
  RESULTS
  Three series of twenty benzopyran-4-one hydrazone derivatives, nominated N-aminoacetyl-(6-cyano-3,4-dihydrospiro [2H-1-benzopyran-2,1'-cyclohexane]-4)-one hydrazone (I), 2-(6-cyano-3, 4-dihydro-2H-1-benzopyran-4-ylene) hydrazinethiocarboxamide derivatives (II) and N-(2-arylethyl) aminoacetyl-(6-cyano-3,4-dihydro-2H-1-benzopyran)-4-one hydrazone (III), have been synthesized. They (I1-9, II1-4 and III1-7) are new compounds. Their chemical structures were determined by IR, 1HNMR, MS and elemental analysis. The vasorelaxant effects of those novel compounds indicated that some of the compounds have vasorelaxant activities at 1 x 10(-6) mol.L-1.
  
  
  CONCLUSIONS
  The vasorelaxant activities of compounds I9, III2 and III5 in inhibiting low KCl-induced vasocontraction at 1 x 10(-6) mol.L-1 are less potent than the reference compound emakalim. However they are more potent than emakalim to inhibition high concentration KCl-induced vasocontraction at 1 x 10(-5) mol.L-1. It is worthy of further study.
authors.affiliation: New Drug Research Center, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Sheng-yin
authors.initials: SY
authors.lastname: Zhao
authors.forename: Wen-long
authors.initials: WL
authors.lastname: Huang
authors.forename: Hui-bin
authors.initials: HB
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001011:Aorta / Q000187:drug effects; D001578:Benzopyrans / Q000138:chemical synthesis* / Q000494:pharmacology; D015394:Molecular Structure; D015221:Potassium Channels / Q000819:agonists; D051381:Rats; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000138:chemical synthesis* / Q000494:pharmacology
chemical_list: D001578:Benzopyrans; D015221:Potassium Channels; D014665:Vasodilator Agents