title: Novel milrinone analogs of pyridine-3-carbonitrile derivatives as promising cardiotonic agents.
abstract: In an attempt to design new inotropic drugs for congestive heart failure (CHF) with less proarrhythmic potential, three series of compounds analogous to milrinone were prepared, namely, 4-aryl-6-(4-pyridyl)-2-oxo-1,2-dihydropyridine-3-carbonitriles 2a-g, 4-aryl-6-(4-pyridyl)-2-thioxo-1,2-dihydropyridine-3-carbonitriles 3a-g and 2-amino-4-aryl-6-(4-pyridyl)-pyridine-3-carbonitriles 4a-g. The first series was prepared by reacting 4-acetyl pyridine with the appropriate aldehyde, ethyl cyanoacetate and ammonium acetate in ethanol. Reaction of 2a-g with phosphorus pentasulfide afforded the second series 3a-g. The third target compounds 4a-g were prepared applying the same procedure used to synthesize 2a-g using malononitrile instead of ethyl cyanoacetate. All the newly synthesized compounds were evaluated for their cardiotonic activity and their in vivo cardiovascular effects. In addition, their oral and parenteral acute toxicity were determined. Compounds 2a, 2b, 2c, 4c and 4f proved to exert cardiotonic activity comparable to that of milrinone using spontaneously beating atria model from reserpine-treated guinea pigs. In addition these compounds proved to be non-toxic and well tolerated by mice up to 250 mg kg(-1) orally and up to 125 mg kg(-1) through parenteral route.
authors.affiliation: Department of pharmaceutical chemistry, faculty of pharmacy, university of Alexandria, Alexandria 21521, Egypt. adnbekhit@hotmail.com
authors.forename: Adnan A
authors.initials: AA
authors.lastname: Bekhit
authors.forename: Azza M
authors.initials: AM
authors.lastname: Baraka
mesh_terms: D000243:Adenosine Deaminase / Q000187:drug effects; D000284:Administration, Oral; D000818:Animals; D001145:Arrhythmias, Cardiac / Q000188:drug therapy; D002316:Cardiotonic Agents / Q000008:administration & dosage / Q000138:chemical synthesis* / Q000494:pharmacology*; D004195:Disease Models, Animal; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D020105:Milrinone / Q000031:analogs & derivatives / Q000138:chemical synthesis* / Q000494:pharmacology*; D015394:Molecular Structure; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D009570:Nitriles / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*; D051381:Rats; D013329:Structure-Activity Relationship
chemical_list: D002316:Cardiotonic Agents; D009570:Nitriles; D011725:Pyridines; C509176:pyridine-3-carbonitrile; D000243:Adenosine Deaminase; D020105:Milrinone