Pharmacological evaluation of some new 6-amino/methyl pyridine derivatives

In the present study, a series of 2-substituted-pyridines were synthesized and characterized by IR, (1)H-NMR and Elemental Analysis. The compounds were assayed against seizures induced by maximal electro shock (MES) and pentylenetetrazole (scMet). Neurologic deficit was evaluated by the rotarod test. The decrease in the elevated motor activity by introceptive chemical stimuli (amphetamine antagonistic activity) was studied at the dose level of 25 and 50 mg/kg, antihistaminic and cardiac activity were also studied. All the compounds exhibited significant anticonvulsant activity. Compounds 2-(2-hydroxy-3-piperazinopropylamino)-6-aminopyridine, 2-[2-hydroxy-3-(1-imidazolyl)propylamino]-6-aminopyridine, 2-[2-(1-imidazolyl)ethylamino]-6-methylpyridine and 2-[2-(methylamino)ethylamino]-6-methylpyridine were most active of the series against MES-induced seizures. Compounds 2-[2-(phenylamino)ethylamino]-6-aminopyridine, 2-[2-[bis(2-hydroxyethyl)amino]ethylamino]-6-aminopyridine, 2-[2-(diethylamino)ethylamino]-6-methylpyridine and 2-[2-hydroxy-3-(1-imidazolyl)propylamino]-6-methylpyridine exhibited significant decrease in the elevated motor activity at the dose of 50 mg/kg. Remarkable sympathetic blocking activity was observed with 2-(2-hydroxy-3-piperazinopropylamino)-6-aminopyridine, 2-(2-hydroxy-3-morpholinopropylamino)-6-methylpyridine and 2-(2-hydroxy-3-piperazinopropylamino)-6-methylpyridine only. Compounds 2-[2-(diethylamino)ethylamino]-6-aminopyridine, 2-[2-[bis(2-hydroxyethyl)amino]ethylamino]-6-aminopyridine, and 2-[2-(diethylamino)ethylamino]-6-methylpyridine exhibited significant blocking of histamine induced contraction on guinea pig ileum.