Definition: Compounds of the general formula R:N.NR2, as resulting from the action of hydrazines with aldehydes or ketones. (Grant & Hackh's Chemical Dictionary, 5th ed)
simendan [ ((4-(1,4,5,6-tetrahydro-4-methyl-6-oxo-3-pyridazinyl)phenyl)hydrazono)propanedinitrile,Abbott brand of Levosimendan,Levosimendan,OR 1259,OR-1259,OR-1855,Simadax,dextrosimendan ] neuroprotectant; a troponin modifier, a phosphodiesterase III inhibitor, and an inhibitor of voltage-sensitive Ca(2+) current; structure given in second source