Monoamine oxidase inhibition by substituted benzylideneamino guanidines and their CNS activities.

The present study reports the synthesis and characterization of eight new substituted benzylideneamino guanidines. All compounds inhibited the monoamine oxidase (MAO) activity of rat brain mitochondria in vitro. The I50 values were determined and were found to be in the range of 10(-4) to 10(-5) mol/l. Preincubation, dialysis and kinetic studies carried out with isolated brain mitochondria by conventional Dixon plot revealed reversible and noncompetitive type of MAO inhibition. These compounds were also screened for anticonvulsant and antidepressant activities. In the present series of compounds only one compound -- 1-amino-3-(4-chloromethylbenzylidene-amino)guanidine hydroiodide -- was found to afford 20% protection against pentetrazol-induced seizures in mice. 1-Amino-3-(3,4-dichlorobenzylideneamino)guanidine hydroiodide which produced maximum inhibition of MAO activity, also produced reversal of reserpine-induced sedation and miosis into excitation and mydriasis in mice.