Deprenyl

Deprenyl, also known by its developmental code name E-250 and as N-propargylmethamphetamine, is the racemic mixture of D -deprenyl and  L -deprenyl (selegiline). It was discovered in 1961 in Hungary at Chinoin Pharmaceutical Company by Zoltan Ecseri and Joseph Knoll, was patented in 1962, and was first described in the literature in 1964 or 1965.

The drug is a monoamine oxidase inhibitor and norepinephrine–dopamine releasing agent. It is a prodrug of methamphetamine and amphetamine, which mediates the latter action. Deprenyl was studied clinically at high doses of 50 to 100mg/day and was described as a psychostimulant and antidepressant. At lower doses, selective MAO-B inhibition would be expected, but at these higher doses, dual inhibition of MAO-A and MAO-B would occur, on the basis of L -deprenyl.

Subsequent to its synthesis, the stereoisomers of deprenyl were separated. The dextrorotatory isomer, D -deprenyl, was found to be more toxic, producing effects like hyperthermia and more potent psychostimulation in rodents. The levorotatory isomer, selegiline, was much more potent as an MAO-B inhibitor, and was subsequently developed for the treatment of Parkinson's disease and depression.