MPDP+ has been recognized to be an intermediary metabolite in the conversion of MPTP into MPP+. MPDP+ disproportionates at physiological pH into MPTP and MPP+. MPTP, MPDP+ and MPP+ are inhibitors of monoamineoxidase B, and all three inhibit dopamine uptake in rat synaptosomal preparations. New synthesis of MPDP+ were developed and analogs of MPTP with the phenyl group at different positions of the tetrahydropyridine ring, and with N-alkyl groups instead of an N-methyl group were prepared. The biological effects demonstrated by MPTP were not shown by any of its analogs prepared thus far.
