Methylenedioxyphenylpropylaminopentane

1-(3,4-Methylenedioxyphenyl)-2-propylaminopentane (MPAP), also known as 3,4-methylenedioxy-α,N-dipropylphenethylamine, N-propyl-1,3-benzodioxolylpentanamine (PDBP), or propyl-K, is a monoaminergic activity enhancer (MAE) of the phenethylamine, amphetamine, and α-propylphenethylamine families that is closely related to phenylpropylaminopentane (PPAP). It is an analogue of PPAP and benzofuranylpropylaminopentane (BPAP) with a benzodioxole ring instead of a phenyl or benzofuran ring, respectively.

MAEs are agents that enhance the action potential-mediated release of monoamine neurotransmitters. MPAP is a MAE of serotonin, norepinephrine, and dopamine, all with similar potency. This is similar to BPAP, but is in contrast to PPAP and selegiline, which act exclusively as catecholaminergic activity enhancers (CAEs) and do not enhance serotonin. Like PPAP and BPAP, but in contrast to amphetamines, MPAP has no classical monoamine releasing agent actions.

MPAP has comparable potency to PPAP and selegiline as a MAE in terms of enhancing the monoamine neurotransmitters in the isolated rat brain stem ex vivo. However, it was 5-fold more potent than PPAP and selegiline as a MAE in rodents in vivo in terms of the minimum dose that significantly antagonized the behavioral depression induced by tetrabenazine in the shuttle box. On the other hand, MPAP was 20-fold less potent than the highly potent BPAP in the shuttle box. As with BPAP and PPAP, the negative enantiomer (i.e., (–)-MPAP) is more biologically active as a MAE. The effects of MAEs seem to be mediated by intracellular TAAR1 agonism coupled with uptake by monoamine transporters into monoaminergic neurons.