Naphyrone, also known as O-2482 and naphthylpyrovalerone,. is a drug derived from pyrovalerone that acts as a triple reuptake inhibitor, producing stimulant effects and has been reported as a novel designer drug. No safety or toxicity data is available on the drug.[
The drug has been marketed under the name NRG-1, although only a minority of samples of substances sold under this name have been found to actually contain naphyrone,. and even samples that proved to contain genuine β-naphyrone were in some cases also found to contain the 1-naphthyl isomer α-naphyrone in varying proportions, further confusing the reported effects profile.
|Chemical and physical data|
|Molar mass||281.391 g/mol g·mol−1|
|3D model (JSmol)|
As a triple reuptake inhibitor, naphyrone has been shown in vitro to affect the reuptake of the neurotransmitters serotonin, dopamine and norepinephrine by interacting with the serotonin transporter (SERT), dopamine transporter (DAT), and norepinephrine transporter (NET).
One study found that the dissociation constant of naphyrone interacting with SERT is 33.1nM ± 1.1, with DAT is 20.1nM ± 7.1 and with NET is 136nM ± 27. The concentration of naphyrone required to inhibit the transporters by 50% is 46.0nM ± 5.5 for SERT, 40.0nM ± 13 for DAT and 11.7nM ± 0.9 for NET. Of a number of pyrovalerone analogues tested, naphyrone was found to be the only triple reuptake inhibitor found to be active at nM concentrations.
Some samples of β-naphyrone sold have also been found to contain the alternative isomer α-naphyrone, presumably produced accidentally as an impurity in synthesis..The in vitro data available in the scientific literature was all obtained using pure β-naphyrone, and the pharmacological properties of α-naphyrone are unknown, further complicating the pharmacological profile of this little-studied designer drug.