|Chemical and physical data|
|Molar mass||283.371 g·mol−1|
|3D model (JSmol)|
PRL-8-53 is a nootropic research chemical derived from benzoic acid and phenylmethylamine (Benzylamine) that has been shown to act as a hypermnesic drug in humans; it was first synthesized by medical chemistry professor Nikolaus Hansl at Creighton University in the 1970s as part of his work on amino ethyl meta benzoic acid esters.
PRL-8-53 is not a medical treatment for disease or illness, although a nootropic effect in healthy individuals has been claimed. A single study in humans was reported in 1978. The double-blind trial of PRL-8-53 in 47 healthy volunteers measured its effects on a variety of cognitive measures. 5 mg of the drug was administered orally 2–2.5 hours before the study tasks. Overall improvements in recollection differed based on how many words were recalled under placebo, with the poor performers (six words or fewer) experiencing an 87.5-105% increase in recollection and the high performers (eight or more words) a 7.9-14% increase which failed to reach statistical significance; when controlling for subjects over the age of 30 only, a 108-152% increase was noted. The researchers noted that this was likely a result of a ceiling effect due to many of their subjects scoring close to 100% on the recall test even on placebo. No side effects were reported during the trial.
Mechanism of action
The exact mechanism of action of PRL-8-53 remains unknown. Doses up to 200 mg/kg are not observed to have stimulant properties, and a dosage of 20 mg/kg does not potentiate the effects of dextroamphetamine in rats. It displays possible cholinergic properties, and potentiates dopamine while partially inhibiting serotonin. PRL-8-53 reverses the catatonic and ptotic effects of reserpine.
PRL-8-53 is relatively non-toxic, with an oral LD50 in mice of 860 mg/kg, giving the drug a high therapeutic index. Doses above 8 mg/kg have brief hypotensive effects in canines. High doses depress motor activity in the rat and mouse, with the ED50 for a 50% reduction in motor activity of mice at 160 mg/kg. PRL-8-53 displays spasmolytic effects.
Methyl 3-(2-(benzylmethylamino)ethyl)benzoate hydrochloride
3-(2-benzylmethylaminoethyl) benzoic acid methyl ester hydrochloride
3-(2-(Methyl(phenylmethyl)amino)ethyl)benzoic acid methyl ester hydrochloride
- Hansl NR, Mead BT (April 1978). "PRL-8-53: enhanced learning and subsequent retention in humans as a result of low oral doses of new psychotropic agent". Psychopharmacology. 56 (3): 249–53. doi:10.1007/BF00432846. PMID 418433. S2CID 21036209.
- US Patent 3870715 A: Substituted amino ethyl meta benzoic acid esters
- Hansl NR (March 1974). "A novel spasmolytic and CNS active agent: 3-(2-benzylmethylamino ethyl) benzoic acid methyl ester hydrochloride". Experientia. 30 (3): 271–2. doi:10.1007/BF01934822. PMID 4824605. S2CID 918343.