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PRL-8-53

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PRL-8-53
Clinical data
Routes of
administration
Oral
ATC code
  • none
Legal status
Legal status
  • In general: unscheduled
Identifiers
  • Methyl 3-[2-[benzyl(methyl)amino]ethyl]benzoate
CAS Number
PubChem CID
ChemSpider
UNII
CompTox Dashboard (EPA)
Chemical and physical data
FormulaC18H21NO2
Molar mass283.371 g·mol−1
3D model (JSmol)
  • CN(CCc1cccc(c1)C(=O)OC)Cc2ccccc2
  • InChI=1S/C18H21NO2/c1-19(14-16-7-4-3-5-8-16)12-11-15-9-6-10-17(13-15)18(20)21-2/h3-10,13H,11-12,14H2,1-2H3
  • Key:IGJQEMHBYKNIQR-UHFFFAOYSA-N

PRL-8-53 is a nootropic substituted phenethylamine 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.[1][2]

Mechanism of action

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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.[1] It displays possible cholinergic properties, and potentiates dopamine while partially inhibiting serotonin.[1] PRL-8-53 reverses the catatonic and ptotic effects of reserpine.[1][3]

Toxicity

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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.[3]

Reasons for discontinuation

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It is uncertain as to exactly why PRL-8-53's development was halted. PRL-8-53 did not exhibit obvious side effects that would warrant discontinuation in animals or in its single human trial. Factors not limited to the retirement of Dr. Nikolaus Hansl in 1985 and a lawsuit filed between Hansl and Creighton University may be to blame.

Hansl v. Creighton University

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On July 1, 1985 Dr. Nikolaus Hansl entered into a settlement agreement with Creighton University.[4] The terms of the agreement guaranteed Dr. Hansl access to his laboratory facilities and office space at the university for a period of 2 years.[4] Upon returning from a 4-month absence. Hansl found that the refrigerator he had used to store various experimental compounds had been unplugged, purportedly rendering the compounds unusable.[4]

It is uncertain if samples of PRL-8-53 were stored in the fridge or if they would have been degraded significantly under room temperature conditions.

Patent

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Dr. Hansl's patent for the synthesis of PRL-8-53 has expired.[5]

Synonyms

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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

See also

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References

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  1. ^ a b c d 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.
  2. ^ US Patent 3870715 A: Substituted amino ethyl meta benzoic acid esters
  3. ^ a b 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.
  4. ^ a b c "Hansl v. Creighton University". Justia Law. Retrieved 2022-10-16.
  5. ^ Nikolaus R. Hansl; Process for hydrolyzing 3-trifluoromethyl phenethylamines (US patent 3 792 048) 1974