A UHPLC-(ESI)MS/MS method for the determination of the psychedelic secondary metabolite mescaline in San Pedro (Trichocereus spp.) and its applicability for screening mescaline in other cacti varieties.

Summary

Mescaline concentrations in ornamental San Pedro cacti vary widely, posing risks of unintended low or high doses if used illicitly. A new UHPLC-(ESI)MS/MS method rapidly and reliably quantifies mescaline in these cacti and screens others. Preliminary results suggest higher mescaline levels in the chlorenchyma than in the parenchyma of San Pedro. Screening revealed mescaline in two varieties of Echinopsis subdenudata for the first time, at concentrations from 36 μg/g to 2.45 mg/g, while six other cacti had none. This finding supports the chemotaxonomic argument that Trichocereus and Echinopsis genera may not be distinct and should be combined. The discovery of mescaline in a popular ornamental cactus highlights the need for routine forensic screening to keep pace with emerging psychedelic drug trends.

Study at a glance

Abstract

Commencements of clinical trials of psychedelic therapies for intractable forms of mental illnesses have drawn increased public attention to plants containing psychedelic substances. Whilst the psychoactive alkaloid mescaline has limited clinical trials, the San Pedro ( Trichocereus spp.) cacti from which it is found have a long history of Indigenous medical and spiritual use. Traditional use remains licit in some jurisdictions, as supervised psychedelic dosage is typically regarded as tolerable with reports of only mild intoxications and few persisting negative psychological effects. However, mescaline concentration in ornamental San Pedro is highly variable, introducing risk of unintentional low or high dosage if misdirected for illicit use. This paper reports a validated UHPLC-(ESI)MS/MS method for the convenient and rapid quantification of mescaline in San Pedro, and for screening twelve potentially untested cacti. Preliminary results indicated that there may be higher amounts of mescaline in the chlorenchyma than the parenchyma of San Pedro. While six cacti lacked detectable mescaline, our screening enabled the first quantifications of mescaline in two varieties of Echinopsis subdenudata from 36 μg g −1 to 2.45 mg g −1 . Chemotaxonomically, this amount of mescaline in a species from the traditional Echinopsis genus further suggests that the Trichocereus genus is not distinct and may support their contested combination into a single genus. Forensically, the identification of a popular ornamental cactus that was previously not known to contain mescaline demonstrates the need for routine screening of other cacti for the forensic sciences to remain ahead of emerging trends in psychedelic drug use. • Validated UHPLC-(ESI)MS/MS method screened cacti for mescaline. • Trichocereus spp. may have more mescaline in the chlorenchyma than the parenchyma. • Mescaline was discovered in varieties of ornamental Echinopsis subdenudata . • Mescaline chemotaxonomy may support combining Echinopsis and Trichocereus genera.