Journal of psychoactive drugs
June 1, 2005
J C Callaway
Decoctions of Banisteriopsis caapi, often combined with Psychotria viridis, show considerable variation in alkaloid profiles both within and between sources. N,N-dimethyltryptamine (DMT) was not detected in all samples. Tetrahydroharmine may be formed from harmine and harmaline during preparation. One decoction's alkaloid composition remained stable after 80 days at room temperature, but its acidic pH was neutralized by natural fermentation after 50 days.
Journal of psychoactive drugs
June 1, 2005
J C Callaway, Glacus S Brito, Edison S Neves
Phytochemical analyses of 32 Banisteriopsis caapi and 36 Psychotria viridis samples collected from 22 sites across Brazil revealed wide variation in alkaloid content. All B. caapi samples contained harmine, harmaline, and tetrahydroharmine (THH). Some P. viridis samples had little or no detectable N,N-dimethyltryptamine (DMT). Leaves from one P. viridis plant analyzed over a 24-hour cycle also showed DMT variation.
Journal of ethnopharmacology
June 1, 1999
J C Callaway, D J McKenna, C S Grob et al.
After ingesting 2 ml/kg of hoasca (ayahuasca) tea, the four main alkaloids—DMT, harmine, harmaline, and tetrahydroharmine (THH)—were measured in the plasma of 15 volunteers. Peak psychoactive effects coincided with high alkaloid concentrations, especially DMT, which reached its maximum concentration at an average of 107.5 minutes. DMT's pharmacokinetics correlated with harmine's, while THH showed a relatively independent profile. The tea's harmala alkaloids inhibit monoamine oxidase A and weakly inhibit serotonin uptake, increasing serotonergic activity and enabling DMT's psychoactivity.