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Felipe Rebello Lourenço

Department of Pharmacy, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil.

3 papers in the library · 63 citations · publishing 2020

Papers

Stability Evaluation of DMT and Harmala Alkaloids in Ayahuasca Tea Samples

Molecules April 29, 2020 Gabriela de Oliveira Silveira, Rafael G. Dos Santos, Felipe Rebello Lourenço et al. 36 citations

Ayahuasca tea, a hallucinogenic beverage used in religious and therapeutic contexts, was tested for the stability of its main alkaloids—DMT, harmine, tetrahydroharmine, and harmaline—under three storage conditions: one year in a refrigerator (plastic or glass containers), seven days at 37°C (simulating mail transport), and three freeze-thaw cycles. DMT showed no significant degradation in any condition. However, harmala alkaloids exhibited substantial variation, including degradation and concentration increases, likely due to inter-conversion and leaching from tea precipitate. Thus, quantifying alkaloids before administration in controlled studies is essential.

Essential oil-based dispersive liquid-liquid microextraction for the determination of N,N-dimethyltryptamine and β-carbolines in human plasma: A novel solvent-free alternative

Talanta December 9, 2020 Gabriela de Oliveira Silveira, Felipe Rebello Lourenço, Ana Miguel Fonseca Pego et al. 15 citations

A new sample-preparation method uses eucalyptus essential oil, instead of conventional organic solvents, to extract four ayahuasca-related compounds (DMT, harmine, harmaline, and tetrahydroharmine) from human plasma. After optimizing the procedure with factorial experiments, the method was validated and applied to 13 real plasma samples. Detection limits were ≤1.0 ng/mL, and the method was linear up to 150 ng/mL. Recovery averaged 50%, and matrix effects showed ion suppression of 56–83%. The approach is simple, fast, and environmentally friendly, offering a green alternative for forensic and clinical drug analysis.

Fast Hollow Fiber Liquid-Phase Microextraction as a Greener Alternative for the Determination of N,N-Dimethyltryptamine and Harmala Alkaloids in Human Urine.

Frontiers in chemistry January 1, 2020 Gabriela de Oliveira Silveira, Felipe Rebello Lourenço, Vitor Bruno et al. 12 citations

A greener, faster method using hollow fiber liquid-phase microextraction (HF-LPME) and LC-MS/MS was developed to measure DMT and three harmala alkaloids in human urine. The method avoids large amounts of toxic solvents. It detects DMT at 1.0 ng/ml and harmala alkaloids at 2.0 ng/ml, with a quantifiable range of 5-200 ng/ml. Precision, accuracy, and recovery (above 80%) met acceptance criteria. Analysis of urine from four subjects confirmed the method's feasibility. The approach offers a simple, time-saving alternative for studying ayahuasca components in biological samples.