Development of analytical methods for the determination of ayahuasca alkaloids in different matrices applying green analytical chemistry strategies

Author(s)

Gabriela de Oliveira Silveira

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Conjunto das Químicas (IQ e FCF) (CQ/DBDCQ)
• Defense date: 2020-11-06

Examining board members

Maurício Yonamine; Eduardo Geraldo de Campos; José Luiz da Costa; Tania Marcourakis

• Advisor: Maurício Yonamine

Abstract

Ayahuasca is an indigenous beverage with psychedelic properties, historically used for shamanic and spiritual purposes by the inhabitants of the Amazon basin region. With its widespread use in Brazil and other countries, the ayahuasca tea is usually prepared by decoction of the Psicotria viridis and Banisteriopsis caapi plants. The synergistic effect that occurs between the β-carboline alkaloids (present in the B. Caapi vine) and the hallucinogen DMT (dimethyltryptamine, present in the leaves of P. viridis) allows the final psychoactive response in serotoninergic receptors, which grants a prominent position to ayahuasca beverages in the scientific community due to its therapeutic potential. Therefore, several methods have been developed to determine the active constituents of ayahuasca in different matrices, which are associated with clinical, experimental, and forensic contexts. Additionally, taking into account the current requirements for more eco-friendly analytical alternatives, the aim of the current study was to develop a series of analytical methods for the determination of ayahuasca alkaloids in the beverage, as well as in human plasma and urine applying Green Analytical Chemistry strategies (GAC) and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Thus, the current study is presented as a combination of unpublished data and article collection, according to chapters 4 to 8. Initially, a simple dilute-and-shoot method using a buffer solution has been developed for the analysis of tea samples and applied to several authentic specimens obtained from various collaborators. This method has been also applied for the investigation of the stability of tea samples submitted to three different storage conditions for periods up to 12 months. The results of this evaluation have generated the manuscript presented in chapter 6 (Article II). Chapter 5 presents Article I, a study derived from the review of existing knowledge regarding the application of GAC, particularly in forensic contexts. The miniaturization of extraction techniques a valuable strategy when applying GAC principles is first presented in chapter 7. As described in Article III, the method consists in a hollow-fiber liquid-phase microextraction (HF-LPME) for the treatment of urine specimens. After optimization by design of experiments and full validation, this technique has showed great performance when used for the analysis of real urine samples. Then, a dispersive liquid-liquid microextraction (DLLME) alternative is presented in chapter 8 (Article IV), which has been developed and validated for the analysis of plasma samples. This technique has demonstrated the opportunity to replace toxic organic solvents for essential oils, an alternative of negligible environmental impact from natural sources which has been reported for the first time in the current study. Finally, it may be concluded that the extraction and preparation alternatives employed in the present work fit the GAC requirements and allow the reduction, replacement, and elimination of extraction solvents. Nevertheless, the developed methods are eco-friendly, cost-effective, time-saving, and safe. (AU)

• FAPESP's process: 16/06810-2 - Development of analytical methods for the determination of ayahuasca alkaloids in different matrices applying green analytical chemistry strategies
• Grantee: Gabriela de Oliveira Silveira
• Support Opportunities: Scholarships in Brazil - Doctorate