Biochemistry and pharmacology of tryptamines and beta-carbolines. A minireview

Psychedelic-like Activity of Norpsilocin Analogues

Primary metabolites of mushroom tryptamines, psilocybin and baeocystin (i.e., psilocin and norpsilocin), exhibit potent agonist activity at the serotonin 2A receptor (5-HT2A) in vitro but differ in their 5-HT2A-mediated effects in vivo. In particular, psilocin produces centrally mediated psychedelic effects in vivo, whereas norpsilocin, differing only by the loss of an N-methyl group, is devoid of psychedelic-like effects. These observations suggest that the secondary methylamine group in norpsilocin impacts its central nervous system (CNS) bioavailability but not its receptor pharmacodynamics. To test this hypothesis, eight norpsilocin derivatives were synthesized with varied secondary alkyl-, allyl-, and benzylamine groups, primarily aiming to increase their lipophilicity and brain permeability. Structure-activity relationships for the norpsilocin analogues were evaluated using the mouse head-twitch response (HTR) as a proxy for CNS-mediated psychedelic-like effects. HTR studies revealed that extending the N-methyl group of norpsilocin by a single methyl group, to give the corresponding secondary N-ethyl analogue (4-HO-NET), was sufficient to produce psilocin-like activity (median effective dose or ED50 = 1.4 mg/kg). Notably, N-allyl, N-propyl, N-isopropyl, and N-benzyl derivatives also induced psilocin-like HTR activity (ED50 = 1.1-3.2 mg/kg), with variable maximum effects (26-77 total HTR events). By contrast, adding bulkier tert-butyl or cyclohexyl groups in the same position did not elicit psilocin-like HTRs. Pharmacological assessments of the tryptamine series in vitro demonstrated interactions with multiple serotonin receptor subtypes, including 5-HT2A, and other CNS signaling proteins (e.g., sigma receptors). Overall, our data highlight key structural requirements for CNS-mediated psychedelic-like effects of norpsilocin analogues.

Assessment of Bioactivity-Modulating Pseudo-Ring Formation in Psilocin and Related Tryptamines

Psilocybin (1) is the major alkaloid found in psychedelic mushrooms and acts as a prodrug to psilocin (2, 4‐hydroxy‐N,N‐dimethyltryptamine), a potent psychedelic that exerts remarkable alteration of human consciousness. In contrast, the positional isomer bufotenin (7, 5‐hydroxy‐N,N‐dimethyltryptamine) differs significantly in its reported pharmacology. A series of experiments was designed to explore chemical differences between 2 and 7 and specifically to test the hypothesis that the C‐4 hydroxy group of 2 significantly influences the observed physical and chemical properties through pseudo‐ring formation via an intramolecular hydrogen bond (IMHB). NMR spectroscopy, accompanied by quantum chemical calculations, was employed to compare hydrogen bond behavior in 4‐ and 5‐hydroxylated tryptamines. The results provide evidence for a pseudo‐ring in 2 and that sidechain/hydroxyl interactions in 4‐hydroxytryptamines influence their oxidation kinetics. We conclude that the propensity to form IMHBs leads to a higher number of uncharged species that easily cross the blood‐brain barrier, compared to 7 and other 5‐hydroxytryptamines, which cannot form IMHBs. Our work helps understand a fundamental aspect of the pharmacology of 2 and should support efforts to introduce it (via the prodrug 1) as an urgently needed therapeutic against major depressive disorder.

Evaluation of the Cytotoxicity of Ayahuasca Beverages

Ayahuasca is a beverage consumed at shamanic ceremonies and currently has gained popularity on recreational scenarios. It contains beta-carboline alkaloids and N,N-dimethyltryptamine, which possesses hallucinogenic effects. Only a few studies have elicited the psychoactive effects and the dose of such compounds on neurological dopaminergic cells or animals. In this work, we aimed to study the cytotoxic effects of these compounds present in ayahuasca beverages and on five different teas (Banisteriopsis caapi, Psychotria viridis, Peganum harmala, Mimosa tenuiflora and Dc Ab (commercial name)) preparations on dopaminergic immortalized cell lines. Moreover, a characterization of the derivative alkaloids was also performed. All the extracts were characterized by chromatographic systems and the effect of those compounds in cell viability and total protein levels were analyzed in N27 dopaminergic neurons cell line. This is the first article where cytotoxicity of ayahuasca tea is studied on neurological dopaminergic cells. Overall, results showed that both cell viability and protein contents decreased when cells were exposed to the individual compounds, as well as to the teas and to the two mixtures based on the traditional ayahuasca beverages.

Toxicokinetics and Toxicodynamics of Ayahuasca Alkaloids N,N-Dimethyltryptamine (DMT), Harmine, Harmaline and Tetrahydroharmine: Clinical and Forensic Impact

Ayahuasca is a hallucinogenic botanical beverage originally used by indigenous Amazonian tribes in religious ceremonies and therapeutic practices. While ethnobotanical surveys still indicate its spiritual and medicinal uses, consumption of ayahuasca has been progressively related with a recreational purpose, particularly in Western societies. The ayahuasca aqueous concoction is typically prepared from the leaves of the N,N-dimethyltryptamine (DMT)-containing Psychotria viridis, and the stem and bark of Banisteriopsis caapi, the plant source of harmala alkaloids. Herein, the toxicokinetics and toxicodynamics of the psychoactive DMT and harmala alkaloids harmine, harmaline and tetrahydroharmine, are comprehensively covered, particularly emphasizing the psychological, physiological, and toxic effects deriving from their concomitant intake. Potential therapeutic utility, particularly in mental and psychiatric disorders, and forensic aspects of DMT and ayahuasca are also reviewed and discussed. Following administration of ayahuasca, DMT is rapidly absorbed and distributed. Harmala alkaloids act as potent inhibitors of monoamine oxidase A (MAO-A), preventing extensive first-pass degradation of DMT into 3-indole-acetic acid (3-IAA), and enabling sufficient amounts of DMT to reach the brain. DMT has affinity for a variety of serotonergic and non-serotonergic receptors, though its psychotropic effects are mainly related with the activation of serotonin receptors type 2A (5-HT_2A). Mildly to rarely severe psychedelic adverse effects are reported for ayahuasca or its alkaloids individually, but abuse does not lead to dependence or tolerance. For a long time, the evidence has pointed to potential psychotherapeutic benefits in the treatment of depression, anxiety, and substance abuse disorders; and although misuse of ayahuasca has been diverting attention away from such clinical potential, research onto its therapeutic effects has now strongly resurged.

Understanding the neurobiological effects of drug abuse: Lessons from zebrafish models

Drug abuse and brain disorders related to drug comsumption are public health problems with harmful individual and social consequences. The identification of therapeutic targets and precise pharmacological treatments to these neuropsychiatric conditions associated with drug abuse are urgently needed. Understanding the link between neurobiological mechanisms and behavior is a key aspect of elucidating drug abuse-related targets. Due to various molecular, biochemical, pharmacological, and physiological features, the zebrafish (Danio rerio) has been considered a suitable vertebrate for modeling complex processes involved in drug abuse responses. In this review, we discuss how the zebrafish has been successfully used for modeling neurobehavioral phenotypes related to drug abuse and review the effects of opioids, cannabinoids, alcohol, nicotine, and psychedelic drugs on the central nervous system (CNS). Moreover, we summarize recent advances in zebrafish-based studies and outline potential advantages and limitations of the existing zebrafish models to explore the neurochemical bases of drug abuse and addiction. Finally, we discuss how the use of zebrafish models may present fruitful approaches to provide valuable clinically translatable data.

Toxicological Aspects and Determination of the Main Components of Ayahuasca: A Critical Review

Ayahuasca is a psychoactive beverage prepared traditionally from a mixture of the leaves and stems of Psychotria viridis and Banisteriopsis caapi, respectively, being originally consumed by indigenous Amazonian tribes for ritual and medicinal purposes. Over the years, its use has spread to other populations as a means to personal growth and spiritual connection. Also, the recreational use of its isolated compounds has become prominent. The main compounds of this tea-like preparation are N,N-dimethyltryptamine (DMT), β-Carbolines, and harmala alkaloids, such as harmine, tetrahydroharmine, and harmaline. The latter are monoamine-oxidase inhibitors and are responsible for DMT psychoactive and hallucinogenic effects on the central nervous system. Although consumers defend its use, its metabolic effects and those on the central nervous system are not fully understood yet. The majority of studies regarding the effects of this beverage and of its individual compounds are based on in vivo experiments, clinical trials, and even surveys. This paper will not only address the toxicological aspects of the ayahuasca compounds but also perform a comprehensive and critical review on the analytical methods available for their determination in biological and non-biological specimens, with special focus on instrumental developments and sample preparation approaches.

Validation of an analytical method for the determination of the main ayahuasca active compounds and application to real ayahuasca samples from Brazil

Ayahuasca is a brew prepared from the water decoction of two Amazonian plants, which is legally used for religious, cultural or therapeutic activities. The potential use of ayahuasca as a natural or phytotherapeutic drug is directly linked to the action of its active compounds and their connection with the therapeutic efficacy of the beverage. In this context, the aim of the present study was to establish a selective, sensitive and reproducible analytical method for the quantification of the main active ayahuasca compounds. Thirty-eight samples from the state of São Paulo, Brazil, were analyzed and the simultaneous quantifications of N,N-dimethyltryptamine (DMT), tetrahydroharmine (THH), harmine (HME) and harmaline (HML) were performed. This study enabled the development of a fast validated analytical method with minimal matrix interference and high reproducibility for the tracing of active ayahuasca compound concentrations for the first time. This method is important as an auxiliary tool for the study of active compound effects in biological responses using different multi-omic platforms.

Mutagenicity of Ayahuasca and Their Constituents to the Salmonella/Microsome Assay

Ayahuasca is a beverage used in religious rituals of indigenous and nonindigenous groups, and its therapeutic potential has been investigated. Ayahuasca is obtained by decoction of the Banisteriopsis caapi that contains β-carbolines (harmine, harmaline, and tetrahydroharmine) plus Psychotria viridis that contains N,N-dimethyltryptamine. Although plants used in folk medicine are recognized as safe, many of them have genotoxic potential. The Salmonella/microsome assay is usually the first line of the mutagenicity evaluation of products intended for therapeutic use. Our objective was to evaluate the mutagenicity of ayahuasca beverage and their constituents using the Salmonella/microsome assay with TA98 and TA100. We analyzed two ayahuasca samples, and also beverage samples prepared each individual plant P. viridis and B. caapi. Harmine and harmaline were also tested. All beverage samples were chemically characterized and both ayahuasca samples could be considered representative of the beverages consumed in religious rituals. Both ayahuasca samples were mutagenic for TA98 and TA100 with and without S9, with similar potencies. The beverage obtained from P. viridis was not mutagenic, and beverage obtained from B. caapi was mutagenic for TA98 with and without S9. Harmine was nonmutagenic and harmaline was mutagenic only for TA98 without S9. Harmaline fully explain the mutagenicity observed with TA98 without S9 of both ayahuasca samples and the B. caapi beverage samples. We conclude that the ayahuasca samples are mutagenic and this effect is partially explained by harmaline, one of the β-carbolines present in the beverage. Other mutagenic compounds seem to be present and need to be further investigated. Environ. Mol. Mutagen. 60:269-276, 2019. © 2018 Wiley Periodicals, Inc.

Effect of Ritualistic Consumption of Ayahuasca on Hepatic Function in Chronic Users

Ayahuasca is a beverage obtained from decoctions of the liana Banisteriopsis caapi plus the shrub Psychotria viridis. This beverage contains a combination of monoamine oxidase inhibitors (harmine, harmaline, and tetrahydroharmine) and N,N-dimethyltryptamine, the main substance responsible for its visionary effect. The ritualistic use of ayahuasca is becoming a global phenomenon. Most members of ayahuasca churches consume this beverage throughout their life, and many reports have discussed the therapeutic potential of this beverage. Ayahuasca is consumed orally, and the liver, as the major organ for the metabolism and detoxification of xenobiotics absorbed from the alimentary tract, may be susceptible to injury by compounds present in the ayahuasca decoction. In this study, we evaluated biochemical parameters related to hepatic damage in the serum of 22 volunteers who consumed ayahuasca twice a month or more for at least one year. There was no significant alteration in the following parameters: alanine aminotransferase, aspartate aminotransferase, bilirubin, creatinine, urea, lactate dehydrogenase, alkaline phosphatase, and gamma glutamyl transferase. These findings indicate that chronic ayahuasca consumption in a religious context apparently does not affect hepatic function.

The epidemiology of 5-methoxy- N, N-dimethyltryptamine (5-MeO-DMT) use: Benefits, consequences, patterns of use, subjective effects, and reasons for consumption

BACKGROUND/AIM

5-Methoxy- N,N-dimethyltryptamine (5-MeO-DMT) is a psychoactive compound found in several plants and in high concentrations in Bufo alvarius toad venom. Synthetic, toad, and plant-sourced 5-MeO-DMT are used for spiritual and recreational purposes and may have psychotherapeutic effects. However, the use of 5-MeO-DMT is not well understood. Therefore, we examined patterns of use, motivations for consumption, subjective effects, and potential benefits and consequences associated with 5-MeO-DMT use.

METHODS

Using internet-based advertisements, 515 respondents ( M_age=35.4. SD=11.7; male=79%; White/Caucasian=86%; United States resident=42%) completed a web-based survey.

RESULTS

Most respondents consumed 5-MeO-DMT infrequently (<once/year), for spiritual exploration, and had used less than four times in their lifetime. The majority (average of 90%) reported moderate-to-strong mystical-type experiences ( M_intensity=3.64, SD=1.11; range 0-5; e.g., ineffability, timelessness, awe/amazement, experience of pure being/awareness), and relatively fewer (average of 37%) experienced very slight challenging experiences ( M_intensity=0.95, SD=0.91; range 0-5; e.g., anxiousness, fear). Less than half (39%) reported repeated consumption during the same session, and very few reported drug craving/desire (8%), or legal (1%), medical (1%), or psychiatric (1%) problems related to use. Furthermore, of those who reported being diagnosed with psychiatric disorders, the majority reported improvements in symptoms following 5-MeO-DMT use, including improvements related to post-traumatic stress disorder (79%), depression (77%), anxiety (69%), and alcoholism (66%) or drug use disorder (60%).

CONCLUSION

Findings suggest that 5-MeO-DMT is used infrequently, predominantly for spiritual exploration, has low potential for addiction, and might have psychotherapeutic effects. Future research should examine the safety and pharmacokinetics of 5-MeO-DMT administration in humans using rigorous experimental designs.

Biological Effects and Biodistribution of Bufotenine on Mice

Bufotenine is an alkaloid derived from serotonin, structurally similar to LSD and psilocin. This molecule is able to inhibit the rabies virus infection in in vitro and in vivo models, increasing the survival rate of infected animals. Being a very promising molecule for an incurable disease and because of the fact that there is no consensus regarding its neurological effects, this study aimed to evaluate chronic treatment of bufotenine on behavior, pathophysiology, and pharmacokinetics of mice. Animals were daily treated for 21 consecutive days with 0.63, 1.05, and 2.1 mg/animal/day bufotenine and evaluated by open field test and physiological parameters during all the experiment. After this period, organs were collected for histopathological and biodistribution analysis. Animals treated with bufotenine had mild behavioral alterations compared to the control group, being dose-response relationship. On the other hand, animals showed normal physiological functions and no histological alterations in the organs. With high doses, an inflammatory reaction was observed in the site of injection, but with no cellular damage. The alkaloid could be found in the heart and kidney with all doses and in the lungs and brain with higher doses. These results show that the effective dose, 0.63 mg/day, is safe to be administered in mice, since it did not cause significant effects on the animals' physiology and on the CNS. Higher doses were well tolerated, causing only mild behavioral effects. Thus, bufotenine might be a drug prototype for rabies treatment, an incurable disease.

Indolethylamine-N-methyltransferase Polymorphisms: Genetic and Biochemical Approaches for Study of Endogenous N,N,-dimethyltryptamine

N,N-dimethyltryptamine (DMT) is a powerful serotonergic psychedelic whose exogenous administration elicits striking psychedelic effects in humans. Studies have identified DMT and analogous compounds (e.g., 5-hydroxy-DMT, 5-methoxy-DMT) alongside of an enzyme capable of synthesizing DMT endogenously from tryptamine, indolethylamine-N-methyltransferase (INMT), in human and several other mammalian tissues. Subsequently, multiple hypotheses for the physiological role of endogenous DMT have emerged, from proposed immunomodulatory functions to an emphasis on the overlap between the mental states generated by exogenous DMT and naturally occurring altered states of consciousness; e.g., schizophrenia. However, no clear relationship between endogenous DMT and naturally occurring altered states of consciousness has yet been established from in vivo assays of DMT in bodily fluids. The advent of genetic screening has afforded the capability to link alterations in the sequence of specific genes to behavioral and molecular phenotypes via expression of identified single nucleotide polymorphisms (SNPs) in cell and animal models. As SNPs in INMT may impact endogenous DMT synthesis and levels via changes in INMT expression and/or INMT structure and function, these combined genetic and biochemical approaches circumvent the limitations of assaying DMT in bodily fluids and may augment data from prior in vitro and in vivo work. Therefore, all reported SNPs in INMT were amassed from genetic and biochemical literature and genomic databases to consolidate a blueprint for future studies aimed at elucidating whether DMT plays a physiological role.

NPS: Medical Consequences Associated with Their Intake

Over the last decade, the 'traditional' drug scene has been supplemented - but not replaced - by the emergence of a range of novel psychoactive substances (NPS), which are either newly created or existing drugs, including medications, now being used in novel ways. By the end of 2014, in excess of 500 NPS had been reported by a large number of countries in the world. Most recent data show, however, that synthetic cathinones, synthetic cannabinoids, and psychedelics/phenethylamines account for the largest number of NPS.The present chapter aims at providing an overview of the clinical and pharmacological issues relating to these most popular NPS categories. Given the vast range of medical and psychopathological issues associated with the molecules here described, it is crucial for health professionals to be aware of the effects and toxicity of NPS. A general overview of the acute management of NPS adverse events is provided as well, although further studies are required to identify a range of evidence-based, index molecule-focused, treatment strategies. The rapid pace of change in the NPS online market constitutes a major challenge to the provision of current and reliable scientific knowledge on these substances.

The Therapeutic Potentials of Ayahuasca: Possible Effects against Various Diseases of Civilization

Ayahuasca is an Amazonian psychoactive brew of two main components. Its active agents are β-carboline and tryptamine derivatives. As a sacrament, ayahuasca is still a central element of many healing ceremonies in the Amazon Basin and its ritual consumption has become common among the mestizo populations of South America. Ayahuasca use amongst the indigenous people of the Amazon is a form of traditional medicine and cultural psychiatry. During the last two decades, the substance has become increasingly known among both scientists and laymen, and currently its use is spreading all over in the Western world. In the present paper we describe the chief characteristics of ayahuasca, discuss important questions raised about its use, and provide an overview of the scientific research supporting its potential therapeutic benefits. A growing number of studies indicate that the psychotherapeutic potential of ayahuasca is based mostly on the strong serotonergic effects, whereas the sigma-1 receptor (Sig-1R) agonist effect of its active ingredient dimethyltryptamine raises the possibility that the ethnomedical observations on the diversity of treated conditions can be scientifically verified. Moreover, in the right therapeutic or ritual setting with proper preparation and mindset of the user, followed by subsequent integration of the experience, ayahuasca has proven effective in the treatment of substance dependence. This article has two important take-home messages: (1) the therapeutic effects of ayahuasca are best understood from a bio-psycho-socio-spiritual model, and (2) on the biological level ayahuasca may act against chronic low grade inflammation and oxidative stress via the Sig-1R which can explain its widespread therapeutic indications.

New World Tryptamine Hallucinogens and the Neuroscience of Ayahuasca

New World indigenous peoples are noted for their sophisticated use of psychedelic plants in shamanic and ethnomedical practices. The use of psychedelic plant preparations among New World tribes is far more prevalent than in the Old World. Yet, although these preparations are botanically diverse, almost all are chemically similar in that their active principles are tryptamine derivatives, either DMT or related constituents. Part 1 of this paper provides an ethnopharmacological overview of the major tryptamine-containing New WorldNew World hallucinogensHallucinogens .

Novel psychoactive substances of interest for psychiatry

Novel psychoactive substances include synthetic cannabinoids, cathinone derivatives, psychedelic phenethylamines, novel stimulants, synthetic opioids, tryptamine derivatives, phencyclidine-like dissociatives, piperazines, GABA-A/B receptor agonists, a range of prescribed medications, psychoactive plants/herbs, and a large series of performance and image enhancing drugs. Users are typically attracted by these substances due to their intense psychoactive effects and likely lack of detection in routine drug screenings. This paper aims at providing psychiatrists with updated knowledge of the clinical pharmacology and psychopathological consequences of the use of these substances. Indeed, these drugs act on a range of neurotransmitter pathways/receptors whose imbalance has been associated with psychopathological conditions, including dopamine, cannabinoid CB1, GABA-A/B, 5-HT2A, glutamate, and k opioid receptors. An overall approach in terms of clinical management is briefly discussed.

An analysis of the synthetic tryptamines AMT and 5-MeO-DALT: emerging 'Novel Psychoactive Drugs'

Novel Psychoactive Drugs (NPD) can be sold without restriction and are often synthetic analogues of controlled drugs. The tryptamines are an important class of NPD as they bind to the various serotonin (5-HT) receptor subtypes and cause psychosis and hallucinations that can lead to injury or death through misadventure. Here we report on the structure elucidation and receptor binding profiles of two widely marketed tryptamine-derived NPDs, namely alpha-methyl-tryptamine and 5-methoxy-N,N-diallyl-tryptamine.

Methodology for determining major constituents of ayahuasca and their metabolites in blood

There is an increasing interest in potential medical applications of ayahuasca, a South American psychotropic plant tea with a long cultural history of indigenous medical and religious use. Clinical research into ayahuasca will require specific, sensitive and comprehensive methods for the characterization and quantitation of these compounds and their metabolites in blood. A combination of two analytical techniques (high-performance liquid chromatography with ultraviolet and/or fluorescence detection and gas chromatography with nitrogen-phosphorus detection) has been used for the analysis of some of the constituents of ayahuasca in blood following its oral consumption. We report here a single methodology for the direct analysis of 14 of the major alkaloid components of ayahuasca, including several known and potential metabolites of N,N-dimethyltryptamine and the harmala alkaloids in blood. The method uses 96-well plate/protein precipitation/filtration for plasma samples, and analysis by HPLC-ion trap-ion trap-mass spectrometry using heated electrospray ionization to reduce matrix effects. The method expands the list of compounds capable of being monitored in blood following ayahuasca administration while providing a simplified approach to their analysis. The method has adequate sensitivity, specificity and reproducibility to make it useful for clinical research with ayahuasca.

Methodology for and the determination of the major constituents and metabolites of the Amazonian botanical medicine ayahuasca in human urine

Ayahuasca, also known as caapi or yage among various South American groups, holds a highly esteemed and millennia-old position in these cultures' medical and religious pharmacopeia. There is now an increasing interest in the potential for modern medical applications of ayahuasca, as well as concerns regarding its increasing potential for abuse. Toxicological and clinical research to address these issues will require information regarding its metabolism and clearance. Thus, a rapid, sensitive and specific method for characterization and quantitation of the major constituents and of the metabolites of ayahuasca in urine is needed. The present research provides a protocol for conducting such analyses. The characteristics of the method, conducted by sample dilution and using HPLC-electrospray ionization (ESI)-selected reaction monitoring (SRM)-tandem mass spectrometry, are presented. The application of the analytical protocol to urine samples collected from three individuals that were administered ayahuasca has also been demonstrated. The data show that the major metabolite of the hallucinogenic component of ayahuasca, N,N-dimethyltryptamine (DMT), is the corresponding N-oxide, the first time this metabolite has been described in in vivo studies in humans. Further, very little DMT was detected in urine, despite the inhibition of monoamine oxidase afforded by the presence of the harmala alkaloids in ayahuasca. The major harmala alkaloid excreted was tetrahydroharmine. Other excretion products and metabolites were also identified and quantified. The method described would be suitable for use in further toxicological and clinical research on ayahuasca.

Direct analysis of psychoactive tryptamine and harmala alkaloids in the Amazonian botanical medicine ayahuasca by liquid chromatography-electrospray ionization-tandem mass spectrometry

A direct injection/liquid chromatography-electrospray ionization-tandem mass spectrometry procedure has been developed for the simultaneous quantitation of 11 compounds potentially found in the increasingly popular Amazonian botanical medicine and religious sacrament ayahuasca. The method utilizes a deuterated internal standard for quantitation and affords rapid detection of the alkaloids by a simple dilution assay, requiring no extraction procedures. Further, the method demonstrates a high degree of specificity for the compounds in question, as well as low limits of detection and quantitation despite using samples for analysis that had been diluted up to 200:1. This approach also appears to eliminate potential matrix effects. Method bias for each compound, examined over a range of concentrations, was also determined as was inter- and intra-assay variation. Its application to the analysis of three different ayahuasca preparations is also described. This method should prove useful in the study of ayahuasca in clinical and ethnobotanical research as well as in forensic examinations of ayahuasca preparations.

Identification of N,N-dimethyltryptamine and beta-carbolines in psychotropic ayahuasca beverage

Recently many people have shown great interest in traditional indigenous practices and popular medicine, involving the ingestion of natural psychotropic drugs. We received a request to analyze and determine the nature of a dark green liquid with a dark brown plant sediment, which the police had seized at an airport and inside the home of a person belonging to the 'Santo Daime' religious movement. Gas chromatography/mass spectrometry analysis of the extract identified N,N-dimethyltryptamine, a potent hallucinogen, and the beta-carboline alkaloids harmine and harmaline, revealing monoamine oxidase A-inhibiting properties. These substances are typical components of Ayahuasca, a South American psychotropic beverage obtained by boiling the bark of the liana Banisteriopsis caapi together with the leaves of various admixture plants, principally Psychotria viridis.

Assessment of the roles of serines 5.43(239) and 5.46(242) for binding and potency of agonist ligands at the human serotonin 5-HT2A receptor

We assessed the relative importance of two serine residues located near the top of transmembrane helix 5 of the human 5-HT(2A) receptor, comparing the wild type with S5.43(239)A or S5.46(242)A mutations. Using the ergoline lysergic acid diethylamide (LSD), and a series of substituted tryptamine and phenethylamine 5-HT(2A) receptor agonists, we found that Ser5.43(239) is more critical for agonist binding and function than Ser5.46(242). Ser5.43(239) seems to engage oxygen substituents at either the 4- or 5-position of tryptamine ligands and the 5-position of phenylalkylamine ligands. Even when a direct binding interaction cannot occur, our data suggest that Ser5.43(239) is still important for receptor activation. Polar ring-substituted tryptamine ligands also seem to engage Ser5.46(242), but tryptamines lacking such a substituent may adopt an alternate binding orientation that does not engage this residue. Our results are consistent with the role of Ser5.43(239) as a hydrogen bond donor, whereas Ser5.46(242) seems to serve as a hydrogen bond acceptor. These results are consistent with the functional topography and utility of our in silico-activated homology model of the h5-HT(2A) receptor. In addition, being more distal from the absolutely conserved Pro5.50, a strong interaction with Ser5.43(239) may be more effective in straightening the kink in helix 5, a feature that is possibly common to all type A GPCRs that have polar residues at position 5.43.

Tetrahydro-beta-carboline derivatives in aged garlic extract show antioxidant properties

This study used the hydroden peroxide scavenging assay to investigate antioxidant chemical constituents derived and separated from aged garlic extract, a unique garlic extract produced by soaking sliced garlic in an aqueous ethanol solution for >10 mo. Four types of 1, 2, 3, 4-tetrahydro-beta-carboline derivatives (THbetaCs); 1-methyl-1, 2, 3, 4-tetrahydro-beta-carboline-3-carboxylic acid, and 1-methyl-1, 2, 3, 4-tetrahydro-beta-carboline-1, 3-dicarboxylic acid (MTCdiC), from both diastereoisomers, were isolated and identified by use of liquid chromatography-mass spectrometry. All these compounds indicate strong hydrogen peroxide scavenging activities and inhibit 2, 2'-azobis(2-amidinopropane) hydrochloride-induced lipid peroxidation. Particularly, (1S, 3S)-MTCdiC had the most potent hydrogen peroxide scavenging activity, more than ascorbic acid. The (1R, 3S)- and (1S, 3S)-MTCdiC at 50-100 micromol/L and 10-100 micromol/L inhibited LPS-induced nitrite production. Interestingly, THbetaCs were not detected in raw garlic and other processed garlic preparations, but they were generated and increased during the natural aging garlic extraction process. These data suggest that THbetaCs, which are formed during the natural aging process, are potent antioxidants in aged garlic extract and thus may be useful for the prevention of diseases associated with oxidative damage.

Simultaneous determination of nineteen hallucinogenic tryptamines/β-calbolines and phenethylamines using gas chromatography–mass spectrometry and liquid chromatography–electrospray ionisation-mass spectrometry

To investigate the trend of non-controlled drugs of abuse, simultaneous analytical methods were developed using GC-MS and LC-ESI-MS for 8 tryptamines/beta-carbolines, 6 phenethylamines of typically non-controlled substances in Japan, and, additionally, five legally controlled tryptamines and phenethylamines originally found in fungi or plants. Moreover, the proposed methods were applied to analyses of these drugs in 99 kinds of products (a total number of 123 products purchased at adult shops or via the Internet over the past 2 years in Japan), which potentially advertised psychotropic/psychoactive effects. The samples were extracted with methanol under ultrasonication. After centrifugation, the extracts were filtered prior to injections. GC-MS analysis was performed using a DB-5MS capillary column. Regarding the LC-ESI-MS analysis; the separation of the target drugs was optimized on an ODS column in acetonitrile/MeOH (7:3)-10 mM ammonium formate buffer (pH 3.5)/acetonitrile (95:5) by a linear gradient program and a quantitative analysis was carried out by the monitoring of each [M+H]+ in the positive ion mode of ESI-MS. As a result of the analyses using GC-MS and LC-ESI-MS, 5-MeO-DIPT (the synthetic substance known by the street name "Foxy") was found in 8 out of the 99 kinds of products. Additionally, AMT (from brown powder), DMT (from dried plant), harmine and harmaline (from dried plant) were also found in some of the 99 products. These analytical methods could be useful for the investigation of the distribution of the non-controlled psychotropic tryptamines/beta-carbolines and phenethylamines in the market.

Sensitive determination of alpha-methyltryptamine (AMT) and 5-methoxy-N,N-diisopropyltryptamine (5MeO-DIPT) in whole blood and urine using gas chromatography–mass spectrometry

We devised a sensitive and simple method to determine alpha-methyltryptamine (AMT) and 5-methoxy-N,N-diisopropyltryptamine (5MeO-DIPT) in whole blood and urine, using gas chromatography-mass spectrometry (GC-MS). AMT and 5MeO-DIPT were extracted using an Extrelut column with an internal standard, bupivacaine, followed by derivatization with acetic anhydride. The derivatized extract was used for GC-MS analysis of EI-SIM mode. The calibration curves of AMT and 5MeO-DIPT were linear in the concentration range from 10 to 750 ng/ml in both blood and urine samples. The method detection limit (MDL) of AMT and 5MeO-DIPT were 1 ng/ml each in whole blood and 5 ng/ml each in urine. This method should be most useful to accurately determine the presence of these drugs in blood and urine in clinical and forensic cases.

Ayahuasca and Human Destiny

In this essay, the author shares his personal reflections gleaned from a lifetime of research with ayahuasca, and speculates on the societal, political, planetary, and evolutionary implications of humanity's aeons-old symbiosis with this shamanic plant. The thesis is developed that at this critical historical juncture, ayahuasca has developed a strategy to broadcast its message to a wider world--a reflection of the urgent need to avert global ecological catastrophe. While ayahuasca has much to teach us, the critical question is, will humanity hear it, and heed it, in time?

Harmane and harmalan are bioactive components of classical clonidine-displacing substance

Elucidation of the structure of the endogenous ligand(s) for imidazoline binding sites, clonidine-displacing substance (CDS), has been a major goal for many years. Crude CDS from bovine lung was purified by reverse-phase high-pressure liquid chromatography. Electrospray mass spectrometry (ESMS) and nuclear magnetic resonance ((1)H NMR) analysis revealed the presence of L-tryptophan and 1-carboxy-1-methyltetrahydro-beta-carboline in the active CDS extract. Competition radioligand binding studies, however, failed to show displacement of specific [(3)H]clonidine binding to rat brain membranes for either compound. Further purification of the bovine lung extract allowed the isolation of the beta-carbolines harmane and harmalan as confirmed by ESMS, (1)H NMR, and comparison with synthetic standards. Both compounds exhibited a high (nanomolar) affinity for both type 1 and type 2 imidazoline binding sites, and the synthetic standards were shown to coelute with the active classical CDS extracts. We therefore propose that the beta-carbolines harmane and harmalan represent active components of classical CDS. The identification of these compounds will allow us to establish clear physiological roles for CDS.

A diversity oriented four-component approach to tetrahydro-β-carbolines initiated by Sonogashira coupling

A consecutive four-component synthesis of highly-substituted tetrahydro-beta-carbolines can be achieved by a coupling-aminatio-aza-annulation-Pictet-Spengler (CAAPS) sequence creating five new sigma-bonds and four new stereocenters in a one-pot fashion. The structures were unambiguously supported by X-ray structure analyses.

Hallucinogens

Hallucinogens (psychedelics) are psychoactive substances that powerfully alter perception, mood, and a host of cognitive processes. They are considered physiologically safe and do not produce dependence or addiction. Their origin predates written history, and they were employed by early cultures in a variety of sociocultural and ritual contexts. In the 1950s, after the virtually contemporaneous discovery of both serotonin (5-HT) and lysergic acid diethylamide (LSD-25), early brain research focused intensely on the possibility that LSD or other hallucinogens had a serotonergic basis of action and reinforced the idea that 5-HT was an important neurotransmitter in brain. These ideas were eventually proven, and today it is believed that hallucinogens stimulate 5-HT(2A) receptors, especially those expressed on neocortical pyramidal cells. Activation of 5-HT(2A) receptors also leads to increased cortical glutamate levels presumably by a presynaptic receptor-mediated release from thalamic afferents. These findings have led to comparisons of the effects of classical hallucinogens with certain aspects of acute psychosis and to a focus on thalamocortical interactions as key to understanding both the action of these substances and the neuroanatomical sites involved in altered states of consciousness (ASC). In vivo brain imaging in humans using [(18)F]fluorodeoxyglucose has shown that hallucinogens increase prefrontal cortical metabolism, and correlations have been developed between activity in specific brain areas and psychological elements of the ASC produced by hallucinogens. The 5-HT(2A) receptor clearly plays an essential role in cognitive processing, including working memory, and ligands for this receptor may be extremely useful tools for future cognitive neuroscience research. In addition, it appears entirely possible that utility may still emerge for the use of hallucinogens in treating alcoholism, substance abuse, and certain psychiatric disorders.

Clinical investigations of the therapeutic potential of ayahuasca: rationale and regulatory challenges

Ayahuasca is a hallucinogenic beverage that is prominent in the ethnomedicine and shamanism of indigenous Amazonian tribes. Its unique pharmacology depends on the oral activity of the hallucinogen, N,N-dimethyltryptamine (DMT), which results from inhibition of monoamine oxidase (MAO) by beta-carboline alkaloids. MAO is the enzyme that normally degrades DMT in the liver and gut. Ayahuasca has long been integrated into mestizo folk medicine in the northwest Amazon. In Brazil, it is used as a sacrament by several syncretic churches. Some of these organizations have incorporated in the United States. The recreational and religious use of ayahuasca in the United States, as well as "ayahuasca tourism" in the Amazon, is increasing. The current legal status of ayahuasca or its source plants in the United States is unclear, although DMT is a Schedule I controlled substance. One ayahuasca church has received favorable rulings in 2 federal courts in response to its petition to the Department of Justice for the right to use ayahuasca under the Religious Freedom Restoration Act. A biomedical study of one of the churches, the Uñiao do Vegetal (UDV), indicated that ayahuasca may have therapeutic applications for the treatment of alcoholism, substance abuse, and possibly other disorders. Clinical studies conducted in Spain have demonstrated that ayahuasca can be used safely in normal healthy adults, but have done little to clarify its potential therapeutic uses. Because of ayahuasca's ill-defined legal status and variable botanical and chemical composition, clinical investigations in the United States, ideally under an approved Investigational New Drug (IND) protocol, are complicated by both regulatory and methodological issues. This article provides an overview of ayahuasca and discusses some of the challenges that must be overcome before it can be clinically investigated in the United States.

A novel one-pot four-component access to tetrahydro-β-carbolines by a coupling-amination-aza-annulation-Pictet–Spengler sequence (CAAPS)

The four-component coupling-amination-aza-annulation-Pictet-Spengler (CAAPS) sequence of acid chlorides 1, terminal alkynes 2, tryptamine derivatives 6, and acryloyl chloride derivatives 4 represents a facile and rapid one-pot access to tetrahydro-beta-carbolines 7 in moderate to good yields.

Snuff synergy: preparation, use and pharmacology of yopo and Banisteriopsis caapi among the Piaroa of southern Venezuela

Current understanding of the preparation and use of yopo, a hallucinogenic snuff made from the ground seeds of the Anadenanthera peregrina tree, has departed little from the accounts of scientists and travelers made over a century ago. Schultes and others have made refinements to these early accounts. While several scholars have drawn attention to the fact that little ethnographic work has been conducted to assess the ethnobotanical diversity and cultural framework of the snuff hallucinogen complex, few subsequent studies deal with botanical variations in preparation and use. This article contrasts historical accounts of yopo preparation with ethnographic data I have recently collected among the Piaroa of southern Venezuela to demonstrate one way in which yopo preparation and use deviates from the basic model established by Humboldt, Spruce and Safford. Piaroa shamans include B. caapi cuttings in the preparation of yopo and consume doses of B. caapi prior to snuff inhalation concomitant with the strength of visions desired for particular tasks. I argue that the combined use of yopo and B. caapi by Piaroa shamans is pharmacologically and ethnobotanically significant, and substantiates claims of the use of admixtures in snuff; further ethnographic investigation of the snuff hallucinogen complex is necessary.

Antioxidant effects of tetrahydro-beta-carboline derivatives identified in aged garlic extract

1,2,3,4-Tetrahydro-beta-carboline derivatives (THbetaCs) are formed through Pictet-Spengler chemical condensation between tryptophan and aldehydes during food production, storage and processing. In the present study, in order to identify the antioxidants in aged garlic extract (AGE), we fractionated it and identified four THbetaCs; 1-methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acids (MTCC) and 1-methyl-1,2,3,4-tetrahydro-beta-carboline-1,3-dicarboxylic acid (MTCdiC) in both diastereoisomers using liquid chromatography mass spectrometry (LC-MS). Interestingly, these compounds were not detected in raw garlic, but the contents increased during the natural aging process of garlic. In in vitro assay systems, all of these compounds have shown strong hydrogen peroxide scavenging activities. (1S, 3S)-MTCdiC was found to be stronger than the common antioxidant, ascorbic acid. MTCC and MTCdiC inhibited AAPH-induced lipid peroxidation. Both MTCdiCs also inhibited LPS-induced nitrite production from murine macrophages at 10-100 microM. Our data suggest that these compounds are potent antioxidants in AGE, and thus may be useful for prevention of disorders associated with oxidative stress.

Drug information libraries on the Internet

In the past several years there has been a dramatic proliferation of drug-related sites on the Internet. This article reviews the information found at selected Internet drug information libraries, and comments on its accuracy and implications. Drug-related sites were found by initially performing an Internet search on "psychoactive drugs" and then exploring links among the sites identified. Sites were chosen on the basis of comprehensiveness of information and positive or tolerant attitude toward drug use. While all classes of drugs are discussed at these sites, the primary foci of interest are synthetic and naturally occurring hallucinogens. Many of the biological materials discussed are legal and readily available. Information surveyed at these sites was largely accurate regarding the effects of various substances and biological sources of psychoactive compounds.

CONCLUSIONS

Internet drug information libraries contain large amounts of information about a wide variety of drugs, including previously little-known biological sources of hallucinogens. The availability of this information could have significant effects on patterns of drug use.

Bufotenine: toward an understanding of possible psychoactive mechanisms

A review of the neuropharmacology of the alleged hallucinogen bufotenine is presented, including recent experimental results showing activity similar to LSD and other known hallucinogens (psilocin and 5-MeO-DMT) at the purported hallucinogenic serotonin (5-HT) receptors, 5-HT2A and 5-HT2C. In addition, current reports of computer modeling of the receptors and ligand binding sites give evidence of bufotenine's ability to bind and activate these receptors. While binding and activation of the purported hallucinogenic receptors are not the full extent of the hallucinogenic signature, this evidence shows support for the rationale that the reported lack of the drug's classic hallucinogenic response in human experiments is due to poor ability to cross the blood brain barrier (BBB), not lack of activation of the appropriate brain receptors. Further evidence is reviewed that in some physiological states, some drugs with characteristics similar to bufotenine which do not normally cross the BBB, cross it and enter the brain. While direct human experimental evidence of bufotenine's hallucinogenic activity seems lacking, the above combined factors are considered, and possible explanations of bufotenine's reported psychoactivity are suggested. Additionally, updated experimental models testing the possible nature of bufotenine's hallucinogenic potential are proposed.

Electrospray ionization-tandem mass spectrometry for the analysis of tryptophan derivatives in food

Our knowledge about bioactive tryptophan derivatives in the diet is rather limited. Consequently, our attention was focused on the efficient profiling, i.e. the structure specific detection, of novel tetrahydro-beta-carbolines and tryptophan glycoconjugates in food samples. Applying HPLC-MS/MS for screening and structural characterization, numerous products derived from the reaction of tryptophan with alpha-oxo acids and carbohydrates could be identified by means of neutral loss scanning. Subsequently, product ion experiments followed by the synthesis of the respective reference compounds accomplished structure elucidation of tryptophan derivatives.

Pharmacokinetics of Hoasca alkaloids in healthy humans

N,N-Dimethyltryptamine (DMT), harmine, harmaline and tetrahydroharmine (THH) are the characteristic alkaloids found in Amazonian sacraments known as hoasca, ayahuasca, and yajè. Such beverages are characterized by the presence of these three harmala alkaloids, where harmine and harmaline reversibly inhibit monoamine oxidase A (MAO-A) while tetrahydroharmine weakly inhibits the uptake of serotonin. Together, both actions increase central and peripheral serotonergic activity while facilitating the psychoactivity of DMT. Though the use of such 'teas' has be known to western science for over 100 years, little is known of their pharmacokinetics. In this study, hoasca was prepared and administered in a ceremonial context. All four alkaloids were measured in the tea and in the plasma of 15 volunteers, subsequent to the ingestion of 2 ml hoasca/kg body weight, using gas (GC) and high pressure liquid chromatographic (HPLC) methods. Pharmacokinetic parameters were calculated and peak times of psychoactivity coincided with high alkaloid concentrations, particularly DMT which had an average Tmax of 107.5 +/- 32.5 min. While DMT parameters correlated with those of harmine, THH showed a pharmacokinetic profile relatively independent of harmine's.

Synthesis and serotonin receptor affinities of a series of trans-2-(indol-3-yl)cyclopropylamine derivatives

A series of four racemic ring-substituted trans-2-(indol-3-yl)cyclopropylamine derivatives was synthesized and tested for affinity at the 5-HT1A receptor, by competition with [3H]-8-OH-DPAT in rat hippocampal homogenates, and for affinity at the agonist-labeled cloned human 5-HT2A, 5-HT2B, and 5-HT2C receptor subtypes. None of the compounds had high affinity for the 5-HT1A receptor, with the 5-methoxy substitution being most potent (40 nM). At the 5-HT2A and 5-HT2B receptor isoforms, most of the compounds lacked high affinity. At the 5-HT2C receptor, however, affinities were considerably higher. The 5-fluoro-substituted compound was most potent, with a Ki at the 5-HT2C receptor of 1.9 nM. In addition, the 1R,2S-(-) and 1S,2R-(+) enantiomers of the unsubstituted compound were also evaluated at the 5-HT2 isoforms. While the 1R,2S enantiomer had higher affinity at the 5-HT2A and 5-HT2B sites, the 1S,2R isomer had highest affinity at the 5-HT2C receptor. This reversal of stereoselectivity may offer leads to the development of a selective 5-HT2C receptor agonist. The cyclopropylamine moiety therefore appears to be a good strategy for rigidification of the ethylamine side chain only for tryptamines that bind to the 5-HT2C receptor isoform.

High-performance liquid chromatography-electrospray ionisation-tandem mass spectrometry for the analysis of 1,2,3,4-tetrahydro-beta-carboline derivatives

A rapid and sensitive method is described for the detection of 1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid, 1-methyl-1,2,3,4- tetrahydro-beta-carboline-3-carboxylic acid and 1-methyl-1,2,3,4-tetrahydro-beta-carboline by electrospray ionization tandem mass spectrometry coupled to liquid chromatography. In combination with selected reaction monitoring (SRM) detection limits of 3 ng ml-1 (ca. 75 fmol on column) were established by the use of model solutions. Due to the excellent selectivity and sensitivity of SRM no sample preparation step was required prior to analysis of food samples. In addition, any artifactual formation of tetrahydro-beta-carbolines could be excluded. Application of the method revealed that all food samples analyzed contained both tetrahydro-beta-carboline-carboxylic acids at ng ml-1 to microgram ml-1 concentrations, whereas 1-methyl-1,2,3,4-tetrahydro- beta-carboline was identified in most samples as a minor constituent.