Mix of new substances psychoactive, NPS, found in blotters sold in two Colombian cities.

The new psychoactive substances (NPS) in Colombia are detected by national authorities, in blotters strip, in different circumstances and places: airports, music concerts, discos and parks. Blotters are marketed as LSD and cause several cases of intoxication and death in some consumers: due to acute intoxication or when mixed with other drugs and may have different effects on the central nervous system (CNS). This study was conducted to research into and identify the chemical composition of the drugs impregnated in the blotters sold in two Colombian cities. This research provides the analysis of 70 doses coming from forensic cases of the Colombian Attorney General's Office in Bogota and from the Laboratory of Narcotics of the Colombian National Institute of Legal Medicine and Forensic Sciences (North Headquarter) in Barranquilla. Mixtures of drugs, such as DOB, 25I-NBOMe, MDMA and 25I-NBOMe imine were found within the blotters through gas chromatography coupled to mass spectrometry (CGMS); these drugs are classified by international authorities as NPS belonging to the phenylethylamines group. The results clearly warn about a growing public health problem in the country.

Comparison of the behavioral responses induced by phenylalkylamine hallucinogens and their tetrahydrobenzodifuran ("FLY") and benzodifuran ("DragonFLY") analogs.

In recent years, rigid analogs of phenylalkylamine hallucinogens have appeared as recreational drugs. Examples include 2-(8-bromo-2,3,6,7-tetrahydrobenzo[1,2-b:4,5-b']difuran-4-yl)ethan-1-amine (2C-B-FLY) and 1-(8-bromobenzo[1,2-b;4,5-b']difuran-4-yl)-2-aminopropane (Bromo-DragonFLY, DOB-DFLY). Although some rigid compounds such as DOB-DFLY reportedly have higher potency than their non-rigid counterparts, it is not clear whether the same is true for 2C-B-FLY and other tetrahydrobenzodifurans. In the present study, the head twitch response (HTR), a 5-HT2A receptor-mediated behavior induced by serotonergic hallucinogens, was used to assess the effects of 2,5-dimethoxy-4-bromoamphetamine (DOB) and its α-desmethyl homologue 2,5-dimethoxy-4-bromophenethylamine (2C-B), as well as their benzodifuranyl and tetrahydrobenzodifuranyl analogs, in C57BL/6J mice. DOB (ED50 = 0.75 µmol/kg) and 2C-B (ED50 = 2.43 µmol/kg) induced the HTR. The benzodifurans DOB-DFLY (ED50 = 0.20 µmol/kg) and 2C-B-DFLY (ED50 = 1.07 µmol/kg) had significantly higher potency than DOB and 2C-B, respectively. The tetrahydrobenzodifurans DOB-FLY (ED50 = 0.67 µmol/kg) and 2C-B-FLY (ED50 = 1.79 µmol/kg), by contrast, were approximately equipotent with their non-rigid counterparts. Three novel tetrahydrobenzodifurans (2C-I-FLY, 2C-E-FLY and 2C-EF-FLY) were also active in the HTR assay but had relatively low potency. In summary, the in vivo potency of 2,5-dimethoxyphenylalkylamines is enhanced when the 2- and 5-methoxy groups are incorporated into aromatic furan rings, whereas potency is not altered if the methoxy groups are incorporated into dihydrofuran rings. The potency relationships for these compounds in mice closely parallel the human hallucinogenic data. The high potency of DOB-DFLY is probably linked to the presence of two structural features (a benzodifuran nucleus and an α-methyl group) known to enhance the potency of phenylalkylamine hallucinogens.

Rewarding and reinforcing effects of 4-chloro-2,5-dimethoxyamphetamine and AH-7921 in rodents.

New psychoactive substances (NPSs), i.e., newly designed substances with chemical residues that are slightly different from those of known psychoactive substances, have been emerging since the late 2000s, and social problems related to the use of these substances are increasing globally. Two such NPSs are 4-chloro-2,5-dimethoxyamphetamine (DOC), a psychedelic substance that is structurally related to amphetamine, and AH-7921, an opioid analgesic that is used for recreational purposes and has a potency similar to that of morphine. Currently, scientific evidence for the dependence liability or toxicity of NPSs is lacking. Therefore, in this study, we performed animal behavioral tests to evaluate the dependence liability of DOC and AH-7921. The rewarding and reinforcing effects of DOC and AH-7921 were evaluated using the conditioned place preference (CPP) paradigm in mice and the self-administration (SA) procedure in rats. Both DOC and AH-7921 increased the preference for the drug-paired compartment in the CPP test at a dose of 0.3 mg/kg and increased the number of responses to the active lever in the SA test at 0.01 mg/(kg·infusion). Collectively, the data suggest that DOC and AH-7921 may have both rewarding and reinforcing effects. Further studies are needed to confirm the reinforcing effects in broader dose ranges with various schedules.

Abuse potential of methylenedioxymethamphetamine (MDMA) and its derivatives in zebrafish: role of serotonin 5HT2-type receptors.

RATIONALE: The synthetic phenethylamines are recreational drugs known to produce psychostimulant effects. However, their abuse potential has not been widely studied. OBJECTIVES: Here, we investigated the rewarding and the hallucinatory effects of 2,5-dimetoxy-4-bromo-amphetamine hydrobromide (DOB) and para-methoxyamphetamine (PMA) in comparison with the classical 3,4-methylenedioxymethamphetamine (MDMA). In addition, the role of serotonin 5-HT2-like receptor on the abovementioned effects was evaluated. METHODS: Zebrafish were intramuscularly (i.m.) treated with a wide range of doses of DOB (0.1-20 mg/kg), PMA (0.0005-2 mg/kg), or MDMA (0.5-160 mg/kg). Animals were submitted to a conditioned place preference (CPP) task, to investigation of the rewarding properties, and to the evaluation of hallucinatory behavior in terms of appearance of a trance-like behavior. The serotonin 5-HT2 subtype receptor antagonist ritanserin (0.025-2.5 mg/kg) in association with the maximal effective dose of MDMA, DOB, and PMA was given i.m., and the effect on CPP or hallucinatory behavior was evaluated. RESULTS: MDMA and its derivatives exhibited CPP in a biphasic fashion, being PMA the most potent. This effect was accompanied, for DOB (2 mg/kg) and PMA (0.1 mg/kg), by a trance-like hallucinatory behavior. MDMA at a high dose as 160 mg/kg did not induce any hallucinatory behavior. Ritanserin significantly blocked the rewarding and hallucinatory effects suggesting the involvement of serotonin 5HT2 subtype receptor. CONCLUSION: Collectively, these findings demonstrate for the first time that the rewarding properties of DOB and PMA are accompanied by hallucinatory behavior through a serotonergic system and reinforce zebrafish as an emerging experimental model for screening new hallucinogens.

Identification and quantitation of 4-bromo-2,5-dimethoxyamphetamine in seized blotters.

Blotters are usually impregnated with hallucinogens such as lysergic acid diethylamide (LSD); only rarely other psychoactive substances are detected. In this work we identified 4-bromo-2,5-dimethoxyamphetamine (DOB) and 2,5-dimethoxyamphetamine (DMA) in illicit blotters seized in Italy. This report describes a rapid method for the simultaneous identification and quantitation of DOB and its precursor (DMA) by liquid chromatography tandem mass spectrometry (LC-MS-MS), using 2,3-dimethoxyphenethylamine-d3 as internal standard. Regression equations were linear over the tested concentration range with good correlation coefficients. The achieved levels of sensitivity may be suitable to confirm the possible presence of DOB and DMA also in low concentration or in traces in seized material for forensic analysis. The developed method showed good reproducibility and sensitivity, and could be used for similar routine analysis. To our knowledge, this is the first report describing the detection of DOB and DMA from blotters.

Tolerance to LSD and DOB induced shaking behaviour: differential adaptations of frontocortical 5-HT(2A) and glutamate receptor binding sites.

Serotonergic hallucinogens, such as lysergic acid diethylamide (LSD) and dimethoxy-bromoamphetamine (DOB), provoke stereotype-like shaking behaviour in rodents, which is hypothesised to engage frontocortical glutamate receptor activation secondary to serotonin2A (5-HT2A) related glutamate release. Challenging this hypothesis, we here investigate whether tolerance to LSD and DOB correlates with frontocortical adaptations of 5-HT2A and/or overall-glutamate binding sites. LSD and DOB (0.025 and 0.25 mg/kg, i.p.) induce a ketanserin-sensitive (0.5 mg/kg, i.p., 30-min pretreatment) increase in shaking behaviour (including head twitches and wet dog shakes), which with repeated application (7× in 4 ds) is undermined by tolerance. Tolerance to DOB, as indexed by DOB-sensitive [(3)H]spiroperidol and DOB induced [(35)S]GTP-gamma-S binding, is accompanied by a frontocortical decrease in 5-HT2A binding sites and 5-HT2 signalling, respectively; glutamate-sensitive [(3)H]glutamate binding sites, in contrast, remain unchanged. As to LSD, 5-HT2 signalling and 5-HT2A binding, respectively, are not or only marginally affected, yet [(3)H]glutamate binding is significantly decreased. Correlation analysis interrelates tolerance to DOB to the reduced 5-HT2A (r=.80) as well as the unchanged [(3)H]glutamate binding sites (r=.84); tolerance to LSD, as opposed, shares variance with the reduction in [(3)H]glutamate binding sites only (r=.86). Given that DOB and LSD both induce tolerance, one correlating with 5-HT2A, the other with glutamate receptor adaptations, it might be inferred that tolerance can arise at either level. That is, if a hallucinogen (like LSD in our study) fails to induce 5-HT2A (down-)regulation, glutamate receptors (activated postsynaptic to 5-HT2A related glutamate release) might instead adapt and thus prevent further overstimulation of the cortex.

A fatal intoxication of 2,5-dimethoxy-4-chloroamphetamine: a case report.

Designer drugs appear to be increasing in popularity because of the ease of obtaining these constituents, the lack of ability to identify the substance(s) in routine drug screening, the appeal of the drug(s) being 'safe' due to them being marketed as a 'legal high' and possibly due to stronger restrictions that are being placed on prescription drugs. As components of designer drugs are identified and regulated by the DEA, new constituents, or analogs, of these designer drugs are being manufactured to circumvent legislation. 2,5-Dimethoxy-4-chloroamphetamine (DOC) is a substituted alpha-methylated phenethylamine and acts as a selective serotonin receptor partial agonist. There is limited literature on this particular compound and no literature that attributes death to use of this drug alone. We present a case of a 37-year-old male found at home lying face down next to a book titled 'Psychedelic Chemistry' by Michael Valentine Smith and in the early stages of decomposition. The decedent was a known methamphetamine abuser. A peripheral blood sample collected at autopsy was sent to toxicology for routine analysis. Results yielded negative for the drugs of abuse classes on the enzyme-linked immunosorbent assay screen but was positive for DOC during routine GC-MS analysis. A urine sample collected at autopsy was subjected to a routine urine liquid/liquid analysis via GC-MS, and the specimen was positive for DOC. Quantification analyses showed DOC concentration levels to be 377 ng/mL in iliac blood; 3,193 ng/mL in urine; 3,143 ng/g in liver and 683 ng/g in brain. DOC was not detected in the gastric contents. Caffeine was the only other compound detected in blood and urine. Due to the lack of literature, we believe that this is the first case where death can be attributed to DOC alone.

GC-MS and GC-IRD studies on brominated dimethoxyamphetamines: regioisomers related to 4-Br-2,5-DMA (DOB).

A series of regioisomeric bromodimethoxyamphetamines have mass spectra essentially equivalent to the controlled drug substance 4-Br-2,5-dimethoxyamphetamine (4-Br-2,5-DMA; DOB); all have molecular weight of 274 and major fragment ions in their electron ionization mass spectra at m/z 44 and m/z 230/232. The trifluoroacetyl, pentafluoropropionyl and heptafluorobutryl derivatives of the primary regioisomeric amines were prepared and evaluated in gas chromatography-mass spectrometry (GC-MS) studies. The mass spectra for these derivatives did not show unique fragment ions for specific identification of individual isomers. However, the mass spectra do serve to divide the compounds into three groups, depending on their base peak. Gas chromatography with infrared detection (GC-IRD) provides direct confirmatory data for the identification of the designer drug 4-bromo-2,5-dimethoxyamphetamine from the other regioisomers involved in the study. The perfluoroacylated derivatives of the six regioisomeric bromodimethoxyamphetamines were successfully resolved on non-polar stationary phases such as a 100% dimethylpolysiloxane stationary phase (Rtx-1) and 50% phenyl - 50% methyl polysiloxane (Rxi-50).

First case report of recreational use of 2,5-dimethoxy-4-chloroamphetamine confirmed by toxicological screening.

Routine toxicological screening is generally not undertaken in patients with recreational drug toxicity. We report here the benefits of toxicological screening in confirming drugs that have been ingested and potentially detecting drugs that have not previously been reported in the medical literature. In this case, the patient was reported to have ingested a combination of 2,5-dimethoxy-4-iodoamphetamine and methylenedioxymetamphetamine and developed sympathomimetic toxicity, but on extended toxicological screening he was shown to have actually ingested 2,5-dimethoxy-4-chloroamphetamine and methylenedioxymetamphetamine. As 2,5-dimethoxy-4-chloroamphetamine is a substituted amphetamine, it is covered under the generic Misuse of Drugs act (1971) in the UK; although in the majority of the EU it remains uncontrolled, as there is no similar generic drug legislation. We believe that discrepancies in the legal status of recreational drugs in the EU limit the effectiveness of drug enforcement policies and that EU drug legislation should be harmonized to ensure consistency.

2,5-Dimethoxyamphetamine-derived designer drugs: studies on the identification of cytochrome P450 (CYP) isoenzymes involved in formation of their main metabolites and on their capability to inhibit CYP2D6.

The designer drugs 4-methyl-2,5-dimethoxy-amphetamine (DOM), 4-iodo-2,5-dimethoxy-amphetamine (DOI), 4-chloro-2,5-dimethoxy-amphetamine (DOC), 4-bromo-2,5-dimethoxy-amphetamine (DOB), 4-bromo-2,5-dimethoxy-methamphetamine (MDOB), and 2,4,5-trimethoxy-amphetamine (TMA-2) are potent serotonin 5HT(2) receptor agonists and have appeared on the illicit drug market. These drugs are mainly metabolized by O-demethylation or in case of DOM by hydroxylation of the methyl moiety. In an initial activity screening using microsomes of insect cells heterologously expressing human CYPs, CYP2D6 was found to be the only CYP isoenzyme involved in the above-mentioned main metabolic steps whereas the amounts of metabolites formed were very small. As inhibition of CYP2D6 by other amphetamines had been described, the inhibitory effects of the 2,5-dimethoxyamphetamine derivatives were studied using insect cell microsomes with heterologously expressed human CYP2D6 and pooled human liver microsomes (HLM) as enzyme sources and dextromethorphan O-demethylation as probe reaction. All studied drugs were observed to be non-mechanism-based competitive inhibitors of CYP2D6 with inhibition constants (K(i)) from 7.1 to 296microM using recombinant CYP2D6 and 2.7-19.9microM using HLM. For comparison, the K(i) values for quinidine and fluoxetine were 0.0092 and 8.2microM using recombinant CYP2D6 and 0.019 and 0.93microM using HLM. As the K(i) values of the drugs were much higher than that of quinidine and, with the exception of DOI, higher than that of fluoxetine, interactions with other CYP2D6 substrates are possible but rather unlikely.

'Hybrid' benzofuran-benzopyran congeners as rigid analogs of hallucinogenic phenethylamines.

Phenylalkylamines that possess conformationally rigidified furanyl moieties in place of alkoxy arene ring substituents have been shown previously to possess the highest affinities and agonist functional potencies at the serotonin 5-HT(2A) receptor among this chemical class. Further, affinity declines when both furanyl rings are expanded to the larger dipyranyl ring system. The present paper reports the synthesis and pharmacological evaluation of a series of 'hybrid' benzofuranyl-benzopyranyl phenylalkylamines to probe further the sizes of the binding pockets within the serotonin 5-HT(2A) agonist binding site. Thus, 4(a-b), 5(a-b), and 6 were prepared as homologs of the parent compound, 8-bromo-1-(2,3,6,7-tetrahydrobenzo[1,2-b:4,5-b']difuran-4-yl)-2-aminopropane 2, and their affinity, functional potency, and intrinsic activity were assessed using cells stably expressing the rat 5-HT(2A) receptor. The behavioral pharmacology of these new analogs was also evaluated in the two-lever drug discrimination paradigm. Although all of the hybrid isomers had similar, nanomolar range receptor affinities, those with the smaller furanyl ring at the arene 2-position (4a-b) displayed a 4- to 15-fold greater functional potency than those with the larger pyranyl ring at that position (5a-b). When the furan ring of the more potent agonist 4b was aromatized to give 6, a receptor affinity similar to the parent difuranyl compound 2 was attained, along with a functional potency equivalent to 2, 4a, and 4b. In drug discrimination experiments using rats trained to discriminate LSD from saline, 4b was more than two times more potent than 5b, with the latter having a potency similar to the classic hallucinogenic amphetamine 1 (DOB).

Disposition of 4-bromo-2,5-dimethoxyphenethylamine (2C-B) and its metabolite 4-bromo-2-hydroxy-5-methoxyphenethylamine in rats after subcutaneous administration.

The psychedelic compound 4-bromo-2,5-dimethoxyphenethylamine (2C-B) has appeared as an agent in drug abuse or overdose cases in humans. The human pharmacokinetics of this drug is unknown and only partial information is available on its metabolites. Our experimental study was focused on the disposition and kinetic profile of 2C-B in rats after subcutaneous administration using a GC-MS validated method. One of the major metabolites 4-bromo-2-hydroxy-5-methoxyphenethylamine (2H5M-BPEA) was confirmed in rat tissues of lung, brain, liver and was quantitatively evaluated as well. The disposition of 2C-B was characterized by its estimated half-life 1.1h and estimated volume of distribution 16L/kg. The lung susceptibility for drug retention and gradual temporal release parallel to the brain were ascertained. The drug penetrating the blood/brain barrier was without significant delay. 2C-B brain to serum ratio attained a maximum value of 13.9 and remained over the value of 6.5 to the end of our observation (6h after the dose). The distribution of the hydroxylated metabolite 2H5M-BPEA into the lipophilic brain tissue was less efficient in relation to the parent compound. The kinetics of the drug partitioning between blood to brain may be important for the subsequent assessment of its psychotropic or toxic effects.

Metabolism and toxicological detection of the designer drug 4-chloro-2,5-dimethoxyamphetamine in rat urine using gas chromatography-mass spectrometry.

Studies are described on the metabolism and the toxicological analysis of the amphetamine-derived designer drug 4-chloro-2,5-dimethoxyamphetamine (DOC) in rat urine using gas chromatographic-mass spectrometric techniques. The metabolites identified indicated that DOC was metabolized by O-demethylation at position 2 or 5 of the phenyl ring partly followed by glucuronidation and/or sulfation. The authors' systematic toxicological analysis procedure using full-scan gas chromatography-mass spectrometry after acid hydrolysis, liquid-liquid extraction and microwave-assisted acetylation allowed the detection of an intake of a dose of DOC in rat urine that corresponds to a common drug user's dose. Assuming similar metabolism, the STA procedure described should be suitable as proof of an intake of DOC in human urine.

Simultaneous determination of new thioamphetamine designer drugs in plasma by capillary electrophoresis coupled with mass spectrometry.

A simple method for the simultaneous identification and quantification of four 2,5-methylenedioxy derivatives of 4-thioamphetamine (ALEPH series) in plasma samples was developed. The method consists of solid-phase extraction (SPE) using a Bond Elut C(18) cartridge and capillary electrophoresis coupled with electrospray ionisation mass spectrometry (CE/ESI-MS). The SPE method used required only simple steps and provided a clean extract from which identification of each drug was feasible, even at low concentrations. The method was validated according to international guidelines. The calibration curves were linear over the concentration range of 50 to 1000 ng/mL for all drugs with correlation coefficients that exceeded 0.998. The lower limits of detection of the drugs were 23-43 ng/mL. The absolute recoveries for the drugs were 64-92% and 75-96% at concentrations of 100 and 500 ng/mL, respectively. The validation data (precision, accuracy, and recovery) show the reproducibility and selectivity of the method. This clean and simple method allows the routine detection of designer drugs such as thioamphetamines which may become a serious problem in the control of illegal drugs.

Distribution profile of 2,5-dimethoxy-4-bromoamphetamine (DOB) in rats after oral and subcutaneous doses.

2,5-Dimethoxy-4-bromoamphetamine (DOB) is one of the potent hallucinogenic phenylalkylamines, whose ingestion has already caused several deaths reported all over the world. However, there is insufficient information on DOB properties based on controlled pharmacokinetic studies available. The aim of this study was to clarify the distribution profile of DOB and its phenolic metabolite 2-methoxy-5-hydroxy-4-bromoamphetamine (2M5H4BA) in blood and biological tissues of experimental rats. The rats were administered a 20 mg/kg dose of DOB.HCl by oral ingestion or subcutaneous injection. Plasma and brain, liver and lung tissues were collected at 0.5, 1, 2, 4, 8, 16, and 32 h after dosing (three animals per time point). The samples were prepared by a liquid-liquid extraction procedure and the extracts were assayed by GC-MS. After per oral application, DOB peak plasma level of 320 ng/mL was reached after one-hour post dosing as well as 2M5H4BA peak concentration of 203 ng/mL. A rapid phase of DOB absorption, 2M5H4BA formation and their tissue distribution during the first two hours after application were followed by a slow decrease rate of the elimination process until 32 h. After subcutaneous application, high plasma levels of the unchanged parent drug and relatively reduced formation of its metabolite 2M5H4BA were observed. DOB maximum plasma concentration of 1143 ng/mL was reached after one-hour post application, whereas its metabolite peak level after 8 h was 213 ng/mL. The concentration profiles of both compounds in plasma after per oral and subcutaneous administration revealed the existence of significant first pass effect after per oral administration that significantly affected DOB bioavailability. DOB tissue concentrations exceeded plasma and the highest values were found in the lungs, where drug accumulation occurred with prolonged retention till 32 h after subcutaneous dose. Although the plasma/tissue transfer was more effective for the lipophilic parent drug than for its hydroxylated metabolite 2M5H4BA, the metabolite tissue levels were significant. The hallucinogenic potential of 2M5H4BA appearing in brain remains unclear as nothing is known about its pharmacological activity at present.

Metabolism and toxicological detection of the designer drug 4-iodo-2,5-dimethoxy-amphetamine (DOI) in rat urine using gas chromatography-mass spectrometry.

The amphetamine-derived designer drug 4-iodo-2,5-dimethoxy-amphetamine (DOI) is an upcoming substance on the illicit drug market. In the current study, the identification of its metabolites in rat urine and their toxicological detection in the authors' systematic toxicological analysis (STA) procedure were examined. DOI is extensively metabolized by O-demethylation and beside small amounts of parent compound it was found to be excreted mainly in form of metabolites. The STA procedure using full-scan GC-MS allowed proving an intake of a common drug users' dose of DOI by detection of the two O-demethyl metabolite isomers in rat urine. Assuming similar metabolism, the described STA procedure should be suitable for proof of an intake of DOI in human urine.

A selective positive allosteric modulator of metabotropic glutamate receptor subtype 2 blocks a hallucinogenic drug model of psychosis.

Recent clinical studies reveal that selective agonists of group II metabotropic glutamate (mGlu) receptors have robust efficacy in treating positive and negative symptoms in patients with schizophrenia. Group II mGlu receptor agonists also modulate the in vivo activity of psychotomimetic drugs and reduce the ability of psychotomimetic hallucinogens to increase glutamatergic transmission. Because increased excitation of the medial prefrontal cortex (mPFC) has been implicated in pathophysiology of schizophrenia, the ability of group II mGlu receptor agonists to reduce hallucinogenic drug action in this region is believed to be directly related to their antipsychotic efficacy. A novel class of ligands, termed positive allosteric modulators, has recently been identified, displaying exceptional mGlu2 receptor selectivity. These compounds do not activate mGlu2 receptors directly but potentiate the ability of glutamate and other agonists to activate this receptor. We now report that the mGlu2 receptor-selective positive allosteric modulator biphenyl-indanone A (BINA) modulates excitatory neurotransmission in the mPFC and attenuates the in vivo actions of the hallucinogenic 5-HT(2A/2C) receptor agonist (-)2,5-dimethoxy-4-bromoamphetamine [(-)DOB]. BINA attenuates serotonin-induced increases in spontaneous excitatory postsynaptic currents in the mPFC, mimicking the effect of the mGlu2/3 receptor agonist (2S,2'R,3'R)-2-(2',3'-dicarboxycyclopropyl)glycine (DCG-IV). In addition, BINA reduced (-)DOB-induced head twitch behavior and Fos expression in mPFC, effects reversed by pretreatment with the mGlu2/3 receptor antagonist 2S-2-amino-2-(1S,2S-2-carboxycyclopropan-1-yl) -3 - (xanth-9-yl-)propionic acid (LY341495). These data confirm the relevance of excitatory signaling in the mPFC to the behavioral actions of hallucinogens and further support the targeting of mGlu2 receptors as a novel strategy for treating glutamatergic dysfunction in schizophrenia.

Functional selectivity of hallucinogenic phenethylamine and phenylisopropylamine derivatives at human 5-hydroxytryptamine (5-HT)2A and 5-HT2C receptors.

2,5-Dimethoxy-4-substituted phenylisopropylamines and phenethylamines are 5-hydroxytryptamine (serotonin) (5-HT)(2A/2C) agonists. The former are partial to full agonists, whereas the latter are partial to weak agonists. However, most data come from studies analyzing phospholipase C (PLC)-mediated responses, although additional effectors [e.g., phospholipase A(2) (PLA(2))] are associated with these receptors. We compared two homologous series of phenylisopropylamines and phenethylamines measuring both PLA(2) and PLC responses in Chinese hamster ovary-K1 cells expressing human 5-HT(2A) or 5-HT(2C) receptors. In addition, we assayed both groups of compounds as head shake inducers in rats. At the 5-HT(2C) receptor, most compounds were partial agonists for both pathways. Relative efficacy of some phenylisopropylamines was higher for both responses compared with their phenethylamine counterparts, whereas for others, no differences were found. At the 5-HT(2A) receptor, most compounds behaved as partial agonists, but unlike findings at 5-HT(2C) receptors, all phenylisopropylamines were more efficacious than their phenethylamine counterparts. 2,5-Dimethoxyphenylisopropylamine activated only the PLC pathway at both receptor subtypes, 2,5-dimethoxyphenethylamine was selective for PLC at the 5-HT(2C) receptor, and 2,5-dimethoxy-4-nitrophenethylamine was PLA(2)-specific at the 5-HT(2A) receptor. For both receptors, the rank order of efficacy of compounds differed depending upon which response was measured. The phenylisopropylamines were strong head shake inducers, whereas their phenethylamine congeners were not, in agreement with in vitro results and the involvement of 5-HT(2A) receptors in the head shake response. Our results support the concept of functional selectivity and indicate that subtle changes in ligand structure can result in significant differences in the cellular signaling profile.

Designer drugs 2,5-dimethoxy-4-bromo-amphetamine (DOB) and 2,5-dimethoxy-4-bromo-methamphetamine (MDOB): studies on their metabolism and toxicological detection in rat urine using gas chromatographic/mass spectrometric techniques.

Studies are described on the metabolism and the toxicological analysis of the amphetamine-derived designer drug 2,5-dimethoxy-4-bromo-amphetamine (DOB) and its corresponding N-methyl analogue 2,5-dimethoxy-4-bromo-methamphetamine (MDOB) in rat urine using gas chromatographic/mass spectrometric techniques. The identified metabolites indicated that DOB was metabolized by O-demethylation followed by oxidative deamination to the corresponding ketone as well as deamination followed by reduction to the corresponding alcohol. Other metabolic pathways were O,O-bisdemethylation or hydroxylation of the side chain followed by O-demethylation and deamination to the corresponding alcohol. The expected oxo compound after deamination could not be detected. All metabolites carrying hydroxy groups were found to be partly excreted in the conjugated form. MDOB underwent O-demethylation, O,O-bisdemethylation, or hydroxylation of the side chain followed by O-demethylation. Additional N-demethylation to DOB occurred, including the above-mentioned metabolites. Again, all metabolites carrying hydroxy groups were found to be partly excreted in the conjugated form. The authors' systematic toxicological analysis (STA) procedure using full-scan GC/MS after acid hydrolysis, liquid-liquid extraction, and microwave-assisted acetylation allowed the detection of an intake of a dose of DOB and MDOB in rat urine that corresponds to a common drug user's dose. Assuming a similar metabolism, the described STA procedure in human urine should be suitable as proof of an intake of DOB and MDOB.