Distinguishing of 2-MAPB and 6-MAPB: Solution of the problem

Alpha-methyltryptamine and 5-(2-methylaminopropyl)-benzofuran (5-MAPB) fatal co-intoxication: case report and review of literature

The scientific literature contains little reliable data regarding new psychoactive substances and designer drugs, making it difficult to assess toxic blood levels and potentially lethal threshold. Here, we report a fatal co-intoxication involving two uncommon drugs ‒ alpha-methyltryptamine (AMT) and 5-(2-methylaminopropyl)-benzofuran (5-MAPB) ‒ combined with exposure to benzodiazepines, ephedrine, and norephedrine. AMT and 5-MAPB were quantified using ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC/MS-MS), revealing concentrations of AMT 4690 ng/mL and 5-MAPB 101 ng/mL in postmortem peripheral blood. We additionally reviewed the literature to help interpret the likely roles of these molecules in the occurrence of death.

Structural confirmation of position isomers 2-(2-methylaminoprolyl)benzofuran and 5-(2-methylaminopropyl)benzofuran: a combined mass spectrometric and computational study

RATIONALE

Phenylethylamines are one of the most common types of new psychoactive substances, following synthetic cannabinoids and synthetic cathinones. They are regulated in many countries because of their strong hallucinogenic effects, which can cause serious nerve damage. There is a wide variety of phenylethylamines, exhibiting rapid renewal and extremely similar structures, therefore accurate qualitative analysis of isomers is a difficult problem in current drug analysis.

METHODS

The dissociation pathways of the position isomers 2-(2-methylaminoprolyl)benzofuran (2-MAPB) and 5-(2-methylaminopropyl)benzofuran (5-MAPB) were investigated by gas chromatography-mass spectrometry and liquid chromatography coupled to high-resolution quadrupole Orbitrap MS. The dissociation patterns of the phenethylamine-based designer drugs 2-MAPB and 5-MAPB were explored and extended in this work based on MS combined with density functional theory studies.

RESULTS

For electron ionization mass spectrometry (EI-MS) analysis, the dissociation patterns of 2-MAPB were similar to those of 5-MAPB. For electrospray ionization mass spectrometry (ESI-MSn ) analysis, the hydrogen atom on amino group was facile to form a intramolecular hydrogen bond with the oxygen atom on the parent nucleus of benzofuran in the structure of 2-MAPB, leading to higher abundance of the product ion at m/z 58. However, there was a conjugated system between the positive charge formed by the cleavage of the 5-MAPB side chain and the benzofuran ring, enabling the 5-MAPB to generate a product ion at m/z 131. Computational study showed that energy barrier and spin density difference distribution jointly control the selective dissociation in EI-MS, while different types of orbital interaction induced by intramolecular hydrogen bond led to different dissociation results in ESI-MSn .

CONCLUSIONS

These different dissociation patterns could be used to distinguish 2-MAPB from 5-MAPB. This could assist forensic laboratories in the differentiation and characterization of potential isomers in these kinds of compounds, especially in mixtures.

Toxicological investigations in a death involving 2-MAPB

New psychoactive substances are becoming increasingly popular. However, there is a lack of mass spectral information on parent substances and their corresponding metabolites as well as fatal concentrations in body liquids and tissues. Only very few clinical reports and user reports exist. This is also the case for methylaminopropylbenzofuran (MAPB) isomers. Urine from a decedent was screened using different immuno assays, gas chromatography-mass spectrometry (GC-MS), and liquid chromatography-high resolution mass spectrometry (LC-HRMS/MS). Additionally, respective targets were quantitated in all analyzed specimens by LC-MS/MS. Gas chromatography-infrared spectroscopy (GC-IR) was applied to confirm the identity of the intoxication. GC-MS and the amphetamine immuno assay were useful to track the putative intoxication. However, the chemical structure of 2-MAPB was only elucidated by means of LC-HRMS/MS and GC-IR. 2-MAPB was highest in urine (167 µg/mL), followed by gastric content (98.9 µg/mL), bile fluid (30.8 µg/mL), liver (22.2 µg/g), heart blood (16.7 µg/mL), and lowest in femoral blood (7.3 µg/mL). Besides the parent substance, we detected N-demethyl-2-MAPB and hydroxy-2-MAPB in the urine sample. This case report presents an intoxication caused by 2-MAPB. The 2-MAPB concentration found in femoral blood exceeded those reviewed for 5/6-MAPB. The concentrations of the other specimens cannot be evaluated because there exist no comparative data. The values presented can be applied to assess 2-MAPB intoxications in the future.

Interpol review of controlled substances 2016-2019

This review paper covers the forensic-relevant literature in controlled substances from 2016 to 2019 as a part of the 19th Interpol International Forensic Science Managers Symposium. The review papers are also available at the Interpol website at: https://www.interpol.int/content/download/14458/file/Interpol%20Review%20Papers%202019.pdf.