title: Identification of (2-aminopropyl)indole positional isomers in forensic samples.
abstract: In 2012, 5-(2-aminopropyl)indole (5-API, 5-IT) was reported by Norwegian authorities to the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) via the Early Warning System (EWS). The 3- isomer, 3-(2-aminopropyl)indole (3-API, AMT, alpha-methyltryptamine), has been available on the recreational drugs market for a somewhat longer time, having first been reported to the EMCDDA by Finnish authorities in 2001. Both isomers are available from online vendors of 'legal highs'. Recently, three forensic drug cases (two tablets and one powder) were presented for routine analysis and the active constituent was tentatively identified as an API isomer. The six positional isomers (2-, 3-, 4-, 5-, 6- and 7-(2-aminopropyl)indoles) were synthesized and analyses by a combination gas chromatography-mass spectrometry (GC-MS), and liquid chromatography-mass spectrometry (LC-MS) showed that these could be readily discriminated thus facilitating the identification of 3-API in the tablets and 5-API in the powder. With exception of 5- and 6-APIs, which co-eluted, it was found possible to separate the isomers by GC without derivatization. LC separation also proved to be a feasible method for the discrimination of the isomers. Although the 2- and 7- isomers were not fully resolved by LC, it was found possible to distinguish them using their product ion spectra as the 2- isomer produced the m/z 132 fragment ion formed by loss of vinylamine, whereas the 7- isomer formed m/z 158 through loss of methylamine. In the synthesis 2-API, a novel tricyclic by-product was formed in an annulation reaction where the reaction solvent, tetrahydrofuran, was incorporated into the molecule.
authors.affiliation: Department of Pharmacology and Therapeutics, Trinity Centre for Health Sciences, St James's Hospital, Dublin 8, Ireland.
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Scott
authors.forename: John D
authors.initials: JD
authors.lastname: Power
authors.forename: Seán D
authors.initials: SD
authors.lastname: McDermott
authors.forename: John E
authors.initials: JE
authors.lastname: O'Brien
authors.forename: Brian N
authors.initials: BN
authors.lastname: Talbot
authors.forename: Michael G
authors.initials: MG
authors.lastname: Barry
authors.forename: Pierce V
authors.initials: PV
authors.lastname: Kavanagh
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods; D044707:Forensic Sciences; D008401:Gas Chromatography-Mass Spectrometry; D013287:Illicit Drugs / Q000737:chemistry*; D007211:Indoles / Q000032:analysis / Q000302:isolation & purification*; D007536:Isomerism; D011208:Powders; D015813:Substance Abuse Detection / Q000379:methods; D013607:Tablets
chemical_list: C583010:3-(2-aminopropyl)indole; D013287:Illicit Drugs; D007211:Indoles; D011208:Powders; D013607:Tablets; C583009:5-(2-aminopropyl)indole
keywords: 2-aminopropylindole; API; discrimination; forensic; isomer; legal high; separation