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Shirley Lee HZ, Koh HB, Tan S, Goh BJ, Lim R, Lim JLW, Angeline Yap TW. Identification of closely related new psychoactive substances (NPS) using solid deposition gas-chromatography infra-red detection (GC–IRD) spectroscopy. Forensic Sci Int 2019; 299:21-33. [PMID: 30954004 DOI: 10.1016/j.forsciint.2019.03.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 03/06/2019] [Accepted: 03/15/2019] [Indexed: 02/05/2023]
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Abdel-Hay KM, Belal TS, Abiedalla Y, Thaxton-Weissenfluh A, DeRuiter J, Smith F, Clark CR. Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography-Infrared (GC-IR) Analyses of the Chloro-1- n-pentyl-3-(1-naphthoyl)-Indoles: Regioisomeric Cannabinoids. APPLIED SPECTROSCOPY 2019; 73:433-443. [PMID: 30347999 DOI: 10.1177/0003702818809998] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The analytical differentiation of the indole ring regioisomeric chloro-1- n-pentyl-3-(1-naphthoyl)-indoles is described in this report. The regioisomeric chloroindole precursor compounds, N- n-pentyl chloroindole synthetic intermediates, and the target chloro-substituted naphthoylindoles showed the equivalent gas chromatographic elution order based on the position of chlorine substitution on the indole ring. The regioisomeric chloro-1- n-pentyl-3-(1-naphthoyl)-indoles yield electron ionization mass spectra having equivalent major fragments resulting from cleavage of the groups attached to the central indole nucleus. Fragment ions occur at m/z 127 and 155 for the naphthyl and naphthoyl cations common to all indoles having the naphthoyl group substituted at the indole-3 position. Fragments resulting from the loss of the naphthoyl and/or n-pentyl groups from the molecular radical cation yield the cations at m/z 318, 304, 248, and 178. The characteristic (M-17)+ fragment ion at m/z 358 resulting from the loss of OH radical is significant in the mass spectra of all these compounds with 1-naphthoyl groups substituted at the indole-3 position. The vapor phase infrared spectra provide a number of characteristic absorption bands to identify the individual isomers.
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Affiliation(s)
- Karim M Abdel-Hay
- 1 Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
- 2 Department of Chemistry, College of Science, Eastern Kentucky University, Richmond, KY, USA
- 3 Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| | - Tarek S Belal
- 3 Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| | - Younis Abiedalla
- 1 Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
- 4 Department of Medicinal Chemistry, Faculty of Pharmacy, Omar Al-Mukhtar University, El-Beida, Libya
| | - Amber Thaxton-Weissenfluh
- 1 Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
| | - Jack DeRuiter
- 1 Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
| | - Forrest Smith
- 1 Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
| | - C Randall Clark
- 1 Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
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Spectroscopic differentiation and chromatographic separation of regioisomeric indole aldehydes: Synthetic cannabinoids precursors. Forensic Chem 2019. [DOI: 10.1016/j.forc.2018.12.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Thaxton-Weissenfluh A, Belal TS, DeRuiter J, Smith F, Abiedalla Y, Neel L, Abdel-Hay KM, Clark CR. GC-MS and GC-IR Analyses of the Methoxy-1-n-pentyl-3-(1-naphthoyl)-indoles: Regioisomeric Designer Cannabinoids. J Chromatogr Sci 2018; 56:779-788. [PMID: 29920587 DOI: 10.1093/chromsci/bmy059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 05/23/2018] [Indexed: 11/13/2022]
Abstract
The indole ring regioisomeric methoxy-1-n-pentyl-3-(1-naphthoyl)-indoles represent indole ring-substituted analogs of the synthetic cannabinoid JWH-018. The electron ionization mass spectra show equivalent regioisomeric major fragments resulting from cleavage of the groups attached to the central indole nucleus. The characteristic (M-17)+ fragment ion at m/z 354 resulting from the loss of OH group is significant in the mass spectra of all four compounds. Fragmentation of the naphthoyl and/or pentyl groups yields the cations at m/z 314, 300, 244 and 216. The vapor-phase infrared spectra provide a number of characteristic absorption bands to identify the individual isomers. Gas chromatographic separations on a capillary column containing a film of trifluoropropylmethyl polysiloxane (Rtx-200) provided excellent resolution of these compounds, their precursor indoles and intermediate pentylindoles. The elution order appears related to the degree of crowding of indole ring substituents.
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Affiliation(s)
- Amber Thaxton-Weissenfluh
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
| | - Tarek S Belal
- Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| | - Jack DeRuiter
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
| | - Forrest Smith
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
| | - Younis Abiedalla
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA.,Department of Medicinal Chemistry, Faculty of Pharmacy, Omar Al-Mukhtar University, El-Beida, Libya
| | - Logan Neel
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
| | - Karim M Abdel-Hay
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA.,Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| | - C Randall Clark
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
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DeRuiter J, Smith F, Abiedalla Y, Neel L, Clark CR. GC-MS and GC-IR analysis of regioisomeric cannabinoids related to 1-(5-fluoropentyl)-3-(1-naphthoyl)-indole. Forensic Chem 2018. [DOI: 10.1016/j.forc.2018.07.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Smith LW, Thaxton-Weissenfluh A, Abiedalla Y, DeRuiter J, Smith F, Clark CR. Correlation of vapor phase infrared spectra and regioisomeric structure in synthetic cannabinoids. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2018; 196:375-384. [PMID: 29486418 DOI: 10.1016/j.saa.2018.02.052] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 02/07/2018] [Accepted: 02/19/2018] [Indexed: 06/08/2023]
Abstract
The twelve 1-n-pentyl-2-, 3-, 4-, 5-, 6- and 7-(1- and 2-naphthoyl)-indoles each have the same substituents attached to the indole ring, identical elemental composition (C24H23NO) yielding identical nominal and accurate masses. These twelve isomers cover all possible positions of carbonyl bridge substitution for both indole (positons 2-7) and naphthalene rings (positions 1 and 2). Regioisomeric compounds can represent significant challenges for mass based analytical methods however, infrared spectroscopy is a powerful tool for the identification of positional isomers in organic compounds. The vapor phase infrared spectra of these twelve uniquely similar compounds were evaluated in GC-IR experiments. These spectra show the bridge position on the indole ring is a dominating influence over the carbonyl absorption frequency observed for these compounds. Substitution on the pyrrole moiety of the indole ring yields the lowest CO frequency values for position 2 and 3 giving a narrow range from 1656 to 1654cm-1. Carbonyl absorption frequencies are higher when the naphthoyl group is attached to the benzene portion of the indole ring yielding absorption values from 1674 to 1671cm-1. The aliphatic stretching bands in the 2900cm-1 region yield a consistent triplet pattern because the N-alkyl substituent tail group remains unchanged for all twelve regioisomers. The asymmetric CH2 stretch is the most intense of these three bands. Changes in positional bonding for both the indole and naphthalene ring systems results in unique patterns within the 700 wavenumber out-of-plane region and these absorption bands are different for all 12 regioisomers.
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Affiliation(s)
- Lewis W Smith
- Forensic Spectral Research, Bridgeton, NJ 08302, USA
| | - Amber Thaxton-Weissenfluh
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL 36849, USA
| | - Younis Abiedalla
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL 36849, USA; Department of Medicinal Chemistry, Faculty of Pharmacy, Omar Al-Mukhtar University, El-Beida, Libya
| | - Jack DeRuiter
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL 36849, USA
| | - Forrest Smith
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL 36849, USA
| | - C Randall Clark
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL 36849, USA.
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