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Dadiotis E, Cui M, Gerasi M, Mitsis V, Melliou E, Makriyannis A, Logothetis DE, Magiatis P. A Simple Chiral 1H NMR Method for the Discrimination of ( R)- and ( S)-Cannabichromene in Complex Natural Mixtures and Their Effects on TRPA1 Activity. JOURNAL OF NATURAL PRODUCTS 2024; 87:77-84. [PMID: 38158562 DOI: 10.1021/acs.jnatprod.3c00796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
In recent years, the enantiomeric ratio of cannabichromene (CBC) within the cannabis plant has attracted significant attention. Cannabichromene is one of the well-known cannabinoids found in cannabis, along with THC (tetrahydrocannabinol) and CBD (cannabidiol). Cannabichromene exists as a scalemic mixture, meaning it has two enantiomers, (S)-cannabichromene and (R)-cannabichromene, with the ratio between these enantiomers varying among different cannabis strains and even within individual plants. This study presents an accurate and robust chiral NMR method for analyzing cannabichromene's enantiomeric ratio, a well-investigated cannabinoid with numerous pharmacological targets. The use of Pirkle's alcohol as the chiral solvating agent (CSA) or, alternatively, the use of (S)-ibuprofen as a chiral derivatizing agent (CDA) facilitated this analysis. Moreover, the chiral NMR method proves to be a user-friendly tool, easily applicable within any NMR facility, and an expanded investigation of cannabichromene chirality may provide insights into the origin, cultivation, treatment, and processing of Cannabis sativa plants. This study also undertakes a pharmacological examination of the (R)- and (S)-cannabichromenes concerning their most extensively studied pharmacological target, the TRPA1 channels, with the two enantiomers showing the same strong agonistic effect as the racemic mixture.
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Affiliation(s)
- Evangelos Dadiotis
- Laboratory of Pharmacognosy and Natural Products Chemistry, Department of Pharmacy, National and Kapodistrian University of Athens, Panepistimioupolis Zografou, 15771 Athens, Greece
- Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts 02115, United States
| | - Meng Cui
- Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts 02115, United States
| | - Maria Gerasi
- Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts 02115, United States
- Chemistry and Chemical Biology, College of Science, Northeastern University, Boston, Massachusetts 02115, United States
| | | | - Eleni Melliou
- Laboratory of Pharmacognosy and Natural Products Chemistry, Department of Pharmacy, National and Kapodistrian University of Athens, Panepistimioupolis Zografou, 15771 Athens, Greece
| | - Alexandros Makriyannis
- Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts 02115, United States
- Chemistry and Chemical Biology, College of Science, Northeastern University, Boston, Massachusetts 02115, United States
- Center for Drug Discovery, Northeastern University, Boston, Massachusetts 02115, United States
| | - Diomedes E Logothetis
- Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts 02115, United States
- Chemistry and Chemical Biology, College of Science, Northeastern University, Boston, Massachusetts 02115, United States
- Center for Drug Discovery, Northeastern University, Boston, Massachusetts 02115, United States
| | - Prokopios Magiatis
- Laboratory of Pharmacognosy and Natural Products Chemistry, Department of Pharmacy, National and Kapodistrian University of Athens, Panepistimioupolis Zografou, 15771 Athens, Greece
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Lankhorst PP, Duchateau ALL, Netscher T. Discrimination of stereoisomers by one-dimensional 13 C NMR: All 16 stereoisomers of 4-hydroxy-α-tocopherol resolved. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2021; 59:1146-1153. [PMID: 34380173 DOI: 10.1002/mrc.5202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/04/2021] [Accepted: 08/08/2021] [Indexed: 06/13/2023]
Abstract
All 16 resolved! A vitamin E-derived compound containing four chiral centers is the first example where all stereoisomers, that is, eight diastereomeric pairs of enantiomers, could be discriminated in a single NMR run. Measurement at 176 MHz in the presence of Pirkle's alcohol as a chiral solvating agent is a relatively robust, simple, easy-to-set-up, and fast method.
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Affiliation(s)
| | | | - Thomas Netscher
- DSM Nutritional Products, Research and Development, Basel, Switzerland
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Lankhorst PP, van Rijn JHJ, Duchateau ALL. One-Dimensional 13C NMR Is a Simple and Highly Quantitative Method for Enantiodiscrimination. Molecules 2018; 23:molecules23071785. [PMID: 30036942 PMCID: PMC6100457 DOI: 10.3390/molecules23071785] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 07/13/2018] [Accepted: 07/17/2018] [Indexed: 12/04/2022] Open
Abstract
The discrimination of enantiomers of mandelonitrile by means of 1D 13C NMR and with the aid of the chiral solvating agent (S)-(+)-1-(9-anthryl)-2,2,2-trifluoroethanol (TFAE) is presented. 1H NMR fails for this specific compound because proton signals either overlap with the signals of the chiral solvating agent or do not show separation between the (S)-enantiomer and the (R)-enantiomer. The 13C NMR method is validated by preparing artificial mixtures of the (R)-enantiomer and the racemate, and it is shown that with only 4 mg of mandelonitrile a detection limit of the minor enantiomer of 0.5% is obtained, corresponding to an enantiomeric excess value of 99%. Furthermore, the method shows high linearity, and has a small relative standard deviation of only 0.3% for the minor enantiomer when the relative abundance of this enantiomer is 20%. Therefore, the 13C NMR method is highly suitable for quantitative enantiodiscrimination. It is discussed that 13C NMR is preferred over 1H NMR in many situations, not only in molecules with more than one chiral center, resulting in complex mixtures of many stereoisomers, but also in the case of molecules with overlapping multiplets in the 1H NMR spectrum, and in the case of molecules with many quaternary carbon atoms, and therefore less abundant protons.
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Affiliation(s)
- Peter P Lankhorst
- DSM Biotechnology Center, P.O. Box 1, 2600 MA Delft, The Netherlands.
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Recent Advances in Multinuclear NMR Spectroscopy for Chiral Recognition of Organic Compounds. Molecules 2017; 22:molecules22020247. [PMID: 28178223 PMCID: PMC6155827 DOI: 10.3390/molecules22020247] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 01/26/2017] [Accepted: 01/30/2017] [Indexed: 12/17/2022] Open
Abstract
Nuclear magnetic resonance (NMR) is a powerful tool for the elucidation of chemical structure and chiral recognition. In the last decade, the number of probes, media, and experiments to analyze chiral environments has rapidly increased. The evaluation of chiral molecules and systems has become a routine task in almost all NMR laboratories, allowing for the determination of molecular connectivities and the construction of spatial relationships. Among the features that improve the chiral recognition abilities by NMR is the application of different nuclei. The simplicity of the multinuclear NMR spectra relative to 1H, the minimal influence of the experimental conditions, and the larger shift dispersion make these nuclei especially suitable for NMR analysis. Herein, the recent advances in multinuclear (19F, 31P, 13C, and 77Se) NMR spectroscopy for chiral recognition of organic compounds are presented. The review describes new chiral derivatizing agents and chiral solvating agents used for stereodiscrimination and the assignment of the absolute configuration of small organic compounds.
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