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González B, Fagúndez C, Peixoto de Abreu Lima A, Suescun L, Sellanes D, Seoane GA, Carrera I. Efficient Access to the Iboga Skeleton: Optimized Procedure to Obtain Voacangine from Voacanga africana Root Bark. ACS OMEGA 2021; 6:16755-16762. [PMID: 34250335 PMCID: PMC8264847 DOI: 10.1021/acsomega.1c00745] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 05/26/2021] [Indexed: 06/01/2023]
Abstract
Iboga alkaloids are a group of monoterpenoid indole alkaloids with promising and intriguing biological activities. Ibogaine is the representative member of the series and has become widely known as a potent atypical psychedelic with promising effects to treat substance use disorder. Nowadays, an efficient and scalable enantioselective total synthesis of ibogaine and related iboga alkaloids is still lacking, so direct extraction from natural sources or semi-synthetic schemes are the methods of choice to obtain them in a preparative scale. In particular, ibogaine can be obtained either by a low yielding direct isolation from Tabernanthe iboga or using a semi-synthetic procedure from voacangine, an iboga alkaloid occurring in a higher yield in the root bark of Voacanga africana. In this work, we describe an optimized process to obtain voacangine from V. africana root bark as a precursor of the iboga scaffold. Using a direct acetone-based extraction procedure (0.5 kg of root bark), voacangine was isolated in ∼0.8% of root bark dried weight, while the major alkaloids isolated from the bark were identified as iboga-vobasinyl dimers (∼3.7%) such as voacamine and voacamidine. Since these alkaloids contain the voacangine moiety in their structure, the cleavage of the dimers was further optimized, affording an extra amount of voacangine in ∼50% isolated molar yield. In this manner, the total amount of voacangine obtained by application of the whole procedure to the plant material (extraction and dimer cleavage) could almost duplicate the content originally found in the root bark.
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Affiliation(s)
- Bruno González
- Laboratorio
de Síntesis Orgánica, Departamento de Química
Orgánica, Facultad de Química, Universidad de la República, 11800 Montevideo, Uruguay
| | - Catherine Fagúndez
- Laboratorio
de Síntesis Orgánica, Departamento de Química
Orgánica, Facultad de Química, Universidad de la República, 11800 Montevideo, Uruguay
| | - Alejandro Peixoto de Abreu Lima
- Laboratorio
de Síntesis Orgánica, Departamento de Química
Orgánica, Facultad de Química, Universidad de la República, 11800 Montevideo, Uruguay
| | - Leopoldo Suescun
- Laboratorio
de Cristalografía, Química del Estado Sólido
y Materiales, Departamento de Experimentación y Teoría
de la Estructura de la Materia y sus Aplicaciones, Facultad de Química, Universidad de la República, 11800 Montevideo, Uruguay
| | - Diver Sellanes
- Siquimia
SRL, Instituto Polo Tecnológico de Pando, Facultad de Química, Universidad de la República, 91000 Montevideo, Uruguay
| | - Gustavo A. Seoane
- Laboratorio
de Síntesis Orgánica, Departamento de Química
Orgánica, Facultad de Química, Universidad de la República, 11800 Montevideo, Uruguay
| | - Ignacio Carrera
- Laboratorio
de Síntesis Orgánica, Departamento de Química
Orgánica, Facultad de Química, Universidad de la República, 11800 Montevideo, Uruguay
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Iyer RN, Favela D, Zhang G, Olson DE. The iboga enigma: the chemistry and neuropharmacology of iboga alkaloids and related analogs. Nat Prod Rep 2021; 38:307-329. [PMID: 32794540 DOI: 10.1039/d0np00033g] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Covering: 2000 up to 2020 Few classes of natural products have inspired as many chemists and biologists as have the iboga alkaloids. This family of monoterpenoid indole alkaloids includes the anti-addictive compound ibogaine as well as catharanthine, a precursor to the chemotherapeutic vinblastine. Despite being known for over 120 years, these small molecules continue to challenge our assumptions about biosynthetic pathways, catalyze our creativity for constructing complex architectures, and embolden new approaches for treating mental illness. This review will cover recent advances in both the biosynthesis and chemical synthesis of iboga alkaloids as well as their use as next-generation neurotherapeutics. Whenever appropriate, we provide historical context for the discoveries of the past decade and indicate areas that have yet to be resolved. While significant progress regarding their chemistry and pharmacology has been made since the 1960s, it is clear that the iboga alkaloids will continue to stoke scientific innovation for years to come.
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Affiliation(s)
- Rishab N Iyer
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA.
| | - David Favela
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA.
| | - Guoliang Zhang
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA.
| | - David E Olson
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA. and Department of Biochemistry & Molecular Medicine, School of Medicine, University of California, Davis, 2700 Stockton Blvd, Suite 2102, Sacramento, CA 95817, USA and Center for Neuroscience, University of California, Davis, 1544 Newton Ct, Davis, CA 95618, USA
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