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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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