Quaternary indole alkaloids from the stem bark of Strychnos guianensis

Penelle, Jacques; Tits, Monique; Christen, Philippe; Molgó, Jordi; Brandt, Viviane; Frédérich, Michel; Angenot, Luc

doi:10.1016/s0031-9422(00)00033-9

Cited by 31 publications

(20 citation statements)

References 34 publications

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“…Methylation of 3 with methyl iodide was followed by the exchange of the iodide anion to chloride anion employing AgCl to provide the 9-methoxy-N b -methylgeissoschizol ( 4 ). The 13 C NMR spectral data of 9-methoxygeissoschizol ( 3 ) and 9-methoxy-N b -methylgeissoschizol ( 4 ) are in excellent agreement with the literature (see Supporting Information for details) 16,18…”

Section: Resultssupporting

confidence: 85%

“…The crude extracts from the root and stem bark displayed muscle-relaxant activity 17. The related 9-methoxy-N b –methylgeissoschizol ( 4 ) as well as other quaternary indole alkaloids have also been identified 18. These geissoschizol bases are biogenetically related to the C orynanthe alkaloids, which enables the design of a general approach to the synthesis of these 9-methoxy-substituted indole alkaloids.…”

Section: Introductionmentioning

confidence: 99%

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General Approach to the Total Synthesis of 9-Methoxy-Substituted Indole Alkaloids: Synthesis of Mitragynine, as well as 9-Methoxygeissoschizol and 9-Methoxy-N_b-methylgeissoschizol

Yin

Zhou

et al. 2008

J. Org. Chem.

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Herein the full details of the synthesis of the 9-methoxy-substituted Corynanthe indole alkaloids mitragynine (1), 9-methoxygeissoschizol (3) and 9-methoxy-Nb-methylgeissoschizol (4) are described. Initially an efficient synthetic route to the optically active 4-methoxytryptophan ethyl ester 20 on a multigram scale was developed via a Mori-Ban-Hegedus indole synthesis. The ethyl ester of (D)-4-methoxytryptophan 20 was obtained with a radical-mediated regioselective bromination of indoline 12 serving as a key step. Alternatively, the key 4-methoxytryptophan intermediate 22 could be synthesized by the Larock heteroannulation of aryl iodide 10b with the internal alkyne 21a. The use of the Boc protected aniline 10b was crucial to the success of this heteroannulation. The α,β-unsaturated ester 6 was synthesized via the Pictet-Spengler reaction as the pivotal step. This was followed by a Ni(COD)2 mediated cyclization to set up the stereocenter at C-15. The benzyloxy group in 31 was removed to provide the intermediate ester 5. This chiral tetracyclic ester 5 was employed to accomplish the first total synthesis of 9-methoxygeissoschizol (3) and 9-methoxy-Nb-methylgeisso-schizol (4) as well as the opioid agonistic indole alkaloid mitragynine (1).

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Section: Resultssupporting

confidence: 85%

Section: Introductionmentioning

confidence: 99%

General Approach to the Total Synthesis of 9-Methoxy-Substituted Indole Alkaloids: Synthesis of Mitragynine, as well as 9-Methoxygeissoschizol and 9-Methoxy-N_b-methylgeissoschizol

Yin

Zhou

et al. 2008

J. Org. Chem.

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“…Sabe-se hoje ser ela o famoso "Bejuco de Mavacure", citado por Humboldt no início do século XIX, como um dos principais ingredientes dos curares de Esmeralda, na Venezuela 4 . Estudos químicos recentes sobre esta espécie levaram ao isolamento de alcalóides quaternários [5][6][7][8] , justificando o seu freqüente emprego na preparação dos mencionados venenos.…”

Section: Introductionunclassified

Lignanas de Strychnos guianensis (Aublet) Mart.

Pinheiro¹,

Rocha²,

Fernandes³

et al. 2004

Quím. Nova

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“…Ticuna [20] essential oil [270,271] ( Tiriyó [21] lignans, alkaloids [289][290][291] Strychnos javariensis Krukoff toothache bark -chewed Ticuna [20] no phytochemical data…”

Section: Lamiaceae (7)mentioning

confidence: 99%

Plants Indicated by Brazilian Indians for Disturbances of the Central Nervous System: A Bibliographical Survey

Rodrigues¹,

Mendes²,

Negri

2006

CNSAMC

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Brazil possesses great biological and cultural diversity, above all, in view of the great number of indigenous ethnic groups -218 in all -that inhabit the five main biomas in Brazil. The purpose of this review is to analyze the relationship between chemical constituents of species utilized by several groups of Brazilian Indians and the uses/indications made of the species by these same groups using ethnopharmacological surveys by different researchers, as from the seventies. The 34 publications selected, involving 26 indigenous ethnic groups, showed a total of 307 species utilized for 67 different diseases or effects possibly related to the Central Nervous System (CNS). These plants belong to 85 taxonomic families, mostly Fabaceae, Asteraceae, Rubiaceae, Poaceae, Apocynaceae, Bignoniaceae, Euphorbiaceae, and Solanaceae. The chemical constitution of these plants was researched as from the Pubmed and Web of Science and the information obtained was crossed with different indigenous uses, grouped in 12 categories according to similarities between their expected effects on the CNS: analgesics, to counteract fever, tonics and/or adaptogens, hallucinogens, anxiolytics, anticonvulsants, head illnesses, hypnotics, stimulants, weight control, memory enhancers, and others. Some phytochemical classes were observed to be more common among plants utilized for certain purposes: flavonoids (analgesia, fever, anxiety, hypnotic, weight control, and as a stimulant), alkaloids (hallucinogens, head illnesses, and as a stimulant), essential oils (fever and anxiety), lignans (hallucinogen), tannins (anxiety), triterpenes and saponins (hypnotic). These data suggest that these phytochemical classes possibly possess a greater number of chemical constituents that perform the effects described or that, in some way, assist in determining the use of the plant by the Indians.

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Quaternary indole alkaloids from the stem bark of Strychnos guianensis

Cited by 31 publications

References 34 publications

General Approach to the Total Synthesis of 9-Methoxy-Substituted Indole Alkaloids: Synthesis of Mitragynine, as well as 9-Methoxygeissoschizol and 9-Methoxy-N_b-methylgeissoschizol

General Approach to the Total Synthesis of 9-Methoxy-Substituted Indole Alkaloids: Synthesis of Mitragynine, as well as 9-Methoxygeissoschizol and 9-Methoxy-N_b-methylgeissoschizol

Lignanas de Strychnos guianensis (Aublet) Mart.

Plants Indicated by Brazilian Indians for Disturbances of the Central Nervous System: A Bibliographical Survey

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Quaternary indole alkaloids from the stem bark of Strychnos guianensis

Cited by 31 publications

References 34 publications

General Approach to the Total Synthesis of 9-Methoxy-Substituted Indole Alkaloids: Synthesis of Mitragynine, as well as 9-Methoxygeissoschizol and 9-Methoxy-Nb-methylgeissoschizol

General Approach to the Total Synthesis of 9-Methoxy-Substituted Indole Alkaloids: Synthesis of Mitragynine, as well as 9-Methoxygeissoschizol and 9-Methoxy-Nb-methylgeissoschizol

Lignanas de Strychnos guianensis (Aublet) Mart.

Plants Indicated by Brazilian Indians for Disturbances of the Central Nervous System: A Bibliographical Survey

Contact Info

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General Approach to the Total Synthesis of 9-Methoxy-Substituted Indole Alkaloids: Synthesis of Mitragynine, as well as 9-Methoxygeissoschizol and 9-Methoxy-N_b-methylgeissoschizol

General Approach to the Total Synthesis of 9-Methoxy-Substituted Indole Alkaloids: Synthesis of Mitragynine, as well as 9-Methoxygeissoschizol and 9-Methoxy-N_b-methylgeissoschizol