- Alkaloids and other compounds from seeds of Tabernaemontana cymosa
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From the seeds of Tabernaemontana cymosa (= T. psychotrifolia) 17 indole alkaloids and six lignan glacosides were isolated, besides triacylglycerols, 9,12-octadecadienoic acid, lupeol, (+)-lyoniresinol, obtusifoliol, sweroside and a glucoside of 3-O-methylgallic acid. 9-(β-D-Glucopyranosyloxy)- tetrahydroalstonine, (+)-5,5'-dimethoxy-9-O-(β-D- glucopyranosyl)lariciresinol, (-)-2α-O-(β-D-glucopyranosyl)-lyoniresinol and 3-O-(β-D-glucopyranosyl)-5-O-methylgallic acid are described for the first time. Structural determination is based on spectroscopic studies and/or on comparison with authentic compounds. Some of the isolated substances exhibited significant antifungal and/or cytotoxic effects.
- Achenbach, Hans,Benirschke, Monika,Torrenegra, Ruben
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- Directed Fischer Indolization as an Approach to the Total Syntheses of (+)-Aspidospermidine and (-)-Tabersonine
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A conceptually new synthetic approach that provides general access to the aspidosperma alkaloids (+)-aspidospermidine and (-)-tabersonine was developed. This method is based on the regioselective indolization of an ene-hydrazide, which was obtained via a base-catalyzed intramolecular aza-Michael reaction, in situ trapping of the resulting enolate, and subsequent C-N coupling with phenyl hydrazide.
- Kim, Joo-Young,Suhl, Chang-Heon,Lee, Joon-Ho,Cho, Cheon-Gyu
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- METHOD AND MEANS FOR MANUFACTURING TERPENE INDOLE ALKALOIDS
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The complex chemistry underlying the extensive transformations involved in terpene indole alkaloid synthesis makes identification of the biosynthetic genes challenging. The present invention relates to methods for producing a terpene indole alkaloid derivative, comprising the steps of: (1) providing a terpene indole alkaloid; and (2) providing a first enzyme termed "Precondylocarpine Acetate Synthase" (PAS) or a functional variant or homologue thereof; and/or a second enzyme termed "Dehydroprecondylocarpine Acetate Synthase" (DPAS) or a functional variant or homologue thereof, and optionally providing further identified enzymes involved in this pathway. The invention also encompasses related kits, enzymes, expression vectors, host cells and plants.
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Page/Page column 11; 31
(2019/10/04)
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- Biosynthesis of an Anti-Addiction Agent from the Iboga Plant
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(-)-Ibogaine and (-)-voacangine are plant derived psychoactives that show promise as treatments for opioid addiction. However, these compounds are produced by hard to source plants, making these chemicals difficult for broad-scale use. Here we report the complete biosynthesis of (-)-voacangine, and de-esterified voacangine, which is converted to (-)-ibogaine by heating, enabling biocatalytic production of these compounds. Notably, (-)-ibogaine and (-)-voacangine are of the opposite enantiomeric configuration compared to the other major alkaloids found in this natural product class. Therefore, this discovery provides insight into enantioselective enzymatic formal Diels-Alder reactions.
- Farrow, Scott C.,Kamileen, Mohamed O.,Caputi, Lorenzo,Bussey, Kate,Mundy, Julia E. A.,McAtee, Rory C.,Stephenson, Corey R. J.,O'Connor, Sarah E.
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supporting information
p. 12979 - 12983
(2019/08/26)
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- Development and Scope of the Arene-Fused Domino Michael/Mannich Reaction: Application to the Total Syntheses of Aspidosperma Alkaloids (-)-Aspidospermidine, (-)-Tabersonine, and (-)-Vincadifformine
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The development and application of the arene-fused domino Michael/Mannich route to the tetrahydrocarbazole (ABE) core of Aspidosperma alkaloids is described. The scope of this novel transformation was studied in terms of the nucleophilic component (i.e., N-sulfinyl metallodienamine) and the electrophilic component (i.e., Michael acceptor). The successful application of this methodology toward the concise total syntheses of classical indole alkaloids (-)-aspidospermidine, (-)-tabersonine, and (-)-vincadifformine in 10-11 steps, respectively, is also discussed.
- Zhao, Senzhi,Andrade, Rodrigo B.
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p. 521 - 531
(2017/04/26)
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- Domino Michael/Mannich/ N-alkylation route to the tetrahydrocarbazole framework of Aspidosperma alkaloids: Concise total syntheses of (-)-aspidospermidine, (-)-tabersonine, and (-)-vincadifformine
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We report a novel, asymmetric domino Michael/Mannich/N-alkylation sequence for the rapid assembly of the tetrahydrocarbazole framework of Aspidosperma alkaloids. This method was utilized in the concise total syntheses of classical targets (-)-aspidospermidine, (-)-tabersonine, and (-)-vincadifformine in 10 or 11 steps. Additional key steps include ring-closing metathesis to prepare the D-ring and Bosch-Rubiralta spirocyclization to prepare the C-ring.
- Zhao, Senzhi,Andrade, Rodrigo B.
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p. 13334 - 13337
(2013/09/24)
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- Efficient total syntheses of (±)-vincadifformine and (-)-tabersonine
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Stereocontrolled biomimetic total syntheses of the title compounds are described. Our syntheses feature a highly efficient preparation of the key intermediate 11 using our novel indole synthesis methodology. A novel amine protecting protocol by means of 2,4-dinitrobenzenesulfonamides has been developed to ensure the formation of the elusive secodine (3) as well as secodine-type intermediate (4) under very mild conditions.
- Kobayashi, Satoshi,Peng, Ge,Fukuyama, Tohru
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p. 1519 - 1522
(2007/10/03)
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- Rearrangement and photolysis of aziridines in the aspidosperma series
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Rearrangement of aziridine 1 by MgBr2 gave 2-H-dihydro-17- dehydrovincadifformine 6. Photolysis transformed aziridines 1 and 11 into the new compounds 1,2-seco-1,21-cyclovincadifformine 10 and 1,2-seco-1,21- cyclotabersonine 12.
- Hoffmann, Norbert,Hugel, Georgette,Nuzillard, Jean-Marc,Royer, Daniel
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p. 7503 - 7506
(2007/10/03)
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- SYNTHESIS OF HEXACYCLIC INDOLE ALKALOIDS RELATED TO VINDOLININE BY SONOCHEMICAL CYCLIZATION
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Upon treatment with sodium in THF under sonication, 19-iodotabersonine underwent cyclization to the vindolinine ring system.The yields and ratio of the diastereomers thus obtained depended on the sonication parameters.
- Hugel, Georgette,Cartier, Dominique,Levy, Jean
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p. 4513 - 4516
(2007/10/02)
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- Biomimetic Alkaloid Syntheses. 15. Enantioselective Syntheses with Epichlorohydrin: Total Syntheses of (+)-, (-)-, and (+/-)-Vindoline and a Synthesis of (-)-Vindorosine
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Total syntheses of vindoline (1) in racemic as well as in each enantiomeric form and of (-)-vindorosine (2) are described.They were achieved by generation and diastereoselective cyclizations of 14-hydroxysecodine intermediates 6 and 7.The subsequent oxidative elaboration of ring E was also studied with 3-oxotabersonine (24), 3-oxovincadifformine (26), and 14β-hydroxyvincadifformine (15).Na-Methyltabersonine (22) was oxidized to a ring-D-contracted α-keto lactam, 23.
- Kuehne, Martin E.,Podhorez, David E.,Mulamba, Tshilundu,Bornmann, William G.
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p. 347 - 353
(2007/10/02)
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- Studies in Biomimetic Alkaloid Syntheses. 12. Enantioselective Total Syntheses of (-)- and (+)-Vincadifformine and of (-)-Tabersonine
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The (-) and (+) enantiomers of vincadifformine (1) were obtained with 98percent ee and 97percent ee, respectively (before purification), from the two enantiomers of epichlorhydrin.This synthetic scheme is based on generation and cyclization of the enantiomeric (hydroxymethyl)norsecodine intermediates 3a,b.By an alternative synthetic route, passing through (14S)-14-hydroxy-Δ20,21-secodine (14), (-)-tabersonine (18b) was obtained with 99percent ee.
- Kuehne, Martin E.,Podhorez, David E.
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p. 924 - 929
(2007/10/02)
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- Isolation, Structure and Oxidative Fragmentation of 16-epi-19-S-Vindolinine - an Alkaloid from the Leaves of Catharanthus roseus
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A new alkaloid has been isolated from the leaves of Catharanthus roseus.Spectroscopic and degradative studies have established its structure to be 16-epi-19-S-vindolinine. - Key words: Indoline Alkaloids, Catharanthus roseus, 13C NMR Spectra, Vindolinine, Lead Tetraacetate
- Atta-ur-Rahman,Bashir, M.,Kaleem, S.,Fatima, T.
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p. 695 - 700
(2007/10/02)
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