- Controlling a structural branch point in ergot alkaloid biosynthesis
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The ergot alkaloids are a diverse class of fungal-derived indole alkaloid natural products with potent pharmacological activities. The biosynthetic intermediate chanoclavine-I aldehyde 1 represents a branch point in ergot biosynthesis. Ergot alkaloids festuclavine 2 and agroclavine 3 derive from alternate enzymatic pathways originating from the common biosynthetic precursor chanoclavine-I aldehyde 1. Here we show that while the Old Yellow Enzyme homologue EasA from the ergot biosynthetic gene cluster of Aspergillus fumigatus acts on chanoclavine-I aldehyde 1 to yield festuclavine 2, EasA from Neotyphodium lolii, in contrast, produces agroclavine 3. Mutational analysis suggests a mechanistic rationale for the switch in activity that controls this critical branch point of ergot alkaloid biosynthesis.
- Cheng, Johnathan Z.,Coyle, Christine M.,Panaccione, Daniel G.,O'Connor, Sarah E.
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- New insights into ergot alkaloid biosynthesis in Claviceps purpurea: An agroclavine synthase EasG catalyses, via a non-enzymatic adduct with reduced glutathione, the conversion of chanoclavine-I aldehyde to agroclavine
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Ergot alkaloids are indole derivatives with diverse structures and biological activities. They are produced by a wide range of fungi with Claviceps purpurea as the most important producer for medical use. Chanoclavine-I aldehyde is proposed as a branch point via festuclavine or pyroclavine to clavine-type alkaloids in Trichocomaceae and via agroclavine to ergoamides and ergopeptines in Clavicipitaceae. Here we report the conversion of chanoclavine-I aldehyde to agroclavine by EasG from Claviceps purpurea, a homologue of the festuclavine synthase FgaFS in Aspergillus fumigatus, in the presence of reduced glutathione and NADPH. EasG comprises 290 amino acids with a molecular mass of about 31.9 kDa. The soluble monomeric His6-EasG was purified after overproduction in E. coli by affinity chromatography and used for enzyme assays. The structure of agroclavine was unequivocally elucidated by NMR and MS analyses.
- Matuschek, Marco,Wallwey, Christiane,Xie, Xiulan,Li, Shu-Ming
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- Regioselective Direct C-4 Functionalization of Indole: Total Syntheses of (-)-Agroclavine and (-)-Elymoclavine
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An efficient rhodium-catalyzed method for direct C-H functionalization at the C4 position of unprotected indoles has been developed. The utility of this method is demonstrated by the concise total syntheses of agroclavine and elymoclavine in a divergent manner. These syntheses feature a Pd-catalyzed asymmetric allylic alkylation reaction to assemble the triyclic indole moiety, and a ring-closing metathesis reaction to form the D ring.
- Lv, Jianbo,Wang, Bin,Yuan, Kuo,Wang, Yuan,Jia, Yanxing
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- Genes and processes for the production of clavine-type alkaloids
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Microorganisms and processes for the recombinant manufacture of clavine-type alkaloids such as cycloclavine, festuclavine, agroclavine, chanoclavine and chanoclavine aldehyde, as well as polypeptides, polynucleotides and vectors comprising such polynucleotides which can be applied in a method for the manufacture of clavine-type alkaloids are provided.
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- Synthetic studies directed toward ergot alkaloids, (±)-6,7-secoagroclavine, (±)-chanoclavine-1, (±)-chanoclavine-II, and (±)-agroclavine-I, by an efficient and common synthetic route
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Novel three synthetic routes to (±)-6,7-secoagroclavine were developed from either methyl 3-(3-formylindol-4-yl)acrylate, indole-4-carbaldehyde, or 4-iodoindole-3-carbaldehyde. The total syntheses of (±)-chanoclavine-I, (±)-chanoclavine-II, and (±)-agroclavine-I were accomplished as well from the synthetic intermediates involved in the synthesis of (±)-6,7-secoagroclavine, culminating in establishing an efficient and common synthetic method for ergot alkaloids.
- Yamada, Fumio,Makita, Yoshihiko,Somei, Masanori
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p. 599 - 620
(2008/03/12)
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- Simple total syntheses of (-)-ergot alkaloids and their (+)-enantiomers by a common synthesis method utilizing optical resolution
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The first and simple total syntheses of (-)-isochanoclavine-1 ((-)-1b), (-)-agroclavine ((-)-3), (-)-agroclavine-1 ((-)-4), and (-)-norchanoclavine-1 ((-)-5c) and their (+)-enantiomers are achieved from indole-3-carboxaldehyde (8) by a common synthesis method utilizing optical resolution. Absolute configuration of (-)-agroclavine-1 is determined to be 5R and 10S for the first time. Preparations of both enantiomers of chanoclavine-1 (1c) are also included.
- Somei, Masanori,Nakagawa, Kyoko
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p. 1263 - 1266
(2007/10/03)
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- TOTAL SYNTHESES OF (+/-)-AGROCLAVINE-I, (+/-)-6-NOR-CHANOCLAVINE-II, AND (+/-)-CHANOCLAVINE-II
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The first total syntheses of (+/-)-6-nor-chanoclavine-II and (+/-)-chanoclavine-II are achieved.Total synthesis of (+/-)-agroclavine-I is also reported.
- Somei, Masanori,Yamada, Fumio,Makita, Yoshihiko
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p. 895 - 898
(2007/10/02)
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- SHORT-STEP SYNTHESIS OF THE ERGOT ALKALOIDS, (+/-)-NORCHANOCLAVINE-I, (+/-)-CHANOCLAVINE-I, (+/-)-ISOCHANOCLAVINE-I, and (+/-)-AGROCLAVINE
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The simple total synthesis of the ergot alkaloids, (+/-)-norchanoclavine-I, (+/-)-chanoclavine-I, (+/-)-isochanoclavine-I, and (+/-)-agroclavine was achieved by a practical and common synthesis method.A new regio-selective oxidation of the Z-methyl group of the isoprenyl system with selenium dioxide is described.Keywords - (+/-)-norchanoclavine-I; (+/-)-norisochanoclavine-I; (+/-)-chanoclavine-I; (+/-)-isochanoclavine-I; (+/-)-agroclavine; ergot alkaloid; total synthesis; common synthesis method; new oxidation
- Somei, Masanori,Makita, Yoshihiko,Yamada, Fumio
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p. 948 - 950
(2007/10/02)
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- A TOTAL SYNTHESIS OF (+/-)-AGROCLAVINE-I. A NEW C/D-cis-8-ERGOLENE ALKALOID
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A new total synthesis of (+/-)-agroclavine-I was described
- Kiguchi, Toshiko,Hashimoto, Chiyomi,Ninomiya, Ichiya
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p. 2891 - 2893
(2007/10/02)
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- A TOTAL SYNTHESIS OF (+/-)-LYSERGENE AND (+/-)-AGROCLAVINE
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A preliminary study on the exploitation of a general synthetic route to the ergoline group of alkaloids on the despyrrole analogs was succesfully extended to the first total synthesis of racemic lysergene and agroclavine via the route involving reductive photocyclization of the furylenamide (10) followed by ring opening of the resulting dihydrofuran ring (11).
- Kiguchi, Toshiko,Hashimoto, Chiyomi,Ninomiya, Ichiya
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