Cycloclavin, ein neues alkaloid aus Ipomoea hildebrandtii vatke—71

Stauffacher, D.; Niklaus, P.; Tscherter, H.; Weber, Hans Peter; Hofmann, Alan F.

doi:10.1016/s0040-4020(01)83095-7

Cited by 65 publications

(32 citation statements)

References 11 publications

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“…In addition to ergot alkaloids known from other Clavicipitaceae, unique ergot alkaloids have been discovered in the Convolvulaceae, notably cycloclavine from Ipomoea hildebrandtii , an African shrub (Stauffacher et al . ). All reports of ergot alkaloids from the Convolvulaceae have come from the speciose tribe Ipomoeeae (ca.…”

Section: Clavicipitaceous Endophytes Of Convolvulaceaementioning

confidence: 97%

Bioactive alkaloids in vertically transmitted fungal endophytes

2013

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Summary1. Plants form mutualistic symbioses with a variety of microorganisms including endophytic fungi that live inside the plant and cause no overt symptoms of infection. Some endophytic fungi form defensive mutualisms based on the production of bioactive metabolites that protect the plant from herbivores in exchange for a protected niche and nutrition from the host plant. Key elements of these symbioses are vertical transmission of the fungus through seed of the host plant, a narrow host range, and production of bioactive metabolites by the fungus. 2. Grasses frequently form symbioses with endophytic fungi belonging to the family Clavicipitaceae. These symbioses have been studied extensively because of their significant impacts on insect and mammalian herbivores. Many of the impacts are likely due to the production of four classes of bioactive alkaloids -ergot alkaloids, lolines, indole-diterpenes and peraminethat are distributed in different combinations among endophyte taxa. 3. Several legumes, including locoweeds, are associated with a toxic syndrome called locoism as a result of their accumulation of swainsonine. Species in two genera were recently found to contain previously undescribed endophytic fungi (Undifilum spp., family Pleosporaceae) that are the source of that toxin. The fungi are strictly vertically transmitted and have narrow host ranges. 4. Some plant species in the morning glory family (Convolvulaceae) also form symbioses with endophytic fungi of the Clavicipitaceae that produce ergot alkaloids and, perhaps in at least one case, lolines. Other species in this plant family form symbioses with undescribed fungi that produce swainsonine. The swainsonine-producing endophytes associated with the Convolvulaceae are distinct from the Undifilum spp. associated with locoweeds and the Clavicipitaceous fungi associated with Convolvulaceae. 5. In the establishment of vertically transmitted symbioses, fungi must have entered the symbiosis with traits that were immediately useful to the plant. Bioactive metabolites are likely candidates for such pre-adapted traits which were likely useful to the free-living fungi as well. With future research, vertically transmitted fungi from diverse clades with narrow host ranges and that produce bioactive compounds are likely to be found as important mutualists in additional plants.

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Section: Clavicipitaceous Endophytes Of Convolvulaceaementioning

confidence: 97%

Bioactive alkaloids in vertically transmitted fungal endophytes

2013

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“…Cycloclavine ( 1 , Scheme 1) was first isolated in 1969 from the seeds of the African morning glory ( Ipomea hildebrandtii ) by Hoffman and coworkers. 2 In spite of its compact size (C 16 H 18 N 2 , MW=238), the perimeter of this clavine alkaloid contains three contiguous stereocenters, two of which are fully substituted and part of a cyclopropane ring, thus posing a respectable synthetic challenge. In 2008, Incze et al completed the first synthesis of (±)-cycloclavine in 14 steps and 0.2% overall yield.…”

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confidence: 99%

Total Synthesis of (±)-Cycloclavine and (±)-5-epi-Cycloclavine

2011

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Novel routes to the naturally occurring indole alkaloid cycloclavine and its unnatural C(5)-epimer are described. Key features include the rapid construction of the heterocyclic core segments by two Diels-Alder reactions. An indole annulation was accomplished by a late-stage intramolecular Diels-Alder furan cycloaddition, and a methylenecyclopropane dienophile was used for a stereoselective intramolecular [4+2] cycloaddition to give the cyclopropa[c]indoline building block present in cycloclavine.

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“…Die Ergot-Alkaloide sind eine große Familie polycyclischer Indolalkaloide,d ie verschiedene biologische Aktivitäten aufweisen (Abbildung 1). [27] Cycloclavin (48), das 1969 aus den Samen der Blütenpflanze Ipomoea hildebrandtii isoliert wurde, [28] hat insektizide und antiparasitäre Eigenschaften. [29] Strukturell ist Cycloclavin unter den Ergot-Al-…”

Section: (à)-Cycloclavin (Dong 2018)unclassified

Übergangsmetallvermittelte Spaltung von C‐C‐Einfachbindungen

2020

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Schema 1. Beispiele fürfrühere Synthesen A) mit CC -Bindungsspaltung ohne Übergangsmetalle, B) mit übergangsmetallvermittelter Spaltung von CC -Einfachbindungen unter Bildung eines reaktiven metallorganischen Intermediats (Zwei-Elektronen-Reaktivität) und C) mit übergangsmetallvermittelter Spaltung von CC -Einfachbindungen unter Bildung eines reaktiven radikalischen Intermediats (Ein-Elektronen-Reaktivität). Cp = Cyclopentadienyl, DMPU = Dimethylpropylenharnstoff, Piv = Pivaloyl, TBS = tert-Butyldimethylsilyl, TIPS = Triisopropylsilyl.

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Cycloclavin, ein neues alkaloid aus Ipomoea hildebrandtii vatke—71

Cited by 65 publications

References 11 publications

Bioactive alkaloids in vertically transmitted fungal endophytes

Bioactive alkaloids in vertically transmitted fungal endophytes

Total Synthesis of (±)-Cycloclavine and (±)-5-epi-Cycloclavine

Übergangsmetallvermittelte Spaltung von C‐C‐Einfachbindungen

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