Shearinines D–K, new indole triterpenoids from an endophytic Penicillium sp. (strain HKI0459) with blocking activity on large-conductance calcium-activated potassium channels

Xu, Min-Juan; Geßner, Guido; Groth, Ingrid; Lange, C. C.; Christner, Arnulf; Bruhn, Torsten; Deng, Zhiwei; Li, Xiang; Heinemann, Stefan H.; Grabley, Susanne; Bringmann, Gerhard; Sattler, Isabel; Lin, Wenhan

doi:10.1016/j.tet.2006.10.050

Cited by 88 publications

(100 citation statements)

References 30 publications

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“…NOE correlations between H 3 ‐33 and H‐14β as well as between H‐11 and H‐14α suggested the α‐orientation of the hydroxy group at C‐13 (Figure S9). Based on the study by Xu et al . and biosynthetic considerations we suggest the absolute configuration of shearinine L ( 1 ) to be identical to that of shearinine D ( 3 ) which is also produced by E. weberi .…”

Section: Resultsmentioning

confidence: 67%

“…The relative configuration of ring fusions in shearinine M ( 2 ) is identical to shearinine L ( 1 ) based on the NOESY correlations: H 3 ‐32/H‐17α, H‐16/H 3 ‐33, H 3 ‐33/H‐14β and H‐11 and H‐14α (Figure S17B). Because shearinine M ( 2 ) is closely related to shearinine L ( 1 ) and D ( 3 ) it is expected to have the same absolute configuration as shearinine D ( 3 ) …”

Section: Resultsmentioning

confidence: 99%

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Secondary Metabolites from Escovopsis weberi and Their Role in Attacking the Garden Fungus of Leaf‐Cutting Ants

Dhodary

Schilg

Wirth

et al. 2018

Chemistry A European J

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The specialized, fungal pathogen Escovopsis weberi threatens the mutualistic symbiosis between leaf-cutting ants and their garden fungus (Leucoagaricus gongylophorus). Because E. weberi can overwhelm L. gongylophorus without direct contact, it was suspected to secrete toxins. Using NMR and mass spectrometry, we identified several secondary metabolites produced by E. weberi. E. weberi produces five shearinine-type indole triterpenoids including two novel derivatives, shearinine L and shearinine M, as well as the polyketides, emodin and cycloarthropsone. Cycloarthropsone and emodin strongly inhibited the growth of the garden fungus L. gongylophorous at 0.8 and 0.7 μmol, respectively. Emodin was also active against Streptomyces microbial symbionts (0.3 μmol) of leaf-cutting ants. Shearinine L instead did not affect the growth of L. gongylophorus in agar diffusion assays. However, in dual choice behavioral assays Acromyrmex octospinosus ants clearly avoided substrate treated with shearinine L for the garden fungus after a 2 d learning period, indicating that the ants quickly learn to avoid shearinine L.

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Section: Resultsmentioning

confidence: 67%

Section: Resultsmentioning

confidence: 99%

Secondary Metabolites from Escovopsis weberi and Their Role in Attacking the Garden Fungus of Leaf‐Cutting Ants

Dhodary

Schilg

Wirth

et al. 2018

Chemistry A European J

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“…Indole‐diterpenes have various types of core structures and are widely distributed natural products in fungi; more than 100 family members have been reported 1. 19–21 Nearly 70 % of these, including aflatrems ( 1 and 2 ), paxilline ( 4 ), lolitrems, and penitrems have a characteristic hexacyclic skeleton that is presumably derived from paspaline ( 3 ; Schemes and ). Recently, we heterologously expressed the paxilline biosynthetic genes from Penicillium paxilli and successfully elucidated the biosynthetic pathway of the characteristic hexacyclic skeleton (Scheme ) 14.…”

Section: Methodsmentioning

confidence: 99%

Rapid Reconstitution of Biosynthetic Machinery for Fungal Metabolites in Aspergillus oryzae: Total Biosynthesis of Aflatrem

et al. 2014

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Reconstitution of the biosynthetic machinery for fungal secondary metabolites in Aspergillus oryzae provides an opportunity both for stepwise determination of the biosynthetic pathways and the total biosynthesis of fungal natural products. However, to maximize the utility of the reconstitution system, a simple and rapid strategy for the introduction of heterologous genes into A. oryzae is required. In this study, we demonstrated an effective method for introducing multiple genes involved in the biosynthesis of fungal metabolites by using the expression vectors pUARA2 and pUSA2, each of which contains two cloning sites. The successful introduction of all the aflatrem biosynthetic genes (seven genes in total) after two rounds of transformation enabled the total biosynthesis of aflatrem. This rapid reconstitution strategy will facilitate the functional analysis of the biosynthetic machinery of fungal metabolites.

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“…Nonetheless, there are a few examples, such as those of knipholone anthrone (5) or xylogranatin F (6), for which TDDFT calculations are not sufficient to reproduce the ex- Figure 9. Further selected examples of structurally diverse compounds with different types of stereogenic elements, the absolute configurations of which were established by quantum chemical CD calculations (saludimerin A, [83] ancistrotanzanin A, [84] bi [10]paracyclophanes, [56] joziknipholone A, [85] γ-rubromycin, [86] a Tröger's base derivative, [87] resistoflavin, [88] shearinine D, [89] nigerone; [90] for other examples see ref. [91] ).…”

Section: Conclusion: Semiempirical Methods Dft or Mrci?mentioning

confidence: 99%

The Assignment of Absolute Stereostructures through Quantum Chemical Circular Dichroism Calculations

et al. 2009

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The determination of the absolute configuration of a chiral compound of synthetic or natural origin is a problem that every organic chemist willl certainly have to face some day. An efficient and reliable method for the assignment of absolute stereostructures, independent of empirical CD rules, is the combination of experimental circular dichroism (CD) investigations with quantum chemical CD calculations. The availability of a broad variety of quantum chemical methods and the continuing appearance of new approaches permits -but also requires -the most appropriate method to be selected in each particular case, with respect to accuracy, time con-

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Shearinines D–K, new indole triterpenoids from an endophytic Penicillium sp. (strain HKI0459) with blocking activity on large-conductance calcium-activated potassium channels

Cited by 88 publications

References 30 publications

Secondary Metabolites from Escovopsis weberi and Their Role in Attacking the Garden Fungus of Leaf‐Cutting Ants

Secondary Metabolites from Escovopsis weberi and Their Role in Attacking the Garden Fungus of Leaf‐Cutting Ants

Rapid Reconstitution of Biosynthetic Machinery for Fungal Metabolites in Aspergillus oryzae: Total Biosynthesis of Aflatrem

The Assignment of Absolute Stereostructures through Quantum Chemical Circular Dichroism Calculations

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