A New 5-Alkenylresorcinol Sch 725681 from Aspergillus sp.

Yang, Shu‐Wei; Chan, Tze‐Ming; Terracciano, Joseph; Loebenberg, David; Patel, Mahesh; Gullo, Vincent P.; Chu, Min

doi:10.1038/ja.2006.27

Cited by 9 publications

(6 citation statements)

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“…The configurations of Δ 9 and Δ 11 in 8 were the same as those in 6 , and they were assigned as cis and trans , respectively, based on the coupling constants of H-9/H-10 ( J 9,10 = 11.0 Hz) and H-11/H-12 ( J 11,12 = 15.0 Hz) in CD 3 OD. Similarly to the known compound 5-[(3 Z ,5 Z )-3,5-nonadienyl]-1,3-benzenediol, compound 8 was named 5-[(3 Z ,5 E )-3,5-nonadienyl]-1,3-benzenediol.…”

Section: Resultsmentioning

confidence: 99%

Phenolic C-Glycosides and Aglycones from Marine-Derived Aspergillus sp. and Their Anti-Inflammatory Activities

et al. 2019

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A chemical investigation of the secondary metabolites of a marine-derived Aspergillus sp. led to the isolation and characterization of 13 phenolic compounds, including 10 new compounds (1–10). Seven new compounds (1–7) are unusual phenolic C-glycosides, while the other new compounds (8–10) are structurally related aglycones. The chemical structures of these new compounds were elucidated by 1D and 2D NMR and HRESIMS spectroscopic analyses. The absolute configurations of these new C-glycosides were determined by comparison of experimental electronic circular dichroism spectra with those of calculated ones. In addition, the anti-inflammatory activities of these compounds were evaluated, and compound 9 significantly inhibited nitric oxide production with an IC50 value of 6.0 ± 0.5 μM in lipopolysaccharide-induced RAW264.7 cells. Moreover, compound 9 also showed anti-inflammatory activity by inhibiting the NF-κB-activated pathway.

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Section: Resultsmentioning

confidence: 99%

Phenolic C-Glycosides and Aglycones from Marine-Derived Aspergillus sp. and Their Anti-Inflammatory Activities

et al. 2019

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“…2Ј-Oxoalkylresorcinol is known to be a metabolite of a basidiomycete (20), rice (21) and wheat and rye (22), suggesting the occurrence of type III PKSs with ORAS activity in these organisms. It is also possible that ORAS-like enzymes are involved in the synthesis of some tetraketide alkylresorcinols in other fungi, such as Aspergillus (23) and Fusarium (24).…”

Section: Discussionmentioning

confidence: 99%

Pentaketide Resorcylic Acid Synthesis by Type III Polyketide Synthase from Neurospora crassa

Funa

Awakawa

Horinouchi

2007

Journal of Biological Chemistry

123

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Type III polyketide synthases (PKSs) are responsible for aromatic polyketide synthesis in plants and bacteria. Genome analysis of filamentous fungi has predicted the presence of fungal type III PKSs, although none have thus far been functionally characterized. In the genome of Neurospora crassa, a single open reading frame, NCU04801.1, annotated as a type III PKS was found. In this report, we demonstrate that NCU04801.1 is a novel type III PKS catalyzing the synthesis of pentaketide alkylresorcylic acids. NCU04801.1, hence named 2-oxoalkylresorcylic acid synthase (ORAS), preferred stearoyl-CoA as a starter substrate and condensed four molecules of malonyl-CoA to give a pentaketide intermediate. For ORAS to yield pentaketide alkylresorcylic acids, aldol condensation and aromatization of the intermediate, which is still attached to the enzyme, are presumably followed by hydrolysis for release of the product as a resorcylic acid. ORAS is the first type III PKS that synthesizes pentaketide resorcylic acids.Polyketides are synthesized by so-called polyketide synthases (PKSs) 2 that fall into three groups, types I to III (1). Ketosynthase, which is a pivotal domain for polyketide synthesis, catalyzes the sequential decarboxylative condensation of extender substrates by a process closely similar to fatty acid biosynthesis. In contrast to type I and II megasynthases composed of ketosynthases and accessory enzymes, type III PKSs are a dimer of ketosynthase that accomplishes a complex set of reactions, such as priming of a starter substrate, decarboxylative condensation of extender substrates, ring closure, and aromatization of the polyketide chain, in a multifunctional active site pocket (2). A growing number of type III PKSs catalyzing the synthesis of aromatic polyketides have been found from plants and bacteria, and their catalytic properties have been characterized. Chalcone synthases, the representative of type III PKSs in plants, catalyze the synthesis of naringenin chalcone, which is a common precursor of all flavonoids produced by plants (2). RppA, the first type III PKS found in bacteria, catalyzes the synthesis of 1,3,6,8-tetrahydroxynaphthalene, which is a precursor of hexahydroxyperylenequinone melanin in a bacterium, Streptomyces griseus (3).Filamentous fungi produce a vast array of polyketides such as melanins, antibiotics, and mycotoxins (4). The pathways and regulation of biosynthesis of the aromatic polyketides in filamentous fungi have been studied extensively for mycotoxins, including aflatoxin and fumonisin, produced by food spoilage fungi (5) and for melanogenesis associated with infection of plant-pathogenic fungi (6). In addition, the clinical benefit of lovastatin, a cholesterol-lowering agent, produced by Aspergillus terreus (7), promotes isolation of the biosynthetic genes for polyketides in fungi. Nevertheless, the enzyme systems for the synthesis of fungal polyketides have been confined to iterative type I PKSs, which are composed of a large multifunctional polypeptide containing discrete fu...

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“…Three methyl, one methylene, and two methine signals were observed in the aliphatic region, and six resonances were observed in the olefinic/aromatic region. In the 13 C NMR spectrum, twenty one carbon signals were detected, in which a conjugated ketone functionality (C-6, d 197.5) was identified. The molecular ion m/z 387, [MϩH] ϩ was observed on an ESI MS instrument, and therefore the molecular formula of 1 was calculated as C 21 H 22 O 7 .…”

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confidence: 99%