A member of the class of isocoumarins that is 1H-isochromen-1-one substituted by a 2,4-dioxopentyl group at position 3 and by hydroxy groups at positions 6 and 8.
Identification
1-(6,8-dihydroxy-1-oxo-1H-isochromen-3-yl)pentane-2,4-dione
1-(6,8-dihydroxy-1-oxo-1H-2-benzopyran-3-yl)pentane-2,4-dione
dehydrocitreoisocoumarin
Species
aspergillus nidulans
NCBI:txid162425 22510154
Europe PubMed Central results
Unraveling polyketide synthesis in members of the genus Aspergillus.
Author: Chiang YM, Oakley BR, Keller NP, Wang CC.
Abstract: Aspergillus species have the ability to produce a wide range of secondary metabolites including polyketides that are generated by multi-domain polyketide synthases (PKSs). Recent biochemical studies using dissected single or multiple domains from PKSs have provided deep insight into how these PKSs control the structural outcome. Moreover, the recent genome sequencing of several species has greatly facilitated the understanding of the biosynthetic pathways for these secondary metabolites. In this review, we will highlight the current knowledge regarding polyketide biosynthesis in Aspergillus based on the domain architecture of non-reducing, highly reducing, and partially reducing PKSs, and PKS-non-ribosomal peptide synthetases.
Illuminating the diversity of aromatic polyketide synthases in Aspergillus nidulans.
Author: Ahuja M, Chiang YM, Chang SL, Praseuth MB, Entwistle R, Sanchez JF, Lo HC, Yeh HH, Oakley BR, Wang CC.
Abstract: Genome sequencing has revealed that fungi have the ability to synthesize many more natural products (NPs) than are currently known, but methods for obtaining suitable expression of NPs have been inadequate. We have developed a successful strategy that bypasses normal regulatory mechanisms. By efficient gene targeting, we have replaced, en masse, the promoters of nonreducing polyketide synthase (NR-PKS) genes, key genes in NP biosynthetic pathways, and other genes necessary for NR-PKS product formation or release. This has allowed us to determine the products of eight NR-PKSs of Aspergillus nidulans, including seven novel compounds, as well as the NR-PKS genes required for the synthesis of the toxins alternariol (8) and cichorine (19).
DOI: 10.1021/ja3016395
SnPKS19 Encodes the Polyketide Synthase for Alternariol Mycotoxin Biosynthesis in the Wheat Pathogen Parastagonospora nodorum.
Author: Chooi YH, Muria-Gonzalez MJ, Mead OL, Solomon PS.
Abstract: Alternariol (AOH) is an important mycotoxin from the Alternaria fungi. AOH was detected for the first time in the wheat pathogen Parastagonospora nodorum in a recent study. Here, we exploited reverse genetics to demonstrate that SNOG_15829 (SnPKS19), a close homolog of Penicillium aethiopicum norlichexanthone (NLX) synthase gene gsfA, is required for AOH production. We further validate that SnPKS19 is solely responsible for AOH production by heterologous expression in Aspergillus nidulans. The expression profile of SnPKS19 based on previous P. nodorum microarray data correlated with the presence of AOH in vitro and its absence in planta. Subsequent characterization of the ΔSnPKS19 mutants showed that SnPKS19 and AOH are not involved in virulence and oxidative stress tolerance. Identification and characterization of the P. nodorum SnPKS19 cast light on a possible alternative AOH synthase gene in Alternaria alternata and allowed us to survey the distribution of AOH synthase genes in other fungal genomes. We further demonstrate that phylogenetic analysis could be used to differentiate between AOH synthases and the closely related NLX synthases. This study provides the basis for studying the genetic regulation of AOH production and for development of molecular diagnostic methods for detecting AOH-producing fungi in the future.
DOI: 10.1128/aem.00278-15
Microbial metabolomics in open microscale platforms.
Author: Barkal LJ, Theberge AB, Guo CJ, Spraker J, Rappert L, Berthier J, Brakke KA, Wang CCC, Beebe DJ, Keller NP, Berthier E.
Abstract: The microbial secondary metabolome encompasses great synthetic diversity, empowering microbes to tune their chemical responses to changing microenvironments. Traditional metabolomics methods are ill-equipped to probe a wide variety of environments or environmental dynamics. Here we introduce a class of microscale culture platforms to analyse chemical diversity of fungal and bacterial secondary metabolomes. By leveraging stable biphasic interfaces to integrate microculture with small molecule isolation via liquid-liquid extraction, we enable metabolomics-scale analysis using mass spectrometry. This platform facilitates exploration of culture microenvironments (including rare media typically inaccessible using established methods), unusual organic solvents for metabolite isolation and microbial mutants. Utilizing Aspergillus, a fungal genus known for its rich secondary metabolism, we characterize the effects of culture geometry and growth matrix on secondary metabolism, highlighting the potential use of microscale systems to unlock unknown or cryptic secondary metabolites for natural products discovery. Finally, we demonstrate the potential for this class of microfluidic systems to study interkingdom communication between fungi and bacteria.
DOI: 10.1038/ncomms10610