The structure of cercosporin, a naturally occurring quinone

Lousberg, R. J. J. C.; Weiß, Ulrich; Salemink, C. A.; Arnone, Alberto; Merlini, Lucio; Nasini, Gianluca

doi:10.1039/c29710001463

Cited by 59 publications

(32 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Cercosporin was first isolated in 1957 by Kuyama and Tamura ( 11) from Cercospora kikuchii, a soybean pathogen. Its characterization and structure were reported independently by Lousberg and co-workers (12) and Yamazaki and Ogawa (20). Cercosporin is toxic to plants, mice, and bacteria (2,21).…”

mentioning

confidence: 99%

Light-Induced Production of Singlet Oxygen and Superoxide by the Fungal Toxin, Cercosporin

Daub¹,

Hangarter²

1983

Plant Physiol.

148

View full text Add to dashboard Cite

Cercosporin, a toxin produced by members of the fungal genus Cercospora, is a photosensitizing compound which rapidly kills plant cells in the light. We have found that cercosporin, when activated by light in the presence ofoxygen, is able to generate both singlet oxygen and superoxide ions. Cercosporin, when illuminated in the presence of 02, reacted with cholesterol to form the Sa-hydroperoxide of cholesterol which is only produced by reaction with singlet oxygen. Cercosporin, in the presence of light, 02, and a reducing substrate, was also able to reduce p-nitro blue tetrazolium chloride, a compound readily reduced by superoxide. Superoxide dismutase, a scavenger of superoxide, inhibited this reaction. Production of both singlet oxygen and superoxide by cercosporin must be considered when studying the possible mechanisms of resistance to cercosporin.

show abstract

mentioning

confidence: 99%

Light-Induced Production of Singlet Oxygen and Superoxide by the Fungal Toxin, Cercosporin

Daub¹,

Hangarter²

1983

Plant Physiol.

148

View full text Add to dashboard Cite

show abstract

“…It was first isolated in 1957 (9) from Cercospora kikuchii, a soybean pathogen, and has since been isolated from a large number of Cercospora species (1,2,7,11,14,23) and from Cercosporainfected plants (7,9,23). Its structure was determined independently by Lousberg et al (10) and Yamazaki and Ogawa (25).…”

mentioning

confidence: 99%

Peroxidation of Tobacco Membrane Lipids by the Photosensitizing Toxin, Cercosporin

Daub

1982

Plant Physiol.

108

View full text Add to dashboard Cite

Cercosporin, a nonspecific toxin from Cercospora species, is a photosensitizing compound which rapidly kills plant cells in the light. Cell death appears to be due to a cercosporin-mediated peroxidation of membrane lipids. Tobacco leaf discs treated with cercosporin showed a large increase in electrolyte leakage I to 2 minutes after irradiation with light. All tobacco protoplasts exposed to cercosporin in the light were damaged within 45 minutes. Chloroform:methanol extracts of toxin-treated suspension cultures gave positive reactions for lipid hydroperoxides in the thiobarbituric acid test. Cercosporin-treated leaf discs emitted high concentrations of ethane 12 to 24 hours after incubation in the light. Cercosporin also oxidized solutions of methyl linolenate as determined by the thiobarbituric acid assay and the emission of ethane. a-Tocopherol had an inhibitory effect on the cercosporin-mediated lipid peroxidation.Cercosporin [1,12-bis(2-hydroxypropyl)-2,1 1-dimethoxy-6,7-methylenedioxy-4,9-dihydroxyperylene-3, 10-quinoneI is a nonspecific phytotoxin produced by members ofthe genus Cercospora. It was first isolated in 1957 (9) from Cercospora kikuchii, a soybean pathogen, and has since been isolated from a large number of Cercospora species (1,2,7,11,14,23) and from Cercosporainfected plants (7,9,23). Its structure was determined independently by Lousberg et al. (10) and Yamazaki and Ogawa (25).Cercosporin is a photosensitizing compound (5, 26), thus, it is not toxic to cells in the dark. In the presence of light, however, photosensitizers absorb the light energy to form electronically excited states and then transfer this energy to oxygen (8,18). This results in the production of toxic oxygen species such as singlet oxygen or superoxide ions, which can damage living cells. Yamazaki et al. (26) showed that mice and bacteria were killed by cercosporin only when they were exposed to light, and that oxygen was involved in the process. Previous work in this laboratory (5) has determined that the action spectrum for the killing of tobacco cells by cercosporin is in close agreement with the absorption spectrum of cercosporin, and that the toxic effect of cercosporin can be inhibited by several quenchers of singlet oxygen.The toxic effects of photosensitizing compounds are well known (8, 18). One of the most common of these effects is damage to cellular membranes. Macri and Vianello (12) MATERIALS AND METHODSCercosporin. Cercosporin was isolated and purified from cultures of Cercospora nicotianae as previously described (5). Stock solutions were prepared in either acetone (for assays that involved cell cultures) or methanol (for assays that utilized leaf tissues). Stock solutions were stored at -20°C in the dark. The final concentration of acetone or methanol in control and cercosporintreated cultures did not exceed 1%.Host Material. Tissue discs for electrolyte leakage and ethane studies were cut from fully expanded leaves of Nicotiana tabacum cv 'Wisconsin 38' grown in the greenhouse. The N. tabacum cv 'W...

show abstract

“…Its chemical structure was determined 30 years ago (Lousberg et al 1971;Yamazaki and Ogawa 1972). However, little progress has been made towards defining the pathway of cercosporin biosynthesis.…”

Section: Introductionmentioning

confidence: 99%

Cercosporin-deficient mutants by plasmid tagging in the asexual fungus Cercospora nicotianae

et al. 2003

View full text Add to dashboard Cite

We have successfully adapted plasmid insertion and restriction enzyme-mediated integration (REMI) to produce cercosporin toxin-deficient mutants in the asexual phytopathogenic fungus Cercospora nicotianae. The use of pre-linearized plasmid or restriction enzymes in the transformation procedure significantly decreased the transformation frequency, but promoted a complicated and undefined mode of plasmid integration that leads to mutations in the C. nicotianae genome. Vector DNA generally integrated in multiple copies, and no increase in single-copy insertion was observed when enzymes were added to the transformation mixture. Out of 1873 transformants tested, 39 putative cercosporin toxin biosynthesis ( ctb) mutants were recovered that showed altered levels of cercosporin production. Seven ctb mutants were recovered using pre-linearized plasmids without the addition of enzymes, and these were considered to be non-REMI mutants. The correlation between a specific insertion and a mutant phenotype was confirmed using rescued plasmids as gene disruption vectors in the wild-type strain. Six out of fifteen rescued plasmids tested yielded cercosporin-deficient transformants when re-introduced into the wild-type strain, suggesting a link between the insertion site and the cercosporin-deficient phenotype. Sequence analysis of a fragment flanking the insert site recovered from one insertion mutant showed it to be disrupted in sequences with high homology to the acyl transferase domain of polyketide synthases from other fungi. Disruption of this polyketide synthase gene ( CTB1) using a rescued plasmid resulted in mutants that were defective in cercosporin production. Thus, we provide the first molecular evidence that cercosporin is synthesized via a polyketide pathway as previously hypothesized.

show abstract

The structure of cercosporin, a naturally occurring quinone

Abstract: The structure suggested for cercosporin, a naturally occurring dihydroxy-perylenequinone, is unusual in having a methylenedioxy-group present in a seven-membered ring bridging a biphenyl system.

Cited by 59 publications

References 0 publications

Light-Induced Production of Singlet Oxygen and Superoxide by the Fungal Toxin, Cercosporin

Light-Induced Production of Singlet Oxygen and Superoxide by the Fungal Toxin, Cercosporin

Peroxidation of Tobacco Membrane Lipids by the Photosensitizing Toxin, Cercosporin

Cercosporin-deficient mutants by plasmid tagging in the asexual fungus Cercospora nicotianae

Contact Info

Product

Resources

About