The Chemistry and Stereochemistry of Cercosporin

Yamazaki, Sunao; Ogawa, Tadatomo

doi:10.1080/00021369.1972.10860458

Cited by 53 publications

(52 citation statements)

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“…The extracts were dried over Na 2 S0 4 and concentrated to dryness, and the residue was fractionated by silica gel column chromatography, using CHCI 3 -MeOH (9: 1) as the eluent, into eight fractions (Fr. [1][2][3][4][5][6][7][8]. Fraction 1 showed two red spots at R f =0.34 and 0.68 on silica gel TLC with CHClrMeOH (95: 5), and showed a yellow spot at R r =0.45 and a blue spot at Rf=0.21 on silica gel TLC with benzene-ethyl acetate (8: 2) by p~anisaldehyde-acetic acid-conc.…”

Section: Methodsmentioning

confidence: 99%

“…The absolute configurations of the asymmetric carbons at C-14 and C-17, and the axial chirality of ( + )-cercosporin (8a) have been established as Rand R, respectively, on the basis of an X-ray analysis and chemical reactions. 7 ) Since the 1 H-NMR spectral data for 1 are identical with those for 8b (Table I), indicating the same relative configuration for both compounds, and the CD spectral curve of 1 is antipodal to that of 8b (Table III) structure, 4,9-dihydroxy-2, 11-dimethoxy-1, 12-(2-hydroxypropyl)-6, 7-methylenedioxyperylene-3, 10-quinone, the absolute configuration of the asymmetric carbons of 1 being S and the axial chirality being confirmed as R. This compound 1, named (+ )-isocercosporin, is a diastereomer of (+ )-cercosporin (8a), and the enantiomer of ( isocercosporin (8b), and is the first atropisomer of ( cercorporin isolated from natural sources. Compound 2 has the molecular formula C31H28011 from EI-HRMS data.…”

Section: ) ( -) -mentioning

confidence: 99%

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Phytotoxic Metabolites Isolated fromScolecotrichum graminisFuckel

Tabuchi

Tajimi

Ichihara

1994

Bioscience, Biotechnology, and Biochemistry

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Section: Methodsmentioning

confidence: 99%

Section: ) ( -) -mentioning

confidence: 99%

Phytotoxic Metabolites Isolated fromScolecotrichum graminisFuckel

Tabuchi

Tajimi

Ichihara

1994

Bioscience, Biotechnology, and Biochemistry

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“…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).…”

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confidence: 99%

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

Daub¹,

Hangarter²

1983

Plant Physiol.

146

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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.

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“…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

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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...

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The Chemistry and Stereochemistry of Cercosporin

Cited by 53 publications

References 8 publications

Phytotoxic Metabolites Isolated fromScolecotrichum graminisFuckel

Phytotoxic Metabolites Isolated fromScolecotrichum graminisFuckel

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

Peroxidation of Tobacco Membrane Lipids by the Photosensitizing Toxin, Cercosporin

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