Determination of the Absolute Configuration of Perylene Quinone‐Derived Mycotoxins by Measurement and Calculation of Electronic Circular Dichroism Spectra and Specific Rotations |
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| Authors: | Prof?Dr Joachim Podlech Dr Stefanie C Fleck Prof?Dr Manfred Metzler Dr Jochen Bürck Prof?Dr Anne S Ulrich |
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| Affiliation: | 1. Institute for Organic Chemistry, Karlsruhe Institute for Technology (KIT), Campus South, Fritz‐Haber‐Weg 6, 76131 Karlsruhe (Germany), Fax: (+49)?721‐608‐47652;2. Institute for Applied Biosciences, Department of Food Chemistry, Karlsruhe Institute for Technology (KIT), Campus South, Adenauerring 20, 76131 Karlsruhe (Germany);3. Institute for Biological Interfaces, Karlsruhe Institute for Technology (KIT), Campus North, P.O. Box 3640, 76021 Karlsruhe (Germany) |
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| Abstract: | Altertoxins I–III, alterlosins I and II, alteichin (alterperylenol), stemphyltoxins I–IV, stemphyperylenol, stemphytriol, 7‐epi‐8‐hydroxyaltertoxin I, and 6‐epi‐stemphytriol are mycotoxins derived from perylene quinone, for which the absolute configuration was not known. Electronic circular dichroism (ECD) spectra were calculated for these compounds and compared with measured spectra of altertoxins I–III, alteichin, and stemphyltoxin III and with reported Cotton effects. Specific rotations were calculated and compared with reported specific rotations. The absolute configuration of all the toxins, except for stemphyltoxin IV, could thus be determined. The validity of the assignment was high whenever reported ECD data were available for comparison, and the validity was lower when the assignment was based only on the comparison of calculated and reported specific rotations. ECD spectra are intrinsically different for toxins with a biphenyl substructure and for toxins derived from dihydroanthracene. |
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| Keywords: | absolute configuration circular dichroism DFT calculations mycotoxins quinones |
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