Pigments of fungi. Part 51.¹ Structure and stereochemistry of coupled pre-anthraquinones of the pseudophlegmacin type from Australian toadstools belonging to the genus Dermocybe

Abstract

(3′R,P)-Anhydropseudophlegmacin-9,10-quinone 6′,8′-di-O-methyl ether 4 and the corresponding 1,6′,8′-tri-O-methyl ether 5 are isolated together with the atropisomeric green pigments austroviridin B 10 and austroviridin A 11 from the fruiting bodies of indigenous Australian toadstools belonging to the genus Dermocybe. The structures of these pigments are determined by spectroscopic methods, while their absolute configurations are established from the respective CD spectra and by reductive cleavage of 5 to a mixture of (R)-torosachrysone 8-O-methyl ether 12 and emodin 1-O-methyl ether 14.

References

1. Part 50, C. Elsworth, M. Gill, A. Gimenez, N. M. Milanovic and E. Raudies, J. Chem. Soc., Perkin Trans. 1, 1999, 119.
2. M. Gill and W. Steglich, Prog. Chem. Org. Nat. Prod., 1987, 51, 1.
3. B. Oertel, Dissertation, Rheinischen Friedrich-Wilhelms-Universität, Bonn, 1984.
4. W. Steglich and B. Oertel, Sydowia, 1984, 37, 284.
5. M. Gill, A. Giménez, A. G. Jhingran and A. R. Palfreyman, Tetrahedron: Asymmetry, 1990, 1, 621.
6. D. W. Cameron and M. J. Crossley, Aust. J. Chem., 1977, 30, 1161.
7. P. M. Morgan, PhD Thesis, University of Melbourne, 1998.
8. S. F. Mason, R. H. Seal and D. R. Roberts, Tetrahedron, 1974, 30, 1671; N. Harada and K. Nakanishi, Circularly Dichroic Spectroscopy-Exciton Coupling in Organic Stereochemistry, University Science Books, Mill Valley, 1983; K. Nakanishi and N. Berova, The Exciton Chirality Method in Circular Dichroism, ed. K. Nakanishi, N. Berova and R. W. Woody, VCH, Weinheim, New York, 1994.
9. V. Prelog and G. Helmchen, Angew Chem., 1982, 94, 614.
10. S. N. Eagle, M. Gill, S. Saubern and J. Yu, Nat. Prod. Lett., 1993, 2, 151.
11. S. Saubern, PhD Thesis, University of Melbourne, 1993.
12. R. H. Thomson, Naturally Occurring Quinones, Academic Press, London, 1971.
13. W. Steglich, E. Töpfer-Petersen and I. Pils, Z. Naturforsch, Teil C, 1973, 28, 354.
14. M. S. Buchanan, M. Gill, A. Gimenez, A. R. Palfreyman, S. Phonh-Axa, E. Raudies and J. Yu., Aust. J. Chem., in the press.
15. M. Gill, P. M. Millar, S. Phonh-Axa, E. Raudies and J. M. White, Aust. J. Chem., in the press.
16. M. Gill, Aust. J. Chem., 1995, 48, 1.
17. G. M. Blackburn, D. E. H. Ekong, A. H. Neilson and A. R. Todd, Chimia, 1965, 19, 208; R. L. Edwards and N. Kale, Tetrahedron, 1965, 21, 2095.
18. A. G. Perkins and A. E. Everest, The Natural Organic Colouring Matters, Longmans, Green and Co., London, 1918, pp. 617–620.
19. R. N. Khanna, P. K. Sharma and R. H. Thomson, J. Chem. Soc., Perkin Trans. 1., 1987, 1821.
20. R. L. Edwards, V. Fawcett, D. J. Maitland, R. Nettleton, L. Shields and A. J. S. Whalley, J. Chem. Soc., Chem. Commun., 1991, 1009.
21. M. Gill and A. Gimenez, Phytochemistry, 1991, 30, 951.
22. M. Müller, Dissertation, Ludwig-Maximillians-Universität, München, 1995.