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Article
Exploring Ground-State Heterogeneity of Hypericin and Hypocrellin A and B:  Dynamic and 2D ROESY NMR Study
Journal of the American Chemical Society
  • Alexandre V. Smirnov, Iowa State University
  • D. Bruce Fulton, Iowa State University
  • Amy H. Andreotti, Iowa State University
  • Jacob W. Petrich, Iowa State University
Document Type
Article
Publication Version
Published Version
Publication Date
8-20-1999
DOI
10.1021/ja9906002
Abstract
A NMR study was conducted on the antiviral and antitumor agents hypericin and hypocrellin A and B, whose activity is light induced. Elucidation of the conformational/tautomeric properties of these polycyclic quinones is important for interpreting their photophysical behavior in the excited state. Evidence for interconversion between ground-state tautomers or other conformational isomers was sought in temperature-dependent 1H NMR and 2D-ROESY studies. For hypericin and hypocrellin B, only one ground-state species is observed. For hypocrellin A, however, three species are significantly populated in the ground state due to the high flexibility of its 7-membered ring. In the latter case dynamic NMR simulations were performed to obtain kinetic and thermodynamic parameters for the sequential interconversion occurring between the three species. The implications of these results for the interpretation of the light-induced primary processes in these systems are discussed.
Comments

Reprinted (adapted) with permission from Journal of the American Chemical Society 121 (1999): 7979, doi:10.1021/ja9906002. Copyright 1999 American Chemical Society.

Copyright Owner
American Chemical Society
Language
en
File Format
application/pdf
Citation Information
Alexandre V. Smirnov, D. Bruce Fulton, Amy H. Andreotti and Jacob W. Petrich. "Exploring Ground-State Heterogeneity of Hypericin and Hypocrellin A and B:  Dynamic and 2D ROESY NMR Study" Journal of the American Chemical Society Vol. 121 Iss. 35 (1999) p. 7979 - 7988
Available at: http://works.bepress.com/amy_andreotti/16/