Structural Analysis of Psoralens and Their Analogues
|Michał A. Dobrowolski , Michal K. Cyranski|
Warsaw University, Faculty of Chemistry, Pasteura 1, Warszawa 02-093, Poland
Psoralens are naturally occurring linear furocoumarins and are used with long-wave UV light as an effective treatment for skin ailments such as psoriasis . They intercalate into double stranded nucleic acids and in the presence of 365-nm UV light, undergo a photochemical reaction with the pyrimidine residues to form photoadducts. It has been experimentally confirmed that preferred base for the process is thymine .
Eight crystal and molecular structures of psoralens and their derivatives (both linear and angular, see Fig. 1) were determined by X-ray diffraction experiment. The extent of π-electron (de)localization in the rings depending on the topological environment was analyzed with use of geometry-based descriptor HOMA  and magnetism-based descriptor NICS . For the latter, model analogues were optimized at B3LYP/6-311+G** level of theory. The comparison of the total energies led to the conclusion the isomers may differ at most by c.a. 18 kcal/mol, what is rationalized on the base of their topology.
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Presentation: poster at 18th Conference on Physical Organic Chemistry, Posters, by Michał A. Dobrowolski
See On-line Journal of 18th Conference on Physical Organic Chemistry
Submitted: 2006-07-11 13:28 Revised: 2009-06-07 00:44
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