Some photochemical and photobiological properties of 8,8-desmethylxanthyletine (homopsoralen), a potential photochemotherapeutic agent.

Abstract

In this paper the photochemical and photobiological properties of 8,8-desmethyl-xanthyletine (homopsoralen) have been studied. This drug forms a molecular complex with DNA undergoing intercalation between two base pairs of the macromolecule. By subsequent irradiation (365 nm) the compound photobinds covalently to the macromolecule showing an initial DNA-photobinding rate higher than that of 8-methoxypsoralen. In the photoreaction with DNA the drug effectively forms inter-strand cross-linkages. Its ability to generate singlet oxygen when irradiated with ultraviolet light is markedly higher than that of 8-MOP. Homopsoralen when irradiated in water solution undergoes effective photolysis. The drug shows a lower antiproliferative activity on diploid yeast (D 7) than 8-MOP and an almost parallel mutagenic activity. Also the gene convertogenic activity, determined on the same yeast strain, is lower than that of 8-MOP. Homopsoralen does not show any skin phototoxicity on guinea-pig skin. Taking into account its DNA-photobinding capacity, its antiproliferative activity, its reduced genotoxicity and lack of skin-phototoxicity homopsoralen may deserve further studies for evaluating its photochemotherapeutic activity.

• Authors: D Vedaldi, F Dall'Acqua, D Averbeck, E Cundari
• Journal: Il Farmaco; edizione scientifica (Farmaco Sci) Vol. 43 Issue 5 Pg. 395-407 (May 1988) ISSN: 0430-0920 [Print] Italy
• PMID: 3065093 (Publication Type: Journal Article)

Chemical References

• Furocoumarins
• Mutagens
• homopsoralen
• DNA
• Oxygen

Topics

• Animals
• Cell Division (drug effects)
• Chemical Phenomena
• Chemistry
• DNA (drug effects)
• Furocoumarins (analysis, pharmacology, radiation effects)
• Gene Conversion (drug effects)
• Guinea Pigs
• Light
• Mutagens
• Oxygen (analysis)
• Photochemotherapy
• Saccharomyces cerevisiae (drug effects, genetics)
• Skin (drug effects)