Relative affinity of 5-methoxypsoralen and 8-methoxypsoralen towards β-cyclodextrin: A fluorescence, circular dichroism and chromatographic study

✍ Scribed by Jocelyne Blais; Patrice Prognon; Georges Mahuzier; Paul Vigny

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 730 KB
• Volume: 2
• Category: Article
• ISSN: 1011-1344
• DOI: 10.1016/1011-1344(88)85074-7

✦ Synopsis

The relative affinity of 5-methoxypsoralen (5-MOP) and 8-methoxypsoralen (8-MOP) towards beta-cyclodextrin, a good model for the study of lipophilic interactions in biological systems and a potential drug carrier, has been investigated using spectroscopic and chromatographic methods. The fluorescence emission of 5-MOP in aqueous solution containing beta-cyclodextrin (10(-2) M) is found to be markedly blue shifted and enhanced by a factor of 6 whereas no significant changes are observed for 8-MOP. The existence of an induced circular dichroism is evidence for the formation of a 1:1 inclusion complex (association constant K = 400 +/- 50 M-1). Moreover, chromatographic results obtained with a beta-cyclodextrin linked stationary phase are consistent with our spectroscopic results and might have interesting analytical implications. These results clearly demonstrate that, in contrast to 8-MOP, 5-MOP exhibits a strong affinity for hydrophobic medium. Interesting pharmacological and analytical applications may result from the possible inclusion of psoralen derivatives into beta-cyclodextrin.