Novel beta-cyclodextrin-eosin conjugates

作者：Benkovics Gabor; Afonso Damien; Darcsi Andras; Beni Szabolcs; Conoci Sabrina; Fenyvesi Eva; Szente Lajos; Malanga Milo; Sortino Salvatore

来源：Beilstein Journal of Organic Chemistry, 2017, 13: 543-551.

DOI：10.3762/bjoc.13.52

• beta-cyclodextrins
• fluorescence
• photodynamic therapy
• photosensitizers
• singlet oxygen
• xanthene

Eosin B (EoB) and eosin Y (EoY), two xanthene dye derivatives with photosensitizing ability were prepared in high purity through an improved synthetic route. The dyes were grafted to a 6-monoamino-beta-cyclodextrin scaffold under mild reaction conditions through a stable amide linkage using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. The molecular conjugates, well soluble in aqueous medium, were extensively characterized by 1D and 2D NMR spectroscopy and mass spectrometry. Preliminary spectroscopic investigations showed that the beta-cyclodextrin-EoY conjugate retains both the fluorescence properties and the capability to photogenerate singlet oxygen of the unbound chromophore. In contrast, the corresponding beta-cyclodextrin-EoB conjugate did not show either relevant emission or photosensitizing activity probably due to aggregation in aqueous medium, which precludes any response to light excitation.

• 出版日期2017-3-15