Benkovics Gábor, Afonso Damien, Darcsi András, Béni Szabolcs, Conoci Sabrina, Fenyvesi Éva, Szente Lajos, Malanga Milo, Sortino Salvatore
CycloLab, Cyclodextrin R&D Ltd, Budapest, H-1097 Illatos út 7, Hungary; Department of Organic Chemistry, Faculty of Science, Charles University in Prague, Hlavová 8, 128 43, Prague 2, Czech Republic.
Laboratory of Photochemistry, Department of Drug Sciences, University of Catania, I-95125 Viale A. Doria 6, Italy.
Beilstein J Org Chem. 2017 Mar 15;13:543-551. doi: 10.3762/bjoc.13.52. eCollection 2017.
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-β-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 β-cyclodextrin-EoY conjugate retains both the fluorescence properties and the capability to photogenerate singlet oxygen of the unbound chromophore. In contrast, the corresponding β-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.
通过改进的合成路线制备了具有光敏能力的两种呫吨染料衍生物——曙红B（EoB）和曙红Y（EoY），且纯度很高。使用偶联剂4-(4,6-二甲氧基-1,3,5-三嗪-2-基)-4-甲基吗啉鎓氯化物，在温和的反应条件下通过稳定的酰胺键将这些染料接枝到6-单氨基-β-环糊精支架上。这些分子共轭物在水介质中具有良好的溶解性，通过一维和二维核磁共振光谱以及质谱对其进行了广泛表征。初步光谱研究表明，β-环糊精-EoY共轭物既保留了荧光特性，又保留了未结合发色团产生单线态氧的能力。相比之下，相应的β-环糊精-EoB共轭物既没有显示出相关发射，也没有显示出光敏活性，这可能是由于在水介质中聚集，从而阻止了对光激发的任何响应。
