High photodynamic activities of water-soluble inclusion complexes of 5,15-diazaporphyrins in cyclodextrin

Water-soluble inclusion complexes of 5,15-diazaporphyrin derivatives in the cavities of two trimethyl-β-cyclodextrins (TMe-β-CDxs) were synthesised. In the 2 : 1 complexes, two aryl groups of the diazaporphyrins protruded from the upper rims of two TMe-β-CDxs. The complexes displayed high photodynamic activity under photoirradiation at wavelengths longer than 620 nm. Although the substituents on the two aryl groups protruding from TMe-β-CDx barely affected intracellular uptake by HeLa cells, the cellular uptake of these complexes was as high as that of a TMe-β-CDx-tetra(4-hydroxyphenyl)porphyrin complex. Furthermore, the diazaporphyrins in the complexes with TMe-β-CDxs were able to generate high levels of singlet oxygen because of their strong absorption of light with wavelengths greater than 620 nm.