Cyclodextrin carriers of positively charged porphyrin sensitizers.
The cationic sensitizer 5,10,15,20-tetrakis(N-methylpyridinium-4-yl)porphyrin (TMPyP) forms supramolecular complexes with native, per-methylated, sulfonated and dimethyl-sulfonated cyclodextrins (CDs). Binding interactions were proved by NMR, mass spectra, capillary zone electrophoresis, UV-Vis and fluorescence spectroscopy. The 2D-NMR experiments on native CDs indicate that the interaction of TMPyP with the external CD surface is the dominant binding mode. The high binding affinity of TMPyP towards sulfonated CDs is due to electrostatic interactions. Binding is accompanied by an increase of the TMPyP basicity. Whereas betaCD does not affect the lifetime of the TMPyP triplet states, binding with sulfonated CDs causes the protonation of the TMPyP triplet states even in neutral solution. The diprotonated anionic sensitizer 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (TPPSH(2)(2+)) forms host-guest complexes with native betaCD and gammaCD, similarly as in its non-protonated state. The positive charge of pyrrole nitrogen atoms does not significantly influence the mode of the interaction. In contrast to TMPyP, the lifetimes of the triplet states of bound TPPSH(2)(2+) to native CDs increase.
Mosinger
Jirí
J
Department of Inorganic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030, 128 43, Prague 2, Czech Republic. mosinger@natur.cuni.cz
Slavetínská
Lenka
L
Lang
Kamil
K
Coufal
Pavel
P
Kubát
Pavel
P
D000042:Absorption / Q000187:drug effects; D000890:Anti-Infective Agents / Q000737:chemistry / Q000627:therapeutic use; D003505:Cyclodextrins / Q000737:chemistry* / Q000494:pharmacology; D004337:Drug Carriers / Q000737:chemistry* / Q000494:pharmacology; D019075:Electrophoresis, Capillary; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000737:chemistry* / Q000627:therapeutic use; D011166:Porphyrins / Q000737:chemistry* / Q000627:therapeutic use; D013056:Spectrophotometry, Ultraviolet; D013997:Time Factors
D000890:Anti-Infective Agents; D003505:Cyclodextrins; D004337:Drug Carriers; D017319:Photosensitizing Agents; D011166:Porphyrins; C016136:tetraphenylporphine sulfonate; C021096:tetra(4-N-methylpyridyl)porphine