Synthesis, characterization, and supramolecular properties of a hydrophilic porphyrin--beta-cyclodextrin conjugate.
Reductive amination of 6-deoxy-6-formyl-beta-cyclodextrin with 5-(p-aminophenyl)-10,15,20-tris(p-sulfonatophenyl)porphyrin in the presence of an excess of sodium cyanoborohydride affords the hydrophilic cyclodextrin-porphyrin conjugate 3 in 23% yield. The structure of 3 was confirmed by NMR spectroscopy and mass spectrometry techniques. Compound 3 showed a marked tendency to dimerize in aqueous conditions via the formation of intermolecular porphyrin-cyclodextrin inclusion complexes and/or through electrostatic interactions. Information on the structure of these aggregates has been obtained by the use of circular dichroism and UV-vis spectroscopy. Aggregation can be avoided by the use of heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin (TM beta CD) that forms a 1:1 inclusion complex with compound 3.
Carofiglio
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double daggerDipartimento di Chimica Inorganica, Università di Padova, Via Marzolo 1, 35100 Padova, Italy. tomcarof@chor.unipd.it
Fornasier
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Lucchini
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Simonato
L
L
Tonellato
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U
D002942:Circular Dichroism; D003505:Cyclodextrins / Q000138:chemical synthesis*; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D011166:Porphyrins / Q000138:chemical synthesis*; D013056:Spectrophotometry, Ultraviolet
D003505:Cyclodextrins; D007202:Indicators and Reagents; D011166:Porphyrins