The facile synthesis of three non-hydrolysable thioglycosylated porphyrinoids is reported. Starting from meso perfluorophenylporphyrin (TPPF20), the non-hydrolysable thioglycosylated porphyrin (PGlc4), chlorin (CGlc4), isobacteriochlorin (IGlc4), and bacteriochlorin (BGlc4) can be made in 2-3 steps. The ability to append a wide range of targeting agents onto the perfluorophenyl moieties, the chemical stability, and the ability to fine-tune the photophysical properties of the chromophores make this a suitable platform for development of biochemical tags, diagnostics, or as photodynamic therapeutic agents. With reduction of one or two pyrrole double bonds, there is a red shift in the lowest energy absorption band and a significant increase in intensity. The fluorescence of these porphyrinoids is in the order PGlc4 = BGlc4 < CGlc4 < IGlc4 and there is a corresponding decrease in the amount of triplet formed. Fluorescence micrographs of cells after treatment with these four porphyrinoids indicate they are taken up. The CGlc4 and IGlc4 may be dual function agents that can detect cancer by luminescence, and treat cancer by photodynamic therapy (PDT).
Porphyrins appended with four rigid hydrogen bonding motifs on the meso positions were synthesized and self-assembled into a cofacial cage with four complementary bis- (decyl)melamine units in dry solvents, these hydrogen-bonded cages were analysed by diffusion-ordered spectroscopy (DOSY) in solution. The hydrocarbon chains on the melamine mediate the formation of nanofilms on surfaces as the solvent slowly evaporates.
A water soluble zinc (II) phthalocyanine symmetrically appended with eight thioglucose units was synthesized from commercially available hexadecafluoro-phthalocyaninato zinc(II) by controlled nucleophilic substitution of the peripheral fluoro groups by thio-sugars. The photophysical properties and cancer cell uptake studies of this nonhydrolyzable thioglycosylated phthalocyanine are reported. The new compound has amphiphilic character, is chemically and photochemically stable, and can potentially be used as a photosensitizer in photodynamic therapy.
A porphyrin bearing pyridyl groups at the meso positions was synthesized using 2,6-diacetamido-4-formylpyridine. A new method has been developed for the synthesis of the precursor aldehyde that avoid much of the problems associated with the earlier synthesis. With this porphyrin it is possible to build hetero-complementary rigid, multi-porphyrin supramolecular arrays via hydrogen bonds. For example, when using naphthalenediimide (NDI) units a checkerboard pattern is expected to be formed using this porphyrin as a donor and NDI as an acceptor where triple hydrogen bond is formed between the diimide and pyridyl units. Energy transfer can be studied through this hydrogen bonded supramolecular assembly.
The synthesis of a triply bridged diporphyrin appended with six thioglucose units is reported. The electronic spectrum of this triply bridged porphyrin has enhanced intensity at low-energy wavelengths that reaches the near infrared region. The goal of this project is to create tumor targeting dyes that can be activated with red wavelengths of light that penetrate deeper into tissues. This new compound is amphiphilic in nature, chemically and photochemically stable, expected to have unusual photophysical and electrochemical properties, and can potentially be used as a photosensitizer in photodynamic therapy.