Derya Topkaya

Fluorescence study on the interaction of bovine serum albumin with two coumarin derivatives

The interactions between bovine serum albumin (BSA) and two substituted hydroxychromone derivatives of coumarin, 3-hydroxy-7,8,9,10-tetrahydro-6H-benzo[c]chromen-6-on (C3) and 1,3-dihydroxy-7,8,9,10-tetrahy-dro-6H-benzo[c]chromen-6-on (C1.3), were investigated by fluorescence quenching spectra and UV-vis absorption spectra. It was proved that the fluorescence quenching of BSA by C3 and C1, 3 was mainly a result of the formation of C3 and C1.3-BSA complexes. The Stern-Volmer quenching constants, binding constants, binding sites and the corresponding thermodynamic parameters ΔHo, ΔSo and ΔGo at different temperatures were calculated. The results indicated that van der Waals interactions and hydrogen bonds were the predominant intermolecular forces in stabilizing each complex. The detection limits of C3 and C1.3 were 5.08 × 10−7 and 1.11 × 10−7 M in the presence of BSA, respectively.

Modulation of singlet oxygen generation and amphiphilic properties of trihydroxylated monohalogenated porphyrins

Two of the properties important for photodynamic therapy applications are systematically investigated on a trihydroxylated monohalogenated porphyrin core. Singlet oxygen generation can be increased thanks to the heavy atom effect, frequently provided by the introduction of halogen atoms on the photosensitizer. We compare the effect of the presence of the four halogen atoms with the analogous halogen-free porphyrin. Cell uptake is crucial as well for successful photodynamic outcome and is directly related to the amphiphilicity of the molecule. The five derivatives bearing H, F, Cl, Br or I atoms are compared in this regard. The presence of iodine atom induces a sharp difference in singlet oxygen generation compared to all the other derivatives investigated, but increases its lipophilicity, still in the limits suitable for biomedical applications.

Iodination improves the phototoxicity of an amphiphilic porphyrin

University of Dokuz Eylul, Department of Chemistry, Faculty of Science, 35160, Tinaztepe, Izmir, Turkey Department of Pharmacy, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia ENS Lyon, Universite de Lyon, Laboratoire de Chimie de l’ENS Lyon, UMR 5182 CNRS-ENS Lyon, 46 allee d’Italie, 69364 Lyon, France Institut de Chimie et Biochimie Moleculaires et Supramoleculaires, CO2-Glyco, UMR 5246, CNRS, Universite Claude Bernard Lyon 1, Universite de Lyon, 43 oulevard du 11 Novembre 1918, F-6922 Villeurbanne, France Gebze Technical University, Department of Chemistry, P.O. Box 141, 41400 Gebze, Kocaeli, Turkey

Phthalocyanine-chalcone conjugates

A phthalocyanine-chalcone conjugate was previously reported to retain the full photodynamic activity of the phthalocyanine and a slightly lowered antivascular effect of the chalcone. Assuming that it was due to an insufficient release of the chalcone, we described here several grafting modes applied to the preparation of phthalocyanine-chalcone conjugates.

Zn phthalocyanine conjugation to H2-ul aptamer for HER2-targeted breast cancer photodynamic therapy: Design, optimization and properties

Tetrasulfonated Zn phthalocyanine was conjugated to a ssDNA aptamer moiety to produce a HER2 targeted photosensitizer. The tetraconjugate obtained was subjected to purification and the monoconjugate was successfully isolated, purified and characterized. This monoconjugate retained the ability to bind to HER2 as well as the potency to generate singlet oxygen.

Covalent or supramolecular combinations of resorcinarenes and porphyrinoids

Cavitands and porphyrinoids are two major groups of molecules. If cyclodextrins are maybe the most famous type of cavitands, the properties of resorcinarenes are now well known and rise rapidly increasing attention. This mini-review aims at detailing all the combinations of resorcinarenes with porphyrinoids reported so far, evidencing the bright future of such combos. In addition, two newly synthesized porphyrins-resorcinarene hybrids are reported.

Disulfide-bridge dimeric porphyrin and their reference compounds for glutathione-based specific tumor-activation

The tumor micro-environment is rich in glutathione. To exploit this feature for tumor-activatable porphyrin-based photosensitizers, a dimeric disulfide-bridged porphyrin has been designed and prepared, together with two reference derivatives, a non-cleavable dimer and a monomer. The three compounds have been investigated from a photochemical and photophysical point of view. It appears that the disulfide-bridged derivative exhibited intramolecular aggregation, but to an insufficient extent to induce a satisfying self-quenching of its photoproperties. Unlike expected, the non-cleavable dimer behaved like the monomeric derivative, due to the superior flexibility of the alkyl bridge over the disulfide bridge.