Journal of Porphyrins and Phthalocyanines

Photodynamic therapy (PDT) effectively induces tumor cell apoptosis, but the tumor selectivity and photosensitivity of common photosensitizers, such as aspartyl chlorin (NPe6), are not sufficient. Cancer cells phagocytose glucose 3 to 20 times more efficiently than normal cells; therefore, we examined whether glycoconjugation improves photosensitizer tumor-localizability. HaCaT cells were incubated with H₂TFPC (unconjugated chlorin), H₂TFPC-SGlc (glycoconjugated chlorin), or NPe6, followed by irradiation with 633 nm LED light (16 J.cm^-2). PDT with 1 μM H₂TFPC-SGlc for 24 h induced significantly more apoptosis (annexinV⁺ cells: 74.5%) than PDT with either H₂TFPC (2.9%) or NPe6 (0.3%). Based on the IC₅₀, PDT with H₂TFPC-SGlc induced tumor cell death more efficiently than NPe6 or H₂TFPC in all cell lines examined. The addition of sodium azide, a singlet oxygen quencher, during irradiation significantly suppressed PDT-induced apoptosis in COLO679 cells (-0.4 ± 0.3% → 119 ± 44%), whereas coincubation with deuterium oxide, a singlet oxygen enhancer, enhanced PDT (72 ± 19 → 27 ± 5%). Confocal microscopy revealed that H₂TFPC-SGlc accumulated in lysosomes and Golgi bodies, but not in mitochondria or endoplasmic reticulum. In melanoma-bearing mice, intratumoral injection of H₂TFPC-SGlc (10^-8 mol or 10^-9 mol), followed 4 h later by irradiation with 633 nm LED light (150 J.cm^-2) controlled tumor growth for 13 consecutive days (10^-8 mol). Thus, PDT with H₂TFPC-SGlc effectively induces apoptosis in tumor cells via singlet oxygen induction.

Free-base phthalocyanine ligands and their zinc derivatives representing functionally monosubstituted (A₃B type) or tetrasubstituted (A₄ type) compounds with 2-diethoxyphosphoryl-4-methylpenta-1,3-dienyl moieties have been synthesized for the first time. Their structures were characterized by MALDI-TOF mass-spectrometry as well as ¹H and ³¹P NMR spectroscopy data. A tendency to aggregation in dependence on the nature of the solvent was demonstrated as well.

A method for obtaining red emission from an organic-light emitting diode has been developed by dissolving red and yellow dyes in a common solvent and thermally evaporating the mixture in a single furnace. Dichlorido-bis(5,7-dichloroquinolin-8-olato)tin(IV) complex (Q₂SnCl₂, Q = 5,7-dichloro-8-hydroxyquinoline) has been synthesized for using as a fluorescent material in organic light-emitting diodes (OLEDs). The electronic states HOMO (Highest Occupied Molecular Orbital)/LUMO (Lowest Occupied Molecular Orbital) energy levels explored by means of cyclic voltammetry measurements. A device with fundamental structure of ITO/PEDOT:PSS (55nm)/PVK (90nm)/Q₂SnCl₂/Al (180nm) was fabricated and its electroluminescence performance at various thicknesses of light emitting layer (LEL) of Q₂SnCl₂ is reported. By following this step, an optimal thickness for the doping effect was also identified and explained. Finally a device with fundamental structure of ITO/PEDOT:PSS (55nm)/PVK (90nm)/meso-tetraphenylporphyrin (TPP):Q₂SnCl₂ (75nm)/Al (180nm) was fabricated and its electroluminescence performance at various concentrations of dye has been investigated. It is shown that this new method is promising candidate for fabrication of low cost OLEDs at more homogeneous layer.

In this study, we have treated nitrate contaminated groundwater using modified magneticnanoparticles. The modification of magnetite nanoparticles were conducted by 3-aminopropyl-triethoxysilane followed by oxovanadium(IV) porphyrin in order to enhance the removal of nitrate ions. Fourier Transform Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and Atomic Force Microscopy (AFM) were used to characterize the synthesized nanoparticles. The effect of pH, contact time, sorbent dosage and some co-existing anions present in aqueous solutions were investigated. The isothermal data of nitrate sorption conformed well to the Langmuir model and the maximum sorption capacity of nanosorbent for nitrate was 76.92 mg.g^-1. Thermodynamic study indicated that the adsorption is endothermic and spontaneous. Regeneration of nitrate adsorbed material could be be possible by NaOH and the modified magnetic nanoparticles exhibited good reusability. The proposed system can provide a fast and efficient removal of the nitrate ion by using just an external magnetic field. The competitive adsorption tests verified that, this system has good adsorption selectivity for nitrate ions.

For the steady-state behavior of diprotonated tetrakis(4-sulfonatophenyl)porphyrin (H₄TPPS^2-) in five imidazolium ionic liquids (ILs), the absorption positions of H₄TPPS^2- primarily depend on the constituent ions of the ILs whereas the emission positions of H₄TPPS^2- strongly depend on the polarity of the ILs. The fluorescence spectra of H₄TPPS^2- with different excitation wavelengths show no red-edge effect in our system. The dynamics of H₄TPPS^2- in ILs is further studied with a streak camera, and the relaxation process of ILs occurs on two different time scales. The short lived component attributed to the local motion of the cations and the anions around the porphine core varies from 32 to 196 ps. The long lived one originated from the collective diffusive motions of the cations and anions varies from 460 to 1072 ps. The average solvation time depends on the viscosity of the ILs. The rotational relaxation times of H₄TPPS^2- decrease as the viscosity of the ILs decreases.

Various density functional theory (DFT) methods with different basis sets to predict the molecular geometry of FbC-M¹⁰Iso-Bn macrocycle, a chlorin-isoimide, are compared in this study. DFT methods, including M06-2X, B3LYP, LSDA, B3PW91, PBEPBE, and BPV86, are examined. Different basis sets, such as 6-31G*, 6-31+G (d, p), 6-311+G (d, p), 6-311++G (d, p), cc-PVDZ, cc-PVTZ, and cc-PVQZ are also considered. The examined hybrid DFT methods are in agreement with the geometry of X-ray crystallography available for comparison. B3LYP/cc-PVDZ level is particularly consistent with available X-ray crystallography in terms of predicting the geometries of FbC-M¹⁰Iso-Bn. Geometries of chlorin-imide and chlorin-isoimide isomeric pairs are described through B3LYP/cc-PVDZ method. The bond lengths of chlorin-isoimide, specifically C13–C14, C14–C15, and C2–C3, increase as bond overlap index decreases because of charge transfer. β-β bond lengths (C2–C3 bond lengths) with a three-substituent benzylcarbamoyl group also increase as bond overlap index decreases compared with other molecules. The bond lengths of chlorin-imide are smaller than those of chlorin-isoimide. Angles with β-β bond lengths, specifically C2–C3–C4 in ring A, also decrease with a three-substituent benzylcarbamoyl group; however, the angles in C1–C2–C3 increase. Potential energy on the surfaces of the chlorin-imide and chlorin-isoimide isomeric pairs is optimized by calculating the total and relative energies at B3LYP/cc-PVDZ level. Results indicate that chlorin-imides are more stable than chlorin-isoimides. Normal-coordinate structural decomposition shows that chlorin-imides exhibit greater deformation than chlorin-isoimides except for FbC-M¹⁰Iso-Ph.

The synthesis of porphyrins conjugated with sugar moieties is described. meso-Aminophenyl-substituted and β-amino-substituted porphyrin derivatives reacted with benzyl protected glucuronic acid leading to gluco-conjugated hybrids, which after reductive deprotection of OH groups (H₂, 10% Pd/C) gave the desired target products of increased hydrophilicity. Alternatively, this type of similar conjugates were obtained through S_NAr reaction of meso-tetrakis(pentafluorophenyl)porphyrin with aminomethyl sacharides. The substitution took place selectively in para-position of meso-perfluorophenyl rings, thus giving rise to one, two, or three times substituted products carrying N-linked glucoside residues.

Using aldehydes with different substituents of the aryl groups, we have synthesized a series of asymmetric porphyrins containing an 8-ethoxycarbonyl-1-naphthyl group by one-pot reactions. Our studies suggest the steric property of substituents is the major factor to affect the reaction yields, the steric hindrance is unfavorable for such reaction. Compared with those para-substituted species, NMR studies of 2,6-substituted species show upfield shifts for their NH and ethyl protons, downfield shifts for their pyrrole protons, which is probably due to the decrease of porphyrin ring current. Three of them have been characterized by X-ray crystallography. Structures show that the ester group is hanging over the porphyrin plane, compound 3 and 4 have much different core conformations from compound 2, which is probably due to the π–π interactions in the solid state.