A novel pro-apoptotic role of zinc octacarboxyphthalocyanine in melanoma me45 cancer cell's photodynamic therapy (PDT)
Abstract Zn-based phthalocyanine acts as drug or photosensitizer in photodynamic therapy (PDT) for the treatment of cancer cells. The activated zinc octacarboxyphthalocyanine (ZnPcOC) reacts with oxygen, to generate reactive oxygen species for the damage of melanoma cancer cells, Me45. This in vitro study aimed at investigating the cytotoxic effects of different concentrations of ZnPcOC activated with a diode laser (λ = 685 nm) on Me45, and normal human fibroblast cells, NHDF. To perform this study 104 cells/ml were seeded in 96-well plates and allowed to attach overnight, after which cells were treated with different concentrations of ZnPcOC (10, 20 and 30 μM). After 4 h, cells were irradi…
Interactions of amino acids with aluminum octacarboxyphthalocyanine hydroxide. Experimental and DFT studies
The influence of albumin and amino acids (l-serine, glycine, l-histidine, l-tryptophan, l-cysteine) on the properties of aluminum octacarboxyphthalocyanine hydroxide (Al(OH)PcOC) was investigated in a phosphate buffer (pH 8.0). Particular attention was paid to the spectroscopic properties and photostability of Al(OH)PcOC. The effect of albumin or amino acids on the photodegradation of Al(OH)PcOC was examined in water using red light: 685 nm and daylight irradiation. Analysis of kinetic curves indicated that interaction with those molecules increases the photostability of Al(OH)PcOC. The molecular structure of Al(OH)PcOC complexes (in vacuum and in water) with axially or equatorially coordin…
Oxidation of diclofenac in the presence of iron(II) octacarboxyphthalocyanine
Abstract This paper presents the results of the research on the influence of catalytic activity of iron(II) octacarboxyphthalocyanines (FePcOC) on the transformation of diclofenac (DCF) which is the most popular anti-inflammatory analgesic. Diclofenac poses a serious threat to the natural environment. The paper demonstrates that diclofenac, in the presence a monomeric form of iron octacarboxyphthalocyanine and hydroxyl radicals (HO•) (from H2O2), undergoes a transformation into diclofenac-2,5-iminoquinone (DCF-2,5-IQ), causing distinct changes in the UV–Vis absorption spectrum. In the presence of iron octacarboxyphthalocyanine and H2O2, the previously colourless diclofenac solution becomes …
Interactions of zinc octacarboxyphthalocyanine with selected amino acids and with albumin
Effect of selected amino acids (glycine, l-histidine, l-cysteine, l-serine, l-tryptophan) and albumin on the spectroscopic properties and photostability of zinc octacarboxyphthalocyanine (ZnPcOC) was explored in the phosphate buffer at a pH of 7.0. The photodegradation of ZnPcOC alone and in the presence of amino acids or albumin has been investigated in aqueous phase using UV-366 nm and daylight irradiation. Kinetic analysis showed that the interaction with amino acids or albumin enhances the photostability of ZnPcOC. To answer the question of how zinc phthalocyanine interacts with amino acids extensive DFT calculations were performed. Analysis of the optimized geometry features of ZnPcOC:…
Synthesis and selected properties of metallo and metal-free 2,3,9,10,16,17,23,24-octacarboxyphthalocyanines
This review article reports methods of synthe sis and selected physicochemical properties of metallo and metal-free 2,3,9,10,16,17,23,24–octacarboxyphthalocyanines. The most frequently used methods of synthesis for this class of co mpounds are described in this article. Moreover, aggregation, catalytic and photocatalytic properties of these complexes are presented. Potential applications of metallo and metal-free 2,3,9,10,16,17,23,24–octacarboxyphthalocyanines are also given.
Spectral studies of zinc octacarboxyphthalocyanine aggregation
The association of zinc octacarboxyphthalocyanine, was studied using UV–vis absorption and fluorescence emission spectroscopy; the effects of dye concentration, pH and solvents on spectra were discussed. Calculations showed that the dye dimerized in aqueous solutions ranging from 5.0 × 10−7 to 5.0 × 10−5 mol/dm3, at 25 °C. The dimerization constant of 106 dm3/mol and the spectral Q band shift of 1185 cm−1 imparted by dimerization indicated strong π–π interactions between phthalocyanine molecules. Red S1 fluorescence of the dye monomer was observed in various solutions which was quenched owing to molecular association and other factors. The strong influence of pH on both aggregation and fluo…
PRACTICAL ASPECTS OF THE ANALYSIS OF THE PROGRESSION CURVES OF FIRST AND PSEUDO-FIRST ORDER REACTIONS
The paper presents a simple method of determining iteratively the progression curve asymptote for first and pseudo-first order reactions. For selected student exercises, thus obtained results were compared (see Supplementary Material) with those found by means of the method of determining asymptotes experimentally. A nonlinear fitting method was additionally employed to assess the accuracy.
A Simple Method for the Consecutive Determination of Protonation Constants through Evaluation of Formation Curves
A simple method is presented for the consecutive determination of protonation constants of polyprotic acids based on their formation curves. The procedure is based on generally known equations that describe dissociation equilibria. It has been demonstrated through simulation that the values obtained through the proposed method are sufficiently consistent with the actual values. In contrast with the universally known and applied Bjerrum’s method, no differences in the accuracy of determination of subsequent protonation constant values are observed. The proposed method requires the value of one of the protonation constants (e.g., of the first one, K1) of the polyprotic acid. An iterative meth…
Effect of quaternary ammonium salts on spectral properties of zinc octacarboxyphthalocyanine
Abstract The paper presents results of the research on the influence of quaternary ammonium salts on UV–vis absorption and emission spectra of zinc octacarboxyphthalocyanine (ZnPcOC). Quaternary ammonium salts which show biological activity play a crucial role. In ZnPcOC solutions with a proper concentration of tetrabutylammonium salts (TBAX), a strong bathochromic shift band (λmax = 760 nm – “R” band) showing red fluorescence appears in time. The presence of tetrabutylammonium salt causes pH increase and, consequently, a gradual dissociation of carboxyl groups in ZnPcOC molecule. It seems that –COO— anions present in the ZnPcOC complex can interact with tetraalkylammonium cations, causing …
PRACTICAL ASPECTS OF THE ANALYSIS OF THE PROGRESSION CURVES OF FIRST AND PSEUDO-FIRST ORDER REACTIONS
The paper presents a simple method of determining iteratively the progression curve asymptote for first and pseudo-first order reactions. For selected student exercises, thus obtained results were compared (see Supplementary Material) with those found by means of the method of determining asymptotes experimentally. A nonlinear fitting method was additionally employed to assess the accuracy.