Physicochemical Properties and Catalytic Applications of Iron Porphyrazines and Phthalocyanines

Porphyrazines and phthalocyanines belong to porphyrinoids, which are macrocyclic compounds consisting of four pyrrole or indole rings, respectively. The aromatic rings of porphyrazines and phthalocyanines are fused together by azamethine bridges (meso nitrogen atoms) in place of methine bridges present in porphyrins. The physicochemical properties of these macrocycles can be modified in two ways. The first is by substitution of metal cation in the core, whereas the second relies on peripheral modification with various substituents. Porphyrazines and phthalocyanines can be modified inside the macrocyclic core with various transition metal cations, including iron(II/III), which impacts their electrochemical properties and influences potential applications in redox reactions. Due to their unique optical and electrochemical properties, porphyrazines and phthalocyanines found many potential and practical applications in medicine and technology. They were mainly researched as photosensitizers in photodynamic therapy, as sensors in biomedical and analytical applications or as building blocks for materials chemistry. This chapter presents physicochemical properties and catalytic applications of iron porphyrazines and phthalocyanines. The first part summarizes the influence of peripheral and axial substituents of iron(II/III) porphyrazines and phthalocyanines on their spectral properties, whereas the second focuses on the electrochemical properties of these molecules. The third part covers the activity of selected iron(II/III) porphyrazines and phthalocyanines of potential value for diverse applications including catalytic reactions

S-seco-porphyrazine as a new member of the seco-porphyrazine family – Synthesis, characterization and photocytotoxicity against cancer cells

An important subgroup within the porphyrazine (Pz) family constitutes seco-porphyrazines, in the chemical structure of which one pyrrole unit is opened in the oxidative process. So far, there are only limited data on N-seco- and C-seco-Pzs. Here, the synthesis of a novel member of the Pzs seco-family, represented by an S-seco-tribenzoporphyrazine analogue, 22,23-bis(4-(3,5-dibutoxycarbonylphenoxy)butylsulfanyl)tribenzo[b,g,l]-22,23-dioxo-22,23-seco-porphyrazinato magnesium(II), is reported, with moderate 34% yield. The new derivative was characterized using NMR spectroscopy, UV–Vis spectroscopy, and mass spectrometry. In the photochemical study performed following the indirect chemical method with 1,3-diphenylisobenzofuran, S-seco-Pz revealed a high singlet oxygen quantum yield of 0.27 in DMF. Potential photocytotoxicity of S-seco-Pz was assessed in vitro on three cancer cell lines – two oral squamous cell carcinoma cell lines derived from the tongue (CAL 27, HSC-3) and human cervical epithelial adenocarcinoma cells (HeLa). In the biological study, the macrocycle was tested in its free form and after loading into liposomes. It is worth noting that S-seco-Pz was found to be non-toxic in the dark, with cell viability levels over 80%. The photocytotoxic IC50 values for free S-seco-Pz were 0.61, 0.18, and 4.1 µM for CAL 27, HSC-3 and HeLa cells, respectively. Four different liposomal compositions were analyzed, and the cationic liposomes revealed the highest photokilling efficacy, with the IC50 values for CAL 27, HSC-3, and HeLa cells at 0.24, 0.25, and 0.31 µM, respectively. The results of the photocytotoxicity study indicate that the new S-seco-tribenzoporphyrazine can be considered as a potential photosensitizer in photodynamic therapy of cancer, along with the developed cationic liposomal nanocarrier

Promising Photocytotoxicity of Water-Soluble Phtalocyanine against Planktonic and Biofilm <i>Pseudomonas aeruginosa</i> Isolates from Lower Respiratory Tract and Chronic Wounds

Alternative methods of killing microbes have been extensively researched in connection with the widespread appearance of antibiotic resistance among pathogenic bacteria. In this study, we report on in vitro antimicrobial phototoxicity research of cationic phthalocyanine with 2-(4-N-methylmorpholin-4-ium-4-yl)ethoxy substituents against selected clinical strains of Pseudomonas aeruginosa isolated from the lower respiratory tract and chronic wounds. The microorganisms tested in the research were analyzed in terms of drug resistance and biofilm formation. The photocytotoxic effect of phthalocyanine was determined by the reduction factor of bacteria. The studied cationic phthalocyanine at a concentration of 1.0 × 10−4 M, when activated by light, revealed a significant reduction factor, ranging from nearly 4 to 6 log, of P. aeruginosa cells when compared to the untreated control group. After single irradiation, a decrease in the number of bacteria in biofilm ranging from 1.3 to 4.2 log was observed, whereas the second treatment significantly improved the bacterial reduction factor from 3.4 to 5.5 log. It is worth mentioning that a boosted cell-death response was observed after the third irradiation, with a bacterial reduction factor ranging from 4.6 to 6.4 log. According to the obtained results, the tested photosensitizer can be considered as a potential antimicrobial photodynamic therapy against multidrug-resistant P. aeruginosa

Liposomal formulations of magnesium sulfanyl tribenzoporphyrazines for the photodynamic therapy of cancer

Photodynamic therapy (PDT) is a treatment that uses light to activate a photosensitizer in the presence of oxygen, leading to the damage of targeted cells by the generation of reactive oxygen species. PDT is used to treat various cancers and cardiovascular, dermatological and ophthalmic diseases as well as different microbial and viral infections. The main drawbacks of currently used photosensitizers, including porphyrinoids, are poor aqueous solubility and the tendency to form aggregates. These issues have been addressed by developing drug delivery systems of which liposomes are considered one of the best and most promising. In this study, previously synthesized dendritic magnesium tribenzoporphyrazineswere incorporatedinto four types of liposome

Liposomal formulations of magnesium sulfanyl tribenzoporphyrazines for the photodynamic therapy of cancer

Photodynamic therapy (PDT) is a treatment that uses light to activate a photosensitizer in the presence of oxygen, leading to the damage of targeted cells by the generation of reactive oxygen species. PDT is used to treat various cancers and cardiovascular, dermatological and ophthalmic diseases as well as different microbial and viral infections. The main drawbacks of currently used photosensitizers, including porphyrinoids, are poor aqueous solubility and the tendency to form aggregates. These issues have been addressed by developing drug delivery systems of which liposomes are considered one of the best and most promising. In this study, previously synthesized dendritic magnesium tribenzoporphyrazineswere incorporatedinto four types of liposome

Physicochemical properties of liposome-incorporated 2-(morpholin-4-yl)ethoxy phthalocyanines and their photodynamic activity against oral cancer cells

Three 2-(morpholin-4-yl)ethoxy-substituted phthalocyanines with zinc(II) or magnesium(II) ion in the core were subjected to optical and photochemical studies, and their photodynamic activity against oral cancer cell lines was evaluated. Phthalocyanine derivatives were studied both as free compounds and after incorporation into liposomes used as drug delivery vehicles. The introduction of electron-donating 2-(morpholin-4-yl)ethoxy groups in non-peripheral positions significantly affected physicochemical and optical properties of the phthalocyanines. The increased number of substituents led to increased hydrophilicity, decreased tendency to aggregate, and a larger shift of the phthalocyanine Q band toward the red region of the spectra. The incorporation of the hydrophobic zinc(II) phthalocyanine derivative possessing two 2-(morpholin-4-yl)ethoxy substituents into liposomes triggered most pronounced changes in its physicochemical properties compared to octasubstituted compounds. The disubstituted derivative expressed a promising biological effect against oral squamous cell carcinoma with IC50 values of 22 nM and 29 nM for the free and encapsulated compound, respectively. Our results indicate that liposomes can be used as a drug delivery vehicle for hydrophobic phthalocyanines in further biological studies

Physicochemical properties of liposome-incorporated 2-(morpholin-4-yl)ethoxy phthalocyanines and their photodynamic activity against oral cancer cells

The aim of the study was to develop a liposomal carrier for novel 2-(morpholin-4-yl)ethoxy-substituted phthalocyanines (Pcs 3 – 5) and to determine at what extent liposomal incorporation of Pcs 3 - 5 can affect physicochemical properties of these compounds and in vitro antiproliferative activity against oral cancer cells

Physicochemical properties of liposome-incorporated 2-(morpholin-4-yl)ethoxy phthalocyanines and their photodynamic activity against oral cancer cells

The aim of the study was to develop a liposomal carrier for novel 2-(morpholin-4-yl)ethoxy-substituted phthalocyanines (Pcs 3 – 5) and to determine at what extent liposomal incorporation of Pcs 3 - 5 can affect physicochemical properties of these compounds and in vitro antiproliferative activity against oral cancer cells

Metal Nanoparticle-Flavonoid Connections: Synthesis, Physicochemical and Biological Properties, as Well as Potential Applications in Medicine

Flavonoids are polyphenolic compounds widely occurring throughout the plant kingdom. They are biologically active and have many medical applications. Flavonoids reveal chemopreventive, anticarcinogenic, and antioxidant properties, as well as being able to modulate the immune system response and inhibit inflammation, angiogenesis, and metastasis. Polyphenols are also believed to reverse multidrug resistance via various mechanisms, induce apoptosis, and activate cell death signals in tumor cells by modulating cell signaling pathways. The main limitation to the broader usage of flavonoids is their low solubility, poor absorption, and rapid metabolism. To tackle this, the combining of flavonoids with nanocarriers could improve their bioavailability and create systems of wider functionalities. Recently, interest in hybrid materials based on combinations of metal nanoparticles with flavonoids has increased due to their unique physicochemical and biological properties, including improved selectivity toward target sites. In addition, flavonoids have further utilities, even in the initial step of preparation of metal nanomaterials. The review offers knowledge on multiple possibilities of the synthesis of flavonoid-metal nanoparticle conjugates, as well as presents some of their features such as size, shape, surface charge, and stability. The flavonoid-metal nanoparticles are also discussed regarding their biological properties and potential medical applications