Phthalocyanine Derivatives Research Articles

Phthalocyanine photosensitizers with bathochromic shift, of suitable brightness, capable of producing singlet oxygen with effective efficiency

• New phthalocyanine derivatives as photosensitizers were designed and synthesized. • The phthalocyanines dissolve well in common solvents without aggregation. • The phthalocyanines have improved fluorescence and optical absorption properties. • The phthalocyanines have improved photochemical properties and photostability. • The phthalocyanines can be used as photosensitizers in photocatalytic applications. In this study, novel 3-(2,3-dimethoxyphenoxy)phthalonitrile 2 and its non-peripheral tetra-2,3-dimethoxyphenoxy substituted metal-free phthalocyanine 3 compounds were synthesized. Then, the magnesium(II), zinc(II), and indium(III) acetate phthalocyanine complex derivatives ( 4-6 ) of compound 3 were synthesized using the corresponding metal salts by the template effect. The structures of novel phthalonitrile derivative 2 and its metal-free phthalocyanine compounds 3 as well as different metal-containing phthalocyanine complexes ( 4-6 ) were characterized by elemental analysis, FTIR, UV-vis, 1 H NMR, and MALDI-TOF mass spectroscopic techniques. The phthalocyanines ( 3-6 ) can dissolve well in different polar protic, polar aprotic, and non-polar solvent types without aggregation, with maximum absorption intensity and bathochromic effect. Photophysicochemical properties of the phthalocyanines ( 3-6 ) in dimethyl sulfoxide and important spectral parameter values such as molar extinction coefficient, oscillator strength, and electrical dipole strength were determined, and they were also compared with each other and with their unsubstituted counterparts. It was determined that the phthalocyanines ( 3-6 ) have suitable and sufficient fluorescence quantum yields, fluorescence lifetimes, fluorescence brightness, and other photophysical properties, as well as singlet oxygen generation, phototoxic power, and photostability properties. The phthalocyanines ( 3-6 ), particularly zinc(II) and indium(III) acetate phthalocyanines have remarkable potential for use as Type II photosensitizers for cancer therapy in photodynamic therapy. The phthalocyanines ( 3-6 ) may be promising candidates for various applications as photosensitizers for photodynamic therapy, especially in combination with fluorescent imaging.

Solution-processed near-infrared organic photodetector based on a liquid crystalline phthalocyanine derivative for vital signal monitoring

In this study, near-infrared (NIR) organic photodetectors (OPDs) based on a liquid crystalline phthalocyanine derivative, 1,4,8,11,15,18,22,25-octaoctyl-phthalocyanine (8H2Pc), and phenyl-C61-butyric acid methyl ester (PC61BM) were realized. The best device had a blend ratio of 1:1 by weight and exhibited responsivity of 0.2 A W−1, external quantum efficiency of 29% and shot-noise-limited specific detectivity of 1.3 × 1012 Jones at 740 nm with −1 V reverse bias. This notable performance was attributed to the uniformity and smooth surface morphology of the spin-coated active layer and the intermixed condition of the liquid crystalline 8H2Pc and PC61BM, resulting in smaller domain sizes and better separation of photogenerated exciton pairs. Finally, the future prospects of the realized NIR OPD in practical applications were demonstrated by monitoring the vital signals of a human subject with a very simple experimental setup.

In VitroPhotodynamic Activities of Amphiphilic Phthalocyanine‐Amino Appendedβ‐Cyclodextrin Conjugates as Efficient Schiff Base Photosensitizer

AbstractWater‐soluble phthalocyanine has been considered as a potential photosensitizer for photodynamic therapy (PDT) applications. To achieve the best efficiency of phthalocyanine in PDT, amphiphilic zinc phthalocyanine was purposely designed and synthesized by conjugation withβ‐cyclodextrin. Herein, we synthesized two novel zinc phthalocyanine derivatives connected toβ‐cyclodextrin moieties through covalent Schiff base linkage (TFP‐ZnPc/AβCD). In this procedure, aldehyde substituted phthalocyanine and amino‐appendedβ‐cyclodextrins with different length amino side chains were used. The compounds were characterized using FT‐IR,1H NMR, MALDI‐TOF, and UV‐vis. The newly designed photosensitizers did not self‐assemble in water and generated significant singlet oxygenvia1,3‐DPBF (1,3‐diphenylisobenzofuran) bleaching. Simultaneously, longer amino side chains increase1O2production efficiency. The PDT activity of the new TFP‐ZnPc/AβCD complexes was then examined on human breast cancer (MDA‐MB‐231) and fibroblast cells.In vitroresults show that PDT is more effective against cancer cells than normal cells. The new TFP‐ZnPc/AβCD could be an effective PDT drug.

Zn(II) phthalocyanines having fluoroether groups: Synthesis, characterization, photo-physicochemical and biological properties

Tetra non-peripheral and peripheral substituted Zn(II) phthalocyanine (Pc) derivatives bearing 2,2-difluoro-2-[1,1,2,2-tetrafluoro-2-(trifluoromethoxy)ethoxy]ethoxy groups (KH-69, KH-71) were synthesized and characterized to be antioxidant and antimicrobial agents. Photo-physicochemical properties of these compounds were investigated. Then, the DPPH free radical scavenging activity of the Pc derivatives was found as 97.74% and 94.89%, respectively. Both the Pc complexes showed perfect DNA nuclease activity with double strain break against pBR 322 plasmid DNA at 100 mg/L concentration. KH-69 and KH-71 indicated good antimicrobial activity against studied Gram-positive and Gram-negative bacteria, and fungal strains. Moreover, the Pcs showed excellent cell viability inhibition activity even at the lowest concentration. These Pc derivatives inhibited P. aeroginasa and S. aureus biofilm formation. The Pcs showed the highest biofilm inhibition with photodynamic therapy against S. aureus and P. aeroginasa with 95.40% and 90.03%, respectively.

Synthesis of 4-methylthiophenyl silicon phthalocyanines axially substituted with carboxylic acids for MOF materials

Two new peripherally substituted with 4 and 8 electron-donating 4-methylthiophenyl silicon phthalocyanines, [Formula: see text] 1 and [Formula: see text] 2, axially substituted with carboxylic acids have been synthesized using microwave irradiation in a very good yield. The new compounds have been characterized by 1H-NMR, UV-vis, fluorescence, differential pulse voltammograms, and HR-MALDI-TOF mass spectrometry. An study of the stability of the axial chlorinated SiPcs in the function of the number of thiophenyl substituents indicates than [Formula: see text] 10 degradates faster, to its corresponding unreactive dihydrosilicon phthalocyanine derivative [Formula: see text] 11, than [Formula: see text]. The new SiPcs are excellent candidates as photoactive linkers for the construction of MOF materials.

Generation of singlet oxygen by porphyrin and phthalocyanine derivatives regarding the oxygen level

Background. The principle of photodynamic effect is based on the combined action of photosensitiser, molecular oxygen and light, which produce various reactive oxygen species and are associated with significant cellular damage. Singlet oxygen is one of the most serious representatives, which is characterised by powerful oxidising properties. Moreover, concomitant hyperbaric oxygen treatment can support these effects. Therefore, the subject of our study was to compare the yields of singlet oxygen for four different photosensitizers in dependency on the oxygen concentration. Material and methods. Four different photosensitizers 5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphyrin tetra(p-toluenesulfonate), tetramethylthionine chloride, 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin zinc(II) and zinc phthalocyanine disulfonate were investigated to determine the yield of singlet oxygen in PBS by Singlet Oxygen Sensor Green reagent under different partial pressures of oxygen (0.4 and 36 mg/l). Results. There were no noticeable shifts in the excitation and emission fluorescence spectra regarding the oxygen concentration. Concerning the same molar concentration of photosensitizers the production of singlet oxygen was highest for 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin zinc(II), where the rate of the fluorescence change was more than 3 times higher than that obtained for 5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphyrin tetra(p-toluenesulfonate). On the other hand, zinc phthalocyanine disulfonate showed the lowest yield in singlet oxygen production. Conclusions. Singlet oxygen production, within the range of oxygen concentrations achievable in tissues under normoxia or hyperoxia, does not depend on these concentrations. However, the singlet oxygen generation is significantly influenced by the type of photosensitizer, with the highest yield belonging to 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin zinc(II).

Ethylenediamine control of the supramolecular chemistry of magnesium phthalocyanine

The two axially ligated magnesium phthalocyanine derivatives, MgPc(EDA) and MgPc(H2O), were obtained directly by thermal reaction of MgPc in ethylenediamine (EDA) solution. Both complexes, MgPc(EDA) and MgPc(H2O), co-crystallize with the water molecule yielding good-quality single crystals 1. Presence in the crystals 1 the MgPc(H2O) results from the high affinity of MgPc to trace of water in the solvent as well as due to the high affinity of MgPc to moisture in air. The axially substituted magnesium phthalocyanine derivatives, MgPc(EDA) and MgPc(H2O), are, as expected, non-planar MPcs and interact with each other through a solvated water molecule to form supramolecular aggregates linked by NH…O and OH…N hydrogen bonds. Supramolecular arrangement of the non-planar MgPc-derivatives in crystal is characterized by a reduction of π···π interactions and an improvement in inter-system crossing in relation to parent MgPc, which results in increase its solubility and improved photophysical and photochemical properties. The aggregation behavior of the MgPc(EDA) and MgPc(H2O) complexes building crystals 1 in EDA and ethanol solutions was investigated. The MgPc(EDA) and MgPc(H2O) complexes building crystals 1 in an ethanol solution are stable, while in the EDA solution, one of them undergoes demetallation with formation of a metal-free phthalocyanine, since the UV–vis absorption spectrum versus time shown additional electronic absorption band in the region known as the Q-band which is typical for the spectrum of H2Pc. Besides, the UV–Vis spectroscopic characterization of the crystals 1 in solutions, the diffuse reflectance spectroscopic (DSR) characterization on the solid sample of 1 was performed. The DSR spectra of 1 exhibit broad bands with a small blue-shift that might be attributed to a larger exciton coupling resulting from closer contacts between the molecules than in solution. In order to support and verify the experimental results, the DFT and time-dependent (TD) DFT calculations were performed.

Solar-light-driven photocatalytic hydrogen evolution by push-pull thiophenoxy-substituted zinc phthalocyanines

Two zinc phthalocyanine derivatives (ZnPc 1 and 2) carrying bulky 2,6-diisopro-pylthiophenoxy peripheral substituents have been synthesized and their performances as photosensitizers in photochemical hydrogen production evaluated. To examine the influence of the spacer on the performance of ZnPc 1 and 2, the carboxyl group has been linked to the macrocycle ring either directly or via the phenyl ring, respectively. The photocatalytic activities of ZnPcs (ZnPc 1 and ZnPc 2) as sensitizers of TiO2 for hydrogen production were investigated in the presence of Pt. ZnPc 1 and ZnPc 2 sensitized TiO2 produced 0.687 mmolg[Formula: see text]h[Formula: see text] and 0.436 mmol g[Formula: see text]h[Formula: see text] hydrogens, which also reached 3.986 and 2.091 mmolg[Formula: see text] after 8h illumination, respectively, under visible light ([Formula: see text] 420 nm) irradiation. In addition, STH efficiencies of ZnPc 1/TiO2 and ZnPc 2/TiO2 were determined as 1.77% and 1.12%, respectively. ZnPc 1/TiO2 exhibited 1.9-fold more photocatalytic hydrogen amount than ZnPc 2/TiO2, and the hydrogen evolution performance of the photocatalyst in the presence of Pt enhanced to 3.021 mmol g[Formula: see text]h[Formula: see text] and 0.911mmol g[Formula: see text]h[Formula: see text] for ZnPc 1 and ZnPc 2, respectively.

Molecular Engineering of Silicon Phthalocyanine to Improve the Charge Transport and Ammonia Sensing Properties of Organic Heterojunction Gas Sensors

AbstractNovel organic heterostructures fabricated with a bilayer consisting of an axially substituted silicon phthalocyanine (R2‐SiPc) derivative and lutetium bis‐phthalocyanine (LuPc2) are investigated for their ammonia sensing properties. Surface and microstructure characterization of the heterostructure films reveal either compact or highly porous surface topography in (345F)2‐SiPc and Cl2‐SiPc‐based heterostructures, while electrical characterization reveals a strong influence of the axial substituent in R2‐SiPc on NH3 sensing capabilities. Electrical characterization further demonstrates an apparent energy barrier for interfacial charge transport, which is higher in the (345F)2‐SiPc/LuPc2 heterojunction device. In‐depth charge transport studies by impedance spectroscopy further reveal a resistive interface in (345F)2‐SiPc/LuPc2 and faster bulk and interfacial charge transport in Cl2‐SiPc/LuPc2 heterojunction devices. Different interfacial charge transport capabilities and surface topographies affect NH3 sensing properties of the two heterojunction devices, in which (345F)2‐SiPc/LuPc2 reveals a fast and non‐linear response with a limit of detection (LOD) of 310 ppb, while Cl2‐SiPc/LuPc2 exhibits a slow, and linear response to NH3 with LOD of 100 ppb. Finally, different metrological parameters of the two sensors are correlated to the respective gas‐material interactions, in which adsorption and diffusion regimes are modulated by the surface topography and hydrophobicity of the sensing layer.

Reactions of polyaromatic molecules in crystals under electron beam of the transmission electron microscope

Reactivity of a series of related molecules under the 80 keV electron beam have been investigated and correlated with their structures and chemical composition. Hydrogenated and halogenated derivatives of hexaazatrinaphthylene, coronene, and phthalocyanine were prepared by sublimation in vacuum to form solventless crystals then deposited onto transmission electron microscopy (TEM) grids. The transformation of the molecules in the microcrystals were triggered by an 80 keV electron beam in the TEM and studied using correlated selected area electron diffraction, conventional bright field imaging, and energy dispersive X-ray spectroscopy. The critical fluence (ē nm-2) required to cause a disappearance of the diffraction pattern was recorded and used as a measure of the reactivity of the molecules. The same electron flux (102 ē nm-2 s-1) was used throughout. Fully halogenated molecules were found to be the most stable and did not change significantly under our experimental conditions, followed by fully hydrogenated molecules with critical fluences of 104 ē nm-2. Surprisingly, semi-halogenated molecules that contained an equal number of hydrogen and halogen atoms were found to be the least stable, with critical fluences an order of magnitude lower at 103 ē nm-2. This is attributed to elimination of H-X (where X = F or Cl), followed by polymerisation of aryne / aryl radicals within the crystal. The critical fluence for the semi-fluorinated hexaazatrinaphthylene is the lowest as the presence of water molecules in its crystal lattice significantly decreased the stability of the organic molecules under the electron beam. Semi-halogenation reduces the beam stability of organic molecules compared to the parent hydrogenated molecule, thus providing the chemical guidance for design of electron beam stable materials. Understanding of molecular reactivity in the electron beam is necessary for advancement of molecular imaging and analysis methods by the TEM, molecular materials processing, and electron beam-driven synthesis of novel materials.

Synergistic effect of ultrasound and light to efficient singlet oxygen formation for photodynamic purposes

As cancer is one of the leading causes of death globally, it is highly desirable to explore the therapeutic potential of new sensitizers in photodynamic therapy (PDT). In recent years, PDT applications performed with the help of ultrasound have attracted attention. Also, the importance of phthalocyanines, which are used as sensitizers in photodynamic and/or sonodynamic therapy (SDT), is increasing. The most important properties of phthalocyanines for therapeutic applications are their ability to generate reactive oxygen species (ROS) at the appropriate wavelength. To improve ROS production by phthalocyanines applying ultrasounds seems to be the reasonable pathway of development for this treatment method. In this context, to evaluate potentials for sonophotodynamic therapy (SPDT), the syntheses of highly soluble non-peripherally substituted metal-free (2), gallium (3), and indium (4) phthalocyanines were completed by substituting 3-methoxybenzyloxy groups. All prepared compounds were elucidated using many different spectroscopic approaches encompassing Fourier transform infrared (FT-IR), ultraviolet–visible (UV–Vis), 1H NMR, and matrix-assisted laser deionization/ionization time-of-flight mass spectroscopy (MALDI-TOF MS) techniques. Additionally, photophysical, photochemical, and sono-photochemical evaluations of the novel phthalocyanines are presented. The combination of ultrasound and light had an enhancing effect on singlet oxygen production in all phthalocyanine derivatives (2–4). Singlet oxygen quantum yields increased between 50% and 80% for metal-free, gallium, and indium phthalocyanines. Density Functional Theory (DFT) and time-dependent (TD-DFT) were used for the description of optical and electronic properties of metal-free, gallium, and indium phthalocyanines. The Spin Orbital Coupling Constant (SOCC) for these molecules was also calculated through the quasi-degenerate perturbation theory method. Considering the singlet and triplet states of lower energy, we have calculated the most probable intersystem spin crossing (ISC) pathways. Our results suggest that all the phthalocyanines have potential application in PDT, however, indium phthalocyanine has greater applicability in PDT.

Kinetic Study of the Oxidation of Hydrogen Sulfide and Ethyl Mercaptan with Molecular Oxygen in the Presence of an Ammonia Solution of Cobalt Phthalocyanine Derivatives

Kinetic Study of the Oxidation of Hydrogen Sulfide and Ethyl Mercaptan with Molecular Oxygen in the Presence of an Ammonia Solution of Cobalt Phthalocyanine Derivatives

Intra-ring proton transfer effect on the Structure-NLO property relationships of phthalocyanine derivatives

Based on the phthalocyanine, four models (1–4) are designed to explore the intra-ring proton transfer effect on structure–property relationships. The results show that small differences in structure bring fascinating changes in nucleus-independent chemical shifts (NICS) values, anisotropy of the induced current density (AICD), natural population analysis (NPA) charge, electrostatic potential (ESP), UV–vis absorption spectrum as well as unit sphere representation (USR). Significantly, the largest static first hyperpolarizability βtot value (1.47 × 104) of 4 is approximately 15 times larger than that (8.98 × 102 au) of 1 due to the intra-ring proton transfer regulating conjugation degree of the conjugation section. Furthermore, the dynamic first hyperpolarizability βHRS at the wavelengths λ = 1907, 1460 nm is elaborated in detail. We hope that the present work may evoke the possibility to probe into a promising field for nonlinear optics (NLO) application.

Extended Near‐Infrared Photovoltaic Responses of Perovskite Solar Cells by p‐Type Phthalocyanine Derivative

AbstractThe absent photo‐response in near‐infrared (NIR) light (>800 nm) of lead‐based perovskite solar cells (PSCs) limits the further improvement of their power conversion efficiency (PCE). Here, a narrow bandgap p‐type phthalocyanine derivative (Copper(II) 2,3,9,10,16,17,23,24‐octakis((4‐(bis(4‐methoxyphenyl)amino)phenyl)ethynyl)phthalocyanine –8TPAEPC) with NIR absorption is synthesized to extend the photovoltaic response of perovskite to 850 nm. After doping the 8TPAEPC into the perovskite photoactive layer, the perovskite crystal quality is improved, resulting in its good electrical conductivity and less surface defects. Furthermore, the molecules stacking on the grain boundaries construct the charge transportation paths, as well as the p–n bulk heterojunction with enhanced built‐in potential. The target PSCs are optimized with notably enhanced PCE from 20% up to 22.10%, and excellent stability that is over 80% of the initial level at 70–80% relative humidity can be maintained for more than 500 h, benefiting from the improved hydrophobicity of 8TPAEPC. In addition, 8TPAEPC also serves as a dopant‐free, highly carrier‐mobile, and moreover, NIR‐responsive hole transport layer (HTL) with boosted PCE of 20.42% that reaches state of the art level among the dopant‐free metal phthalocyanines HTL‐based PSCs.

High Performance Solution Processed n‐Type OTFTs through Surface Engineered F–F Interactions Using Asymmetric Silicon Phthalocyanines

AbstractTwo novel asymmetric silicon phthalocyanine (SiPc) derivatives consisting of one axially substituted fluorine and one tri‐alkyl silane group are synthesized and characterized in n‐type solution processed bottom‐gate top‐contact organic thin‐film transistors (OTFTs). The effect of surface energy and fluorination are investigated at the dielectric/semiconductor interface by thin‐film X‐ray diffraction, atomic force microscopy, bright field real‐color microscopy, and grazing‐incidence wide‐angle X‐ray scattering to assess alterations in film conformation, microstructure, and morphology. Low surface energy dielectric modification and the presence of fluorine interactions produce films with large area crystalline domains that promote charge carrier transport resulting in high performing OTFTs, with a clear relationship determined between surface energy, fluorination, and OTFT operation. Through modifying deposition solvent and the exploitation of fluorine–fluorine interactions, the asymmetric SiPc derivative, (tri‐n‐hexylsilyl oxide) fluorosilicon phthalocyanine (F‐3HS‐SiPc), leads to high performing n‐type OTFTs with an average field‐effect mobility of 0.13 cm2 V−1 s−1 and a threshold voltage of 26.3 V. These results successfully demonstrate the use of asymmetric axial fluorination as a route to high performance n‐type OTFT devices through controlled self‐assembly by fluorine–fluorine interactions.

Beyond the Conventional Photodynamic Therapy by Water‐Soluble Phthalocyanines

AbstractCompared to the classical chemotherapy applications, PDT applications are based on a non‐toxic compound that can be specifically activated by shining a certain wavelength of light. Constitituvely active chemotherapy drug agents lead to detrimental and unwanted side effects that halt the normal life standards of the cancer patients. Localized and controlled activation of the drug agents by PDT applications aims to overcome the side effects associated with the treatment. In our study we synthesized a unique set of phthalocyanine molecules that are water soluble to make them biocompatible. Moreover, these compounds anti‐cancer activities were measured from multiple angles. Anti‐cancer PDT activities of the derivatives were studied by testing their effects on the cell proliferation, apoptosis and cell cycle progression. Moreover, these derivatives anti‐metastatic, anti‐angiogenic and immunomodulatory photodynamic activities were comprehensively studied by focusing on the intracellular signaling pathways that may play important roles in carcinogenesis, angiogenesis, metastasis and immune reactions. For the first time to our knowledge we are presenting data beyond the classical or canonical PDT applications in which generation of the reactive oxygen species (ROS) is explained as the main mechanism of the action for the PDT applications. Our results suggest that non‐canonical PDT activity can be observed independent of the ROS generation efficiencies probably by affecting the intracellular signaling pathways. These novel set of phthalocyanine derivatives may find applications against colon, lung, breast and prostate cancer.

Synthesis, photophysical and photochemical properties of unsymmetrical zinc(II) phthalocyanines bearing 8-hydroxyquinoline unit

8-Hydroxyquinolines (8-HQs) are very important molecules in the field of biochemistry. They may play different roles due to their chelating ability. Especially, its interaction with different metals such as iron and copper, which have important functions in the growth of cancer cells, helps inhibit proliferation. Moreover, the metal complexes of 8-HQ derivatives contribute to the generation of singlet oxygen species. On the other hand, phthalocyanines are macrocyclic compounds that have the capacity to generate singlet oxygen species and anticancer activity by photodynamic therapy. In this study, unsymmetrical zinc(II) phthalocyanine derivatives bearing one 8-HQ group and three tert-butyl groups (8-MeQ-ZnPc and 8-HQ-ZnPc) were prepared. For the synthesis of target molecules, unsymmetrical zinc(II) phthalocyanine containing methoxyquinoline unit (8-MeQ-ZnPc) was prepared first, and then the demethylation reaction was successfully carried out with BBr3 for obtaining hydroxyquinoline counterpart (8-HQ-ZnPc). The fluorescence, singlet oxygen, and photodegradation quantum yields of 8-MeQ-ZnPc and 8-HQ-ZnPc were measured in DMSO, and the results show that the photosensitizers can be a promising anticancer agent candidates.

THE BENEFICIAL EFFECT OF A MOUTHWASH CONTAINING A PHTHALOCYANINE DERIVATIVE IN PATIENTS HOSPITALIZED WITH COVID-19

ObjectivesTo evaluate the clinical outcome, such as length of hospital stay (LOS), need for referral to the intensive care unit (ICU), and number of deaths of patients with COVID-19 with the use of a mouthwash containing a phthalocyanine derivative.Study DesignA randomized triple-blind clinical trial in which a total of 41 hospitalized patients with COVID-19 were followed up. Patients were divided into 2 groups and both received a mouthwash containing active (AM) and nonactive (NAM) ingredients. They were instructed to use mouthwash and gargle for 1 minute 5 times a day and continue using the solution until discharge.ResultsThe median LOS of the AM group was significantly shortened (4 days) compared with the NAM group (7 days; P = .0314). Additionally, gargling/rinsing with anionic phthalocyanine derivative was very helpful in reducing the severity of symptoms (no ICU care was needed) compared to not gargling/rinsing with APD (28.6% of patients in the NAM group needed ICU care, and 50% of this ICU subgroup died; P = .0207).ConclusionsThis study showed that the action of the mouthwash containing phthalocyanine derivatives had effects against SARS-CoV-2 and can reduce the symptoms of patients and reduce the length of hospital stay.

Photoredox catalysis may be a general mechanism in photodynamic therapy

Elucidating the underlying photochemical mechanisms of action (MoA) of photodynamic therapy (PDT) may allow its efficacy to be improved and could set the stage for the development of new classes of PDT photosensitizers. Here, we provide evidence that "photoredox catalysis in cells," wherein key electron transport pathways are disrupted, could constitute a general MoA associated with PDT. Taking the cellular electron donor nicotinamide adenine dinucleotide as an example, we have found that well-known photosensitizers, such as Rose Bengal, BODIPY, phenoselenazinium, phthalocyanine, and porphyrin derivatives, are able to catalyze its conversion to NAD+. This MoA stands in contrast to conventional type I and type II photoactivation mechanisms involving electron and energy transfer, respectively. A newly designed molecular targeting photocatalyst (termed CatER) was designed to test the utility of this mechanism-based approach to photosensitizer development. Photoexcitation of CatER induces cell pyroptosis via the caspase 3/GSDME pathway. Specific epidermal growth factor receptor positive cancer cell recognition, high signal-to-background ratio tumor imaging (SBRTI = 12.2), and good tumor growth inhibition (TGI = 77.1%) are all hallmarks of CatER. CatER thus constitutes an effective near-infrared pyroptotic cell death photo-inducer. We believe the present results will provide the foundation for the synthesis of yet-improved phototherapeutic agents that incorporate photocatalytic chemistry into their molecular design.

Zinc(II), Palladium(II), and Metal-Free Phthalocyanines Bearing Nipagin-Functionalized Substituents against Candida auris and Selected Multidrug-Resistant Microbes.

Due to the rapidly increasing problem of antibiotic resistance in recent years, the use of phthalocyanines as photosensitizers with their superior properties in photodynamic antimicrobial therapy (PACT) applications has become important. In this study, magnesium(II) 1,4,8,11,15,18,22,25-octakis(4-[4-butoxycarbonylphenoxy]butyloxy)phthalocyanine was used in the demetalation reaction in trifluoroacetic acid, and subsequently subjected to metalation reaction in dimethylformamide with zinc(II) acetate and bis(benzonitrile)palladium(II) chloride towards zinc(II) and palladium(II) derivatives. Three phthalocyanines, including a demetalated one as well as two metalated, in the core with zinc(II) and palladium(II) were characterized using 1D and 2D NMR spectroscopy and mass spectrometry. In addition, all macrocycles were subjected to absorption and emission studies as well as photostability tests. In a photochemical study, zinc(II) and palladium(II) phthalocyanine complexes appeared to be efficient singlet oxygen generators. There were noted quantum yields of singlet oxygen generation for zinc(II) phthalocyanine derivative in DMF and DMSO at 0.55 and 0.72, whereas for palladium(II) complex at 0.73 and 0.77, respectively. Liposomal formulations of phthalocyanine derivatives were prepared, and their activity was evaluated against a broad spectrum of antibiotic-resistant microorganisms, such as methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli (ESBL+), Candida albicans resistant to fluconazole, C. auris, and against dermatophytes. Phthalocyanine palladium(II) complex showed the highest bactericidal activity against all antibiotic-resistant microorganisms, including reducing C. auris growth at 3.54 log.