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A supramolecular artificial light‐harvesting system (LHS) is successfully constructed in an aqueous environment using carbon dots (CDs) and α, β, γ, δ‐Tetrakis(1‐methylpyridinium‐4‐yl) porphyrin p‐Toluenesulfonate (TMPyP) via electrostatic interactions. Specifically, the CDs act as a donor, and TMPyP, which is loaded to the surface of the CDs, acts as an acceptor for the LHS. Energy transfer occurs from the CDs to the TMPyP in the assembled CDs‐TMPyP upon UV excitation. To demonstrate the applicability, the CDs‐TMPyP system is used as a sensor for Hg(II) in an aqueous solution. Subsequently, a functional material suitable for the detection and removal of Hg(II) is fabricated by integrating the CDs‐TMPyP into a polymer network. [ABSTRACT FROM AUTHOR]

Photodynamic therapy (PDT) is a great potential anti-tumor therapy owing to its non-invasiveness and high spatiotemporal selectivity. However, systemically administered photosensitizers diffuse in the skin and the eyes for a long duration, which cause phototoxicity to bright light and sunlight. Therefore, following PDT, patients must avoid exposure of to light and sunlight to avoid this phototoxicity. In this study, we have developed a locally administered PDT using nano-adhesive porphyrin with polycations consisting of quaternary ammonium salt groups (aHP) as a photosensitizer. The aHP, approximately 3.0 nm in diameter, adhered the negatively charged cell membrane via electrostatic interaction. The aHP localized to the endosome via cell adhesion and induced apoptosis upon 635 nm light irradiation. On being administered subcutaneously on the tumor, 30% of the injected aHP remained in the administered sites. However, low-molecular-weight hematoporphyrin dihydrochloride (HP) disappeared due to rapid diffusion. PDT with locally administered aHP showed a higher anti-tumor effect after light irradiation at 635 nm for three days compared to low-molecular-weight HP. Intraperitoneal administration of HP caused severe phototoxicity upon irradiation with ultraviolet A at 10 J cm−2, whereas aHP did not cause phototoxicity because its diffusion into the skin could be suppressed, probably due to the high-molecular weight of aHP. Therefore, locally administered PDT with aHP is a potential PDT having high therapeutic efficacy without phototoxicity. [ABSTRACT FROM AUTHOR]

The growing emergence of microbes resistant to commercially available antibiotic therapies poses a threat to healthcare systems worldwide. Multiple factors have been associated with the increasing incidence of hospital-acquired infections caused by antibiotic-resistant pathogens, including the indiscriminate use of broad-spectrum antibiotics, the massive application of antibiotics in hospitals as a prophylactic measure, self-medication, and nonadherence to pharmacological therapies by patients. In this study, we developed a novel treatment to mitigate the impact of microbial resistance. We synthesized a benzoporphyrin derivative, 5,10,15,20-tetrakis (4-ethylphenyl) porphyrin (TEtPP), with a reaction yield close to 50%. TEtPP exhibited excellent photophysical properties (Φf = 0.12 ± 0.04 and ΦΔ = 0.81 ± 0.23) and was thereby assessed as a potential agent for antibacterial photodynamic therapy. The photophysical properties of the synthesized porphyrin derivative were correlated with the assayed antimicrobial activity. TEtPP showed higher activity against the MRSA strain under irradiation than in the absence of irradiation (minimum inhibitory concentration (MIC) = 69.42 µg/mL vs. MIC = 109.30 µg/mL, p < 0.0001). Similar behavior was observed against P. aeruginosa (irradiated MIC = 54.71 µg/mL vs. nonirradiated MIC = 402.90 µg/mL, p < 0.0001). TEtPP exhibited high activity against S. aureus in both the irradiated and nonirradiated assays (MIC = 67.68 µg/mL vs. MIC = 58.26 µg/mL, p = 0.87). [ABSTRACT FROM AUTHOR]

In our research, we produced some novel porphyrin derivatives 4a–g in high yields. We also synthesized and characterized some of their metalloporphyrin complexes 5–11. The structures of these novel porphyrins were assured by spectroscopic techniques. The geometric structure and magnetic properties of metallo-porphyrins 5–11 have also been studied. Antiviral and antitumor activities were estimated and the structures activity relationships were accomplished. The Porphyrin derivatives 4g, 4f, 9, 10 and 11 displayed strong antiviral activity for HSV-1 compared to Aphidicoline as reference. While derivatives 4g and 6 exhibited very strong activity against HIV-1. Porphyrin derivatives 4g, 6, 9, and 10, in general, displayed strong activity against all the tested human cell lines. [ABSTRACT FROM AUTHOR]

The G‐quadruplex planar‐ligand complex is used to detect heavy metal cations such as Ag+, Cu2+, Pb2+, Hg2+, organic molecules, nucleic acids, and proteins. The interaction of the three planar porphyrins (L1), 5,10,15,20‐tetrakis (1‐ethyl‐1‐λ4‐pyridine‐4‐yl) porphyrin (L2), and 5,10,15,20‐tetrakis (1‐methyl‐1‐λ4‐pyridine‐4‐yl) porphyrin (L3), coming from the porphyrin family, with G‐quadruplex obtained from human DNA telomeres in the presence of lithium, sodium, potassium, rubidium, cesium, magnesium, and calcium ions was studied by molecular dynamics simulation. When G‐quadruplex containing divalent ions of magnesium and calcium interacts with L1, L2, and L3 ligands, the hydrogen bonds of the lower G‐quadruplex sheet are more affected by ligands and the distance between guanines in the lower tetrad increases. In the case of G‐quadruplex interactions containing monovalent ions with ligands, the hydrogen bond between the sheets does not follow a specific trend. For example, in the presence of lithium ions, the upper and middle sheets are more affected by ligands, while they are less affected by ligands in the presence of sodium. The binding pocket and the binding energy of the three ligands to the G‐quadruplex were also obtained in the various systems. The results show that ligands make the G‐quadruplex more stable through the penetration between the sheets and the interaction with the loops. Among the ligands mentioned, the interaction level of the ligand L2 is greater than the others. Our calculations are consistent with the previous experimental observations so that it can help to understand the molecular mechanism of porphyrin interaction and its derivatives with the G‐quadruplex. [ABSTRACT FROM AUTHOR]

Here, a post synthetic modification strategy is presented to prepare multifunctional Bi−MOF−Co by introducing Co atom into the porphyrin units of bismuth‐porphyrin metal organic framework (Bi−MOF). Under milder conditions (0.1 MPa, 80 °C), CO2 cycloaddition is achieved to form cyclic carbonate in 96 % yield catalyzed by Bi−MOF−Co. The recyclability of catalysts is confirmed by five cycle experiments without loss of activity. Moreover, alkyne hydration is also catalyzed by Bi−MOF−Co in 99 % yield. The hydration protocol exhibites excellent functional group compatibility. [ABSTRACT FROM AUTHOR]

By using a catalytic amount of a porphyrin‐based covalent organic framework (Por‐Ad‐COF) as the efficient recyclable photocatalyst, the photocatalytic oxidative [3+2] cycloaddition reaction between tetrahydroisoquinolines and N‐substituted maleimides was developed under aerobic conditions at room temperature. Various substituted pyrrolo[2,1‐a]isoquinolines were obtained in moderate to good yields via the dipolar [3+2] cycloaddition and oxidative aromatization cascade process under visible light irradiation. This was the first example to employ the covalent organic framework as the heterogeneous photocatalyst to perform the photocatalytic dipolar [3+2] cycloaddition reaction for the synthesis of pyrrolo[2,1‐a]isoquinolines. [ABSTRACT FROM AUTHOR]

The electronic absorption and vibrational spectra of deprotonated 5,10,15,20-tetrakis(p-hydroxyphenyl)porphyrin (THPP) are studied as a function of solvent polarity in H2O-DMF, H2O-acetone, H2O-methanol, and DMF-acetone mixtures. The maximum absorption wavelength (λmax) of the lowest energy electronic absorption band of deprotonated THPP shows an unusual solvatochromism-a bathochromic followed by a hypsochromic shift with reduced polarity. According to the correlation analysis, both specific interactions (H-bonds) and nonspecific interactions affect the spectral changes of this porphyrin. Furthermore, the solvent polarity scale ET(30) can explain both shifts very well. At higher polarity (ET(30) > 48), THPP exists as a hyperporphyrin. The ET(30) is linear with λmax and a decrease in solvent polarity is accompanied by a bathochromic shift of λmax. These results can be rationalized in terms of the cooperative effects of H-bonds and nonspecific interactions on the spectra of hyperporphyrin. At relatively low polarity (45.5 < ET(30) < 48), hyperporphyrin gradually becomes Na2P as ET(30) reaches the critical value of 45.5. The spectrum of the hyperporphyrin turns into the three-band spectrum of the metalloporphyrin, which is accompanied by a hypsochromic shift of λmax. [ABSTRACT FROM AUTHOR]

Heme is an iron-containing tetrapyrrole that plays a critical role in various biological processes, including oxygen transport, electron transport, signal transduction, and catalysis. However, free heme is hydrophobic and potentially toxic to cells. Organisms have evolved specific pathways to safely transport this essential but toxic macrocycle within and between cells. The bacterivorous soil-dwelling nematode Caenorhabditis elegans is a powerful animal model for studying heme-trafficking pathways, as it lacks the ability to synthesize heme but instead relies on specialized trafficking pathways to acquire, distribute, and utilize heme. Over the past 15 years, studies on this microscopic animal have led to the identification of a number of heme-trafficking proteins, with corresponding functional homologs in vertebrates. In this review, we provide a comprehensive overview of the heme-trafficking proteins identified in C. elegans and their corresponding homologs in related organisms. [ABSTRACT FROM AUTHOR]

A study has been carried out on enhancing the destruction of protein tryptophanyl residues and lipid peroxidation in isolated erythrocyte membranes photosensitized by Zn-tetraphenylporphin and Zn-tetramethylpyridylporphyrin by adding CCl4 and CHBr3. This effect was attributed to photoinduced electron transfer from the Zn-porphins to the halomethanes leading to highly reactive halomethyl radicals. Hydrophilic Zn-tetramethylpyridylporphyrin is more active in the halomethane-mediated photosensitization of membrane protein damage, while hydrophobic Zn-tetraphenylporphin is more effective in photosensitizing lipid oxidation. [ABSTRACT FROM AUTHOR]

The metalloporphyrin heme acts as the oxygen-complexing prosthetic group of hemoglobin in blood. Heme has been noted to survive for many millions of years in fossils. Here, we investigate its stability and degradation under various conditions expected to occur during fossilization. Oxidative, reductive, aerobic, and anaerobic conditions were studied at neutral and alkaline pH values. Elevated temperatures were applied to accelerate degradation. High-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) identified four main degradation products. The vinyl residues are oxidized to formyl and further to carboxylate groups. In the presence of air or H2O2, cleavage of the tetrapyrrole ring occurs, and hematinic acid is formed. The highest stability of heme was observed under anaerobic reductive conditions (half-life 9.5 days), while the lowest stability was found in the presence of H2O2 (half-life 1 min). We confirmed that the iron cation plays a crucial role in degradation, since protoporphyrin IX, lacking iron, remained significantly more stable. Under anaerobic, reductive conditions, the above-mentioned degradation products were not observed, suggesting a different degradation pathway. To our knowledge, this is the first molecular taphonomy study on heme, which will be useful for understanding its fate during fossilization. [ABSTRACT FROM AUTHOR]

Porphyrin derivatives have been known for their photodynamic therapy (PDT) application potential. In the present work, we have studied an asymmetric tetraphenyl substituted porphyrin derivative synthesized previously. Although traditional PDT applications focus on antibacterial and anti-cancer activities of the drug candidates, these compounds may have functional properties at subtoxic concentrations due to the chemically active groups that they carry. In this study, we aimed to investigate the anti-inflammatory PDT potential of this porphyrin derivative. For this purpose, mammalian macrophage cells were used. Trypan blue staining was done to confirm that this compound was effective at non-toxic concentrations. Moreover, TNF and IL6 ELISAs were done to the supernatants of the stimulated cells. Xenon light exposure was done to activate the porphyrin derivative. Our results suggest that this derivative had differential effects on these cytokine production levels by activated macrophages. These effects are light activation-dependent which makes this derivative a viable option for anti-inflammatory PDT applications. Moreover, it did not exert any cytotoxic effect at concentration used both in the dark and under light conditions. [ABSTRACT FROM AUTHOR]

Cr(VI) is a common heavy metal pollutants present in the aquatic environment, which possess toxic and carcinogenic properties. In this study, a solvothermal reaction was used to prepare porphyrin (TCPP)-modified UiO-66-NH2 (UNT). The UNT integrated adsorption and photocatalytics in the application for dealing with Cr(VI). The photocatalytic reduction activities of UNT for Cr(VI) were investigated under visible light illumination. We found that the TCPP doping amount of 15 mg UNT (15-UNT) had a 10 times higher reduction rate of Cr(VI) than pristine UiO-66-NH2. The optimal 15-UNT photocatalyst demonstrated the highest photocatalytic activity, and Cr(VI) was completely removed within 80 min. In addition, the introduction of porphyrin not only enhanced the absorption of light but also enabled the transport of photogenerated electrons from porphyrin to UiO-66-NH2, which promoted the separation of charge carriers. Furthermore, the effects of factors such as porphyrin content, pH and light source on the photocatalytic reduction performances of UNT were also explored. Overall, this work presented a possible relationship between the crystal structures and the performance of UNT. [ABSTRACT FROM AUTHOR]

Progression of oral mucosal lesions is generally marked by changes in the concentration of the intrinsic fluorophores such as collagen, nicotinamide adenine dinucleotide (NADH), flavin adenine dinucleotide (FAD) and porphyrin present in the human oral tissue. In this study, we have probed the changes in FAD and porphyrin by exciting with 405 nm laser light on different sites (tongue, buccal mucosa, lip etc.) of the oral cavity. Testing has been done by an in-house developed fluorescence-based portable imaging device on oral squamous cell carcinoma (OSCC) patients, dysplastic patients and control (normal) group. Fluorescence images recorded from OSCC and dysplastic patients have displayed an enhancement in the red band (porphyrin) as compared to those from the normal volunteers. Porphyrin to FAD intensity ratio (IPorphyrin/IFAD), referred to red to green ratio (Ired/Igreen) has been taken as the diagnostic marker for classification among the groups. Receiver operating characteristic (ROC) analysis applied on IPorphyrin/IFAD is able to discriminate OSCC to normal, dysplasia to normal and OSCC to dysplasia with sensitivities of 100%, 81%, 92% and specificities of 100%, 93% and 92% respectively. Fluorescence imaging probe can capture a large area of oral lesions in a single scan and hence would be useful for initial scanning. On comparison with spectroscopy studies performed by our group, it is found that combining both spectroscopy and imaging as a device may be effective for the early detection of oral lesions. This clinical study was registered on the date 13/10/2017 in the clinical trials registry-India (CTRI) with registration number CTRI/2017/10/010102. [ABSTRACT FROM AUTHOR]

Since ammonia is water-soluble, environmental studies have shown that the industrial waste such as fertilizer manufacturing, food products, palm oil, urea fertilizer industry can cause very serious damage to water body ecosystems if not properly managed, resulting in a decrease in water quality. Devices based on optical technology, especially devices that combine optical fibers and nanomaterials, are identified as highly sensitive to the species of interest by detecting changes in physicochemical properties. A practical, easy-to-use, inexpensive instrument for detecting ammonia level was proposed using tapered optical fiber (TOF) coated with titanium dioxide-incorporated porphyrin. TOF was fabricated by simultaneously stretching and heating. The preparation of TiO2/porphyrin/gelatine was prepared to coat tapered optical fiber by dipping. SEM analysis shows an increase in length and a decrease in diameter, also the successful coating of titanium dioxide and porphyrin in the taper region. The EDX analysis also proves the presence of the Ti element in the TOF layer. The TOF produces significant sensing performances toward the ammonia liquid concentration level. The TOF coated with titanium dioxide-incorporated porphyrin can detect a one ppm difference in ammonia concentration with a certain range of output voltage for every concentration has. [ABSTRACT FROM AUTHOR]

The active site engineering of electrocatalysts, as one of the most economical and technological approaches, is a promising strategy to enhance the intrinsic activity and selectivity towards electrochemical CO2 reduction reaction. Herein, an indium-based porphyrin framework (In-TCPP) with a well-defined structure, highly dispersed catalytic center, and good stability was constructed for efficient CO2-to-formate conversion. In-TCPP could achieve a high Faraday efficiency for formate (90%) and a cathodic energy efficiency of 63.8% in flow cells. In situ attenuated total reflectance Fourier transform infrared spectroscopy and density functional theory calculation confirm that the crucial intermediate is *COOH species which contributes to the formation of formate. This work is expected to provide novel insights into the precise design of active sites for high-performance electrocatalysts towards electrochemical CO2 reduction reaction. [ABSTRACT FROM AUTHOR]

Immune therapy based on programmed death-ligand 1 (PD-L1) is widely used to treat human tumors. The current strategies to improve immune checkpoint blockade therapy fail in rescuing increased expression of PD-L1 in tumor issues. Here, we for the first time synthesized the metal—organic framework (MOF) nanocrystals of rare-earth element dysprosium (Dy) coordinated with tetrakis(4-carboxyphenyl) porphyrin (TCPP), which show well-defined two-dimensional morphologies. The MOF nanocrystals of Dy-TCPP could apparently reduce PD-L1 expression in tumor cells both in vitro and in vivo, and therefore display effective tumor treatment through immune therapy without any immune checkpoint inhibitor drugs. Considering the sensitivity of TCPP ligand toward ultrasound, the prepared Dy-TCPP can also realize sonodynamic therapy (SDT) besides immune therapy. In addition, the Dy-TCPP nanocrystals can efficiently obtain T2-weight magnetic resonance imaging (MRI) of tumor sites. Our study provides the Dy-TCPP nanocrystals as promising diagnostic MRI-guided platforms for the combined treatment on tumors with SDT and immune therapy. Moreover, this strategy succeeds in reducing the elevated expression of PD-L1 in tumor cells, which might serve as a novel avenue for tumor immunotherapy in future. [ABSTRACT FROM AUTHOR]

The photodynamic treatment is a non-aggressive and clinically accepted procedure for removing selected cancer cells with the activation of a photosensitizer agent at a specific light. In this study, the zinc porphyrin (Zn[TPP]) was prepared and encapsulated into the MIL-101 (Zn[TPP]@MIL-101). It was used in photodynamic therapy (PDT) against MCF-7 breast cancer cells under a red light-emitting diode. The structure, morphology, surface area, and compositional changes were investigated using conventional characterization methods including FTIR, FESEM, EDX, and BET analyses. The MTT assay was performed under light and dark conditions to explore the ability of Zn[TPP]@MIL-101 in PDT. The results have demonstrated the IC50 of 14.3 and 81.6 mg/mL for light and dark groups, respectively. As the IC50 revealed, the Zn[TPP]@MIL-101 could efficiently eradicate cancer cells using PDT. [ABSTRACT FROM AUTHOR]

One striking feature of enzyme is its controllable ability to trap substrates via synergistic or cooperative binding in the enzymatic pocket, which renders the shape‐selectivity of product by the confined spatial environment. The success of shape‐selective catalysis relies on the ability of enzyme to tune the thermodynamics and kinetics for chemical reactions. In emulation of enzyme's ability, we showcase herein a targeting strategy with the substrate being anchored on the internal pore wall of metal‐organic frameworks (MOFs), taking full advantage of the sterically kinetic control to achieve shape‐selectivity for the reactions. For this purpose, a series of binding site‐accessible metal metalloporphyrin‐frameworks (MMPFs) have been investigated to shed light on the nature of enzyme‐mimic catalysis. They exhibit a different density of binding sites that are well arranged into the nanospace with corresponding distances of opposite binding sites. Such a structural specificity results in a facile switch in selectivity from an exclusive formation of the thermodynamically stable product to the kinetic product. Thus, the proposed targeting strategy, based on the combination of porous materials and binding events, paves a new way to develop highly efficient heterogeneous catalysts for shifting selectivity. [ABSTRACT FROM AUTHOR]

Selective and sensitive detection of inorganic pyrophosphate (PPi) are of great significance both for clinical applications and fundamental research. In this work, a ratiometric fluorescent probe was developed by decorating a porphyrin‐based metal‐organic framework (PCN‐224) with sulfur nanodots (S‐dots). The red‐fluorescence of PCN‐224 was significantly promoted (more than 6‐fold) by S‐dots through inhibiting molecular motion of porphyrin ligand, which also provided active sites for the detection of Cu2+ and PPi. Cu2+ could selectively quench the red‐fluorescence of PCN‐224 through coordination with porphyrin ligand, and the competition reaction between PPi and Cu2+ resulted in the decomposing of coordination and recovery of red‐fluorescence. The blue‐fluorescence from S‐dots was deemed as effective reference, which provided a built‐in correction in complex environments. Based on these photophysical properties, a ratiometric fluorescence assay was developed for the quantitative detection of Cu2+ and PPi, with a limit of detection of 0.11 and 2.66 μM, respectively. The accuracy and practical applications of assays were also demonstrated by detection in tap water and human serum samples. [ABSTRACT FROM AUTHOR]

Skin cancer is one of the cancers that registers the highest number of new cases annually. Among all forms of skin cancer, melanoma is the most invasive and deadliest. The resistance of this form of cancer to conventional treatments has led to the employment of alternative/complementary therapeutic approaches. Photodynamic therapy (PDT) appears to be a promising alternative to overcome the resistance of melanoma to conventional therapies. PDT is a non-invasive therapeutic procedure in which highly reactive oxygen species (ROS) are generated upon excitation of a photosensitizer (PS) when subjected to visible light of an adequate wavelength, resulting in the death of cancer cells. In this work, inspired by the efficacy of tetrapyrrolic macrocycles to act as PS against tumor cells, we report the photophysical characterization and biological assays of isobacteriochlorins and their corresponding chlorins and porphyrins against melanoma cancer cells through a photodynamic process. The non-tumoral L929 fibroblast murine cell line was used as the control. The results show that the choice of adequate tetrapyrrolic macrocycle-based PS can be modulated to improve the performance of PDT. [ABSTRACT FROM AUTHOR]

Photocatalytic CO2 reduction to valuable hydrocarbon solar fuel is of great significance but still challenging. Strong CO2 enrichment ability and easily adjustable structures make metal-organic frameworks (MOFs) potential photocatalysts for CO2 conversion. Even though pure MOFs have the potential for photoreduction of CO2, the efficiency is still quite low due to rapid photogenerated electron–hole recombination and other drawbacks. In this work, graphene quantum dots (GQDs) were in situ encapsulated into highly stable MOFs via a solvothermal method for this challenging task. The GQDs@PCN-222 with encapsulated GQDs showed similar Powder X-ray Diffraction (PXRD) patterns to PCN-222, indicating the retained structure. The porous structure was also retained with a Brunauer–Emmett–Teller (BET) surface area of 2066 m2/g. After incorporation of GQDs, the shape of GQDs@PCN-222 particles remained, as revealed by the scanning electron microscope (SEM). As most of the GQDs were covered by thick PCN-222, it was hard to observe those GQDs using a transmission electron microscope (TEM) and a high-resolution transmission electron microscope (HRTEM) directly, the treatment of digested GQDs@PCN-222 particles by immersion in a 1 mM aqueous KOH solution can make the incorporated GQDs visible in TEM and HRTEM. The linker, deep purple porphyrins, make MOFs a highly visible light harvester up to 800 nm. The introduction of GQDs inside PCN-222 can effectively promote the spatial separation of the photogenerated electron–hole pairs during the photocatalytic process, which was proved by the transient photocurrent plot and photoluminescence emission spectra. Compared with pure PCN-222, the obtained GQDs@PCN-222 displayed dramatically enhanced CO production derived from CO2 photoreduction with 147.8 μmol/g/h in a 10 h period under visible light irradiation with triethanolamine (TEOA) as a sacrificial agent. This study demonstrated that the combination of GQDs and high light absorption MOFs provides a new platform for photocatalytic CO2 reduction. [ABSTRACT FROM AUTHOR]

The carboxyl-functionalized porphyrin entangled with benzimidazolium-based ionic liquid (CFPBIL) was successfully synthesized and characterized by FT-IR, FT-NMR and TGA analysis. The proton level was determined by the Hammett acidity function, and DR spectra have been supported to confirm the band gap of photocatalyst. The present study reveals the metal-free, conventional photocatalytic acetalization of furfural to biofuel components under visible light irradiations using carboxyl-functionalized porphyrin catalyst. The effect of different parameters on the photocatalytic reaction, catalyst loading, ratio of furfural:alcohol, duration and intensity of light were investigated. The model reaction of furfural and ethanol in a home-made photoreactor using a 5-W LED presented that a very high yield of furfural acetal (92%) could be obtained under optimized conditions. Moreover, the eco-friendly method of acetalization reactions with higher alcohols (1-butanol, 1-pentanol, 1-hexanol, 1-octanol) was carried out at optimized reaction conditions which also afforded good to excellent yield of the target products, demonstrating the potential of CFPBIL as a highly active, stable and recyclable heterogeneous photocatalyst. Moreover, physical properties of biodiesel–diesel blends comprising B10, B20 and B30 were determined and furfural acetals were found as a potential fuel additive. [ABSTRACT FROM AUTHOR]

Supramolecular self‐assembly is a promising strategy for stabilizing the photo‐sensitive components in photocatalysis. However, the underlying correlation between the enhanced photostability and supramolecular structure at the molecular level has not yet been fully understood. Herein, we develop a biomimetic vesicular membrane‐based polyporphyrin photocatalyst exhibiting excellent photocatalytic stability with at least activity time of 240 h in hydrogen generation. Time‐domain ab initio modelling together with transient absorption spectroscopy, visual frontier orbitals and Gibbs free energy calculation disclose that the ordered aggregation of porphyrin units in the vesicle membrane facilitates "hot" electron relaxation and the rapid dissipation of photo‐generated charges, thereby contributing to the longevity. This work deepens the molecular‐level understanding on photostability and photocatalytic mechanism of supramolecular photocatalysts. [ABSTRACT FROM AUTHOR]

Density functional theory (DFT) has been carried out to investigate the electronic characteristics, UV–VIS–NIR absorption spectra, and nonlinear optical (NLO) properties of two series of zinc porphyrin analogs (FPD‐Nx and TPD‐Nx, x = 0–4) with donor‐π‐donor frameworks. The design of these analogs is based on previously synthesized furan‐linked zinc porphyrins (FPDs) and thiophene‐linked zinc porphyrins (TPDs). It is noted that their electro‐optical features are sensitive to the numbers of N‐coordination atoms and the attached groups. A dramatic enhancement of static first and second hyperpolarizabilities (β0 and γ0) occurs when two furan/thiophene rings are attached to the zinc porphyrin. Among the two series, FPD‐N3 and TPD‐N3 have the largest β0 values of about 7600 a.u. The static γ0 values of these complexes range from 0.41 × 106 to 1.79 × 106 a.u. The FPD‐Nx has a larger γ0 value than the corresponding TPD‐Nx, but the γ0 value of FPD‐N2 is close to that of TPD‐N2. In the dynamic NLO process, the electro‐optical Pockels effect, second harmonic generation, and electro‐optic Kerr effect can be enhanced at the wavelength of 1907 nm. This study provides a new strategy for the experimental design of high‐performance NLO materials. [ABSTRACT FROM AUTHOR]

Transforming solar energy into chemical bonds is a promising and viable way to store solar energy. Porphyrins are natural light-capturing antennas, and graphitic carbon nitride (g-C3N4) is an effective, artificially synthesized organic semiconductor. Their excellent complementarity has led to a growing number of research papers on porphyrin/g-C3N4 hybrids for solar energy utilization. This review highlights the recent progress in porphyrin/g-C3N4 composites, including: (1) porphyrin molecules/g-C3N4 composite photocatalysts connected via noncovalent or covalent interactions, and (2) porphyrin-based nanomaterials/g-C3N4 composite photocatalysts, such as porphyrin-based MOF/g-C3N4, porphyrin-based COF/g-C3N4, and porphyrin-based assembly/g-C3N4 heterojunction nanostructures. Additionally, the review discusses the versatile applications of these composites, including artificial photosynthesis for hydrogen evolution, CO2 reduction, and pollutant degradation. Lastly, critical summaries and perspectives on the challenges and future directions in this field are also provided. [ABSTRACT FROM AUTHOR]

The formation of G4 structures in a DNA double helix competes with the complementary strand interaction. The local environment in DNA can change equilibrium of G4 structures, which are studied on single-stranded (ss) models by classical structural methods. A relevant task is to develop methods for detecting and localizing G4 structures in extended native double-stranded (ds) DNA in the promoter regions of the genome. The ZnP1 porphyrin derivative selectively binds to G4 structures and leads to photo-induced oxidation of guanine in ssDNA and dsDNA model systems. We have shown the oxidative effect of ZnP1 on native sequences of MYC and TERT oncogene promoters, which can form G4 structures. Single-strand breaks in the guanine-rich sequence because of ZnP1 oxidation and subsequent cleavage of the DNA strand with Fpg glycosylase have been identified and assigned to the nucleotide sequence. The detected break sites have been shown to correspond to sequences capable of forming G4 structures. Thus, we have demonstrated the possibility of using porphyrin ZnP1 for the identification and localization of G4 quadruplexes in extended regions of the genome. Here we have shown the novel data on a possibility of folding G4 structures in the presence of complementary strand in native DNA double helix. [ABSTRACT FROM AUTHOR]

Sn(IV)-porphyrin complex with trans-dihydroxo axial-ligands and 2-pyridyl peripheral substituents, namely (trans-dihydroxo)[5,10,15,20-tetrakis(2-pyridyl)porphyrinato]tin(IV) was synthesized and fully characterized by various techniques such as elemental analysis, 1H NMR spectroscopy, ESI-MS spectrometry, UV-visible spectroscopy, and fluorescence spectroscopy. [ABSTRACT FROM AUTHOR]

A small receptor molecule composed of a porphyrin core with tetrakis-ammonium glycine pickets (liptin 3e) appears to target anionic phosphatidylglycerol (PG) lipid head groups through multifunctional binding-pocket complementarity. Although a major component of bacterial cell membranes, PG is not widely found in animal cells, making PG potentially selective for bacterial targeting. Growth of microbial isolates was monitored in liquid cultures treated with liptin 3e by dilution plate counts and turbidity. Inhibition of growth by liptin 3e was observed for the ESKAPE human pathogens (Enterobacter aerogenes, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterococcus faecium), Escherichia coli, Mycobacterium smegmatis, Streptococcus sobrinus, and methicillin-resistant S. aureus (MRSA), with certain species suppressed at <1 μg/mL (sub-μM) concentrations. Prolonged lag phases were observed, although cell viability was mainly unaffected, suggesting that liptin treatment caused bacteriostasis. Cultures treated with liptin 3e eventually recovered, resumed growth, and reached the same final densities as untreated cultures. Growth of the fungus Candida albicans was not appreciably inhibited by liptin 3e. If liptins exhibit bacteriostasis through broad extracellular binding to PG head groups, thereby disrupting cellular processes, liptins may be considered for development into preclinical drug candidates or be useful as a targeting system for molecular beacons or antibacterial drugs. [ABSTRACT FROM AUTHOR]

Abstract Background Low-dose spiral computed tomography (LDCT) may not lead to a clear treatment path when small to intermediate-sized lung nodules are identified. We have combined flow cytometry and machine learning to develop a sputum-based test (CyPath Lung) that can assist physicians in decision-making in such cases. Methods Single cell suspensions prepared from induced sputum samples collected over three consecutive days were labeled with a viability dye to exclude dead cells, antibodies to distinguish cell types, and a porphyrin to label cancer-associated cells. The labeled cell suspension was run on a flow cytometer and the data collected. An analysis pipeline combining automated flow cytometry data processing with machine learning was developed to distinguish cancer from non-cancer samples from 150 patients at high risk of whom 28 had lung cancer. Flow data and patient features were evaluated to identify predictors of lung cancer. Random training and test sets were chosen to evaluate predictive variables iteratively until a robust model was identified. The final model was tested on a second, independent group of 32 samples, including six samples from patients diagnosed with lung cancer. Results Automated analysis combined with machine learning resulted in a predictive model that achieved an area under the ROC curve (AUC) of 0.89 (95% CI 0.83–0.89). The sensitivity and specificity were 82% and 88%, respectively, and the negative and positive predictive values 96% and 61%, respectively. Importantly, the test was 92% sensitive and 87% specific in cases when nodules were

The effects of radiation from laser and LED sources with wavelengths λ = 405 and 445 nm on the metabolic activity of cultured somatic cells were compared. A more pronounced inhibitory effect was observed upon exposure to light with λ = 405 nm. Fundamental differences in the action of monochromatic and quasi-monochromatic light were not noted. The photobiological effect was shown to be due to photochemical processes involving various reactive oxygen species, the contribution of which to cell inactivation depended on the time after the termination of irradiation. Porphyrin components were detected for the first time in fluorescence spectra of suspensions of living cells in addition to the flavin component. It was concluded based on a comparison of the absorption characteristics of flavin and porphyrin sensitizers, chemiluminescence analysis, and the biological effects of radiation with λ = 405 and 445 nm that endogenous porphyrins with the most intense absorption in this area made the determining contribution to singlet oxygen formation in cells when exposed to radiation with λ = 405 nm. The contribution of flavins was more pronounced under the action of radiation with λ = 445 nm, which corresponded to their absorption spectrum maximum and the absorption minimum of endogenous porphyrins. [ABSTRACT FROM AUTHOR]

Experimental temperature dependences (77–293 K) of absorption and photoluminescence spectra of CdSe/ZnS semiconductor quantum dots (QDs) were analyzed based on modern models of exciton–phonon coupling. It was proven that the first excitonic transition absorption band formed with participation primarily of optical phonons of the CdSe core while the photoluminescence properties reflected the interaction of the ZnS layer with optical phonons. Photoluminescence quenching for CdSe/ZnS QDs of various diameters upon formation of nanoassemblies with porphyrin molecules was analyzed in the framework of a quantum-mechanical model. It was shown that the quenching rate constant decreased with increasing QD diameter and that the quenching process under quantum confinement conditions was due to the electron of an excited electron–hole pair tunneling onto the QD surface with subsequent localization on surface traps. [ABSTRACT FROM AUTHOR]

In this manuscript, a pyridyl containing porphyrin, C46H36N8O4 (denoted as Tris@NTPP) and its derived polyoxometalate-porphyrin hybrid, [C4H9)4N]3[C41H26N7NHCO(NH)C(OCH2)3MnMo6 O18(OCH2)3C(NH)CONHN7 H26C41] (denoted as NTPP@POM) in which two pyridyl containing porphyrin moieties hanged onto one Anderson polyoxometalate, have been successfully synthesized and thoroughly characterized. Fluorescence quenching was observed in NTPP@POM as compared with its precursor Tris@NTPP inferring the transfer of electron/energy from porphyrin moiety to POM moiety. NTPP@POM showed notably enhanced nonlinear absorption (β = 2.32 × 10–5 esu) than Tris@NTPP (β = 0.73 × 10–5 esu). These NLO responses were associated with fluorescence decay mechanism which oriented the singlet excited(*S) states and triplet excited(*T) states of Tris@NTPP and NTPP@POM. Life time decay studies revealed that NTPP@POM (τ2 = 5.32 ns) were stayed for shorter time in excited triplet state than Tris@NTPP (τ2 = 10 ns), implying shorter life time led towards higher NLO responses. [ABSTRACT FROM AUTHOR]

Photopharmacology is an approach that aims to be an alternative to classical chemotherapy. Herein, the different classes of photoswitches and photocleavage compounds and their biological applications are described. Proteolysis targeting chimeras (PROTACs) containing azobenzene moieties (PHOTACs) and photocleavable protecting groups (photocaged PROTACs) are also mentioned. Furthermore, porphyrins are referenced as successful photoactive compounds in a clinical context, such as in the photodynamic therapy of tumours as well as preventing antimicrobial resistance, namely in bacteria. Porphyrins combining photoswitches and photocleavage systems are highlighted, taking advantage of both photopharmacology and photodynamic action. Finally, porphyrins with antibacterial activity are described, taking advantage of the synergistic effect of photodynamic treatment and antibiotic therapy to overcome bacterial resistance. [ABSTRACT FROM AUTHOR]

Porphyrins is a unique heterocyclic molecule with four modified pyrrole rings interconnected at α carbon atoms via methine groups. The potential of porphyrin has been enhanced by developing the linked nanostructures with nanocarbons (carbon nanotube, graphene and fullerene) through physical/covalent electron donor-acceptor interactions. The porphyrin linked nanocarbon nanostructures have been reinforced in the polymeric matrices such as thermoplastic and conjugated polymers using facile approaches. The polymer/porphyrin linked nanocarbon nanocomposite revealed several remarkable characteristics like high surface area, conductivity, optical, thermal, mechanical capacitance, sensing and photocatalytic features. The high-performance nanocomposite nanostructures have been employed in sensor, supercapacitor and solar cell applications. [ABSTRACT FROM AUTHOR]

Comedogenic skin care receives little attention compared to the care or treatment of more serious acne manifestations. Traditional therapies may have limited success with potential side effects. Cosmetic care supported by the effect of a biostimulating laser may offer a desirable alternative. The aim of the study was to evaluate the biological effectiveness of combined cosmetic treatment with lasotherapy on comedogenic skin type using noninvasive bioengineering methods. Twelve volunteers with comedogenic skin type underwent a 28-week application of Lasocare Basic 645® cosmetic gel containing Lactoperoxidase and Lactoferrin in combination with laser therapy (Lasocare® method). The effect of treatment on skin condition was monitored using noninvasive diagnostic methods. The parameters were the amount of sebum, the pore count, the ultraviolet-induced red fluorescence assessment of comedonic lesions (percentage of the area and quantification of orange-red spots), hydration, transepidermal water loss, and pH. A statistically significant decrease in sebum production was observed on the skin of the treated volunteers, as well as a decrease in porphyrins, indicating the presence of Cutibacterium acnes populating comedones and causing enlarged pores. The balance of epidermal water in the skin was regulated adjusting the acidity of the skin coat in individual zones, which decreased the presence of Cutibacterium acnes. Cosmetic treatment in combination with the Lasocare® method successfully improved the condition of comedogenic skin. In addition to transient erythema, there were no other adverse effects. The chosen procedure appears to be a suitable and safe alternative to traditional treatment procedures known from dermatological practice. [ABSTRACT FROM AUTHOR]

There is a growing demand for clean-label products. This study aimed to obtain a food-grade coloring ingredient for meat products based on the formation of Zn-protoporphyrin from porcine livers, thus contributing to the development of nitrite-free products. First, the effects of sodium disulfite and acetic, ascorbic, and lactic acids on the formation of Zn-protoporphyrin and the total microbial count were studied. The combination of ascorbic and acetic acids resulted in a higher Zn-protoporphyrin content than acetic acid alone, and microbial levels were maintained (ca. 3 log CFU/mL). Second, a response surface methodology was used to maximize Zn-protoporphyrin while maintaining microbiological food standards. To that end, the effects of pH (4.2–5.4), incubation time (3–30 h), and temperature (25–50 °C) were studied. The selected conditions for Zn-protoporphyrin formation involved anaerobic incubation at pH 4.8 and 45 °C for 24 h. The safety was validated through challenge testing for relevant pathogens (Listeria monocytogenes, Salmonella spp., and Clostridium perfringens). A significant reduction (>6 log units) was observed in the selected conditions for L. monocytogenes and Salmonella, whereas C. perfringens spores remained at the inoculated levels. The optimized procedure is proven to be microbiologically safe, and may improve the color of nitrite-free meat products. [ABSTRACT FROM AUTHOR]

Rings of porphyrins mimic natural light‐harvesting chlorophyll arrays and offer insights into electronic delocalization, providing a motivation for creating larger nanorings with closely spaced porphyrin units. Here, we demonstrate the first synthesis of a macrocycle consisting entirely of 5,15‐linked porphyrins. This porphyrin octadecamer was constructed using a covalent six‐armed template, made by cobalt‐catalyzed cyclotrimerization of an H‐shaped tolan with porphyrin trimer ends. The porphyrins around the circumference of the nanoring were linked together by intramolecular oxidative meso‐meso coupling and partial β‐β fusion, to give a nanoring consisting of six edge‐fused zinc(II) porphyrin dimer units and six un‐fused nickel(II) porphyrins. STM imaging on a gold surface confirms the size and shape of the spoked 18‐porphyrin nanoring (calculated diameter: 4.7 nm). [ABSTRACT FROM AUTHOR]