Search Results (11)

Diabetes mellitus is a characteristic metabolic disorder with diverse complications. α-Amylase and α-glucosidase, as key digestive enzymes regulating blood glucose, are important targets for diabetes prevention and management through their inhibition. This study investigated the inhibitory effects of six porphyrin compounds (TAPP, TCPP, THPP, Cu–TCPP, Fe–TCPP, Ni–TCPP) on two enzymes through in vitro inhibition assays, spectroscopic experiments, and molecular docking techniques. All six compounds effectively inhibited the activities of both enzymes. For α-amylase, the inhibitory potency (IC₅₀ = 13.03–245.04 μg/mL) followed the order TAPP > THPP > TCPP > Fe–TCPP > Ni–TCPP > Cu–TCPP. All six compounds exhibited more potent inhibitory activity against α-glucosidase (IC₅₀ = 0.24–25.43 μg/mL), with potency in the order of THPP > Ni–TCPP > Fe–TCPP > TCPP > Cu–TCPP > TAPP. Fluorescence quenching experiments revealed that all compounds statically quenched the intrinsic fluorescence of both enzymes (with Fe–TCPP exhibiting static-dominant mixed quenching against α-amylase), indicating complex formation. These interactions significantly altered the enzymes’ conformations, the microenvironments of Tyr/Trp residues, and secondary structure content, consequently reducing their catalytic activity. By examining the inhibitory impact of porphyrin compounds on α-amylase and α-glucosidase, this research establishes a vital experimental and theoretical basis for diabetes therapeutics. Full article

Obesity is a chronic epidemic caused by abnormal fat metabolism. As a key digestive enzyme, pancreatic lipase (PL) is an important target for regulating fat metabolism. The inhibitory potential of 5,10,15,20-Tetrakis (4-aminophenyl) porphyrin (TAPP), 5,10,15,20-Tetrakis (4-hydroxyphenyl) porphyrin (THPP), meso-Tetra (4-carboxyphenyl) porphine (TCPP), Cu (II) meso-Tetra (4-carboxyphenyl) porphine (Cu-TCPP) on PL was studied by enzymatic kinetics, multi-spectral, and molecular simulation technology. THPP, TCPP, TAPP, and Cu-TCPP all had good PL inhibitory activity (IC₅₀ range: 97.49–248.70 μM) and were uncompetitive inhibitors. The order of inhibitory ability was: THPP > TCPP > TAPP > Cu-TCPP. The fluorescence quenching mechanism of THPP to PL was a mixed quenching dominated by static quenching, while TCPP, TAPP, and Cu-TCPP were static quenching. The binding of THPP, TCPP and TAPP to PL was mainly driven by hydrogen bonds and van der Waals forces, while Cu-TCPP was mainly driven by a hydrophobic interaction. Four porphyrin compounds changed the conformation of PL, affected the microenvironment of Tyr and Trp residues, and induced changes in the secondary structure of PL, thereby reducing the stability and catalytic activity of PL. Hydrogen bonds played an important role in the binding stability of THPP, TCPP, TAPP, and PL. Full article

In this study, two types of Cu-MOFs (Cu-TCPP and CuO-TCPP) with a two-dimensional layered porous structure were prepared via in situ polymerization using Cu²⁺, CuO, and TCPP as raw materials. Both Cu-MOFs exhibited peroxidase-like activity, capable of catalyzing the oxidation of TMB by H₂O₂ to form oxTMB, resulting in an absorption peak at 652 nm and a color change from colorless to blue. Subsequently, the addition of AA can reduce oxTMB back to TMB, causing the color of the system to lighten or become colorless. Based on this principle, a simple and rapid colorimetric method for AA detection was established and successfully applied to the detection of TAC in fruits and vegetables. The results showed that Cu-TCPP and CuO-TCPP had a large linear range of ascorbic acid detection of 0.01–100 mM (Cu-TCPP) and 0.05–100 mM (CuO-TCPP). This study not only provides a novel method for preparing nanozymes with peroxidase-like activity, but also offers a simple approach for analyzing the TAC of food. Full article

Dopamine (DA) is an important neurotransmitter. Abnormal concentration of DA can result in many neurological diseases. Developing reliable determination methods for DA is of great significance for the diagnosis and monitoring of neurological diseases. Here, a novel and simple electrochemical sensing platform for quantitative analysis of DA was constructed based on the Cu-TCPP/graphene composite (TCPP: Tetrakis(4-carboxyphenyl)porphyrin). Cu-TCPP frameworks were selected in consideration of their good electrochemical sensing potential. The graphene nanosheets with excellent conductivity were then added to further improve the sensing efficiency and stability of Cu-TCPP frameworks. The electrochemical properties of the Cu-TCPP/graphene composite were characterized, showing its large electrode active area, fast electron transfer, and good sensing performance toward DA. The signal enhancement mechanism of DA was explored. Strong accumulation ability and high electrocatalytic rate were observed on the surface of Cu-TCPP/graphene-modified glassy carbon electrode (Cu-TCPP/graphene/GCE). Based on the synergistic sensitization effect, an ultrasensitive and simple DA electrochemical sensor was developed. The linear range is 0.02–100 and 100–1000 µM, and the detection limit is 3.6 nM for the first linear range. It was also successfully used in detecting DA in serum samples, and a satisfactory recovery was obtained. Full article

Fighting against bacterial infection and accelerating wound healing remain important and challenging in infected wound care. Metal–organic frameworks (MOFs) have received much attention for their optimized and enhanced catalytic performance in different dimensions of these challenges. The size and morphology of nanomaterials are important in their physiochemical properties and thereby their biological functions. Enzyme-mimicking catalysts, based on MOFs of different dimensions, display varying degrees of peroxidase (POD)-like activity toward hydrogen peroxide (H₂O₂) decomposition into toxic hydroxyl radicals (•OH) for bacterial inhibition and accelerating wound healing. In this study, we investigated the two most studied representatives of copper-based MOFs (Cu-MOFs), three-dimensional (3D) HKUST-1 and two-dimensional (2D) Cu-TCPP, for antibacterial therapy. HKUST-1, with a uniform and octahedral 3D structure, showed higher POD-like activity, resulting in H₂O₂ decomposition for •OH generation rather than Cu-TCPP. Because of the efficient generation of toxic •OH, both Gram-negative Escherichia coli and Gram-positive methicillin-resistant Staphylococcus aureus could be eliminated under a lower concentration of H₂O₂. Animal experiments indicated that the as-prepared HKUST-1 effectively accelerated wound healing with good biocompatibility. These results reveal the multivariate dimensions of Cu-MOFs with high POD-like activity, providing good potential for further stimulation of specific bacterial binding therapies in the future. Full article

In this work, tetra(4-carboxyphenyl)porphyrin (TCPP) and two Anderson-type polyoxomolybdates (containing Cu and Zn, respectively; CuPOM, ZnPOM) were synthesized and deposited on TiO₂ thin films. The properties of the obtained materials were characterized through UV–vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR), diffuse reflection spectroscopy, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The adsorption and photodegradation under the visible light irradiation of methylene blue (MB) were studied for TiO₂, TCPP/TiO₂, TCPP/CuPOM/TiO₂ and TCPP/ZnPOM/TiO₂ thin films in aqueous solution. The results of the diffuse reflectance showed two bands in the visible light spectrum for the TCPP/POM/TiO₂ systems compared to unmodified TiO₂ that does not show any bands in the same region of the spectrum. The TCPP/POM/TiO₂ systems showed a higher removal of MB, with an adsorption rate near to 31% for the TCPP/CuPOM/TiO₂ film compared to 9% adsorption on the TiO₂ film. The kinetic results show that the pseudo-second order model was the best fitting model for the MB adsorption process onto fabricated materials. The photodegradation studies under visible light showed a better performance on TCPP/POM/TiO₂ thin films, with an efficiency in the MB photodegradation of near 49% and 44% in aqueous solution for TCPP/CuPOM/TiO₂ and TCPP/ZnPOM/TiO₂, respectively. The reusability test indicated that the porphyrin films are moderately stable after the performed cycles. Full article

Reactive oxygen species (ROS) are highly reactive oxidant molecules that can kill cancer cells through irreversible damage to biomacromolecules. ROS-mediated cancer therapies, such as chemodynamic (CDT) and photodynamic therapy (PDT), are often limited by the hypoxia tumor microenvironment (TME) with high glutathione (GSH) level. This paper reported the preparation, characterization, in vitro and in vivo antitumor bioactivity of a meso-tetra(4-carboxyphenyl)porphine (TCPP)-based therapeutic nanoplatform (CMMFTP) to overcome the limitations of TME. Using Cu²⁺ as the central ion and TCPP as the ligand, the 2D metal-organic framework Cu-TCPP was synthesized by the solvothermal method, then CMMFTP was prepared by modifying MnO₂, folic acid (FA), triphenylphosphine (TPP), and poly (allylamine hydrochloride) (PAH) on the surface of Cu-TCPP MOFs. CMMFTP was designed as a self-oxygenating ROS nanoreactor based on the PDT process of TCPP MOFs and the CDT process by Cu(II) and MnO₂ components (mainly through Fenton-like reaction). The in vitro assay suggested CMMFTP caused a 96% lethality rate against Hela cells (MTT analysis) in specific response to TME stimulation. Moreover, the Cu(II) and MnO₂ in CMMFTP efficiently depleted the glutathione (80%) in tumor cells and consequently amplified ROS levels to improve CDT/PDT effects. The FA-induced tumor targeting and TPP-induced mitochondria targeting further enhanced the antitumor activity. Therefore, the nanoreactor based on dual targeting and self-oxygenation-enhanced ROS mechanism provided a new strategy for cancer therapy. Full article

It is quite important to develop sensitive, simple, and convenient methods for the simultaneous determination of Hydroquinone (HQ) and Catechol (CC) due to their wide existence, the difficulty of degradation, and the high toxicity. Herein, Cu-TCPP nanosheets were prepared in N,N-dimethylformamide (DMF) through the solvent exfoliation method. The morphology and electrochemical performance of Cu-TCPP were characterized, revealing its stacked sheet structure with abundant pores, a fast electron transfer ability, and a large electrode active area. Using Cu-TCPP nanosheets as the sensitive material to modify the glassy carbon electrodes (Cu-TCPP/GCEs), it was found that they had an obvious enhancement effect on the electrochemical oxidation currents of HQ and CC. The signal enhancement mechanism was explored. The Cu-TCPP nanosheets not only enhanced the accumulation abilities of HQ and CC, but also improved their apparent catalytic rate, displaying high sensitivity for HQ and CC. The values of the detection limit were calculated to be 3.4 and 2.3 nM for HQ and CC. A satisfactory recovery was obtained when this method was used in measuring HQ and CC in the water samples. Full article

Highly sensitive and specific detection of biomolecular markers is of great importance to the diagnosis and treatment of related diseases. Herein, Cu-TCPP@MOFs thin films were synthesized with tetrakis(4-carboxyphenyl) porphyrin (H₂TCPP) as organic ligands and copper ions as metal nodes. The as-synthesized Cu-TCPP@MOFs thin films as electrode modifiers were used to modify the pre-treated glassy carbon electrode (GCE) and the electrochemical performances of Cu-TCPP@MOFs/GCE were evaluated by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Furthermore, as the working electrode, the constructed Cu-TCPP@MOFs/GCE was used for the investigation of ascorbic acid (AA) due to its outstanding electrocatalytic activities towards AA by several electrochemical methods, including cyclic voltammetry (CV), differential pulse voltammetry (DPV), and chronoamperometry (CA). The well-linear relationship was established based on different AA concentration ranges and the ideal detection limits (LOD) were obtained in the above-mentioned electrochemical methods, respectively. Furthermore, a Cu-TCPP MOFs@GCE sensing platform was used as a photoelectrochemical (PEC) sensor to quantitatively detect AA based on the strong absorption properties of Cu-TCPP ingredients in Cu-TCPP MOFs in a visible light band of 400~700 nm. PEC sensing platform based on Cu-TCPP@MOFs exhibited a more extensive linear concentration range, more ideal detection limit, and better sensitivity relative than the other electrochemical methods for AA. The well linear regression equations were established between the peak current intensity and AA concentrations in different electrochemical technologies, including CV, DPV, and CA, and PEC technology. AA concentration ranges applicable to various electrochemical equations were as follows: 0.45~2.10 mM of CV, 0.75~2.025 mM of DPV, 0.3~2.4 mM of CA, 7.5~480 μM of PEC, and the corresponding detection limits for AA were 1.08 μM (S/N = 3), 0.14 μM (S/N = 3), 0.049 μM (S/N = 3), and 0.084 nA/μM. Moreover, the proposed Cu-TCPP MOFs@GCE electrochemical and photoelectrochemical sensing platform was applied to determine the AA concentration of a real human serum sample; the results reveal that Cu-TCPP MOFs@GCE sensing platform could accurately determine the concentration of AA of the human serum under other potential interferences contained in the human serum samples. Full article

The photocatalytic reduction of carbon dioxide (CO₂) into CO and hydrocarbon fuels has been considered as an ideal green technology for solar-to-chemical energy conversion. The separation/transport of photoinduced charge carriers and adsorption/activation of CO₂ molecules play crucial roles in photocatalytic activity. Herein, tetrakis (4-carboxyphenyl) porphyrin (H₂TCPP) was incorporated with different metal atoms in the center of a conjugate macrocycle, forming the metalloporphyrins TCPP-M (M = Co, Ni, Cu). The as-obtained metalloporphyrin was loaded as a cocatalyst on commercial titania (P25) to form TCPP-M@P25 (M = Co, Ni, Cu) for enhanced CO₂ photoreduction. Among all of the TCPP-M@P25 (M = Co, Ni, Cu), TCPP-Cu@P25 exhibited the highest evolution rates of CO (13.6 μmol⋅g⁻¹⋅h⁻¹) and CH₄ (1.0 μmol⋅g⁻¹⋅h⁻¹), which were 35.8 times and 97.0 times those of bare P25, respectively. The enhanced photocatalytic activity could be attributed to the improved photogenerated electron-hole separation efficiency, as well as the increased adsorption/activation sites provided by the metal centers in TCPP-M (M = Co, Ni, Cu). Our study indicates that metalloporphyrin could be used as a high-efficiency cocatalyst to enhance CO₂ photoreduction activity. Full article

Antibiotics represent essential drugs to contrast the insurgence of bacterial infections in humans and animals. Their extensive use in livestock farming, including aquaculture, has improved production performances and food safety. However, their overuse can implicate a risk of water pollution and related antimicrobial resistance. Consequently, innovative strategies for successfully removing antibiotic contaminants have to be advanced to protect human health. Among them, photodegradation TiO₂-driven under solar irradiation appears not only as a promising method, but also a sustainable pathway. Hence, we evaluated several composite TiO₂ powders with H₂TCPP, CuTCPP, ZnTCPP, and SnT4 porphyrin for this scope in order to explore the effect of porphyrins sensitization on titanium dioxide. The synthesis was realized through a fully non-covalent functionalization in water at room conditions. The efficacy of obtained composite materials was also tested in photodegrading oxolinic acid and oxytetracycline in aqueous solution at micromolar concentrations. Under simulated solar irradiation, TiO₂ functionalized with CuTCPP has shown encouraging results in the removal of oxytetracycline from water, by opening the way as new approaches to struggle against antibiotic’s pollution and, finally, to represent a new valuable tool of public health. Full article