Journal of Inorganic Biochemistry最新文献

The overuse of antibiotics can lead to the development of antibiotic-resistant bacteria, which can be even more difficult to treat and pose an even greater threat to public health. In order to address the issue of antibiotic-resistant bacteria, researchers currently are exploring alternative methods of sterilization that are both effective and sustainable. Polyoxometalates (POMs), as emerging transition metal oxide compounds, exhibit significant potential in various applications due to their remarkable tunable physical and chemical performance, especially in antibacterial fields. They constitute a diverse family of inorganic clusters, characterized by a wide array of composition, structures and charges. Presently, several studies indicated that POM-based composites have garnered extensive attention in the realms of the antibacterial field and may become promising materials for future medical applications. Moreover, this review will focus on exploring the antibacterial properties and mechanisms of different kinds of organic-inorganic hybrid POMs, POM-based composites, films and hydrogels with substantial bioactivity, while POM-based composites have the dual advantages of POMs and other materials. Additionally, the potential antimicrobial mechanisms have also been discussed, mainly encompassing cell wall/membrane disruption, intracellular material leakage, heightened intracellular reactive oxygen species (ROS) levels, and depletion of glutathione (GSH). These findings open up exciting possibilities for POMs as exemplary materials in the antibacterial arena and expand their prospective applications.

A novel artificial peroxidase has been developed for the efficient degradation of the non-steroidal anti-inflammatory drug meloxicam by combining computer simulation and genetic engineering techniques. The results showed that the artificial peroxidase was able to completely degrade meloxicam within 90 s, with a degradation rate of 100 %, which was much higher than that of natural lacquer (46 %). The reaction time of the artificial enzyme was significantly shorter than that of natural peroxidase (10 min) and laccase (48 h). Further studies showed that the amino acid arrangement of the active site of the protein plays an important role in the catalytic performance. The degradation pathway of meloxicam was revealed using UPLC-MS analysis. In vitro toxicity assay showed complete disappearance of toxicity after meloxicam degradation. Therefore, the biocatalytic system proved to be an effective route for the green degradation of meloxicam with important application potential.

Two In(III) – pyridinecarboxylates ([In(Pic)₂(NO₃)(H₂O)] (InPic; HPic = picolinic acid), [In(HDpic)(Dpic)(H₂O)₂]·5H₂O (InDpic; H₂Dpic = dipicolinic acid), have been synthesized by one-step procedure. The complexes composition was confirmed by physicochemical analyses and X-ray diffraction confirmed molecular structure of both complexes. Moreover, complex species speciation was described in both systems by potentiometry and ¹H NMR spectroscopy and mononuclear complex species were determined; [In(Pic)]²⁺ (logβ₀₁₁ = 6.94(4)), [In(Pic)₂]⁺ (logβ₀₂₁ = 11.98(9)), [In(Dpic)]⁺ (logβ₀₁₁ = 10.42(6)), [In(Dpic)₂]⁻ (logβ₀₂₁ = 17.58(7)) and [In(Dpic)₂(OH)]²⁻ (logβ₋₁₂₁ = 10.18(6)). To confirm the complexes stability in 1 % DMSO, ¹H NMR spectra were measured (immediately after dissolution up to 96 h). Antimicrobial and anticancer assays indicate a more significant sensitivity of S. aureus bacteria and MDA-MB-231 cancer cells to the InPic complex (IC₅₀ = 25 and 340.7 μM) than to the InDpic (IC₅₀ = 50 and 975.4 μM). The interaction and binding mechanism of picolinic/dipicolinic acid and their indium(III) complexes with HSA (human serum albumin) were studied using fluorescence and CD spectroscopy. The results confirmed that the studied compounds had bound successfully to HSA, and the binding parameters and constants (K_SV, K_q, K_b) were calculated together with the number of binding sites. The binding forces were identified based on calculated thermodynamic parameters (ΔG, ΔH, ΔS). Synchronous spectra were used to study the microenvironment of Tyr and Trp residues and displacement assays revealed that site I was the preferred binding site. After binding, conformational changes were found to have occurred in the HSA molecule and the % α-helical content had decreased.

A series of (C^S)-cyclometallated Au(III) cationic complexes of general formula [Au(dppta)(dtc)]⁺, [Au(dppta)(azmtd)]⁺ and [Au(dppta)(azc)Cl]⁺ (dppta = N,N-diisopropyl-P,P-diphenylphosphinothioic amide-κ²C,S; dtc = dithiocarbamate-κ²S,S′; azc = azolium-2-dithiocarboxylate-κ¹S; azmdt = azol(in)ium-2-(methoxy)methanedithiol-κ²S,S′) were synthetized and tested against a panel of bacterial strains belonging to different Gram-positive and Gram-negative species of the ESKAPE group of pathogens. Among the tested compounds, complex 4c had the higher Therapeutic Index (TI) against multidrug resistant strains of S. aureus, S. epidermidis and A. baumannii, showing a more favourable cytotoxicity profile than the reference gold metalloantibiotic Auranofin.

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Cytochrome c oxidase (CcO) is the terminal enzyme in the electron transfer chain in mitochondria. It catalyzes the four-electron reduction of O₂ to H₂O and harnesses the redox energy to drive unidirectional proton translocation against a proton electrochemical gradient. A great deal of research has been conducted to comprehend the molecular properties of CcO. However, the mechanism by which the oxygen reduction reaction is coupled to proton translocation remains poorly understood. Here, we review the chemical properties of a variety of key oxygen intermediates of bovine CcO (bCcO) revealed by time-resolved resonance Raman spectroscopy and the structural features of the enzyme uncovered by serial femtosecond crystallography, an innovative technique that allows structural determination at room temperature without radiation damage. The implications of these data on the proton translocation mechanism are discussed.

This study investigated the effectiveness and safety of a hybrid thiosemicarbazone ligand (HL) and its metal complexes (Mn^II-L, Fe^III-L, Ni^II-HL, and Zn^II-HL) against epidermoid carcinoma (A-431). The results indicated that Fe^III-L is the most effective, with a high selectivity index of 8.01 and an IC₅₀ of 17.49 ± 2.12 μM for Fe^III-L. The study also revealed that the synthesized complexes effectively inhibited gene expression of the Phosphoinositide 3-kinases (PI3K), alpha serine/threonine-protein kinase (AKT1), epidermal growth factor receptor (EGFR2) axis mechanism (P < 0.0001). Additionally, these complexes trigger a chain of events that include the inhibition of proliferating cell nuclear antigen (PCNA), transforming growth factor β1 (TGF β1), and topoisomerase II, and leading to a decrease in epidermoid cell proliferation. Furthermore, the inhibitory activity also resulted in the upregulation of caspases 3 and 9, indicating the acceleration of apoptotic markers, and the down regulation of miRNA221, suggesting a decrease in epidermoid proliferation. Molecular modeling of Fe^III-L revealed that it had the best binding energy −8.02 kcal/mol and interacted with five hydrophobic π-interactions with Val270, Gln79, Leu210, and Trp80 against AKT1. Furthermore, the binding orientation of Fe^III-L with Topoisomerase II was found to be the most stable, with a binding energy −8.25 kcal/mol. This stability was attributed to the presence of five hydrophobic π-interactions with His759, Guanin13, Cytosin8, and Ala465, and numerous ionic interactions, which were more favorable than those of doxorubicin and etoposide for new regimens of chemotherapeutic activities against skin cancer.

Copper(II) complexes are very promising candidates for platinum-based anticancer agents. Herein, three Cu (II) complexes (1–3) containing 1,8-naphthalimide ligands were synthesized and characterized by FT-IR, elemental analysis, ESI-MS and single crystal X-ray diffraction (complex 3). In addition, a control compound (complex 4) without 1,8-naphthalimide ligand was synthesized and characterized. The in vitro anticancer activity of the synthesized complexes against five cancer cell lines and one normal cell line was evaluated by MTS assay. The results displayed the antitumor activity of complexes 1–3 was controlled by the aliphatic chain length of ligands, their cytotoxicity was in the order 3 > 2 > 1, giving the IC₅₀ values ranging from 2.874 ± 0.155 μM to 31.47 ± 0.29 μM against five cancer cell lines. Complex 4 showed less activity in comparison with complex 1–3. Notably, complexes 1–3 displayed much higher selectivity (SI = 2.65 to 10.16) compared to complex 4 (SI = 1.0), indicated that the introduction of 1,8-naphthalimide group not only increased the activity of this series of compounds but also enhanced their specific selectivity to cancer cells. Compound 3 induced apoptosis in cancer cells and blocked the S-phase and G2/M of cancer cells. The interaction with DNA of complexes 3 and 4 was studied by UV/Vis spectroscopic titrations, competitive DNA-binding experiment, viscometry and CD spectra. The results showed that complex 3 interacted with DNA in an intercalating mode, but the interaction mode of compound 4 with DNA was electrostatic interaction.

Herein, a series of new Ag(I)-NHC complexes containing 1,3-dioxane group were synthesized by the direct reaction of Ag₂O and benzimidazolium salts in light-free conditions. All Ag(I)-NHC complexes were spectrally characterized using ¹H, ¹³C NMR, FT-IR, LC-MS, and elemental analysis. Additionally, the structures of compounds 1a and 1e were elucidated by the single X-ray diffraction techniques. Further, the synthesized Ag(I)-NHC complexes were evaluated for cytotoxicity study on the L-929 cells and the anticancer activity against the HCT 116 and MCF-7 cancer cell lines. Notably, 1a showed significant anticancer activity against HCT 116 with an IC₅₀ of 6.37 ± 0.92 μg/mL compared to cisplatin (IC₅₀ = 36.75 ± 1.76 μg/mL). 1c (IC₅₀ = 3.21 ± 1.96 μg/mL) and 1e (IC₅₀ = 3.72 ± 1.12 μg/mL) exhibited significant anticancer activity against MCF-7 cells and was similar to cisplatin (IC₅₀ = 32.17 ± 2.85 μg/mL). Meanwhile, 1a and 1e displayed the highest selectivity index. Most importantly, the cell viability test showed that 1e induced neglectable cytotoxicity (IC₅₀ = 36.38 ± 2.27 μg/mL) toward L-929 and was similar to cisplatin (IC₅₀ = 36.11 ± 2.09 μg/mL). The anticancer activities of Ag(I)-NHC complexes vary depending on the substituent group of the silver complex and the cell line type. Moreover, the inhibitory mechanism of 1e was not dependent on caspase-associated apoptosis initiated by the lysosomal-mitochondrial pathway. Taken together, we conclude that this work provides a simple and rapid protocol for the synthesis of Ag(I)-NHC complexes and the featured Ag(I)-NHC complexes have an anticancer drug potential for biomedical applications.