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In the present manuscript, three different 4,7-dihydroxycoumarin derivatives were prepared and structurally characterized by crystallographic and spectroscopic techniques in combination with the B3LYP-D3BJ theoretical method. Cytotoxic and antimicrobial activities of investigated compounds were screened against different cell lines and microorganisms. HCT-116 cells were most sensitive to the 3-(1-(2-hydroxyphenyl)amino) ethylidene)-2,4-dioxochroman-7-yl acetate derivative, while the best antimicrobial activity against Bacillus subtilis ATCC 6633 was shown by 3-(1-(2-hydroxyphenyl)amino)ethylidene)-2,4-dioxochroman-7-yl acetate. The molecular docking study for all compounds with important epidermal growth factor receptors (EGFR) was performed. The results indicate that the largest contribution to the binding energy is through conventional hydrogen bonds.

Nowadays, bacteria resistance to many antibiotics is a huge problem, especially in clinics and other parts of the healthcare system. This critical health issue requires a dynamic approach to produce new types of antibacterial coatings to combat various pathogen microbes. In this research, we prepared a new type of carbon quantum dots based on phloroglucinol using the bottom-up method. Polyurethane composite films were produced using the swell–encapsulation–shrink method. Detailed electrostatic force and viscoelastic microscopy of carbon quantum dots revealed inhomogeneous structure characterized by electron-rich/soft and electron-poor/hard regions. The uncommon photoluminescence spectrum of carbon quantum dots core had a multipeak structure. Several tests confirmed that carbon quantum dots and composite films produced singlet oxygen. Antibacterial and antibiofouling efficiency of composite films was tested on eight bacteria strains and three bacteria biofilms. [ABSTRACT FROM AUTHOR]

This aimed to develop a comprehensive theoretical protocol for examining substitution reaction processes. The researchers used a theoretical quantum-mechanical protocol based on the QM-ORSA approach, which estimates the kinetic parameters of thermodynamically favourable reaction pathways. This theoretical protocol was validated by experimentally investigating substitution mechanisms in two previously synthesised Pd(II) complexes: chlorido-[(3-(1-(2-hydroxypropylamino)ethylidene)chroman-2,4-dione)]palladium(II) (C1) and chlorido-[(3-(1-(2-mercaptoethylamino)-ethylidene)-chroman-2,4dione)]palladium(II) (C2), along with biologically relevant nucleophiles, namely L -cysteine (L -Cys), L -methionine (L -Met), and guanosine-5′-monophosphate (5′-GMP). Reactions were investigated under pseudo-first-order conditions, monitoring nucleophile concentration and temperature changes using stopped-flow UV-vis spectrophotometry. All reactions were conducted under physiological conditions (pH = 7.2) at 37 °C. The reactivity of the studied nucleophiles follows the order: L -Cys > L -Met > 5′-GMP, and the reaction mechanism is associative based on the activation parameters. The experimental and theoretical data showed that C2 is more reactive than C1, confirming that the complexes' structural and electronic properties greatly affect their reactivity with selected nucleophiles. The study's findings have confirmed that the primary interaction occurs with the acid–base species L -Cys, mostly through the involvement of the partially negative sulfur atom (87.2%). On the other hand, C2 has a higher propensity for reacting with L -Cys−, primarily through the partially negative oxygen atom (92.6%). The implementation of this theoretical framework will significantly restrict the utilization of chemical substances, hence facilitating cost reduction and environmental protection. [ABSTRACT FROM AUTHOR]

Three newly synthesized triphenyltin(IV) compounds, Ph3SnL1 (L1− = 3-(4-methyl-2-oxoquinolin-1(2H)-yl)propanoato), Ph3SnL2 (L2− = 2-(4-methyl-2-oxoquinolin-1(2H)-yl)ethanoato), and Ph3SnL3 (L3− = 2-(4-hydroxy-2-oxoquinolin-1(2H)-yl)ethanoato), were characterized by elemental microanalysis, FT-IR spectroscopy and multinuclear (1H, 13C and 119Sn) NMR spectroscopy. A single X-ray diffraction study indicates that compounds Ph3SnL1 and Ph3SnL2 exhibit a 1D zig-zag chain polymeric structure, which in the case of Ph3SnL2 is additionally stabilized by π-interactions. In addition, the synthesized compounds were further examined using density functional theory and natural bond orbital analysis. The compounds have been evaluated for their in vitro anticancer activity against three human cell lines: MCF-7 (breast adenocarcinoma), A375 (melanoma), HCT116 (colorectal carcinoma), and three murine cell lines: 4T1 (breast carcinoma), B16 (melanoma), CT26 (colon carcinoma) using MTT and CV assays. The IC50 values fall in the nanomolar range, indicating that these compounds possess better anticancer activity than cisplatin. The study of the effect of the newly developed drug Ph3SnL1 showed its plasticity in achieving an antitumor effect in vitro, which depends on the specificity of the phenotype and the redox status of the malignant cell line and ranges from the initiation of apoptotic cell death to the induction of differentiation to a more mature cell form. In the syngeneic model of murine melanoma, Ph3SnL1 showed the potential to reduce the tumor volume similar to cisplatin, but in a well-tolerated form and with low systemic toxicity, representing a significant advantage over the conventional drug. [ABSTRACT FROM AUTHOR]

Ru(II)‐arene compounds are being investigated as anticancer agents due to the biocompatibility of ruthenium and their structural diversity. Two newly synthesized Ru(II) complexes, [RuCl(η6‐p‐cymene)(3‐DNPH)] (chlorido(η6‐p‐cymene)(3‐nitrophenylhydrazine‐k2N,N′)ruthenium(II)) (1) and [RuCl(η6‐p‐cymene)(3‐CNPH)] (chlorido(3‐chlorophenylhydrazine‐k2N,N′)(η6‐p‐cymene)ruthenium(II)) (2), are experimentally (IR, NMR) and theoretically (B3LYP/6‐31+G(d,p)(H,C,N,Cl)/LanL2DZ(Ru)) characterized. Experimental and theoretical values of 1H and 13C chemical shifts and position of the most intense vibrational bands showed high correlation coefficients and low mean absolute errors, proving the predicted structure and applicability of the selected level of theory. Cell viability studies performed on MDA‐MB‐468, BT‐474, and PC3 cells using MTT and CV assay indicated the activity of the second complex similar to the activity of cisplatin towards BT‐474 breast cancer cells. The spectrofluorimetric measurements of Bovine Serum Albumin showed the binding process's spontaneity of complexes and protein, with a binding energy of around −30 kJ mol−1. Detailed molecular docking analysis allowed the elucidation of the binding mechanism through specific intermolecular interactions. Both compounds showed a higher affinity towards BSA than naproxen and cisplatin. Molecular docking simulations proved the spontaneity of the complexes binding to DNA. Based on these promising results, further biological examinations of these compounds are advised. [ABSTRACT FROM AUTHOR]

Fish are the most commonly cultivated vertebrates in the world. They respond to stress like other vertebrates, and they can feel pain, fear and suffering. These facts are the basis for considering their welfare. The question of formal protection of fish welfare is becoming more relevant with the significant development of aquaculture in the last few decades. However, fish welfare protection is encountering difficulties. Like many terrestrial farm animals, farmed fish are often subjected to poor living conditions and cruelty. Harvesting, transport, and stunning and killing are the most significant welfare issues. This review describes some of the most important procedures that compromise animal welfare during fish farming and the negative effects these procedures have on the fish. It also gives a brief overview of the situation in Serbia in terms of research into fish welfare, public attitudes on this issue, and the state of legislation. Data presented in this paper indicate the need for more effective protection of fish welfare in the legal and executive aspects.

Carbon nanoparticles are a class of materials with extraordinary properties. In the past three decades, four major types of carbon nanoparticles were synthesized and investigated: fullerenes, carbon nanotubes, graphene and carbon quantum dots. One of the main properties of such materials is their hydrophobic nature. At the same time, Langmuir–Blodgett (LB) method the for deposition of thin films of hydrophobic materials provides the possibility to design thin films of different carbon-based nanoparticles with special architectures and features enabling their usage in various fields, particularly in electronics and biomedicine. In this review, the state of art of LB thin films of four types of carbon-based nanoparticles and their application in electronics and biomedicine are presented. The breakthrough in this field was finally achieved by application of carbon quantum dots soluble in solvents optimized for LB deposition. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172003]