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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.

The objective of this research is to assess the breeding value of male individuals and calculate heritability values for body weight and body length at 12 months of age in the rainbow trout population in the Republic of Serbia. The study utilized data on the physical development of trout obtained through the Center for Fisheries and Applied Hydrobiology “Mali Dunav”, Experimental Estate “Radmilovac” of the Faculty of Agriculture, University of Belgrade (CEFAH) Breeding Program for rainbow trout in the Republic of Serbia. The fish were raised in individual tanks under tightly controlled conditions at the CEFAH, until they reached 5 months of age. At this point, the fish were marked (with PIT tags Norway) and transferred to commercial fish farms, where monitoring of their production results continued. To estimate the breeding value for body weight and body length of rainbow trout at 12 months of age, we analyzed data collected between 2016 and 2020, which included a total of 2014 individuals. The breeding values were estimated using a sire model. The mixed model incorporated fixed effects (spawning year and sex) and a random effect for the individual sire. The heritability estimate at 12 months of age was 0.44 for body weight, and 0.45 for body length. The breeding values were estimated for 107 sires, with body weight values ranging from −37.83 to +37.83 g and body length values ranging from −14.00 to +14.00 mm. The substantial variation observed within the studied rainbow trout population suggests the potential for further genetic improvement. The high heritability values confirm that further selection can be based on the phenotype. The inclusion of high-quality and validated males in breeding programs will contribute to the enhancement of production characteristics within the existing rainbow trout population in Serbia.

Ruthenium complexes have gained significant attention due to the ruthenium similarity to iron, lower toxicity, and higher anticancer effectiveness than other compounds. In this contribution, five new isonicotinate-polyethylene glycol ester ligands were synthesised and characterised by NMR and IR spectroscopies. The corresponding Ru(II) complexes were also obtained, and their structure was investigated by traditional methods. The optimisation of structures was performed at B3LYP/6-31+G(d,p) level of theory for H, C, N and O atoms and B3LYP/LanL2DZ for Ru. The intramolecular stabilisation interactions were assessed through the natural bond orbital approach. The NMR chemical shifts were predicted by the gauge independent atomic orbital method and compared to the experimental values. High correlation coefficients and low mean absolute errors between these data sets proved that the predicted structures described well the experimental ones. The theoretical and experimental IR spectra were also compared, and differences in the most notable bands were described. One of the ligands (L5) and complexes (5) showed fluorescent properties due to methylisatoic moiety. The electronic spectra of this compound were modelled by the time dependent-density functional theory method. The difference of 11 nm between the experimental and the theoretical wavelength was explained by the interactions between the solvent and the solute. Further biological and theoretical studies are advised for this series of compounds.

Background: Pathogen bacteria appear and survive on various surfaces made of steel or glass. The existence of these bacteria in different forms causes significant problems in healthcare facilities and society. Therefore, the surface engineering of highly potent antimicrobial coatings is highly important in the 21st century, a period that began with a series of epidemics. Methods: In this study, we prepared two types of photodynamic polyurethane-based composite films encapsulated by N-doped carbon quantum dots and graphene quantum dots irradiated by gamma rays at a dose of 50 kGy, respectively. Further, we investigated their structural, optical, antibacterial, antibiofouling and biocompatibility properties. Results: Nanoelectrical and nanomechanical microscopy measurements revealed deviations in the structure of these quantum dots and polyurethane films. The Young's modulus of elasticity of the carbon and graphene quantum dots was several times lower than that for single-walled carbon nanotubes (SWCNTs) with chirality (6,5). The electrical properties of the carbon and graphene quantum dots were quite similar to those of the SWCNTs (6,5). The polyurethane films with carbon quantum dots were much more elastic and smoother than the films with graphene quantum dots. Antibacterial tests indicated excellent antibacterial activities of these films against a wide range of tested bacteria, whereas the antibiofouling activities of both composite films showed the best results against the Staphylococcus aureus and Escherichia coli biofilms. Biocompatibility studies showed that neither composite film exhibited any cytotoxicity or hemolysis. Conclusions: Obtained results indicate that these composite films could be used as antibacterial surfaces in the healthcare facilities. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic compounds encompass a diverse array of molecules that exhibit remarkable chemical activity and play pivotal roles across various scientific domains. Coumarins represent a diverse class of heterocyclic compounds, which exhibit a wide range of significant biological and pharmacological activities, while containing at least two aromatic rings in their structure. Because chemical, biological, as well as pharmacological properties and activities are highly dependent on the structural characteristics of the molecule, in this paper a detailed structural investigation of the monocrystal structure of newly synthesized (E)-N′-(1-(2,4-dioxochroman-3-ylidene)ethyl)-3,4,5-trimethoxybenzohydrazide was performed. The DFT model that is best suited for describing the structural parameters of coumarin-benzohydrazides was determined. Out of three tested models which were previously proven to be excellent in describing structures of organic compounds, B3LYP-D3BJ was found to be the best in describing the structure of investigated coumarin derivative in regard to the obtained X-ray and spectroscopic data. Determination of the best theoretical model allows for better structural characterization of the coumarin-benzohydrazides for which monocrystals and consequently X-ray structure cannot be obtained. Finally, both experimental and computational analysis indicated (with high mutual correlation) that investigated compound showed excellent binding potential toward the albumin, indicating good distribution through the organism. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the black bullhead Ameiurus melas, an invasive alien fish (IAF) in Serbia, as a bioindicator organism and assess the safety of natural and aquaculture specimens for human consumption. A set of biomarkers was analysed to assess the bioindicator potential at a site exposed to agricultural activities. The genotoxic response was determined by an alkaline comet assay and micronucleus assay in fish erythrocytes, and the metal pollution index (MPI) was calculated to assess the toxic element burden on fish. Water quality was evaluated using physicochemical parameters and faecal indicator bacteria, while sediment was analysed for the presence of pesticides. The concentration of metals and metalloids in fish muscle was monitored to assess the safety for human consumption, and the corresponding indices (MAC, THQ, HI) were calculated. All biomarker responses were linked by the integrated biomarker response (IBR). Water analyses indicated the absence of communal wastewater, while sediment analysis revealed the presence of paclobutrazol, bifenthrin, and cyfluthrin. The IBR showed that June and September had the highest stress indices, coinciding with peak pesticide use and precipitation. All indices confirmed the safety of black bullhead for human consumption. This study highlighted the uses of nature-based solutions to the problem of IAF. [ABSTRACT FROM AUTHOR]

The fossil record of non-human primates in Serbia remains limited, with only one site—Ridjake (Riđake) in northwestern Serbia—yielding remains of fossil monkeys so far: two molars attributed to cf. Paradolichopithecus sp. discovered within a Late Pliocene assemblage. Adding to this sparse collection, we present a newly identified primate specimen from Ridjake: a well-preserved crown of a mandibular third molar (m3) designated NHMBEO 042503. The molar exhibits morphology typical of Papionini (excluding Theropithecus) but larger dimensions than Macaca. Based solely on dental size, this new specimen could belong to either of the two Eurasian Plio-Pleistocene large-bodied papionin genera—Procynocephalus and Paradolichopithecus. However, since Procynocephalus fossils are found exclusively in South and East Asia, the new molar from Ridjake is assigned to cf. Paradolichopithecus sp. in this paper. While sexual dimorphism could explain the size difference between NHMBEO 042503 and the previously described m3 from Ridjake (NHMBEO 042502), the somewhat smaller size of the Ridjake molars compared to other Paradolichopithecus records suggests they might belong to an as-yet-unknown species within this genus. Further research is needed to test this hypothesis. [ABSTRACT FROM AUTHOR]

Background: The aim of this study is to present the synthesis of two new compounds with promising antimicrobial and anti-inflammatory properties using precursors that contain pyrogallol and coumarin units. Methods: The characterization of the obtained compounds (PCHs) (E)-N′-(1-(2,4-dioxochroman-3-ylidene)ethyl)-2,3,4-trihydroxybenzohydrazide (PCH-1) and (E)-N′-(1-(2,4-dioxochroman-3-ylidene)ethyl)-3,4,5-trihydroxybenzohydrazide (PCH-2) was performed using various spectroscopic methods in combination with the DFT methods. To evaluate antimicrobial and anti-inflammatory activities, PCHs were tested against 13 different types of microorganisms and soybean lipoxygenase. To determine the specific mechanisms of anti-LOX activity, molecular docking and molecular dynamics studies were performed. Results: These compounds had the most potent antibacterial activity against the bacterium Proteus mirabilis ATCC 12453, with a MIC value of 31.125 µg/mL. In addition, three standard bacterial species were chosen to evaluate the antibiofilm activity of tested substances. The results showed that the strongest effect of PCH-2 was noticed on the biofilm formation of Staphylococcus aureus ATCC 25923 (BIC50 at 378 µg/mL). The anti-LOX results indicate that PCHs have excellent activity with the IC50 value for PCH-1 = 38.12 μM and PCH-2 = 34.12 μM. Conclusions: The obtained in vitro and in silico results confirm the strong inhibitory potential of the investigated compounds. [ABSTRACT FROM AUTHOR]

Background: The aim of this research is the synthesis and characterization of coumarin-palladium complex and the investigation of the cytotoxicity of both the ligand and the complex. Methods: The palladium(II) complex (CC) was obtained in the reaction between (E)-3-(1-((4-hydroxy-3-methoxyphenyl)amino)ethylidene)-2,4-dioxochroman-7-yl-acetate (CL) and potassium-tetrachloropalladate(II) and characterized using IR and NMR spectra, experimentally and theoretically. Cytotoxicity of CL and CC were determined for human cervical carcinoma HeLa, ovarian cancer A2780, hormone dependent breast cancer MCF7, and colorectal cancer HCT116 lines. The interaction of investigated compounds with HSA was followed by spectrofluorimetric method. The binding mechanism in the active pocket was assessed via molecular docking simulations. Results: A low mean absolute error between experimental and theoretical data proved that the optimized structure corresponded to the experimental one. Both compounds showed a satisfactory selectivity index towards neoplastic cells. The binding affinity of tested compounds to the HSA were confirmed. The molecular docking showed a much lower change in the Gibbs free energy of binding for CC compared to CL. Conclusions: The obtained results revealed that CL and CC exhibit significant effects on several cancer cell lines and good binding properties to HSA, while molecular docking discovered that CC has the most pronounced activity against alpha-fetoprotein. [ABSTRACT FROM AUTHOR]