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The molecular structures of six neutral copper(II) complexes with propylenediamine bridges and different terminal groups have been reported and evaluated. Different antioxidant tests were performed on these complexes. Additionally, the antibacterial and antifungal activities of the investigated compounds were assessed. The study was complemented with data on their interaction with human serum albumin (HSA) and evaluated using spectroscopic fluorescence techniques. The copper(II) complexes were found to bind to HSA at multiple sites (n = 0.82–1.72), displaying relatively high binding constants on the order of Ka = (4.8–8.8) × 104 M−1. Furthermore, binding constants calculated from microscale thermophoresis (MST) data were within the range of 1.27 × 104–1.13 × 105 M−1; these results correlated well with the above Ka values obtained by fluorimetry. Molecular docking simulations were employed to study the ability of the complexes to bind to target macromolecules, such as HSA and DNA. As a significant addition to understanding their biological behavior, an MTT assay was performed to investigate the cytotoxicity of the complexes. The antiproliferative activity of the investigated copper(II) complexes with propylenediamine ligands, along with cisplatin as a reference compound, was evaluated in two human cancer cell lines (LS-174 and MCF-7) and one normal cell line (MRC-5). The obtained results are discussed, providing the structure–activity relationship of the copper(II) complexes with Schiff base tetradentate ligands.

Aflatoxin B1 (AFB1), is a naturally hazardous environmental contaminant, contained mainly in various cereal seeds. The maize (Zea mays L.) seeds containing various levels of the AFB1 was investigated using optical and electron paramagnetic resonance spectroscopies. The changes of lignin content and organic free radicals as indicators of the seeds' defense response to the AFB1-stressor were estimated, in the seeds' inner and outer fractions. The lignin content was determined using the Acetyl Bromide method. No correlation was found between the lignin content and the AFB1 concentration in the inner fraction (R of 0.030, p = 0.943), while a significant positive linear correlation (R of 0.9923, p= 0.00005) between the lignin content and the AFB1 concentration in the outer fraction was obtained. Employing electron paramagnetic resonance (EPR) spectroscopy, the different response of the fractions was observed, regarding the content of free radicals with increasing AFB1 concentrations. In addition, front-face fluorescence spectroscopy in combination with the deconvolution showed a positive linear correlation between the ratio of the green and blue spectral emission components (C4/C2) area and the AFB1 concentration in the outer fraction. Thus lignin content and the (C4/C2) area ratio may be reliable indicators for the screening of lignin changes related to the level of AFB1 in the seeds.

This study presents a detailed characterization of 27 honey samples from the Tara Mountain region in Serbia using different comprehensive techniques and methods. The types of the honey samples were defined as monofloral (4 samples), honeydew (5 samples) and polyfloral (18 samples) honey based on determined polyphenol content, antioxidant activity, electrical conductivity and melissopalynological analyses. Physicochemical parameters such as pH (4.13–4.94), diastase activity (24.20–41.70 DN), acidity (14.60–29.70 meq/kg), content of 5-(hydroxymethyl)furfural (in range below 5, up to 16.90 mg/kg), sucrose (0.20–3.90 g/100 g), and moisture content (15.01–19.23%) confirmed the required quality of the honey samples. Sensory analysis revealed honey characteristics favorable to consumers. Analyses of 19 phenolic compounds using ultra-high-performance liquid chromatography with a diode-array detection and triple quadrupole mass spectrometry (UHPLC-DAD-MS/MS) revealed six phenolic acids and 13 other compounds from the group of flavonoids and their glycosides. In all the samples the highest content was determined for p-coumaric acid, followed by caffeic acid and pinocembrin. Besides total phenolic content and radical scavenging activity, antimicrobial activity was also examined. Most honey samples showed bactericidal activity against Staphylococcus aureus and bacteriostatic activity against Escherichia coli, while none of the honey samples inhibited the growth of Candida albicans. Chemometric analyses were applied for an in-depth study of the results to further evaluate the characteristics of the honey samples studied. Principal component analysis (PCA) was used for assessing the differences in physicochemical parameters, polyphenols content and antioxidant capacity between honey samples. The unrooted cluster tree was used to group the samples based on the melissopalynological analyses.

The influences of the application of mono- and two-component organic modifiers on lipophilicity determination of 12 tetradentate Schiff bases by reversed-phase thin layer chromatography were investigated. The main goal is to estimate types of interaction between observed compounds and components of the applied chromatographic systems and establish some behaviour pattern in order to easier choose a combination of organic modifiers which will simulate interaction in biological systems based on the facts that the same basic intermolecular interactions are responsible for the behaviour of substances in both the biological and chromatographic system. The applied organic modifier shows the ability to modify the surface of the applied sorbent, which affects the manifestation of lipophilicity of the observed compounds. Mono-component organic modifiers from different groups of the Snyder triangle were used, as well as their two-component mixtures. In addition, we compared experimentally determined calculated parameters of lipophilicity.

Background: Diazepam belongs to the group of 1,4-benzodiapines. It is used for the treatment of anxiety, convulsions and as a muscle relaxant. The presence of 4,5-azomethine group enables its electrochemical detection.Introduction: A screen-printed electrode modified with antimony film was used for the determination of diazepam in pharmaceutical preparationsMethods: Electrode modification was done by ex-situ deposition of antimony on commercially available screen-printed electrode. Parameters affecting the electroanalytical response of the sensor, such as deposition potential, deposition time, and antimony concentration, were examined and optimized. The modified electrode showed enhanced electroactivity for diazepam reduction compared to unmodified electrode. Under optimal conditions, linear sweep voltammetry was used for the determination of analyte.Results: The sensor showed linear dependence in the range from 0.5 to 10 μmol/L, the correlation coefficient was 0.9992. The limit of detection was 0.33 μmol/L, corresponding limit of quantification was 1.08 μmol/L. Modification enabled determination of diazepam in the presence of oxygen. Conclusion: The modified electrode was used for the determination of diazepam in tablets. Results confirmed the applicability of the electrochemical sensor.

The study of the chemical composition of wines is nowadays a topic of great interest because of the importance of this market, especially in Italy, and also considering the numerous cases of falsification of famous and very expensive wines. The present paper focused on the analysis of metals and polyphenols in Italian wines belonging to different provenance and types. At this purpose 20 elements were quantified by inductively coupled plasma optical emission spectrometry (ICP-OES) and ICP mass spectrometry (ICP-MS). Regarding polyphenols, a total of 32 were quantified, among 6 were anthocyanins. Furthermore, in 4 samples (1 rosè and 3 red wines) 42 anthocyanins and related compounds were identified by ultra-high performance liquid chromatography (UHPLC)-Orbitrap MS technique (among these, 6 were also quantified). Non-anthocyanins were determined using UHPLC coupled with a diode array detector and triple-quadrupole mass spectrometer (UHPLC–DAD-QqQ-MS). Total phenolic content (TPC) and radical scavenging activity (RSA) were measured using spectrophotometric methods. The results obtained by elemental techniques were submitted to principal components analysis (PCA) allowing to get information on both geographical and botanical origin of the examined wine samples. Some polyphenols have been detected in higher concentrations only in a certain type of wine, as for example in the case of Grechetto wine. Most of the identified anthocyanin derivatives (pyranoanthocyanins) are formed during the aging of wine by reaction with the other wine components.

The influences of the application of mono- and two-component organic modifiers on lipophilicity determination of 12 tetradentate Schiff bases by reversed-phase thin layer chromatography were investigated. The main goal is to estimate types of interaction between observed compounds and components of the applied chromatographic systems and establish some behaviour pattern in order to easier choose a combination of organic modifiers which will simulate interaction in biological systems based on the facts that the same basic intermolecular interactions are responsible for the behaviour of substances in both the biological and chromatographic system. The applied organic modifier shows the ability to modify the surface of the applied sorbent, which affects the manifestation of lipophilicity of the observed compounds. Mono-component organic modifiers from different groups of the Snyder triangle were used, as well as their two-component mixtures. In addition, we compared experimentally determined calculated parameters of lipophilicity.

Different Schiff base complexes have biological activities that make them suitable for drug design. The biological properties of tetradentate Schiff base copper(II) complexed with N,N′-bis(acetylacetone)propylenediimine have been studied. The cytotoxic activity towards Caco-2 cells were determined by MTT, Anexin V and PI apoptosis assays. N,N′-bis(acetylacetone)propylenediimine-copper(II) showed the anti-cancer and anti-proliferative properties by inducing apoptosis in Caco-2 cells. A comparison of the cytotoxic activity of this compound with cisplatin shows that it is more effective on the colorectal cancer cell line Caco-2. The binding capacity and interaction of N,N′-bis(acetylacetone)propylenediimine-copper(II) with HSA were systemically investigated by in vitro fluorescence spectroscopy, CD spectroscopy, and in silico molecular docking study. Furthermore, in vitro and in silico interaction studies indicated that the complex binds to HSA through a static quenching mechanism without changes in protein conformation. The calculated number of binding sites was in line with molecular docking studies. The obtained Ka value suggests that the compound can be released from the protein in target cells. The tetradentate Schiff base copper(II) complex exhibited in vitro biological activities against cancer epithelial cells, which depend on the molecular structure of the complex, causing apoptosis, and the complex can bind to the protein drug carrier in circulation to the target tissue.

This paper describes the determination of Pb and Cu with a Nafion-modified glassy carbon electrode and MnCo2O4 nanoparticles as working electrode for anodic stripping voltammetry. Pb and Cu were accumulated in HCl/KCl (0.1 mol dm-3) at a potential of -1.4 V (vs. Ag/AgCl electrode) for 480 s, followed by a linear sweep anodic stripping voltammetry (ASV) scan from -1.0 to +0.5 V. Under optimum conditions, the calibration curves were linear in the range of 0.01 - 8 and 0.01 - 5 mg dm-3 for Pb and Cu, respectively. Effect of sample dilution, accumulation time and potential were optimized. A study of interfering substances was performed. A significant increase in current was obtained at the modified electrode in comparison with the bare glassy carbon electrode. The modified electrode was successfully applied for determination of Pb and Cu in wine samples after a simple preparation procedure. Pb and Cu content in wine was used for estimation of the target hazard quotient (THQ) values for minimal and maximal levels of the metals.