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The following article discusses the antioxidant properties of mandelic acid and its hydroxy and methoxy derivatives. The antioxidant capacity of these compounds is determined by DPPH, FRAP, CUPRAC and ABTS. The mechanisms underlying the antioxidant properties are described by BDE, IP, PDE, ETE and PA calculation method values and referenced to experimental data. Thermochemistry, HOMO/LUMO energies, dipole moments, charge distribution, IR, RAMAN, NMR frequencies, binding lengths and angles were calculated using the B3LYP method and the 6-311++G(d,p) basis set. The structure of mandelic acid and its derivatives was determined experimentally using IR and RAMAN spectroscopy.

In the present work, the conducted research concerned the determination of the toxicity and oxidative stress generation of the antidepressant fluoxetine (FLU), its metabolite nor-fluoxetine (Nor-FLU), the antibiotic nalidixic acid (NA), caffeic acid (CA) and their mixtures in three different environments: microbial medium (MM), raw wastewaters (RW) and treated wastewaters (TW). We evaluated the following parameters: E. coli cell viability, toxicity and protein damage, sodA promoter induction and ROS generation. It was found that FLU, Nor-FLU, NA, CA and their mixtures are toxic and they have the potency to generate oxidative stress in E. coli strains. We also detected that the wastewater, in comparison to the microbial medium, had an influence on the toxic activity and oxidative stress synthesis of the tested chemicals and their mixtures. Regardless of the environment under study, the strongest toxic activity and oxidative stress generation were detected after bacterial incubation with NA at a concentration of 1 mg/dm3 and the mixture of FLU (1 mg/dm3) with Nor-FLU (0.1 mg/dm3) and with NA (0.1 mg/dm3). The ROS synthesis and sodA promoter induction suggest that, in the case of the examined compounds and their mixtures, oxidative stress is the mechanism of toxicity. The analysis of the types of interactions among the substances constituting the mixtures in the wastewater revealed synergism, potentiation and antagonism.

This article investigated the structure, and the spectroscopic and antimicrobial properties of mandelic acid and its alkali metal salts. The electron charge distribution and aromaticity in the analyzed molecules were investigated using molecular spectroscopy methods (FT-IR, FT-Raman, 1H NMR, and 13C NMR) and theoretical calculations (structure, NBO, HOMO, LUMO, energy descriptors, and theoretical IR and NMR spectra). The B3LYP/6-311++G(d,p) method was used in the calculations. The antimicrobial activities of mandelic acid and its salt were tested against six bacteria: Gram-positive Listeria monocytogenes ATCC 13932, Staphylococcus aureus ATCC 25923, Bacillus subtilis ATCC 6633, and Loigolactobacillus backii KKP 3566; Gram-negative Escherichia coli ATCC 25922 and Salmonella Typhimurium ATCC 14028, as well as two yeast species, Rhodotorulla mucilaginosa KKP 3560 and Candida albicans ATCC 10231.

Seven derivatives of plant-derived hydroxybenzoic acid (HBA)—including 2,3-dihydroxybenzoic (2,3-DHB, pyrocatechuic), 2,4-dihydroxybenzoic (2,4-DHB, β-resorcylic), 2,5-dihydroxybenzoic (2,5-DHB, gentisic), 2,6-dihydroxybenzoic (2,6-DHB, γ-resorcylic acid), 3,4-dihydroxybenzoic (3,4-DHB, protocatechuic), 3,5-dihydroxybenzoic (3,5-DHB, α-resorcylic), and 3,4,5-trihydroxybenzoic (3,4,5-THB, gallic) acids—were studied for their structural and biological properties. Anti-/pro-oxidant properties were evaluated by using DPPH• (2,2-diphenyl-1-picrylhydrazyl), ABTS•+ (2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), FRAP (ferric-reducing antioxidant power), CUPRAC (cupric-reducing antioxidant power), and Trolox oxidation assays. Lipophilicity was estimated by means of experimental (HPLC) and theoretical methods. The antimicrobial activity against Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Staphylococcus aureus (S. aureus), Bacillus subtilis (B. subtilis), Salmonella enteritidis (S. enteritidis), and Candida albicans&nbsp, (C. albicans) was studied. The cytotoxicity of HBAs in MCF-7 and MDA-MB-231 cell lines was estimated. Moreover, the structure of HBAs was studied by means of experimental (FTIR, 1H, and 13C NMR) and quantum chemical DFT methods (the NBO and CHelpG charges, electrostatic potential maps, and electronic parameters based on the energy of HOMO and LUMO orbitals). The aromaticity of HBA was studied based on the calculated geometric and magnetic aromaticity indices (HOMA, Aj, BAC, I6, NICS). The biological activity of hydroxybenzoic acids was discussed in relation to their geometry, the electronic charge distribution in their molecules, their lipophilicity, and their acidity. Principal component analysis (PCA) was used in the statistical analysis of the obtained data and the discussion of the dependency between the structure and activity (SAR: structure–activity relationship) of HBAs. This work provides valuable information on the potential application of hydroxybenzoic acids as bioactive components in dietary supplements, functional foods, or even drugs.

In the presented work the thermal, theoretical (DFT) and spectroscopic (IR, Raman, NMR) properties of alkali metal complexes with quinolinic acid (2,3-pyridinedicarboxylic acid) and dipicolinic acid (2,6-pyridinedicarboxylic acid) were studied. The IR and Raman spectra were registered and analyzed in the range of 400–4000 cm−1. 1H NMR and 13C NMR spectra of analyzed compounds have been registered and assigned. The electronic charge distribution for the studied acids and their salts with lithium, sodium and potassium was calculated. All the calculations were done in the frame of density functional theory (DFT) using 6-311++G(d,p) basis set. The thermal decomposition of the analyzed compounds was done. Keywords: Dipicolinic acid, Quinolinic acid, Pyridinedicarboxylic acid, Dipicolinates, Quinolinates, Alkali metal salts

The new 3d metal complexes of pyrimidine-2-carboxylic (2PCA) and pyrimidine-5-carboxylic (5PCA) acids were synthesized and characterized using thermal analysis (TG–DSC, TG–FTIR), X-ray, spectroscopic (IR, Raman) methods and theoretical (DFT) studies. In the complexes of pyrimidine-2-carboxylic acid of the general formula M(2PCA)2·xH2O (where 2PCA-pyrimidine-2-carboxylate; M = Mn(II), Co(II), Ni(II), Cu(II) and Zn; x = 0 for Mn and Cu; x = 2 for Co, Ni and Zn) coordination of metal ions occurs through nitrogen atom from pyrimidine ring and carboxylate oxygen atom. The complexes of pyrimidine-5-carboxylic acid of the general formula M(5PCA)2·xH2O (where 5PCA—pyrimidine-5-carboxylate; M = Mn(II), Co(II), Ni(II), Cu(II) and Zn; x = 6 for Cu and 4 for remaining complexes) were obtained as monomeric isostructural compounds. Coordination of metal centers occurs through two nitrogen atom from different pyrimidine-5-carboxylate ligand and four oxygen atoms from water molecules. The IR and Raman spectra of free acids as well as obtained metal(II) complexes were described in detail. Aromaticity (HOMA, EN, GEO and I6) of complexes was determined and discussed. The investigated compounds decompose in air in two main stages connected with dehydration and decomposition/burning of anhydrous compounds to the suitable metal oxides. Thermal decomposition in nitrogen leads to the evolution of water, carbon oxides, ammonia and pyrimidine molecules.

In the frame of this work complexes of selected 3d transition metals with 2,3-pyrazinedicarboxylic acid were synthesized and characterized by spectroscopic (IR, Raman) and thermal (TGA, DSC) methods. FT-IR and FT-Raman spectra of 3d metal 2,3-pyrazinedicarboxylates were recorded and analyzed in the region of 4000–400 cm−1. The structures of the three 2,3-pyridazinecarboxylic acid conformers were calculated using density functional (DFT) hybrid method B3LYP with non-local correlation provided by Lee–Young–Parr expression. All calculations were carried out with functional base 6–311++G(d,p) in Gaussian 09 package. The aromaticity indices HOMA and I6 (Bird) for diffraction structures of 2,3-pyrazinedicarboxylates and the theoretical structures of the acid conformers were calculated. Thermal properties of the complexes were studied in the temperature range of 30–900 °C. Measurements were carried out in the atmosphere of oxygen and argon. The products of dehydration and decomposition processes were determined based on TG and DSC curves. Thermal studies revealed that 2,3-pyrazinedicarboxylic acid complexes are hydrated, and upon heating decompose to metal oxides.

In the present work we compared the biological activity of mandelic acid (MA) and its Li, Na, K, Rb and Cs salts. The study also investigated the effect of raw wastewaters (RW) and treated wastewaters (TW), comparable to microbial medium (MM) on the biological activity of the tested chemical compounds used in concentrations of 5; 2.5; 1.25; 0.625; 0.3125 mg/ml. In the present experiment the evaluation of the following parameters was performed: E. coli (ATCC 25922) cells viability, growth inhibition of E. coli (ATCC 25922), the inhibition of GFP protein, genotoxicity and ROS generation. Our results showed that three main factors differentiated the antibacterial activity of MA and its Li, Na, K, Rb and Cs salts: study environment (MM, RW, TW), metal forming salt of mandelic acid and concentration of tested compounds. Additionally, raw and treated wastewater, compared to microbial medium, changes the antimicrobial activity of MA and its salts in relation to the E. coli strain. We also detected that both MA and its salts affect the GFP protein and the induction of the recA promoter (genotoxicity test). The activity of the tested salts in relation to these two parameters is strictly dependent on the type of salt-forming metal and the concentration used. The analysis of ROS synthesis suggests that in the majority of the studied mandelic acid salts, oxidative stress is the dominant mechanism of cytotoxicity and genotoxicity. We also showed that both raw wastewaters (RW) and treated wastewaters (TW), compared to microbial medium (MM), change significantly the activity of MA and its salts.

Dacarbazine, DAC, 5-(3,3-dimethyltriazeno)imidazol-4-carboxamideis is an imidazole-carboxamide derivative, that is structurally related to purines. DAC belongs to the triazene compounds, which are a group of alkylating agents with antitumour and mutagenic properties. DAC is a non-cell cycle specific drug, active on all phases of cellular cycle. In the frame of this work the 3d-metal complexes (cobalt and copper) with dacarbazine were synthesized. Their spectroscopic properties by the use of FT-IR, FT-Raman and 1HNMR were studied. The structures of dacarbazine and its complexes with copper(II) and cobalt(II) were calculated using DFT methods. The effect of metals on the electronic charge distribution of dacarbazine was discussed on the basis of calculated NBO atomic charges. The reactivity of metal complexes in relation to ligand alone was estimated on the basis of calculated energy of HOMO and LUMO orbitals. The aromaticity of imidazole ring in dacarbazine and the complexes was compared (on the basis of calculated geometric indices of aromaticity). Thermal stability of the investigated 3d-metal complexes with dacarbazine and the products of their thermal decomposition were analyzed.

Dacarbazine (DAC) 5-(3,3-dimethyl-1-triazenyl)imidazole-4-carboxamide is an imidazole-carboxamide derivative that is structurally related to purines. DAC belongs to the triazene compounds, which are a group of alkylating agents with antitumor and mutagenic properties. DAC is a non-cell cycle specific drug, active in all phases of the cellular cycle. In the frame of this work the 3d metal complexes (cobalt and copper) with dacarbazine were synthesized. Their spectroscopic properties by the use of FT-IR, FT-Raman, and 1HNMR were studied. The structures of dacarbazine and its complexes with copper(II) and cobalt(II) were calculated using DFT methods. The effect of metals on the electronic charge distribution of dacarbazine was discussed on the basis of calculated NBO atomic charges. The reactivity of metal complexes in relation to ligand alone was estimated on the basis of calculated energy of HOMO and LUMO orbitals. The aromaticity of the imidazole ring in dacarbazine and the complexes were compared (on the basis of calculated geometric indices of aromaticity). Thermal stability of the investigated 3d-metal complexes with dacarbazine and the products of their thermal decomposition were analyzed.

Natural carboxylic acids are plant-derived compounds that are known to possess biological activity. The aim of this review was to compare the effect of structural differences of the selected carboxylic acids (benzoic acid (BA), cinnamic acid (CinA), p-coumaric acid (p-CA), caffeic acid (CFA), rosmarinic acid (RA), and chicoric acid (ChA)) on the antioxidant, antimicrobial, and cytotoxic activity. The studied compounds were arranged in a logic sequence of increasing number of hydroxyl groups and conjugated bonds in order to investigate the correlations between the structure and bioactivity. A review of the literature revealed that RA exhibited the highest antioxidant activity and this property decreased in the following order: RA > CFA ~ ChA > p-CA > CinA > BA. In the case of antimicrobial properties, structure-activity relationships were not easy to observe as they depended on the microbial strain and the experimental conditions. The highest antimicrobial activity was found for CFA and CinA, while the lowest for RA. Taking into account anti-cancer properties of studied NCA, it seems that the presence of hydroxyl groups had an influence on intermolecular interactions and the cytotoxic potential of the molecules, whereas the carboxyl group participated in the chelation of endogenous transition metal ions.

Purpose: Alpha-hydroxy acids (AHAs) are one of the classes of hydroxy acids being beneficial for human health. The manuscript summarizes the biological properties of two popular members of AHAs, i.e., Mandelic Acid (MA) and Gallic Acid (GA), with particular emphasis on antimicrobial properties. Moreover, attempts to design new derivatives improving the natural properties of AHAs by using the chemical and physical approach are discussed. Methods: Antimicrobial properties of MA, an arylalkyl AHA containing phenyl group attached to α-carbon, and GA, an aromatic trihydroxybenzoic acid containing the phenolic ring and carboxylic acid functional group, and their derivatives against common human and plant pathogenic fungi have been reviewed. Results: The antimicrobial activity of MA and GA is a complex phenomenon strictly correlated with other properties exhibited by these acids, e.g., pro-oxidative activity and hydrophobicity. In most cases, the acids derivatives exhibited higher antimicrobial activity than the acids themselves. This is probably because of the higher lipophilicity of moiety that allows better penetration through the cell membrane. Conclusion: MA and GA present an excellent health-promoting tool and are valuable starting materials for the design of new compounds such as metal complexes with alkali, or alkali earth metals. The lipophilic, antimicrobial, and pro-oxidative properties act synergistically supporting the pharmacological and therapeutic effect of acids and their derivatives.

Cichoric acid (CA) is a derivative of both caffeic acid and tartaric acid. It was isolated for the first time from Cichorium intybus L. (chicory) but it also occurs in significant amounts in Echinacea, particularly E. purpurea, dandelion leaves, basil, lemon balm and in aquatic plants, including algae and sea grasses. It has a wide spectrum of biological properties, including antioxidant, antiviral, anti-inflammatory and other. The work yielded cichoric acid complexes with selected transition metals, i.e., copper(II), nickel(II), zinc(II) and cobalt(II). In this work the dependency between the molecular structure and biological activity was discussed. The molecular structure was studied by means of infrared spectroscopy (Fourier transform infrared (FT-IR) Raman (FT-Raman)), electronic absorption spectroscopy (ultraviolet–visible (UV/VIS)) and theoretical calculations (density functional theory (DFT), Hartree–Fock (HF)). Understanding the mechanism of the effect of metals on the electronic system of ligands with biological importance will facilitate in the future the search for new, effective and natural antioxidants. The composition of the studied complexes in aqueous solutions was determined at a constant pH by the Job’s method. Antioxidative properties of the tested compounds were determined using the ferric-reducing antioxidant power (FRAP), DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate free radical method), cupric-reducing antioxidant capacity (CUPRAC) and Superoxide Dismutase Activity Assay (SOD).

The aim of the study was to determine the time of mineral growth in human spine ligaments using a mathematical model. The study was based on our previous research in which the physicochemical analysis and computed microtomography measurements of deposits in ligamenta flava were performed. Hydroxyapatite-like mineral (HAP) constituted the mineral phase in ligament samples, in two samples calcium pyrophosphate dehydrate (CPPD) was confirmed. The micro-damage of collagen fibrils in the soft tissue is the crystallization center. The growth of the mineral nucleus is a result of the calcium ions deposition on the nucleus surface. Considering the calcium ions, the main component of HAP, it is possible to describe the grain growth using a diffusion model. The model calculations showed that the growth time of CPPD grains was ca. a month to 6 years, and for HAP grains &gt, 4 years for the young and &gt, 5.5 years for the elderly patients. The growth time of minerals with a radius &gt, 400 &mu, m was relatively short and impossible to identify by medical imaging techniques. The change of growth rate was the largest for HAP deposits. The mineral growth time can provide valuable information for understanding the calcification mechanism, may be helpful in future experiments, as well as useful in estimating the time of calcification appearance.

The changes in physical, chemical and biological properties of chemical compounds decide about their biological activity. In this paper the molecular structure of alkali metal 3,4-dihydroxyphenylacetates is studied in comparison to 3,4-dihydroxyphenylacetic acid (3,4-DHPAA) using FT-IR, FT-Raman and UV–Vis spectroscopy as well as density functional theory (DFT) calculations. The B3LYP/6-311++G∗∗ method is used to calculate optimized geometrical structures of studied compounds, atomic charges (Mulliken, APT, NBO), dipole moments, energies as well as the wavenumbers and intensities of the bands in vibrational spectra. Theoretical parameters are compared to the experimental data. The relationship between spectroscopic parameters of studied compounds and their biological activity is analyzed. Antioxidant activity is studied using FRAP and DPPH methods. IC50 parameter is also calculated. Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli and Klebsiella oxytoca are used in microbiological analysis of 3,4-DHPAA as well as its sodium and potassium salts. Keywords: 3,4-Dihydroxyphenylacetates, IR, UV, DFT, Biological activity

In this work, the spectroscopic (IR, Raman, UV–Vis) and thermal properties of 3d metal complexes with 4-imidazolecarboxylic acid were studied in order to determine the effect of 3d metals [i.e., Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II)] on the electronic structure and physicochemical properties of the ligand. The spectroscopic studies showed that the 3d-transition metals stabilize the electronic system of 4-imidazolecarboxylic acid. Similar results were obtained previously for benzoic and pyridinecarboxylic acids. The complexes synthesized in an aqueous medium were hydrated, as determined by the elemental and thermogravimetric analysis. The complexes of 4-imidazolecarboxylic acid have the general formula: M(C3N2H3COO)x·nH2O where M = Mn, Fe, Co, Ni, Cu, Zn, x = 3 for iron complex, x = 2 for other complex and n = 0–3. Thermogravimetric analysis conducted in oxygen atmosphere showed that the complexes decompose to metal oxides. During the thermal decomposition process carbon monoxide, carbon dioxide and imidazole ring degradation products are released.

The most important problems of anti-cancer therapy include the toxicity of the drugs applied to healthy cells and the multi-drug cells resistance to chemotherapeutics. One of the most commonly used anticancer drugs is doxorubicin (DOX) used to treat certain leukemias and non-Hodgkin’s lymphomas, as well as bladder, breast, stomach, lung, ovarian, thyroid, multiple myeloma and other cancers. Preliminary studies showed that metal complex with DOX improve its cytostatic activity with changes in their molecular structure and distribution of electrons, resulting in a substantial change of its biological activity (including antitumor activity). Thus, there is a chance to receiving derivatives of DOX with low toxicity for the healthy body cells, thus increasing its therapeutic selectivity. In the present study we examined the influence of Mn, Mg, Fe, Co and Ni, seleno- l -methionine and vitamin C on biological activity of DOX in prokaryotic model - Escherichia coli RFM443, with plasmid transcriptional fusion of recA promoter and luxCDABE as a reporter gene. Cytotoxic potency of tested chemicals was calculated on the basis of the bacteria culture growth inhibition (GI%) values. Genotoxic properties were calculated on the basis of the fold increase (FI) of relative luminescence units (RLU) values compared to control. Obtained results showed that doxorubicin metal complexes particularly with Ni, Co and Fe increased the cyto- and genotoxic activities of DOX. Bacteria culture supplemented with SeMet and vitamin C differentiate the DOX and its metal complexes toxicity. It seems, that DOX-Ni, DOX-Fe and DOX-Co complexes could be potent cytostatic drug candidates. Moreover, we noticed different sensitivity of recA::luxCDABE for 3 h and 24 h cultures of bacteria strain. It suggests, that the potency of genetic construct reactivity- recA::luxCDABE in E. coli depends on the growth-phase of bacterial culture.

Purpose The aim of this study was to examine the cytotoxic, genotoxic, antioxidant and antimicrobial activity of caffeic and rosmarinic acids and their salts with Li, Na and K with use of Escherichia coli K-12 recA:gfp strain as a model organism. Methods Cytotoxic potency of tested chemicals were calculated on the basis on the dose that confers inhibition percentage such as 20% for each concentrations of analysed chemicals. Genotoxic properties were calculated on the basis of the fold increase (FI) of SFI values normalized with control. Antioxidant potencies were established on the base of DPPH assay. Antimicrobial activity of chemicals were established on the value of minimal inhibitory concentration (MIC). Results Obtained results indicated that lower concentrations of tested compounds exhibited stronger GFP fluorescence response after rosmarinic acids and their salts treatment. Genotoxic effects seemed to be independent of the salt ions. The caffeic acid salts with Li, Na and K showed reduced genotoxic effect in comparison to the caffeic acid while increased cytotoxic effect than that of caffeic acid. Moreover, caffeinate salts exhibited better antimicrobial activity against E. coli (MIC = 250 μg/mL) than K caffeinate salt (MIC > 500 μg/mL). The MIC values of Li, Na and K rosmarinate salts were above 500 μg/mL against all tested microorganisms. Conclusion The results of the experiment show that there is no clear positive correlation between the antioxidant potency of caffeic and rosmarinic acids and their Li, Na and K salts and their cytotoxic effect. Used salts ions Li, Na and K do not significantly affect the antioxidant effect of natural phenolic compounds and they do not have a significant impact on the biological parameters such as cyto- and genotoxicity. Perhaps it is connected with the reaction environment including polarity of the solvent (water).

Cinnamic acid (CA), p-coumaric acid (4-hydroxycinnamic acid, 4-HCA), caffeic acid (3,4-vdihydroxycinnamic acid, 3,4-dHCA), and 3,4,5-trihydroxycinnamic acid (3,4,5-tHCA) were studied for their structural, anti-/pro-oxidant properties and biodegradability. The FT-IR, FT-Raman, UV/Vis, 1H and 13C NMR, and quantum chemical calculations in B3LYP/6-311++G** were performed to study the effect on number and position of hydroxyl group in the ring on the molecular structure of molecules. The antioxidant properties of the derivatives were examined using DPPH● and HO● radicals scavenging assays, ferric ion reducing antioxidant power (FRAP), cupric reducing antioxidant capacity (CUPRAC), inhibition of linoleic acid oxidation, as well as the biological antioxidant assay with Saccharomyces cerevisiae. Moreover, the pro-oxidant activity of compounds in Trolox oxidation assay was estimated. The effect of the derivatives on environment on the basis of increasing the carbon and nitrogen compounds transformation processes occurring in biological wastewater treatment was studied.

The influence of lithium, sodium, potassium, rubidium and cesium on the electronic system of the linoleic ( cis -9, cis -12-octadecadienoic) and oleic ( cis -9-octadecenoic) acids was investigated. The complementary analytical methods: vibrational (IR, Raman) and electronic (UV) molecular absorption spectroscopy as well as DFT quantum mechanical calculations (charge distribution, angles between bonds, bond lengths, theoretical IR and NMR spectra) were carried out. The regular shifts of bands connected with carboxylate anion in the spectra of studied salts were observed. Some bonds and angles reduced or elongated in the series: acid→Li→Na→K linoleates/oleinates. The highest changes were noted for bond lengths and angles concerning COO − ion. The electronic charge distribution in studied molecules was also discussed. Total atomic charges of carboxylate anion decrease as a result of the replacement of hydrogen atom with alkali metal cation. The increasing values of dipole moment and decreasing values of total energy in the order: linoleic/oleic acid→lithium→sodium→potassium linoleates/oleinates indicate an increase in stability of the compounds.

Fruits, vegetables as well as processed food products of plant origin are a rich source of beneficial for human health constituents. Among them the polyphenols constitute a large group of compounds. The presented literature survey is devoted to chlorogenic acid the most abundant representative of cinnamate acids esters. Its chemical as well as biological properties are described. © 2017 BioFactors, 43(5):621-632, 2017.

The research was conducted in the "logical series" of seven ligands: chromone, flavone, 3-hydroxyflavone, 3,7-dihydroxyflavone, galangin, kaempferol and quercetin. Each subsequent ligand differs from the previous one, among others by an additional hydroxyl group. The studied chromone derivatives are plant secondary metabolites which play an important role in growth, reproduction, and resistance to pathogens. They are important food ingredients with valuable pro-health properties. The studies of the relationships between their molecular structure and biological activity facilitate searching for new chemical compounds with important biological properties not by trial and error, but concerning the impact of specific changes in their structure on the compound properties. Therefore several pectroscopic methods (FT-IR, FT-Raman, 1H and 13C NMR) were applied to study the molecular structure of the compounds in the series. Moreover the quantum-chemical calculations at B3LYP/6-311++G** were performed to obtained the theoretical NMR spectra, NBO atomic charge, global reactivity descriptors and thermodynamic parameters. The antioxidant activity of the compounds was tested in the DPPH and FRAP assays and the mechanism of antioxidant activity was discussed based on the results on theoretical calculations. The cytotoxicity of the ligands toward human epithelial colorectal adenocarcinoma Caco2 cells was estimated and correlated with the lipophilicity of the compounds. The principal component analyses (PCA) and hierarchical cluster analysis were used to study the dependency between the molecular structure of ligands and their biological activity. The experimental data were related to the theoretical ones. The found regular changes in physicochemical properties correlated well with the systematic changes in antioxidant and biological properties.

The aim of the study was to present the possibility of the sensitivity improvement of the electronic nose (e-nose) and to summarize the detection mechanisms of trace gas concentrations. Our main area of interest is graphene, however, for the better understanding of the sensing mechanisms, it is crucial to review other sensors of similar functions. On the basis of our previous research, we explained the detection mechanism which may stay behind the graphene sensor’s sensitivity improvement. We proposed a qualitative interpretation of detection mechanisms in graphene based on the theory regarding the influence of metals and substituents on the electronic systems of carbon rings and heterocyclic aromatic ligands. The analysis of detection mechanisms suggests that an increase of the electronic density in graphene by attaching a substituent and stabilization of electronic charge distribution leads to the increase of graphene sensor conductivity. The complexation of porphyrins with selected metals stabilizes the electronic system and increases the sensitivity and selectivity of porphyrin-based sensors. Our research summary and proposed conclusions allow us to better understand the mechanisms of a radical change of graphene conductivity in the presence of trace amounts of various gases.

In the present work we compared the biological activity of DCF, 4′-OHDCF and 5-OHDCF as molecules of most biodegradation pathways of DCF and selected transformation products (2-hydroxyphenylacetic acid; 2,5-dihydroxyphenylacetic acid and 2,6-dichloroaniline) which are produced during AOPs, such as ozonation and UV/H2O2. We also examined the interaction of DCF with chlorogenic acid (CGA). CGA is commonly used in human diet and entering the environment along with waste mainly from the processing and brewing of coffee and it can be toxic for microorganisms included in activated sludge. In the present experiment the evaluation of following parameters was performed: E. coli K-12 cells viability, growth inhibition of E. coli K-12 culture, LC50 and mortality of Chironomus aprilinus, genotoxicity, sodA promoter induction and ROS generation. In addition the reactivity of E. coli SM recA:luxCDABE biosensor strain in wastewater matrices was measured. The results showed the influence of DCF, 4′-OHDCF and 5-OHDCF on E. coli K-12 cells viability and bacteria growth, comparable to AOPs by-products. The highest toxicity was observed for selected, tested AOPs by-products, in comparison to the DCF, 4′-OHDCF and 5-OHDCF. Genotoxicity assay indicated that 2,6-dichloroaniline (AOPs by-product) had the highest toxic effect. The oxidative stress assays revealed that the highest level of ROS generation and sodA promoter induction were obtained for DCF, 4′-OHDCF and 5-OHDCF, compared to other tested compounds. We have also found that there is an interaction between chlorogenic acid and DCF, which resulted in increased toxicity of the mixture of the both compounds to E. coli K-12, comparable to parent chemicals. The strongest response of E. coli SM biosensor strain with recA:luxCDABE genetic construct in filtered treated wastewaters, comparable to control sample was noticed. It indicates, that E. coli SM recA:luxCDABE biosensor strains is a good tool for bacteria monitoring in wastewater environment. Due to toxicity and biological activity of tested DCF transformation products, there is a need to use additional wastewater treatment systems for wastewater contaminated with pharmaceutical residues.

The problem of pollution in the current world is growing, however people&rsquo, s awareness of environmental protection and ecology is also increasing. The aim of the study is to present three new Schiff base compounds with Co(II/III) ions and to assess their photocatalytic activity. The study was supported by cyclic voltammetry technique. In due course the complex 2 revealed as the most effective in AR18 degradation, even more than commercially available TiO2. The search for new photocatalysts able to decompose harmful organic dyes into environmentally friendly basic substances is becoming a new trend in the area of chemistry development.

Curcumin is a natural substance known for ages, exhibiting a multidirectional effect in cancer prevention and adjuvant cancer therapies. The great advantage of using nutraceuticals of vegetable origin in comparison to popular cytostatic drugs is the minimized side effect and reduced toxicity. The targets in oncological therapy are, among others, tyrosine kinases, important mediators of signaling pathways whose impaired expression is observed in many types of cancer. Unfortunately, the hydrophobic nature of the curcumin molecule often limits its bioavailability, which is why many studies focus on the chemical modification of this compound. Current research is aimed at modifying structures that improve the pharmacokinetic parameters of curcumin, e.g. the formation of nanoparticles, complexes with metals or the synthesis of curcumin derivatives with functional substituents that allow tumor targeting. The article is a review and analysis of current literature on the properties of curcumin and its derivatives in the treatment of cancers directed to signaling pathways of tyrosine kinases and confronts the problem of low assimilation of curcumin with potential therapeutic effects.

Since the last few years, the growing interest in the use of natural and synthetic antioxidants as functional food ingredients and dietary supplements, is observed. The imbalance between the number of antioxidants and free radicals is the cause of oxidative damages of proteins, lipids, and DNA. The aim of the study was the review of recent developments in antioxidants. One of the crucial issues in food technology, medicine, and biotechnology is the excess free radicals reduction to obtain healthy food. The major problem is receiving more effective antioxidants. The study aimed to analyze the properties of efficient antioxidants and a better understanding of the molecular mechanism of antioxidant processes. Our researches and sparing literature data prove that the ligand antioxidant properties complexed by selected metals may significantly affect the free radical neutralization. According to our preliminary observation, this efficiency is improved mainly by the metals of high ion potential, e.g., Fe(III), Cr(III), Ln(III), Y(III). The complexes of delocalized electronic charge are better antioxidants. Experimental literature results of antioxidant assays, such as diphenylpicrylhydrazyl (DPPH) and ferric reducing activity power assay (FRAP), were compared to thermodynamic parameters obtained with computational methods. The mechanisms of free radicals creation were described based on the experimental literature data. Changes in HOMO energy distribution in phenolic acids with an increasing number of hydroxyl groups were observed. The antioxidant properties of flavonoids are strongly dependent on the hydroxyl group position and the catechol moiety. The number of methoxy groups in the phenolic acid molecules influences antioxidant activity. The use of synchrotron techniques in the antioxidants electronic structure analysis was proposed.

Pyrazinecarboxylic acid and its derivatives show biological properties (inter alia antimicrobial and antifungal). In the frame of this work, the salts of 2-pyrazinecarboxylic and 2,3-pyrazinedicarboxylic acids with alkali metal cations were synthesized as well as the spectroscopic (IR, Raman, NMR), theoretical [density functional theory (DFT)] and thermogravimetric studies of obtained compounds were done. The FT-IR and FT-Raman spectra of alkali metal 2-pyrazinecarboxylates and 2,3-pyrazinedicarboxylates were recorded and analyzed in the region of 4000–400 cm−1. 1H NMR and 13C NMR spectra of analyzed compounds have been registered and assigned. The electronic charge distribution for the studied acids and their salts with lithium, sodium and potassium was calculated. All the calculations were done in the frame of DFT using 6-311++G(d,p) basis set. The thermal decomposition of the analyzed compounds was done.

In our present work, we studied complexes of 3d-transition metals with pyridazine-3-carboxylic and pyridazine-4-carboxylic acids. The synthesis of manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes with pyridazinecarboxylic acids was performed. The effect of selected 3d-transition metal ions on the electronic system of ligands and the thermal properties of the complexes by the use of TG-FTIR were studied. The products of dehydration and decomposition processes of studied compounds were determined from the TG (thermogravimetric) and DSC (differential scanning calorimetry) curves. The crystal structures of manganese(II) pyridazine-3-carboxylate acid and pyridazine-4-carboxylate were analysed by the use of single-crystal X-ray analysis. The geometries, NBO atomic charges, energy of HOMO and LUMO orbitals were calculated in the B3LYP/6-311++G(d,p) level. The aromaticity of ligands and complexes were discussed on the basis of HOMA and Bird’s indices. The influence of the type of metal ion coordination and the location of the carboxylate anion in the pyridazine ring on the aromaticity of complexes were discussed. The comparison of the effect of metal ions on the electronic charge distribution and aromaticity of pyridazynecarboxylic and pyridinecarboxylic acids (i.e. nicotinic and picolinic acids) was done.

Diclofenac (DCF), a non-steroidal anti-inflammatory drug (NSAID) belongs to one of the most frequently detected pharmaceutical residues in the environment. Little is known on the interactions of DCF as well as its major biodegradation metabolites 4′-OHDCF and 5-OHDCF with chemical compounds found in wastewater, including antibiotics such as ampicillin and kanamycin. In the present work we examined the potential interactions between DCF, its metabolites 4′-OHDCF and 5-OHDCF and ampicyllin and kanamycin. We also measured the effect of the mixture of DCF with natural compound – amygdalin. We evaluated the following parameters: E. coli K-12 cells viability, growth inhibition of E. coli K-12 culture, genotoxicity, oxidative stress parameters: sodA promoter induction and ROS generation. The reactivity of E. coli SM recA:luxCDABE biosensor strain in wastewaters matrices contaminated with DCF and kanamycin was also monitored. Obtained results indicated that used antibiotics (ampicyllin, kanamycin) enhanced the toxic effect of DCF used individually and in the mixtures with its metabolites 4′-OHDCF and 5-OHDCF toward E. coli. Similar effect was also obtained in genotoxicity assay. The oxidative stress assays revealed that the highest level of ROS generation and sodA promoter induction were obtained also for the mixtures of DCF, its metabolites with antibiotics. It was also showed that amygdalin influenced the activity of DCF and its biodegradation metabolites. The strongest luminescence response of E. coli SM biosensor strain with recA:luxCDABE genetic construct in filtered treated wastewaters, comparable to control sample was noticed. Obtained results showed that DCF and its biodegradation metabolites 4′-OHDCF and 5-OHDCF can interact with tested antibiotics and compounds of natural origin, i.e. amygdalin to form mixtures showing stronger antimicrobial activity against E. coli than parent chemicals. Moreover the assays in wastewater matrices revealed that E. coli SM recA:luxCDABE biosensor strains is a good tool for bacteria monitoring in wastewater environments.

Fruits, vegetables as well as processed food products of plant origin are a rich source of beneficial for human health constituents. Among them the polyphenols constitute a large group of compounds. The presented literature survey is devoted to chlorogenic acid the most abundant representative of cinnamate acids esters. Its chemical as well as biological properties are described. © 2017 BioFactors, 43(5):621-632, 2017.

Pyrazine-2-carboxylic acid (2-PC) and 3d transition metal pyrazine-2-carboxylates (2-PCA) were characterized by means of X-ray, spectroscopic (Raman, FTIR) and thermogravimetric analysis. X-ray diffraction data were collected at 100 K and the crystal structures were solved and refined. The general formula of the copper(II), manganese(II), nickel(II), zinc(II) and cobalt(II) pyrazine-2-carboxylates was [M(2-PCA)2(H2O)2] (where M is a metal). The cobalt(II), nickel(II), copper(II) and zinc(II) complexes crystallize in the space group P21/c, in the monoclinic crystal system The manganese(II) complex crystallizes in the space group F2dd in the orthorhombic crystal system. The coordination sphere around the metal cations can be described as octahedral, however in the case of the Cu(II) complex, the octahedral geometry is distorted in the axial direction, which is caused by the Jahn–Teller effect. The products of dehydration and decomposition processes of the studied compounds were determined from the TG (thermogravimetric) and DSC (differential scanning calorimetry) curves. The theoretical structures and the IR spectra of pyrazine-2-carboxylic acid and the manganese(II) complex were calculated at the B3LYP/6-311++G(d,p) level of theory. The aromaticity indices (HOMA, I6) were calculated for 2-PC and [M(2-PCA)2(H2O)2]2 on the basis of the theoretical bond lengths in the aromatic ring. The influence of the 3d-metals on the aromatic system of pyrazine-2-carboxylic acid is discussed. 2-PC acid complexes with transition 3d-metals show a very weak antimicrobial effect, as no inhibition of bacterial and fungal growth was noted up to 10 mg/mL.

In this work the influence of lithium, sodium, potassium, rubidium and cesium on the electronic system of the syringic acid (4-hydroxy-3,5-dimethoxybenzoic acid) was studied. This paper presents spectroscopic vibrations (FT-IR, FT-Raman) and NMR ((1)H and (13)C) study of the series of alkali metal syringates from lithium to cesium syringates. Characteristic shifts of band wavenumbers and changes in band intensities along the metal series were observed. Optimized geometrical structures of the studied compounds were calculated by the B3LYP method using the 6-311++G(**) basis set. Aromaticity indices, atomic charges, dipole moments and energies were also calculated. The theoretical wavenumbers and intensities of IR and NMR spectra were obtained. The calculated parameters were compared to experimental characteristics of studied compounds.

The influence of lithium, sodium, potassium, rubidium and cesium cations on the electronic system of phenylacetic acid was studied. The FT-IR, FT-Raman and 1H and 13C NMR spectra were recorded for studied compounds. Characteristic shifts in IR and NMR spectra along alkali metal phenylacetates were observed. Good correlations between the wavenumbers of the vibrational bands in the IR spectra of phenylacetates and some alkali metal parameters such as ionic potential, electronegativity, inverse of atomic mass, atomic radius and ionization energy were found. The density functional hybrid method B3LYP with 6-311++G** basis set was used to calculate optimized geometrical structures of studied compounds. Aromaticity indices, atomic charges, dipole moments and energies were calculated as well as the wavenumbers and intensities of IR spectra and chemical shifts in NMR spectra. The theoretical parameters were compared to experimental characteristic of alkali metal phenylacetates.

Benzoic (BA), p -hydroxybenzoic (HBA), m -methoxybenzoic (MBA), vanillic (VA) and syringic (SGA) acids were studied using both experimental and theoretical tools. The vibrational (FT-IR, FT-Raman) and 1 H and 13 C NMR spectra of benzoic acid derivatives were recorded. Characteristic shifts and changes in intensities of bands along the studied series were observed. The changes of chemical shifts of protons ( 1 H NMR) and carbons ( 13 C NMR) in the series of studied compounds were observed too. Optimized geometrical structures of studied compounds were obtained by B3LYP method using 6-31++G ** , 6-311+G ** and 6-311++G ** basis sets. Aromaticity indices, atomic charges, dipole moments and energies were calculated. The theoretical chemical shifts in 1 H and 13 C NMR spectra and theoretical wavenumbers and intensities of IR and Raman spectra were determined. The calculated parameters were compared to experimental characteristic of studied compounds.

The influence of alkaline earth metal ions on the electronic system of 4-nitrobenzoic acid was studied in this paper. The vibrational (FT-IR) and NMR ( 1 H and 13 C) spectra were recorded for 4-nitrobenzoic acid (4-nba) and its salts (4-nb). The assignment of vibrational spectra was done. Some shifts of band wavenumbers in alkaline earth metal 4-nitrobenzoates spectra were observed in the series from magnesium to barium salts. Good correlations between wavenumbers of the vibrational bands in the IR spectra of studied salts and ionic potential, electronegativity, inverse of atomic mass, ionic radius and ionization energy of studied metals were found. The regular changes in the chemical shifts of protons ( 1 H NMR) and carbons ( 13 C NMR) in the series of studied salts were also observed. Optimized geometrical structures of studied compounds were calculated by B3LYP method using 6-311++G ** as well as LANL2DZ basis sets. Theoretical wavenumbers and intensities in IR and chemical shifts in NMR spectra were also obtained. The calculated parameters were compared with experimental data of studied compounds.

In this paper we investigate the relationship between molecular structure of alkali metal vanillate molecules and their antimicrobial activity. To this end FT-IR, FT-Raman, UV absorption and (1)H, (13)C NMR spectra for lithium, sodium, potassium, rubidium and caesium vanillates in solid state were registered, assigned and analyzed. Microbial activity of studied compounds was tested against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Proteus vulgaris, Bacillus subtilis and Candida albicans. In order to evaluate the dependence between chemical structure and biological activity of alkali metal vanillates the statistical analysis was performed for selected wavenumbers from FT-IR spectra and parameters describing microbial activity of vanillates. The geometrical structures of the compounds studied were optimized and the structural characteristics were determined by density functional theory (DFT) using at B3LYP method with 6-311++G** as basis set. The obtained statistical equations show the existence of correlation between molecular structure of vanillates and their biological properties.