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Three Schiff base Cu(II) complexes, (N,N'-bis(acetylacetone)propylenediimine) copper(II) complex, [Cu(acac2pn)] (1), (N,N'-bis-(benzoylacetone) propylenediimine)copper(II) complex, [Cu(phacac2pn)] (2) and (N,N'-bis-(trifluoroacetylacetone)propylenediimine)copper(II) complex, [Cu(tfacac2pn)] (3), were used to investigate the interactions with calf thymus DNA (ct-DNA) and bovine serum albumin (BSA) using the electronic absorption and spectroscopic fluorescence methods. UV--Vis absorption studies showed that studied complexes interact with DNA molecule and exhibit moderate binding affinity. Fluorescence studies of complexes 1-3 also showed a possibility for DNA intercalation as well as a relatively high binding ability toward BSA. Among the tested complexes, the highest affinity for DNA and BSA molecules was shown by complex 1. Cytotoxic analyses, performed on human colorectal carcinoma HCT-116 and healthy lung fibroblast MRC-5 cell lines, showed that complex 2 exhibited activity on both cell lines, while complexes 1 and 3 did not show any activity. [ABSTRACT FROM AUTHOR]

Cancer remains one of the most common diseases worldwide in terms of deaths and claims many lives every day. Transition metal complexes are candidates in the development of anticancer drugs, with cisplatin being used in chemotherapy worldwide. Copper, an endogenous metal, is known for its pronounced redox potential and nucleophilicity, especially when bound to biological molecules. Cu (II) complexes were synthesized containing ethane‐1,2‐diamine as amine moiety and pentane‐2,4‐dione and/or 1‐phenylbutane‐1,3‐dione, pentane‐2,4‐dione and/or 1,1,1‐trifluoropentane‐2,4‐dione or 1,1,1‐trifluoropentane‐2,4‐dione and/or 1‐phenylbutane‐1,3‐dione as β‐diketone moiety. Standard methods were used to confirm the structure of complexes 1–6. X‐ray crystal structure analysis characterized complex 1 containing the ligand ethane‐1,2‐diamine and pentane‐2,4‐dione. The interactions of complexes 1–6 with calf thymus DNA (ct‐DNA) were followed by electronic absorption and fluorescence spectroscopy methods and by viscosity measurements. In contrast, interaction with Salmon Sperm DNA was investigated using the electrophoretic mobility shift assay. The results indicate a moderate affinity of complexes 1–6 for binding to DNA. Gel electrophoresis also shows that the studied complexes have a concentration‐dependent interaction with DNA. Spectroscopic fluorescence techniques were used to monitor the affinity of the complexes for bovine serum albumin (BSA). Complexes 1–6 showed satisfactory binding ability for BSA. Cytotoxicity analyses were performed on the human colorectal carcinoma HCT‐116 and healthy lung fibroblast MRC‐5 cell lines, showing that complex 5 exhibited selectivity between cancer and normal cells, which is critical for drug development. [ABSTRACT FROM AUTHOR]

An analytical methodology for the simultaneous determination of seven pharmaceuticals and two metabolites belonging to the non-steroidal anti-inflammatory drugs (NSAIDs) and analgesics therapeutic groups was developed based on off-line solid-phase extraction and ultra-high performance liquid chromatography coupled to tandem mass spectrometry (SPE–UHPLC–MS/MS). Extraction conditions were optimized taking into account parameters like sorbent material, sample volume and sample pH. Method detection limits (MDLs) ranging from 0.02 to 8.18 ng/L were obtained. This methodology was successfully applied to the determination of the selected pharmaceuticals in seawater samples of Atlantic Ocean in the Northern Portuguese coast. All the pharmaceuticals have been detected in the seawater samples, with pharmaceuticals like ibuprofen, acetaminophen, ketoprofen and the metabolite hydroxyibuprofen being the most frequently detected at concentrations that can reach some hundreds of ng/L. [ABSTRACT FROM AUTHOR]

The occurrence of seven pharmaceuticals and two metabolites belonging to non-steroidal anti-inflammatory drugs and analgesics therapeutic classes was studied in seawaters. A total of 101 samples covering fourteen beaches and five cities were evaluated in order to assess the spatial distribution of pharmaceuticals among north Portuguese coast. Seawaters were selected in order to embrace different bathing water quality (excellent, good and sufficient). Acetaminophen, ketoprofen and the metabolite hydroxyibuprofen were detected in all the seawater samples at maximum concentrations of 584, 89.7 and 287 ng L − 1 , respectively. Carboxyibuprofen had the highest seawater concentration (1227 ng L − 1 ). The temporal distribution of the selected pharmaceuticals during the bathing season showed that, in general, higher concentrations were detected in August and September. The environmental risk posed by the pharmaceuticals detected in seawaters towards different trophic levels (fish, daphnids and algae) was also assessed. Only diclofenac showed hazard quotients above one for fish, representing a potential risk for aquatic organisms. These results were observed in seawaters classified as excellent bathing water. Additional data is needed in order to support the identification and prioritization of risks posed by pharmaceuticals in marine environment. [ABSTRACT FROM AUTHOR]

This study describes the effects of the substituents on electrochemical behavior and antioxidant activity of the six tetradentate Schiff bases, containing ethane-1,2-diamine or propane-1,2-diamine as the amine part and pentane-2,4-dione and/or 1-phenylbutane-1,3-dione as β-diketone, and corresponding copper(II) complexes. Cyclic voltammograms of these compounds were recorded in dimethylsulfoxide and 0.1 M sodium perchlorate as supporting electrolyte with glassy carbon as working electrode at different scan rates. The voltammograms of Schiff bases alone showed only one irreversible peak. Voltammograms recorded for complexes showed the presence of quasi-reversible processes taking place at the metal center and reversible process at the ligand part. Both steric and inductive effects of substituents and structure of imine bridge of Schiff base ligands as well as complexes were discussed. These effects appear relevant for the antioxidant activity. Antioxidant activity of the investigated compounds expressed as Trolox equivalent antioxidant capacity is also discussed. The electrochemical behavior showed a high correlation with the antioxidant activity for investigated compounds. [ABSTRACT FROM AUTHOR]

A gas-diffusion flow injection method with amperometric detection for the indirect determination of copper on a silver electrode was developed. The flow through system was equipped with two injection valves and a gas-diffusion unit. In the first step, a signal of a cyanide solution was recorded. In the subsequent step, the signal of cyanide in the presence of copper was measured. Interferences (Cd(II), Co(II), Ag(I), Ni(II), Fe(III), Hg(II) and Zn(II)) were investigated and successfully removed. The calibration graph was linear in the range 1-90 µmol dm-3 of copper with a correlation coefficient of 0.993. The regression equation is I = (0.0455±0.0015)c + (0.4611±0.0671), where I is the relative signal decrease in µA and c is concentration in µmol dm-3. Relative standard deviation for six consecutive injections of 30 µmol dm-3 copper(II) was 1.47 % and for 1 µmol dm copper(II), it was 3.40 %. The detection limit, calculated as 3 s/m (where s is a standard deviation of nine measurement of a reagent blank and m is the slope of the calibration curve), was 0.32 µmol dm-3, which corresponds to 2.44 ng of copper(II) (the loop volume was 0.12 cm³). The method enables 60 analyses per hour and it was successfully applied for the determination of copper in drinking water samples. [ABSTRACT FROM AUTHOR]

The knowledge of the structural and chemical properties of biochars is decisive for their application as technical products. For this reason, methods for the characterization of biochars that are generally applicable and allow quality control are highly desired. Several methods that have shown potential in other studies were used to investigate two activated carbons and seven biochars from different processes and feedstock. The chars were chosen to cover a wide range of chemical composition and structural properties as a hardness test for the analytical methods used in this study. Specific problems connected with the pretreatment of samples and drawbacks of some methods for some types of chars could be identified in an integrated consideration of the results from different methods. None of the spectroscopic methods was found to be suitable for the quality control of all types of chars. The most valuable results were obtained by chemical analysis that, however, required the complete determination of the main elements, including that of oxygen, and of inorganic components for adequate results. The combination of X-ray photoelectron spectroscopy (XPS) and FT-IR spectroscopy allows a rough characterization of surface functional groups, but cannot discriminate aliphatic and aromatic OH groups. FT-IR might be a suitable method for the quality control of biochars made at lower temperature. The results of Raman spectroscopy did not well correlate with the amount of sp2 hybridized carbon determined by XPS. A better correlation of XPS data was found with the electrical polarization determined by the method of spectral induced polarization that was used for the first time in conjunction with extensive analytical characterization. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In this paper, a simple, sensitive, and precise flow injection system was optimized and applied to ascorbic acid determination with a carbon paste electrode modified with the Schiff base copper complex. The modified sensor showed increased sensitivity toward ascorbic acid oxidation with a decrease of oxidation potential by 200 mV. Under optimized flow parameters, working potential, gasket thickness, sample and reaction coil volumes, and flow rate, the developed flow system gave a linear response from 5 to 75 μmol/L of ascorbic acid. The calculated limit of detection was 4.5 μmol/L, calculated as 3σ/s which corresponds to the absolute value of 40 ng for the 50 μL sample coil. The precision for six consecutive injections of 5 and 75 μmol/L ascorbic acid solutions was determined as a relative standard deviation of 5.8 % and 1.5 %, respectively. The flow injection system enabled up to 120 analyses per hour. An optimized flow system was applied to the determination of ascorbic acid in dietary supplements, after simple preparation. [ABSTRACT FROM AUTHOR]

A simple modification of bare glassy carbon electrode by electropolymerization of glycine by cyclic voltammetry was applied to the detection of ibuprofen. The polyglycine modified glassy carbon electrode was characterized by cyclic voltammetry and the electroactive surface area was determined. The study of ibuprofen in acetic acid buffer (0.25 M, pH 4.0) presented an electrocatalytic effect toward ibuprofen oxidation, increasing the current response and decrease of oxidation potential, at the modified electrode compared to the bare. Under the optimal conditions, the modified electrode gave a linear response in the ibuprofen concentration range of 10 to 200 μM, obtained correlation coefficient was 0.9993. the calculated limit of detection (3Sb/m) was 1.0 μM and the limit of quantification (10Sb/m) was 3.5 μM. the sensor was successfully used for the determination of ibuprofen in pharmaceutical preparations with satisfactory recoveries, 93–107 %. The new sensor showed good selectivity, repeatability, and reproducibility with satisfactory stability. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Papain is a proteolytic enzyme of great commercial value. It is a cysteine protease highly expressed in Carica papaya fruit latex, but also present in papaya leaves. Purification procedures mostly deal with the latex and include a combination of precipitation and/or chromatographic techniques. Due to its solubility, structure and activity characteristics, the pH and salt content play significant roles in handling papain extracts. Here we report a simple, rapid and easily scalable procedure for papain purification from papaya leaves, which contain different contaminants as compared to papaya latex. Sodium chloride precipitation of contaminants at pH 5 followed by ammonium sulphate precipitation resulted in the removal of other leaf proteins and protein fragments from papain solution and about a 3-fold purification. The procedure also benefits from the suppression of autoproteolysis and preservation of the native structure, as confirmed by FTIR analysis, and the high recovery of activity of over 80%. [ABSTRACT FROM AUTHOR]

• Chemical characterization and biological activity of 7 honey types was evaluated. • Honeydew honeys have significant antioxidant activity. • All tested honeys exhibited antibacterial activity. • Botanical and geographical origin are crucial for elemental composition. A chemical characterization and biological activity of 7 honey types (multifloral, linden, rapeseed, sunflower, phacelia, acacia and honeydew honey) from different regions of Serbia were presented. The physicochemical characteristics, mineral content, antioxidant and antimicrobial activity were estimated and discussed. All honeys showed good nutritional characteristics, according to the adopted criteria of the standard codex for honey. The concentrations of 15 elements in honey samples were determined using inductively coupled plasma optical emission spectroscopy (ICP-OES). Limits of quantification were in the range from 0.003 mg/kg (Cd, Cr, Cu, Mn, and Pb) to 1.50 mg/kg for sodium. Precision was expressed as relative standard deviation and its values were lower than 1.50%. Accuracy was evaluated with certified reference material (fish protein, DORM 4, NRC and cooking chocolate, SRM 2384, NIST) and obtained recovery percentages were 71-127%. The content of the most abundant elements (K, Mg, and Na) and microelements (Al, Cu, Fe, Mn, Ni, Se, Si, and Zn) showed a significant variability in accordance of their botanical and geographical origin, but also the influence of harvest conditions. The levels of toxic metals (As, Cd, Cr, and Pb) are much lower than the maximal allowed for these metals according to European Commission Regulation. The antioxidant activity was evaluated by DPPH (Diphenylpicrylhydrazyl) assay while antimicrobial activity against Gram positive and Gram negative bacteria (E. coli and S. aureus) and fungi Candidi albicans was estimated by microdilution assay. The free radical scavenging assay (%RSA) varies significantly among the honey samples. The highest antioxidant activity was observed with honeydew honeys (over 75% RSA) and the lowest was observed in the acacia, ranging from 22.96 to 24.57% RSA. All honeys tested in this study exhibited antibacterial activity, with inhibition of bacterial growth, generally the higher against E. coli (80% for linden honeys) than against S. aureus (mostly much lower than 50%). Activity against Candidi albicans was almost negligible. The dataset composed of all experimental results was subjected to a chemometric evaluation and cluster analysis as hierarchical nonsupervised method was applied. According to the obtained outcome of applied algorithms, both botanical and geographical origin have important role in the elemental composition, antioxidant and antimicrobial activities. [ABSTRACT FROM AUTHOR]

A new glucose biosensor for selective and sensitive determination of glucose in beverage samples was developed. A copper complex with a Schiff base, N,N'‐bis(acetylacetonato) propylenediimine, was used as a mediator. It was mixed with glucose oxidase (GOx) and prepared as carbon paste electrode (CPE). Cyclic voltammetry was used for electrochemical measurements. The biosensor showed improved sensitivity when enzyme mediator ratio was 1 : 5, and working pH was 6.6 in 0.1 M phosphate buffer. The linear response of the biosensor for glucose concentration was in the range from 0.5 to 10 mM, with low detection limit of 0.36 mM (calculated as 3 s/n) and sensitivity of 0.16 μA/mM. The reproducibility of the biosensor, calculated as relative standard deviation, was 1.9% for 6 intra‐day measurements. Biosensor was stored at +4 °C between experiments, and it was stable during 14 days after the preparation. The developed biosensor was applied on determination of glucose in commercial beverages (apple and cherry juice) and obtained results showed good agreement with the reference method. [ABSTRACT FROM AUTHOR]

The porous spinel oxide nanoparticles, MnCo2O4, were synthesized by citrate gel combustion technique. Morphology, crystallinity and Co/Mn content of modified electrode was characterized and determined by Fourier transform infra-red spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray diffraction pattern analysis (XRD), simultaneous thermogravimetry and differential thermal analysis (TG/DTA). Nanoparticles were used for modification of glassy carbon electrode (GCE) and new sensor was applied for simultaneous determination of Pb(II) and Cd(II) ions in water samples with the linear sweep anodic stripping voltammetry (LSASV).The factors such as pH, deposition potential and deposition time are optimized. Under optimal conditions the wide linear concentration range from 0.05 to 40 μmol/dm3was obtained for Pb(II), with limit of detection (LOD) of 8.06 nmol/dm3 and two linear concentration ranges were obtained for Cd(II), from 0.05 to 1.6 μmol/dm3 and from 1.6 to 40 μmol/dm3, with calculated LOD of 7.02 nmol/dm3. The selectivity of the new sensor was investigated in the presence of interfering ions. The sensor is stable and it gave reproducible results. The new sensor was succesfully applied on determination of heavy metals in natural waters. [ABSTRACT FROM AUTHOR]

This work presents the development of a flow injection system for differential pulse amperometry (DPA) for diazepam determination in the presence of oxygen. The thin flow cell consisted of the bare glassy carbon electrode, reference silver/silver chloride, and stainless steel as the auxiliary electrode. Electrochemical reduction of diazepam (DZP) was characterised by cyclic voltammetry. Azomethine reduction peak was used for DZP quantification. The detector response was linear in the range 20–250 µmol/dm3 of diazepam, with a calculated detection limit of 3.83 µg/cm3. Intraday and interday precision were 1.53 and 10.8%, respectively. The method was applied on three beverage samples, energetic drink, and two different beer samples, and obtained recoveries were from 93.65 up to 104.96%. The throughoutput of the method was up to 90 analyses per hour. [ABSTRACT FROM AUTHOR]

The biological activity of six structurally similar tetradentate Schiff base copper(II) complexes, namely [Cu(ethylenediamine-bis-acetylacetonate)] (CuAA) and five derivatives where two methyl groups are replaced by phenyl, (CuPP), CF3 (CuTT) or by mixed groups CH3/CF3 (CuAT), Ph/CF3 (CuPT), and Ph/CH3 (CuAP) has been investigated. The set of antioxidant assays was performed, and the results were expressed as IC 50 and EC 50 values. The series of complexes showed interesting bioactivity and were investigated for the determination of antioxidant, antifungal, antimicrobial, and cytotoxic activity. A significant antioxidant behavior was exhibited by complex CuAA , greater than Trolox in the Oxygen Radical Absorbance Capacity (ORAC) assay. Antibacterial assay over Gram-positive and Gram-negative pathogenic bacterial strains and some fungal pathogens were studied. Antiproliferative activity of complexes in two human tumor cell lines, breast adenocarcinoma MCF-7, colon adenocarcinoma LS-174, and normal fibroblast cells-MRC-5, examined the effect on cell cycle progression. The significant cytotoxic potential, comparable to cisplatin cytotoxicity, was determined in human breast cancer cell line-MCF-7 with IC 50 values being 17.53–31.40 μM and human colon cancer cell line-LS-174 with IC 50 values being 15.22–23.92 μM. All tested compounds showed nearly twice more selectivity toward cancer cell lines than normal cells. The interactions of complexes with human serum albumin (HSA), the most prominent protein in plasma, were investigated using spectroscopic fluorescence techniques. The complexes bind to human serum albumin at multiple sites (n = 0.2–1.9), displaying a moderate binding constant K a = 4.1–12.4 × 104 M−1. The molecular docking experiment effectively showed complex binding to HSA and DNA molecular fragments. Molecular docking simulations of copper(II) complex [Cu(ethylenediamine-bis-acetylacetonate)] and five derivatives with DNA were studied to assess their biological activity in addition to in vitro investigations. [Display omitted] • The biological activity of six Schiff base Copper(II) complexes has been investigated; • Antioxidant, antimicrobial, and cytotoxicity investigations were performed; • The Schiff base Copper(II) complexes showed good antibacterial and antifungal activity; • Relativel high binding constants show tight binding affinity to protein. [ABSTRACT FROM AUTHOR]

Cobalt(III) complexes derived from thio- and selenosemicarbazone ligands have been studied to elucidate the nature and consequences of S to Se substitution on their possible biological activity. Solid state structures of cobalt(III) complexes with bis-tridentate coordinated 2-quinolinecarboxaldehyde thio- and selenosemicarbazone were determined by single crystal X-ray diffraction analysis. The complexes were also characterized by spectroscopic methods and cyclic voltammetry. Electronic properties of the complexes were studied using DFT and TD-DFT methods. Finally, evident in vitro antioxidant activity of the complexes was demonstrated. [ABSTRACT FROM AUTHOR]

The aggregation of proteins into fibrillar, amyloid-like aggregates generally results in an improved, positive effect on various techno-functional properties within food products, such as gelation, emulsification, and foam stabilization. These highly stable structures, characterized by their repetitive, β-sheet rich motifs, may develop as the result of the thermal treatment of protein-rich food products. Heavy metal ions can influence amyloid-like aggregation of food proteins. Lead(II) and cadmium(II) represent some of the most abundant and common environmental water and food pollutants. In this work, the influence of heavy metal ions, lead and cadmium on amyloid-like aggregation of ovalbumin at high temperatures (90 °C) and under acidic conditions (pH 2.0) was investigated. Ovalbumin is used as a general model for how heavy metals can affect amyloid-like aggregation of a food protein. Structural changes were monitored via Thioflavin T and 8-Anilino-1-naphthalenesulfonic acid fluorescence, Fourier-Transform infrared spectroscopy, atomic force microscopy, dynamic light scattering, as well as computational analyses. The obtained results indicate that the added heavy metal ions bind to different sites within ovalbumin prior to thermal treatment. Lead binding sites are closer to the hydrophobic regions of an protein, while cadmium ion binding sites are more exposed. This specific binding of metal ions affects the morphologies of amyloid-like aggregates, resulting in lead-induced branching of amyloid-like fibrils, or cadmium-induced tangling of fibrils into dense amyloid clusters. This additive effect of heavy metal ions is most evident in ovalbumin samples which contain a mixture of both heavy metal ions. [Display omitted] • Ovalbumin amyloid aggregates further cluster in the presence of cadmium and lead ions. • Cadmium and lead ions preferentially bind to different sites in ovalbumin. • Lead binding induced branching and clustering of amyloid-like aggregates. • Cadmium binding results in the tangling and clustering of amyloid-like aggregates. [ABSTRACT FROM AUTHOR]

The influence of additives (alkyl polyglucoside, Glucopon 600 CS UP and alcohol ethoxylate C18E100) on the behavior of the water/toluene/Lutensol ON 50 (technical oxoalcohol, i-C10E5) microemulsion system as a function of temperature and composition has been investigated. The phase behavior of the microemulsions was determined by vertical sections through the Gibbs phase prism (fish-like phase diagrams). Alkyl polyglucoside shifts the one phase region to lower temperatures compared with water/toluene/Lutensol ON 50 mixtures. This is contrary to the expectation, considering the extreme hydrophilic nature of the sugar headgroup. The addition of hydrophilic alcohol ethoxylate (C18E100) to the water/toluene/Lutensol ON 50 system increases the solubilization capacity of the surfactant, even if the co-surfactant is used in small quantities, and shifts the one-phase region to higher temperature by a few °C. [ABSTRACT FROM AUTHOR]

Schistosomiasis is a serious disease currently estimated to affect more that 207 million people worldwide. Due to the intensive use of praziquantel, there is increasing concern about the development of drug-resistant strains. Therefore, it is necessary to search for and investigate new potential schistosomicidal compounds. This work reports the in vivo effect of the alkaloid epiisopiloturine (EPI) against adults and juvenile worms of Schistosoma mansoni. EPI was first purified its thermal behavior and theoretical solubility parameters charaterised. In the experiment, mice were treated with EPI over the 21 days post-infection with the doses of 40 and 200 mg/kg, and 45 days post-infection with single doses of 40, 100 and 300 mg/kg. The treatment with EPI at 40 mg/kg was more effective in adult worms when compared with doses of 100 and 300 mg/kg. The treatment with 40 mg/kg in adult worms reduced parasite burden significantly, lead to reduction in hepatosplenomegaly, reduced the egg burden in faeces, and decreased granuloma diameter. Scanning electron microscopy revealed morphological changes to the parasite tegument after treatment, including the loss of important features. Additionally, the in vivo treatment against juvenile with 40 mg/kg showed a reduction of the total worm burden of 50.2%. Histopathological studies were performed on liver, spleen, lung, kidney and brain and EPI was shown to have a DL50 of 8000 mg/kg. Therefore EPI shows potential to be used in schistosomiasis treatment. This is the first time that schistosomicidal in vivo activity of EPI has been reported. Author Summary: Schistosomiasis, a disease caused by worms from the genus Schistosoma, is one of the most widespread neglected tropical diseases in the world. Due to the intensive use of praziquantel, some reports of drug resistance have emerged. Thus it is important to search for new chemotherapeutic agents for the treatment disease. This research showed that epiisopiloturine, an imidazole alkaloid extracted from the leaves of Pilocarpus microphylus, has activity against S. mansoni in vivo. This material is produced as a by-product of an existing commercial process, and thus can be produced in large quantities at relatively low cost. The low toxicity and high drug tolerance in mammals shows the potential of epiisopiloturine as a new candidate schistosomicidal compound. [ABSTRACT FROM AUTHOR]

Schistosomiasis is a serious disease currently estimated to affect more that 207 million people worldwide. Due to the intensive use of praziquantel, there is increasing concern about the development of drug-resistant strains. Therefore, it is necessary to search for and investigate new potential schistosomicidal compounds. This work reports the in vivo effect of the alkaloid epiisopiloturine (EPI) against adults and juvenile worms of Schistosoma mansoni. EPI was first purified its thermal behavior and theoretical solubility parameters charaterised. In the experiment, mice were treated with EPI over the 21 days post-infection with the doses of 40 and 200 mg/kg, and 45 days post-infection with single doses of 40, 100 and 300 mg/kg. The treatment with EPI at 40 mg/kg was more effective in adult worms when compared with doses of 100 and 300 mg/kg. The treatment with 40 mg/kg in adult worms reduced parasite burden significantly, lead to reduction in hepatosplenomegaly, reduced the egg burden in faeces, and decreased granuloma diameter. Scanning electron microscopy revealed morphological changes to the parasite tegument after treatment, including the loss of important features. Additionally, the in vivo treatment against juvenile with 40 mg/kg showed a reduction of the total worm burden of 50.2%. Histopathological studies were performed on liver, spleen, lung, kidney and brain and EPI was shown to have a DL50 of 8000 mg/kg. Therefore EPI shows potential to be used in schistosomiasis treatment. This is the first time that schistosomicidal in vivo activity of EPI has been reported. [ABSTRACT FROM AUTHOR]

A method using modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) without clean-up step based on the sample dilution approach followed by the liquid chromatography coupled with the tandem mass spectrometry (LC-MS/MS) has been established for determination of 179 pesticide residues in cabbage and rice samples. Two different LC columns were used and their sensitivity was investigated regarding the sample volume. Evaluation of the matrix effect in context of sample dilution and applied extraction solvents was investigated. The method was validated according to Document SANTE/12682/2019. For cabbage samples, recoveries were 70–120% for concentration level of 5 μg/kg; and 70–115% for concentration level of 50 μg/kg; precision RSDr <17%; limits of detection and quantification were in the ranges of 0.4–5.5 and 1.2–16.7 μg/kg, respectively. For rice samples, recoveries were 70–109% for 10 μg/kg concentration; 70–115% for 100 μg/kg concentration; precision RSDr <14%, while limits of detection and quantification were in the ranges of 0.5–4.2 and 1.5–12.7 μg/kg, respectively. • Development of LC-MS/MS methodology for determination of 179 multiclass pesticides. • Modification of QuEChERS sample preparation without clean-up. • Evaluation of matrix effect on cabbage and rice samples. [ABSTRACT FROM AUTHOR]

Measurement of antithyroglobulin antibodies (TgAb) is an inevitable laboratory tool in the management of thyroid gland diseases. Currently available immunoassays still have limitations underlying the necessity of the introduction of fast, sensitive, and label-free technologies. Our aim was to develop a method for TgAb measurement in human serum based on the quartz crystal microbalance (QCM) technology. We immobilized thyroglobulin on the surface of Attana LNB Carboxyl sensor chip®, prepared standard curve covering the range of 1–50000 kIU/L, and established optimal measurement conditions. The validation included determination of the detection limit (LOD), functional sensitivity, linearity, precision, as well as the comparison with the results of the radioimmunoassay (RIA). The LOD and functional sensitivity were 4.2 kIU/L and 4.7 kIU/L, respectively. The method was linear in the range of 20–10000 kIU/L. The regression equation for comparison with RIA was C QCM = 1.0056 • C RIA – 24.2778 , whereby no significant proportional or systematic difference was present. There was a good agreement with RIA in the classification of patients according to the clinical significance of the results. The developed method has advantages over currently available assays in terms of better LOQ, a higher upper limit of linearity, and precision. The characteristics of the developed method unambiguously show that the application of the QCM biosensors offers a highly reliable novel approach for the measurement of TgAb in human serum. Image 1 • A novel QCM biosensor method for TgAb measurement is established. • Measurement results are in good correlation with the standard RIA method. • The assay shows low LOD, extended upper limit of linearity and high precision. • The method is applicable for human sera analysis. [ABSTRACT FROM AUTHOR]