Modulating Properties of Piroxicam,Meloxicam and Oxicam Analogues against Macrophage-Associated Chemokines in Colorectal Cancer

The mechanisms underlying the antineoplastic effects of oxicams have not been fully elucidated. We aimed to assess the effect of classic and novel oxicams on the expression/secretion of macrophage-associated chemokines (RTqPCR/Luminex xMAP) in colorectal adenocarcinoma cells, and on the expression of upstream the non-steroidal anti-inflammatory drug (NSAID)-activated genes NAG1, NFKBIA, MYD88, and RELA, as well as at the chemokine profiling in colorectal tumors. Meloxicam downregulated CCL4 9.9-fold, but otherwise the classic oxicams had a negligible/non-significant effect. Novel analogues with a thiazine ring substituted with arylpiperazine and benzoyl moieties significantly modulated chemokine expression to varying degree, upregulated NAG1 and NFKBIA, and downregulated MYD88. They inhibited CCL3 and CCL4, and their effect on CCL2 and CXCL2 depended on the dose and exposure. The propylene linker between thiazine and piperazine nitrogens and one arylpiperazine fluorine substituent characterized the most effective analogue. Only CCL19 and CXCL2 were not upregulated in tumors, nor was CXCL2 in tumor-adjacent tissue compared to normal mucosa. Compared to adjacent tissue, CCL4 and CXCL2 were upregulated, while CCL2, CCL8, and CCL19 were downregulated in tumors. Tumor CCL2 and CCL7 increased along with advancing T and CCL3, and CCL4 along with the N stage. The introduction of arylpiperazine and benzoyl moieties into the oxicam scaffold yields effective modulators of chemokine expression, which act by upregulating NAG1 and interfering with NF-κB signaling.     

Discovery of Potential,Dual-Active Histamine H3 Receptor Ligands with Combined Antioxidant Properties

In an attempt to find new dual acting histamine H₃ receptor (H₃R) ligands, we designed a series of compounds, structurally based on previously described in our group, a highly active and selective human histamine H₃ receptor (hH₃R) ligand KSK63. As a result, 15 obtained compounds show moderate hH₃R affinity, the best being the compound 17 (hH₃R K_i = 518 nM). Docking to the histamine H₃R homology model revealed two possible binding modes, with key interactions retained in both cases. In an attempt to find possible dual acting ligands, selected compounds were tested for antioxidant properties. Compound 16 (hH₃R K_i = 592 nM) showed the strongest antioxidant properties at the concentration of 10⁻⁴ mol/L. It significantly reduced the amount of free radicals presenting 50–60% of ascorbic acid activity in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, as well as showed antioxidative properties in the ferric reducing antioxidant power (FRAP) assay. Despite the yet unknown antioxidation mechanism and moderate hH₃R affinity, 16 (QD13) constitutes a starting point for the search of potential dual acting H₃R ligands-promising tools for the treatment of neurological disorders associated with increased neuronal oxidative stress.     

Comparison of Different Sorbents for Solid-Phase Extraction of Phenoxyalkanoic Acid Herbicides

An HPLC procedure for determination of phenoxyalkanoic acid herbicides in water samples is proposed. The analytical column Phenomenex C18(2) Luna 5 µm and UV detection at 225 nm were applied. Baseline resolution was achieved in isocratic mode with a mobile phase consisting of acetonitrile/acetic acid (40/60, v/v), adjusted to pH 2.5. SPE sorbents – C₁₈ BondElut, phenyl-silica, LiChrolut SAX and polymeric sorbents – were compared for isolation and preconcentration of 6 phenoxyalkanoic acid herbicides. Higher (above 95%) and more reproducible recoveries were obtained with polymeric and phenyl-silica sorbents using pure methanol for elution. The method was tested for river water samples with the limit of detection in the range of 2–3 µg L⁻¹ (for 50 mL sample) and a reproducibility of 5% RSD.     

Gas-Phase Fragmentation of Oligoproline Peptide Ions Lacking Easily Mobilizable Protons

The fragmentation of peptides containing quaternary ammonium group, but lacking easily mobilizable protons, was examined with the aid of deuterium-labeled analogs and quantum-chemical modeling. The fragmentation of oligoproline containing quaternary ammonium group involves the mobilization of hydrogens localized at α- and γ- or δ-carbon atoms in the pyrrolidine ring of proline. The study of the dissociation pattern highlights the unusual proline residue behavior during MS/MS experiments of peptides.      

Adsorption of Ni(II) from model solutions using co-precipitated inorganic oxides

The aim of this work was to obtain an inorganic oxide system containing silica and magnesium oxide, and characterized by specific physicochemical properties, in particular well-defined adsorption parameters. The preparation process was carried out according to a co-precipitation method using solutions of sodium silicate and selected inorganic magnesium salt. The oxide system obtained (MgO·SiO₂) was used as a support (adsorbent) of nickel(II) ions, whose precursors were model solutions of nitrates. The effectiveness of the adsorption process was evaluated using many different analytical techniques, including atomic absorption spectroscopy, energy dispersive X-ray spectroscopy and equivalent point titration. Moreover the stability of adsorbent/adsorbate bonding was estimated. The oxide systems—adsorbents—used in the process were also analyzed according to their physicochemical properties, especially changes in adsorption parameters. The last part of the study involved evaluation of the kinetics of the adsorption process depending on time and the pH of the reaction system.     

Synthesis and characterisation of PEG-peptide surfaces for proteolytic enzyme detection

Peptide surfaces were obtained by the covalent immobilisation of fluorescently labelled pentapeptides carboxyfluorescein–glycine–arginine–methionine–leucine–glycine, either directly or through a poly(ethylene glycol) (PEG) linker on modified silicon wafers. Each step during the preparation of the peptide surfaces was confirmed by several surface characterisation techniques. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy were used to determine the surface composition, the wafers philicity was measured by contact angle and atomic force microscopy was used to investigate the surface morphology. Exposure of the peptide surfaces to trypsin resulted in the release of a fluorescently labelled peptide product, which allowed the kinetics of the enzymatic reaction to be followed with the aid of fluorescence spectroscopy. The electrospray ionisation mass spectrometry analysis of the post-digestion solution confirmed that the pentapeptides attached to the solid support undergo specific trypsin hydrolysis at the C-terminus of the arginine residues. Detailed surface analyses before and after the enzyme action was performed using ToF-SIMS. Because of the limited accessibility of the short peptide directly attached to the surface, a quantitative yield of enzymatic hydrolysis was observed only in case when the peptide was bound through the PEG linker. The insertion of the PEG linker increased the number of immobilised peptides and the rate of enzymatic digestion which consequently improved the quality of the enzyme assays. The described approach may be used for different peptide sequences designed for other proteases.

Micro-TLC Approach for Fast Screening of Environmental Samples Derived from Surface and Sewage Waters

In this work we demonstrated analytical capability of micro-planar (micro-TLC) technique comprising one and two-dimensional (2D) separation modes to generate fingerprints of environmental samples originated from sewage and ecosystems waters. We showed that elaborated separation and detection protocols are complementary to previously invented HPLC method based on temperature-dependent inclusion chromatography and UV-DAD detection. Presented 1D and 2D micro-TLC chromatograms of SPE (solid-phase extraction) extracts were optimized for fast and low-cost screening of water samples collected from lakes and rivers located in the area of Middle Pomerania in northern part of Poland. Moreover, we studied highly organic compounds loaded in the treated and untreated sewage waters obtained from municipal wastewater treatment plant “Jamno” near Koszalin City (Poland). Analyzed environmental samples contained number of substances characterized by polarity range from estetrol to progesterone as well as chlorophyll-related dyes previously isolated and pre-purified by simple SPE protocol involving C18 cartridges. Optimization of micro-TLC separation and quantification protocols of such samples were discussed from the practical point of view using simple separation efficiency criteria including total peaks number, log(product ΔhR _F), signal intensity and peak asymmetry. Outcomes of the presented analytical approach, especially using detection involving direct fluorescence (UV366/Vis) and phosphomolybdic acid (PMA) visualization are compared with UV-DAD HPLC-generated data reported previously. Chemometric investigation based on principal components analysis revealed that SPE extracts separated by micro-TLC and detected under fluorescence and PMA visualization modes can be used for robust sample fingerprinting even after long-term storage of the extracts (up to 4 years) at subambient temperature (?20 °C). Such approach allows characterization of wide range of sample components that are present in given extract in high and middle concentration range. Due to protocol simplicity and low cost of analysis this method can be useful for preliminary sample screening.     

Stability of 47Sc-complexes with acyclic polyamino-polycarboxylate ligands

The aim of this study was to evaluate acyclic ligands which can be applied for labeling proteins such as monoclonal antibodies and their fragments with scandium radionuclides. Recently, scandium isotopes (⁴⁷Sc, ⁴⁴Sc) are more available and their properties are convenient for radiotherapy or PET imaging. They can be used together as “matched pair” in theranostic approach. Because proteins denaturize at temperature above 42 °C, ligands which efficiently form complexes at room temperature, are necessary for labelling such biomolecules. For complexation of scandium radionuclides open chain ligands DTPA, HBED, BAPTA, EGTA, TTHA and deferoxamine have been chosen. We found that the ligands studied (except HBED) form strong complexes within 10 min and that the radiolabelling yield varies between 96 and 99 %. The complexes were stable in isotonic NaCl, but stability of ⁴⁶Sc-TTHA, ⁴⁶Sc-BAPTA and ⁴⁶Sc-HBED in PBS buffer was low, due to formation by Sc³⁺stronger complexes with phosphates than with the studied ligands. From the radiolabelling studies with n.c.a. ⁴⁷Sc we can conclude that the most stable complexes are formed by the 8-dentate DTPA and EGTA ligands.     

Catalytic Oxidative Cyclocondensation of o‐Aminophenols to 2‐Amino‐3H‐phenoxazin‐3‐ones

The catalytic oxidative cyclocondensation of the o‐aminophenols 1a–f was investigated. The oxidants used were air/laccase, H₂O₂/horseradish peroxidase, H₂O₂/ebselen (3), and TBHP/diphenyl diselenide 4. The products obtained were 2‐amino‐3H‐phenoxazin‐3‐one—questiomycin A, its derivative 2b, and cinnabarinic acid and actinocin (2c,d). Substrates with methyl groups at 4 and 5 positions of benzene ring were converted to different dihydrophenoxazinones 2g,h. Compounds having chlorine atoms at the same positions underwent oxidation to planar phenoxa-zinones 2e,f with elimination of one hydrochloride molecule.