Reactions and structural characterization of gold(III) complexes with amino acids, peptides and proteins

The present review article highlights recent findings in the field of gold(III) complexes with amino acids, peptides and proteins. The first section of this article provides an overview of the gold(III) reactions with amino acids, such as glycine, alanine, histidine, cysteine and methionine. The second part of the review is mainly focused on the results achieved in the mechanistic studies of the reactions between gold(III) and different peptides and structural characterization of gold(III)-peptide complexes as the final products in these reactions. The last section of this article deals with the reactions of gold(III) complexes with proteins as primary targets for cytotoxic gold compounds. Systematic summaries of these results contribute to the future development of gold(III) complexes as potential antitumor agents and also have importance in relation to the severe toxicity of gold-based drugs.     

Fluorescence Imaging of Heat-Stress Induced Mitochondrial Long-Term Depolarization in Breast Cancer Cells

Various thermotherapies are based on the induction of lethal heat in target tissues. Spatial and temporal instabilities of elevated temperatures induced in therapy targets require optimized treatment protocols and reliable temperature control methods during thermotherapies. Heat-stress induced effects on mitochondrial transmembrane potentials were analyzed in breast cancer cells, species MX1, using the potential sensor JC-1 (Molecular Probes, Invitrogen, Germany). Potential dependant labeling of heat-stressed cells was imaged and evaluated by fluorescence microscopy and compared with control cells. JC-1 stains mitochondria in cells with high mitochondrial potentials by forming orange-red fluorescent J-aggregates while in cells with depolarized or damaged mitochondria the sensor dye exists as green fluorescent monomers. In MX1 cells orange-red and green fluorescence intensities were correlated with each other after various heat-stress treatments and states of mitochondrial membrane potentials were deduced from the image data. With increasing stress temperatures the intensity of red fluorescent J-aggregates decreased while the green fluorescence intensity of JC-1 monomers increased. This heat-stress response happened in a nonlinear manner with increasing temperatures resulting in a nonlinear increase of red/green fluorescence ratios. These data indicated that mitochondria in MX1 cells were increasingly depolarized in response to increasing ambient temperatures.     

Asymptotic dynamics of a deterministic and stochastic predator–prey model with disease in the prey species

In this paper, we discuss a predator–prey model with the Beddington–DeAngelis functional response of predators and a disease in the prey species. At first we study permanence and global stability of a positive equilibrium for the deterministic version of the model. Then we include a stochastic perturbation of the white noise type. We analyse the influence of this stochastic perturbation on the systems and prove that the positive equilibrium is also globally asymptotically stable in this case. The key point of our analysis is to choose appropriate Lyapunov functionals. We point out the differences between the deterministic and stochastic versions of the model. Copyright © 2013 John Wiley & Sons, Ltd.     

CO2 Sorbents Based on Spherical Carbon and Photoactive Metal Oxides: Insight into Adsorption Capacity,Selectivity and Regenerability

This work aimed to obtain hybrid composites based on photoactive metal oxide and carbon having adsorption properties. The materials, composed of titanium dioxide or zinc oxide and spherical carbon, were obtained from resorcinol-formaldehyde resin, treated in a solvothermal reactor heated with microwaves and then subjected to carbonization, were received. The functional groups of pure carbon spheres (unsaturated stretching C=C, stretching C−OH and C−H bending vibrations), CS/ZnO and CS/TiO₂ samples were determined by FT-IR analysis. The characteristic bands for ZnO and TiO₂ were observed below 1000 cm⁻¹. The thermal oxidative properties are similar for TiO₂- and ZnO-modified carbon spheres. We have observed that the increased carbon sphere content in nanocomposites results in starting the decomposition process at a lower temperature, therefore, nanocomposites have a broader combustion temperature range. The effect of the oxides’ addition to carbon spheres on their adsorption properties was evaluated in detail by examining CO₂ adsorption from the gas phase. The selectivity of CO₂ over N₂ at a temperature of 25 °C and pressure of 1 bar (a novelty in testing CS-based sorbents) calculated for 3.00 CS/TiO₂ and 4.00 CS/ZnO was 15.09 and 16.95, respectively. These nanocomposites exhibit excellent cyclic stability checked over 10 consecutive adsorption–desorption cycles.     

[99mTc]Tc-PSMA-T4—Novel SPECT Tracer for Metastatic PCa: From Bench to Clinic

Despite significant advances in nuclear medicine for diagnosing and treating prostate cancer (PCa), research into new ligands with increasingly better biological properties is still ongoing. Prostate-specific membrane antigen (PSMA) ligands show great potential as radioisotope carriers for the diagnosis and therapy of patients with metastatic PCa. PSMA is expressed in most types of prostate cancer, and its expression is increased in poorly differentiated, metastatic, and hormone-refractory cancers; therefore, it may be a valuable target for the development of radiopharmaceuticals and radioligands, such as urea PSMA inhibitors, for the precise diagnosis, staging, and treatment of prostate cancer. Four developed PSMA-HYNIC inhibitors for technetium-99m labeling and subsequent diagnosis were subjected to preclinical in vitro and in vivo studies to evaluate and compare their diagnostic properties. Among the studied compounds, the PSMA-T4 (Glu-CO-Lys-L-Trp-4-Amc-HYNIC) inhibitor showed the best biological properties for the diagnosis of PCa metastases. [^99mTc]Tc-PSMA-T4 also showed effectiveness in single-photon emission computed tomography (SPECT) studies in humans, and soon, its usefulness will be extensively evaluated in phase 2/3 clinical trials.     

Pasta Enriched with Dried and Powdered Leek: Physicochemical Properties and Changes during Cooking

Food enrichment is commonly applied to increase the pro-health and dietary value of final products. This study aimed to evaluate how green leek powder (GL) added to semolina influenced the physicochemical, sensory, and cooking characteristics of the pasta. The pasta was prepared by partially substituting semolina with 0, 1, 2, 3, 4, and 5 g/100 g of GL. Then, the pasta samples were assessed for color, cooking properties, sensory features, mechanical properties, total phenolic content (TPC), and antioxidant activity (AA). The results indicated that GL significantly decreased the lightness and increased the yellowness of cooked pasta. The total color difference between the control pasta and enriched pasta samples ranged from 2.54 to 6.89 and 5.60 to 11.06 (for uncooked and cooked pasta, respectively). The addition of GL also caused an increase in the optimal cooking time and cooking loss. Moreover, a significant increase in stretching force was observed in cooked pasta. Sensory evaluation revealed that substitution of semolina with up to 2 g/100 g GL did not affect the smell, taste, and color of pasta. Most importantly, GL-enriched pasta was characterized by higher TPC and higher AA compared to the control samples. In summary, our results recommend partial replacement of semolina by GL (up to 3 g/100 g) in pasta production.     

Milk Proteins—Their Biological Activities and Use in Cosmetics and Dermatology

Milk and colostrum have high biological potential, and due to their natural origin and non-toxicity, they have many uses in cosmetics and dermatology. Research is ongoing on their potential application in other fields of medicine, but there are still few results; most of the published ones are included in this review. These natural products are especially rich in proteins, such as casein, β-lactoglobulin, α-lactalbumin, lactoferrin, immunoglobulins, lactoperoxidase, lysozyme, and growth factors, and possess various antibacterial, antifungal, antiviral, anticancer, antioxidant, immunomodulatory properties, etc. This review describes the physico-chemical properties of milk and colostrum proteins and the natural functions they perform in the body and compares their composition between animal species (cows, goats, and sheep). The milk- and colostrum-based products can be used in dietary supplementation and for performing immunomodulatory functions; they can enhance the effects of certain drugs and can have a lethal effect on pathogenic microorganisms. Milk products are widely used in the treatment of dermatological diseases for promoting the healing of chronic wounds, hastening tissue regeneration, and the treatment of acne vulgaris or plaque psoriasis. They are also increasingly regarded as active ingredients that can improve the condition of the skin by reducing the number of acne lesions and blackheads, regulating sebum secretion, ameliorating inflammatory changes as well as bestowing a range of moisturizing, protective, toning, smoothing, anti-irritation, whitening, soothing, and antiaging effects.     

Cellular Mechanistic Considerations on Cytotoxic Mode of Action of Phosphino Ru(II) and Ir(III) Complexes

Two piano-stool ruthenium(II) complexes Ru(η⁶-p-cymene)Cl₂PPh₂CH₂OH ( RuPOH ) and Ru(η⁶-p-cymene)Cl₂P(p-OCH₃Ph)₂CH₂OH ( RuMPOH ) and two half-sandwich iridium(III) complexes Ir(η ⁵-Cp*)Cl₂PPh₂CH₂OH ( IrPOH ) and Ir(η ⁵-Cp*)Cl₂P(p-OCH₃Ph)₂CH₂OH ( IrMPOH ) have been studied in terms of potential anticancer activity on previously selected cell line (human lung adenocarcinoma). Based on experimental results obtained in monoculture in vitro model mechanistic considerations on the possible cellular modes of action have been carried out. ICP-MS analysis revealed the higher cellular uptake for less hydrophobic Ir(III) complexes in comparison to the corresponding Ru(II) compounds. Cytometric analysis showed a predominance of apoptosis over the other types of cell death for all complexes. The apoptotic pathway was confirmed by a decrease in mitochondrial membrane potential and the activation of caspases-3/9 for both Ru(II) and Ir(III) complexes. It was concluded that in the case of Ru(II) complexes the intense ROS generation is mainly responsible for the resulting cytotoxicity. The corresponding Ir(III) complexes trigger simultaneously at least three different cytotoxic pathways i. e., depletion of mitochondrial potential, activation of caspases-dependent apoptosis, and ROS-associated oxidation. Thus, it can be assumed that the final accumulation of toxic effects over time via parallel activation of different pathways results in the highest cytotoxicity in vitro exhibited by Ir(III) complexes when compared with Ru(II) complexes.     

The Ethylbenzene/Styrene Preferential Separation with Ionic Liquids in Liquid–Liquid Extraction

The objective of this work was to explore the feasibility of using ionic liquids (ILs), namely N-ethyl-N-methylmorpholinium dicyanamide, [EMMor][DCA], (3-hydroxypropyl)-1-methylmorpholinium dicyanamide, [N-C₃OHMMor][DCA], 1-(3-hydroxypropyl)-3-methylimidazolium dicyanamide, [N-C₃OHMIM][DCA], 1-(3-hydroxypropyl)pyridinium dicyanamide, [N-C₃OHPy][DCA], (3-cyanopropyl)pyridinium dicyanamide, [N-C₃CNPy][DCA], and (3-cyanopropyl)methylpyrrolidinium dicyanamide, [N-C₃CNMPyr][DCA] for the separation of ethylbenzene and styrene. The liquid–liquid equilibrium (LLE) data in ternary systems of {IL (1)?+?styrene (2)?+?ethylbenzene (3)} at T?=?298.15 K and ambient pressure is presented for the six ILs synthesized by us. The final chromatography analysis of the composition of tie-lines has shown that the studied ILs are not found in the raffinate phase and they show interesting results on the selectivity and solute distribution ratio for styrene extraction. A comparison of different ILs is presented for the studied separation problem. It was observed that the best separation selectivities were found for [N-C₃CNPy][DCA] (S_Av?=?2.38) and [N-C₃OHMMor][DCA] (S_Av?=?2.42) in comparison with other studied ILs in this work and those presented in the literature. While the data presented here are useful from a theoretical standpoint, the possibility of applications for these ILs in technological processes is questionable because of low solute distribution ratios, especially those calculated from the masses [N-C₃CNPy][DCA] (β_MAv?=?0.08) and [N-C₃OHMMor][DCA] (β_MAv?=?0.07). The experimental tie-lines were correlated with the non-random two liquid NRTL model.