Oxidative degradation of 1,5-naphthalenedisulfonic acid in aqueous solutions by UV-photolysis in the absence and presence of H2O2

Sulfonated aromatic pollutants such as 1,5-naphthalenedisulfonic acid (NDS or Armstrong's acid) are persistent compounds and thus resist environmental breakdown and microbial treatment. This study investigated the photo-oxidative degradation of such a persistent polar pollutant in the absence and presence of H2O2. The degradation of aqueous NDS solutions by photolysis was found to be efficient only in the presence of H2O2. The combination of UV irradiation and H2O2 leads to progressive degradation of NDS, which is converted into new, more biodegradable and non-toxic species.

The drug targeting and delivery approach applied to pt-antitumour complexes. A coordination point of view

Platinum-based anticancer chemotherapy is associated to severe side effects because of its poor specificity. In particular, the hydrolysis of Pt-based drugs generates cationic complexes with electrophylic properties able to target DNA. The effectiveness of this kind of chemotherapy relies solely on the proliferation index of tumour cells, which is higher than in healthy cells. In recent years, the "drug targeting and delivery" approach has been developed in an attempt to reduce chemotherapy-related systemic side effects by using vectors that selectively deliver the cytotoxic agent to tumour cells, thus sparing healthy cells. These vectors include bioactive substances, such as nutrients, that more readily enter metabolically active tumour cells, or hormones, folates and bile acids, that are selectively conveyed by receptors/transporters often over-expressed in cancer cells (active targeting). Alternatively, macromolecular vectors, exploiting the so-called EPR (enhanced permeability and retention) effect, can be used (passive targeting). The bioactive or macromolecular vector must contain a coordinating arm capable of binding the PtX(2)-unit, acting either as carrier or leaving group for the cytotoxic Pt-moiety. In both cases, the Pt-vector conjugate should be promptly cleaved to generate the active species. The release of platinum drugs from the pharmacophore is crucial for fine-tuning of the overall cytotoxic properties of the conjugates. The "drug targeting and delivery" method represents an exciting field of research for improving the therapeutic potential of the long established, very efficient, but intrinsically non-specific Pt-based drugs.

Oxidative stress and total antioxidant capacity in human plasma

While several tools are already available for the separate measurement of the oxidant and antioxidant pools, a single, quick and easy method for determining total oxidative stress would be advantageous. In the present study, we compare the plasma of untreated patients with leukemia/solid gynecological tumors (n = 50) and current regular smokers (n = 50) with a smoking history of >or=10 cigarettes per day to the plasma of healthy blood donors. Standard tools were used to measure total oxidant status, ceruloplasmin activity, total antioxidant capacity, uric acid content and oxidative stress index. Oxidative stress was also evaluated using the controversial d-ROMs test, a commercial method of reactive oxygen species detection. Statistically significant differences between the smokers and the control group were detected for all of the biochemical parameters. Conversely, the differences in the cancer patients were not statistically significant for oxidative stress.

Authentication and traceability study of hazelnuts from piedmont, Italy

Hazelnut is one of the most important items in high-quality food products from Piedmont, Italy. The 'Tonda Gentile delle Langhe' (TGL) variety is acknowledged all over the world as the best one, and it is particularly appreciated when used to provide flavor in chocolate products. Authentication and/or traceability studies must therefore be developed to safeguard this variety against fraud, which can occur when the product is partially or totally substituted with hazelnuts of lower quality. In this work, a classification of hazelnuts from different countries is presented, showing the possibility to discriminate the TGL from other productions on the basis of the distribution of trace elements as determined by means of inductively coupled plasma-mass spectrometry (ICP-MS), with particular reference to lanthanides. Accuracy of the sample treatment procedure was tested by analysis of biological certified materials. Data from elemental analysis were chemometrically treated with an unsupervised method, such as principal component analysis (PCA), allowing for a good discrimination among groups.

Oxidative degradation of 1,5-naphthalenedisulfonic acid in aqueous solutions by microwave irradiation in the presence of H2O2

Sulfonated aromatic pollutants such as Armstrong's acid, or 1,5-naphthalenedisulfonic acid (NDS), are recalcitrant to environmental breakdown and microbial treatment. This study investigated the effects of H(2)O(2) concentration, pH, microwave (MW) power and irradiation time on the oxidative degradation of NDS in aqueous solutions. The formation of hydroxyl radicals as the active oxidant was confirmed by electron paramagnetic resonance spin trapping. A combination of both H(2)O(2) and MW heating proved essential for NDS degradation. Degradation factors of f70% were obtained after about 20min of irradiation at [H(2)O(2)]:[NDS] ratios=10. Acidic conditions were found to be more favorable to the degradation of NDS, and the process follows pseudo-first-order kinetics. Attempts to scale-up the process using a conventional MW reactor provided less striking results.

The activation of platinum(II) antiproliferative drugs in carbonate medium evaluated by means of a DNA-biosensor

We report on the binding of cisplatin, carboplatin and oxaliplatin to double-stranded DNA in two different (phosphate and carbonate) buffers, using an electrochemical DNA-biosensor. The propensity of the electrophilic agent produced by hydrolysis to interact with DNA was measured as a function of the decrease of guanine oxidation signal of the metal-DNA adduct immobilized on a screen-printed electrode, by using square wave voltammetry. The results obtained confirm that carbonate reacts with platinum drugs to form activated carbonato complexes, which are able to react readily with DNA.

DNA-metallodrugs interactions signaled by electrochemical biosensors: an overview

The interaction of drugs with DNA is an important aspect in pharmacology. In recent years, many important technological advances have been made to develop new techniques to monitor biorecognition and biointeraction on solid devices. The interaction between DNA and drugs can cause chemical and conformational modifications and, thus, variation of the electrochemical properties of nucleobases. The propensity of a given compound to interact with DNA is measured as a function of the decrease of guanine oxidation signal on a DNA electrochemical biosensor. Covalent binding at N7 of guanine, electrostatic interactions, and intercalation are the events that this kind of biosensor can detect. In this context, the interaction between a panel of antitumoral Pt-, Ru-, and Ti-based metallodrugs with DNA immobilized on screen-printed electrodes has been studied. The DNA biosensors are used for semiquantitative evaluation of the analogous interaction occurring in the biological environment.

The RP-HPLC measurement and QSPR analysis of logP(o/w) values of several Pt(II) complexes

The n-octanol/water partition coefficient, logP(o/w), for a set of 24 Pt(II)-complexes was estimated by means of reversed-phase high performance liquid chromatography (RP-HPLC) technique using a C18 (ODS, octadecyl silane) column as a stationary phase and water/methanol mixtures as mobile phases. Based on the known logP(o/w) of several Pt(II)-complexes, we set a method to correlate the partition coefficient of this kind of complexes with the corresponding retention parameters. The best result was obtained from extrapolation to 0% of the organic modifier (MeOH) of the aqueous eluant. A quantitative structure-property relationship (QSPR) was constructed using molecular descriptors derived from density functional theory (DFT) calculations, which was found to correlate and predict these values with good accuracy. The use of DFT calculations is required because group-additive methods fail due to lack of values for appropriate fragments for many Pt(II)-complexes.

Electrochemical biosensor evaluation of the interaction between DNA and metallo-drugs

Electrochemical techniques were used to study the interaction between a panel of antiproliferative metallo-drugs and double-stranded DNA immobilized on screen-printed electrodes as a model of the analogous interaction occurring in solution. The propensity of a given metal drug to interact with DNA was measured as a function of the decrease of guanine oxidation signal, which was detected by square wave voltammetry. Estimates of variations in experimental parameters, such as the concentration of complexes, time following dissolution (ageing time) and the presence of chloride, are provided.

Deoxyribonucleic acid (DNA) biosensors for environmental risk assessment and drug studies

In the present work, electrochemical DNA biosensors are proposed as a screening device for the rapid bio-analysis of environmental pollution and DNA-drug interaction studies. The binding of small molecules to DNA immobilised on disposable screen-printed electrodes has been measured through the variation of the electrochemical signal of guanine by square wave voltammetric scans. These kinds of biosensors were used to evaluate the soil contamination level in an Italian polluted area and the results were compared with several methods for the DNA damage detection, as Comet genotoxicity effects, aberrant anatelophases and micronucleated cells frequency on plant roots, and with fixed wavelength fluorescence (FF) by using 2-aminoanthracene as standard compound. The results showed the ability of the biosensors to distinguish in 11 min low, medium and high contaminated soils with good correlation with well established techniques as well as FF, Comet and genotoxicity tests. The same kind of biosensors was also used to evaluate the interaction of DNA with some anti-proliferative metallo drugs, and the electrochemical responses reflected the kind of interaction. The reproducibility of the electrochemical measurements of DNA guanine peak was estimated as less than 10% of relative standard deviation (R.S.D.%).

An experiment in the electrokinetic removal of copper from soil contaminated by the brass industry

The feasibility of electrokinetic remediation of copper-contaminated soil was evaluated following eight days of electroreclamation. The results indicate that electrokinetic reclamation of Cu is totally ineffective in soil composed primarily of clay minerals and organic matter. The strong absorption of copper by this kind of soil, in our view mainly a result of retention by the clay component, makes it resistant to mobilization by the electrogenerated acidic front as well as by citrates (the competitors of natural chelating agents, i.e., humates). Such conditions, while adverse for the electroremediation process, may cause this kind of soil to act as a natural barrier to the leaching of copper ions.

Enhancement of the cytotoxicity of titanocene dichloride by aging in organic co-solvent

Titanocene dichloride exhibits anti-proliferative activity in a wide spectrum of murine and human tumors. Although it is still unclear as to which species are active in biological media, they all readily deliver Ti(IV) to transferrin, the protein that transports iron in the blood. In this article, we report that aging of the complex in alcohols (namely methanol and ethanol) or dimethyl sulfoxide, the co-solvents used to prepare mother solution of the drug, leads to increased cytotoxic activity (i.e. lower IC(50) values) in HCT116 colon cancer cell lines, to a different extent. The TiCp(2)Cl(2) solvolysis was followed by (1)H NMR, ESI-MS, electrochemical and conductivity measurements, and the intracellular Ti(IV) uptake was evaluated.