Defective TiO2 Nanotube Arrays for Efficient Photoelectrochemical Degradation of Organic Pollutants.

Oxygen vacancies (OVs) are one of the most critical factors that enhance the electrical and catalytic characteristics of metal oxide-based photoelectrodes. In this work, a simple procedure was applied to prepare reduced TiO2 nanotube arrays (NTAs) (TiO2-x) via a one-step reduction method using NaBH4. A series of characterization techniques were used to study the structural, optical, and electronic properties of TiO2-x NTAs. X-ray photoelectron spectroscopy confirmed the presence of defects in TiO2-x NTAs. Photoacoustic measurements were used to estimate the electron-trap density in the NTAs. Photoelectrochemical studies show that the photocurrent density of TiO2-x NTAs was nearly 3 times higher than that of pristine TiO2. It was found that increasing OVs in TiO2 affects the surface recombination centers, enhances electrical conductivity, and improves charge transport. For the first time, a TiO2-x photoanode was used in the photoelectrochemical (PEC) degradation of a textile dye (basic blue 41, B41) and ibuprofen (IBF) pharmaceutical using in situ generated reactive chlorine species (RCS). Liquid chromatography coupled with mass spectrometry was used to study the mechanisms for the degradation of B41 and IBF. Phytotoxicity tests of B41 and IBF solutions were performed using Lepidium sativum L. to evaluate the potential acute toxicity before and after the PEC treatment. The present work provides efficient PEC degradation of the B41 dye and IBF in the presence of RCS without generating harmful products.

Speciation and Bio-Imaging of Chromium in Taraxacum officinale Using HPLC Post-column ID-ICP-MS, High Resolution MS and Laser Ablation ICP-MS Techniques.

A new analytical procedure for the speciation of chromium (Cr) in plants by high performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC-ICP-MS) was developed using a strong anion-exchange Mono Q column for the separation of the Cr species. To optimize the analytical procedure, Cr complexes were first synthesized from Cr-nitrate with the addition of an excess of ligand (90°C). Cr-oxalate, Cr-malate, Cr-citrate, Cr-aconitate and Cr-quinate complexes and Cr-nitrate (pH 6.5) were chromatographically separated from Cr(VI) by applying linear gradient elution from 100% water to 100% NH4Cl at a flow rate of 1.5 ml min-1 in 10 min. The column recoveries ranged from 100 to 104%. The exception was Cr-aconitate (column recovery 33%), where a quantitative synthesis was not possible. Good repeatability of the measurements (relative standard deviations better than ± 3%) and low limits of detection (below 0.37 ng ml-1 Cr) were achieved for the individual Cr species. The developed analytical procedure was applied to Cr speciation for dandelions (Taraxacum officinale) grown in soil with a high Cr content and a study of the uptake and metabolism of Cr species in dandelions grown in soil with a low Cr content treated with solutions of Cr(VI) or Cr-nitrate (5000 ng ml-1 Cr, pH 6.5) for 48 h. The separated Cr species were quantified by post-column isotope dilution ICP-MS, while the identification was based on retention times and was also supported by mass spectra obtained with high resolution mass spectrometry (HR-MS). The data indicate that for dandelions grown in Cr-rich soil and that treated with Cr-nitrate (pH 6.5), the Cr was mainly accumulated in the roots, while in plants treated with Cr(VI) (pH 6.5), the Cr was evenly distributed between the roots and the leaves. The Cr species found in dandelion roots and leaves were Cr-aconitate, Cr-malate, and Cr-quinate. The results revealed that Cr(VI) was completely reduced and metabolized to Cr(III) complexes. LA-ICP-MS data showed that the Cr in a leaf of dandelion grown in Cr-rich soil was localized mainly at the apex of the leaf.

Unravelling the pathways of air plasma induced aflatoxin B1 degradation and detoxification.

Aflatoxins are considered to be a critical dietary risk factor for humans, with aflatoxin B1 (AFB1) identified by the WHO as one of the most potent natural group 1 carcinogen. Despite this, more than half of the world's population is chronically exposed, resulting in up to 170,000 annual cases of human hepatocellular carcinoma cancer. Here we report an easily implemented approach using non-equilibrium plasma for targeted degradation of AFB1. Apart from reaching the 100 % decontamination in less than 120 s of treatment, this is the first study that combines hypersensitive analytical methods such as high-resolution mass spectroscopy (HRMS) and nuclear magnetic resonance spectroscopy (NMR) to provide a detailed description of CAP mediated AFB1 degradation. We identify rapid scission of the vinyl bond between 8- and 9-position on the terminal furan ring of AFB1 as being of paramount importance for the suppression of toxic potential, which is confirmed by the examination of both cytotoxicity and genotoxicity. The plasma reactive species mediated degradation pathways are elucidated, and it is demonstrated that the approach not only renders AFB1 harmless but does so in order of magnitude less time than UV irradiation as one of the other non-thermal methods currently under investigation.

Determination and photodegradation of sertraline residues in aqueous environment.

Sertraline is an antidepressant drug that has been frequently reported in the aquatic environment and biota. While the research has mostly dealt with its occurrence and toxicity, there is a lack of information pertaining to its environmental transformation. The present study aimed to fill in these gaps by giving an insight into mechanisms of sertraline phototransformation in surface waters, which was recognized as the main transformation pathway for this contaminant. We performed photodegradation experiments in presence of photosensitizers or reaction quenchers to determine rate constants and used them to predict sertraline phototransformation kinetics by "Aqueous Photochemistry of Environmentally occurring Xenobiotics" (APEX) software. It was established that sertraline degrades by pseudo-first order kinetics mostly dominated by direct photolysis, while the presence of certain reactive species including •OH, CO3-• and 3CDOM* further accelerate the compound's breakdown rate. To validate the predicted results, sertraline-spiked surface water was irradiated by sunlight, where the half-life of sertraline at around 1.4 days was estimated. While following the photodegradation kinetics, we also identified five transformation products, of which three were determined in Slovenian surface waters. According to the ECOSAR toxicity prediction, these transformation products will either have comparable or lower toxicity than their parent compound.

An optimised series of substituted N-phenylpyrrolamides as DNA gyrase B inhibitors.

ATP competitive inhibitors of DNA gyrase and topoisomerase IV have great therapeutic potential, but none of the described synthetic compounds has so far reached the market. To optimise the activities and physicochemical properties of our previously reported N-phenylpyrrolamide inhibitors, we have synthesized an improved, chemically variegated selection of compounds and evaluated them against DNA gyrase and topoisomerase IV enzymes, and against selected Gram-positive and Gram-negative bacteria. The most potent compound displayed IC50 values of 6.9 nM against Escherichia coli DNA gyrase and 960 nM against Staphylococcus aureus topoisomerase IV. Several compounds displayed minimum inhibitory concentrations (MICs) against Gram-positive strains in the 1-50 µM range, one of which inhibited the growth of Enterococcus faecalis, Enterococcus faecium, S. aureus and Streptococcus pyogenes with MIC values of 1.56 µM, 1.56 µM, 0.78 µM and 0.72 µM, respectively. This compound has been investigated further on methicillin-resistant S. aureus (MRSA) and on ciprofloxacin non-susceptible and extremely drug resistant strain of S. aureus (MRSA VISA). It exhibited the MIC value of 2.5 µM on both strains, and MIC value of 32 µM against MRSA in the presence of inactivated human blood serum. Further studies are needed to confirm its mode of action.

Profiles of the benzotriazole pollutant transformation products in an urban intergranular aquifer.

Benzotriazoles (BTs) are regarded as contaminants of emerging concern. However, their transformation products (BTTPs) in aquifers remains poorly characterized. The present study is the first detailed report on profiles of the BTTPs in an urban oxic intergranular aquifer related to water type, land use and the aquifer's depth. The 2-methyl-2H-benzotriazole (2-MeBT) and 2,4-dimethyl-2H-benzotriazole (2,4-dMeBT) were quantified using the gas chromatography-mass spectrometry (GC-MS) analytical technique based on internal standards. For the first time the relationship between the 2-MeBT and 2,4-dMeBT concentrations was studied in sampled water and discussed with respect to the different flow paths and sources of contamination. Three main sources of BTTPs were determined in urban groundwater: BTs and BTTPs included in the outflow of effluents from wastewater-treatment plants and energy-producing facilities into surface streams that recharge the aquifer and in the leaking effluents from industrial and public wastewater pipelines. The results confirm that the BTTPs are transformed from parent compounds in the aquifer's unsaturated zone in the case when the effluents are temporally stored in sediments with a lower hydraulic conductivity, which is indicated with the highest median concentrations of BTTPs referring to the perched aquifers where the BTTPs proportions were 92-99%. BTTPs dominated over the parent BTs also in groundwater. The highest concentrations of BTTPs (up to 174 and 144 ng L-1 for the 2-MeBT and 2,4-dMeBT ng L-1, respectively) were measured in groundwater abstracted from the upper parts of the aquifer in the area where the losses from industrial wastewater pipelines were evidenced. The 2,4-dMeBT dominated over the 2-MeBT in the BTTPs originating from BTs included in the industrial effluents, which is the opposite to the case when their origin is in the municipal effluents. The median sum concentration of the BTTPs in drinking-water resources (2.0 ng L-1) is lower than the quality criterion recommended for BTs so far. Nevertheless, the abundance of BTs in the environment and the apparent environmental relevance of the BTTPs in urban groundwater indicate the need for a risk assessment of BTTPs with respect to health and the environment.

Isolation and Determination of Fomentariol: Novel Potential Antidiabetic Drug from Fungal Material.

Diabetes mellitus is one of the leading world's public health problems. Therefore, it is of a huge interest to develop new antidiabetic drugs. Apart from traditional therapy of diabetes, nowadays, importance is given to natural substances with antidiabetic potential. Fomes fomentarius is a mushroom widely used for different purposes, due to its range of already confirmed activities. Fomentariol is a constituent of Fomes fomentarius, responsible for its antidiabetic potential. In that respect, it is important to develop a method for isolation and quantification of fomentariol from fungal material, which will be simple and efficient. Multistep, complex extraction applied in the previously reported studies was avoided with ethanol, providing rapid single-step extraction. The presence of fomentariol in ethanolic extract was confirmed by high-resolution mass spectrometry. Semipreparative HPLC method was developed and applied for isolation from ethanol extract and purification of the active compound fomentariol. It was a gradient reversed-phase method with a mobile phase consisting of acetonitrile and 0.1% formic acid in water and total run time of 15 minutes. The amount of 6.5 mg of high-purity fomentariol was determined by quantitative NMR with toluene as internal standard. The isolated and determined amount of substance can be further used for the quantitative estimation of activity of fomentariol.

The fate of benzotriazole pollutants in an urban oxic intergranular aquifer.

Benzotriazoles (BTs) are considered as Contaminants of Emerging Concern (CECs); however, information about their fate in aquifers continues to be absent. This was the focus of the present study, which provides the first evidence for relevant BTs' degradation products (BTTPs) in urban aquifers that may impact the groundwater quality. The mechanisms and biotransformation pathways of BTs were investigated in an oxic intergranular medium. The BTs and BTTPs were identified and quantified by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) analytical techniques based on reference standards and internal materials. The major transformation products were identified as 2-methyl-2H-benzotriazole (2-MeBT) for the degradation of 1H-benzotriazole (BT) and as 2,4-dimethyl-2H-benzotriazole (2,4-dMeBT) and 1,4-dimethyl-1H-benzotriazole (1,4-dMeBT) for the degradation of 4-methyl-1H-benzotriazole (4-MeBT), and most probably also 5-methyl-1H-benzotriazole (5-MeBT). The leakage of wastewater pipelines is most probably the source of BTs. Sediments with a lower hydraulic conductivity give rise to perched aquifer conditions that lead to the temporal storage of leaking effluents and presumably the majority of BTs' transformation processes via methylation and tautomerization. The most stable BTTPs entered the saturated zone of the aquifer, where they prevailed. Concentrations up to 1500 ng L-1 were measured for the 2,4-dMeBT, which suggest a contamination risk for groundwater that is or may be used as a source for drinking water in the case of a constant input of pollutant loads from sewer systems.

Nickel speciation in cocoa infusions using monolithic chromatography - Post-column ID-ICP-MS and Q-TOF-MS.

Nickel (Ni) is considered to be a potentially harmful element for humans. Its levels in foodstuffs are normally low (below 0.2mgkg-1), but sensitive individuals may develop allergy to Ni as a result of dietary consumption. Cocoa contains relatively high Ni concentrations (around 3mgkg-1). Ni bioavailability, its role in the flavour of food and its potential impact on human health depends primarily on its chemical species. However, there is a lack of information about Ni speciation in cocoa. In this work Ni species were separated on a weak convective interaction media diethylamine (CIM DEAE) monolithic chromatographic column and quantified by the post-column isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS). The Ni binding ligands in the separated fractions were identified "off line" by quadrupole time-of-flight mass spectrometry (Q-TOF MS). Ni was found to be present in the cocoa infusions as Ni2+ and Ni-gluconate and Ni-citrate complexes.

Identification and quantification of bleomycin in serum and tumor tissue by liquid chromatography coupled to high resolution mass spectrometry.

Bleomycin is a cytotoxic antibiotic available as a compost of structurally strongly related glycopeptides, which is in vivo found chelated with several metals. Its pharmacotherapy has merely been based on experimental dose - response data, whereas its biodistribution and pharmacokinetics remain fundamentally unknown. This is reasoned by an absence of a specific and sensitive mass spectrometry-based analytical method for its determination in biological tissues. We herein reveal the results of our study on the mass spectrometric behavior of two main bleomycin fractions A2 and B2, including their metal complexes, particularly the predominant copper chelates. In the electrospray ion source bleomycin forms double charged species, where for the metal-free fraction A2 and its copper complex m/z 707.76 and m/z 707.21 are seen, respectively. Hence, the second isotopic ion of the chelate (m/z 707.71) nearly coincides with the first isotopic ion of the metal-free fraction. This phenomenon can only be followed by high-resolution mass spectrometry, and is considered the plausible reason, why the attempts to determine bleomycin with mass spectrometry have been so scarce. The presented paper further describes a sensitive and selective liquid chromatography - mass spectrometry analytical method for determination of bleomycin in serum and tumor tissues. This newly developed method was employed for bleomycin pharmacokinetic studies in serum and tumors of laboratory animals. Additionally, the method was employed for determination of bleomycin pharmacokinetic parameters in elderly patients in order to determine the effective therapeutic window of electrochemotherapy with bleomycin.

Nonpeptidic Selective Inhibitors of the Chymotrypsin-Like (ß5 i) Subunit of the Immunoproteasome.

Elevated expression of the immunoproteasome has been associated with autoimmune diseases, inflammatory diseases, and various types of cancer. Selective inhibitors of the immunoproteasome are not only scarce, but also almost entirely restricted to peptide-based compounds. Herein, we describe nonpeptidic reversible inhibitors that selectively block the chymotrypsin-like (ß5i) subunit of the human immunoproteasome in the low micromolar range. The most potent of the reversibly acting compounds were then converted into covalent, irreversible, nonpeptidic inhibitors that retained selectivity for the ß5i subunit. In addition, these inhibitors discriminate between the immunoproteasome and the constitutive proteasome in cell-based assays. Along with their lack of cytotoxicity, these data point to these nonpeptidic compounds being suitable for further investigation as ß5i-selective probes for possible application in noncancer diseases related to the immunoproteasome.

Lipid Metabolites from the Mushroom Meripilus giganteus.

The phytochemical investigation of the methanolic extract of the white rot fungus Meripilus giganteus resulted in the isolation and identification of complex mixtures of free fatty acids (1), monoacylglycerols (2), cerebrosides (3), ergosterol (4) and ergosterol peroxide (5). The structures of the isolated lipid metabolites (1-5) were determined by chemical and spectroscopic methods. The antioxidant activity of the whole MeOH extract of the fungus was evaluated through in vitro model systems, such as 2,2-diphenyl-l-picrylhydrazyl (DPPH) and superoxide anion. In all two systems, the results indicated that the extract of the fungus showed the same free-radical-scavenging activity with SC50 data of 47.70 µg/mL, compared with the positive control quercetin (DPPH assay). None of the isolated compounds (1-5) showed a significant activity. Compounds 2-4 were isolated from Meripilus giganteus for the first time.

Isolation, analysis and structures of phototoxic fagopyrins from buckwheat.

Buckwheat products are commonly used in health foods and food supplements. However, public awareness regarding the presence of photodynamic naphthodianthrones fagopyrins that can cause photosensitization is low. At least two additional compounds with structures similar to that of fagopyrin are known to exist; however, the structures of these compounds have never been determined. In this work, we improved the extraction procedure and the chromatographic analysis of fagopyrins by developing a simple, sensitive and high-resolution high performance liquid chromatography (HPLC) analytical method using fluorescence detection. We observed at least six fagopyrin derivatives, which were isolated and characterized via UV-Vis absorption, NMR spectroscopy and mass spectrometry. We determined the structures of two new derivatives (fagopyrin A and fagopyrin E) and proved the existence of protofagopyrins that can transform into fagopyrins upon light exposure. Our methods complement the existing knowledge regarding fagopyrins and will allow for their further analysis, isolation and investigation of their biological activity.

Fluorouracil in the environment: analysis, occurrence, degradation and transformation.

5-Fluorouracil (5-FU) is a fluorinated pyrimidine analogue important in the treatment of cancer whose fate in the environment is yet to be fully addressed. Due to its high polarity 5-FU requires challenging sample preparation and therefore we thoroughly investigated different solid phase extraction mechanisms (ion pair, ion exchange, reversed phase), sorbents and derivatisation agents to enable trace-level analysis of 5-FU based on GC-MS/MS in natural and wastewaters. Ion pair and ion exchange retention mechanisms enable the extraction of 5-FU from deionised water, but were inappropriate for complex environmental matrices, where the reversed phase sorbent Isolute ENV+ gave the best extraction efficiencies (53% and 93% for wastewaters and surface waters, respectively). Further, alkylation was rejected in favour of silylation with MTBSTFA. The achieved limits of quantification (LOQ) for waste and surface waters were 1.6 ng/L and 0.54 ng/L, respectively. The method was used to analyse samples of hospital, wastewater treatment plant influent and effluent and surface waters. 5-FU was quantified in four out of the twelve samples of oncological ward wastewaters and municipal wastewater treatment plant influents in concentrations from 4.7 ng/L to 92 ng/L. This work is also the first to study the environmental transformation of 5-FU and its prodrug capecitabine (CAP). Their removal and transformation was simulated using a series of biodegradation and photodegradation experiments, where 5-FU proved more degradable in comparison to CAP. Transformation of 5-FU and CAP was studied by using ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC-QqTOF). Overall, six transformation products for 5-FU and ten for CAP are proposed; 13 of these are to our knowledge published for the first time.

Ni speciation in tea infusions by monolithic chromatography--ICP-MS and Q-TOF-MS.

For humans, Ni is not considered to be an essential trace element. Its compounds, at levels present in foodstuffs and drinks, are generally considered to be safe for consumption, but for individuals who already suffer from contact allergy to Ni and may be subject to develop systemic reactions from its dietary ingestion, dietary exposure to Ni must be kept under control. Being the second most popular beverage, tea is a potential source of dietary Ni. Present knowledge on its speciation in tea infusions is poor. Therefore, complete speciation analysis, consisting of separation by liquid chromatography using a weak CIM DEAE-1 monolithic column, "on-line" detection by inductively coupled plasma mass spectrometry (ICP-MS) and "off-line" identification of ligands by hybrid quadrupole time-of-flight mass spectrometry (Q-TOF MS), was implemented for the first time to study Ni speciation in tea infusions. Total concentrations of Ni in dry leaves of white, green, oolong and black tea (Camellia sinensis) and flowers of herbal chamomile (Matricaria chamomilla) and hibiscus (Hibiscus sabdariffa) tea were determined after microwave digestion by ICP-MS. They lay between 1.21 and 14.4 mg kg(-1). Good agreement between the determined and the certified values of the Ni content in the standard reference material SRM 1573a tomato leaves confirmed the accuracy of the total Ni determination. During the infusion process, up to 85 % of Ni was extracted from tea leaves or flowers. Separation of Ni species was completed in 10 min by applying aqueous linear gradient elution with 0.6 mol L(-1) NH(4)NO(3). Ni was found to be present in the chromatographic fraction in which quinic acid was identified by Q-TOF in all the tea infusions analysed, which had pH values between 5.6 and 6.0. The only exception was the infusion of hibiscus tea with a pH of 2.7, where results of speciation analysis showed that Ni is present in its divalent ionic form.

Steroid toxicity and detoxification in ascomycetous fungi.

In the last couple of decades fungal infections have become a significant clinical problem. A major interest into fungal steroid action has been provoked since research has proven that steroid hormones are toxic to fungi and affect the host/fungus relationship. Steroid hormones were found to differ in their antifungal activity in ascomycetous fungi Hortaea werneckii, Saccharomyces cerevisiae and Aspergillus oryzae. Dehydroepiandrosterone was shown to be the strongest inhibitor of growth in all three varieties of fungi followed by androstenedione and testosterone. For their protection, fungi use several mechanisms to lower the toxic effects of steroids. The efficiency of biotransformation in detoxification depended on the microorganism and steroid substrate used. Biotransformation was a relatively slow process as it also depended on the growth phase of the fungus. In addition to biotransformation, steroid extrusion out of the cells contributed to the lowering of the active intracellular steroid concentration. Plasma membrane Pdr5 transporter was found to be the most effective, followed by Snq2 transporter and vacuolar transporters Ybt1 and Ycf1. Proteins Aus1 and Dan1 were not found to be involved in steroid import. The research of possible targets of steroid hormone action in fungi suggests that steroid hormones inhibit ergosterol biosynthesis in S. cerevisiae and H. werneckii. Results of this inhibition caused changes in the sterol content of the cellular membrane. The presence of steroid hormones most probably causes the degradation of the Tat2 permease and impairment of tryptophan import.

Determination of Zn-citrate in human milk by CIM monolithic chromatography with atomic and mass spectrometry detection.

In human milk zinc (Zn) is bound to proteins and low molecular mass (LMM) ligands. Numerous investigations demonstrated that Zn bioavailability in human milk is for infant much higher than in cow's milk. It was presumed that in the LMM human milk fraction highly bioavailable Zn-citrate prevails. However, literature data are controversial regarding the amount of Zn-citrate in human milk since analytical procedures reported were not quantitative. So, complex investigation was carried out to develop analytical method for quantitative determination of this biologically important molecule. Studies were performed within the pH range 5-7 by the use of synthetic solutions of Zn-citrate prepared in HEPES, MOPS and MES buffers. Zn-citrate was separated on weak anion-exchange convective interaction media (CIM) diethylaminoethyl (DEAE) monolithic chromatographic column using NH(4)NO(3) as an eluent. Separated Zn species were determined by flame atomic absorption spectrometry (FAAS) or inductively coupled plasma mass spectrometry (ICP-MS). Quantitative separation of Zn-citrate complexes ([Zn(Cit)](-) and [Zn(Cit)(2)](4-); column recoveries 94-102%) and good repeatability and reproducibility of results with relative standard deviation (RSD±3.0%) were obtained. In fractions under the chromatographic peaks Zn-binding ligand was identified by electrospray ionization tandem mass spectrometry (ESI-MS-MS). Limits of detection (LOD) for determination of Zn-citrate species by CIM DEAE-FAAS and CIM DEAE-ICP-MS were 0.01 µg Zn mL(-1) and 0.0005 µg Zn mL(-1), respectively. Both techniques were sensitive enough for quantification of Zn-citrate in human milk. Results demonstrated that about 23% of total Zn was present in the LMM milk fraction and that LMM-Zn corresponded to Zn-citrate. The developed speciation method represents a reliable analytical tool for investigation of the percentage and the amount of Zn-citrate in human milk.

The response of filamentous fungus Rhizopus nigricans to flavonoids.

The saprophytic fungus Rhizopus nigricans constitutes a serious problem when thriving on gathered crops. The identification of any compounds, especially natural ones, that inhibit fungal growth, may therefore be important. During its life cycle, Rhizopus nigricans encounters many compounds, among them the flavonoids, plant secondary metabolites that are involved in plant defense against pathogenic microorganisms. Although not being a plant pathogen, Rhizopus nigricans may interact with these compounds in the same way as plant pathogens--in response to the fungitoxic effect of flavonoids the fungi transform them into less toxic metabolites. We have studied the interaction of R. nigricans with some flavonoids. Inhibition of hyphal spreading (from 3% to 100%) was observed by 300 µM flavones, flavanones and isoflavones, irrespective of their basic structure, oxidized or reduced C-ring, and orientation of the B-ring. However, a hydrophobic A-ring was important for the toxicity. R. nigricans transformed some of the flavonoids into glucosylated products. Recognition of substrates for glucosylating enzyme(s) did not correlate with their fungitoxic effect but depended exclusively on the presence of a free -OH group in the flavonoid A-ring and of a hydrophobic B-ring. Although the fungus produced glucosyltransferase constitutively, an additional amount of the enzyme was induced by the substrate flavonoid. Moreover, effective detoxification was shown to require the presence of glucose.

Application of complementary mass spectrometric techniques to the identification of ketoprofen phototransformation products.

Ketoprofen (KP) is a nonsteroidal anti-inflammatory drug, which during UV irradiation rapidly transforms into benzophenone derivatives. Such transformation products may occur after topical application of KP, which is then exposed to sunlight resulting in a photo-allergic reaction. These reactions are mediated by the benzophenone moiety independently of the amount of allergen. The same reactions will also occur during wastewater or drinking water treatment albeit their effect in the aqueous environment is yet to be ascertained. In addition, only a few such transformation products have been recognised. To enable the detection and structural elucidation of the widest range of KP transformation products, this study applies complementary chromatographic and mass spectrometric techniques including gas chromatography coupled to single quadrupole or ion trap mass spectrometry and liquid chromatography hyphenated with quadrupole-time-of-flight mass spectrometry. Based on structural information gained in tandem and multiple MS experiments, and on highly accurate molecular mass measurements, chemical structures of 22 transformation products are proposed and used to construct an overall breakdown pathway. Among the identified transformation products all but two compounds retained the benzophenone moiety--a result, which raises important issues concerning the possible toxic synergistic effects of KP and its transformation products. These findings trigger further research into water treatment technologies that would limit their entrance into environmental or drinking waters.

Synthesis and Characterization of Novel Ruthenium(III) Complexes with Histamine.

Novel ruthenium(III) complexes with histamine [RuCl(4)(dmso-S)(histamineH)] . H( (2) )O (1a) and [RuCl(4)(dmso-S)(histamineH)] (1b) have been prepared and characterized by X-ray structure analysis. Their crystal structures are similar and show a protonated amino group on the side chain of the ligand which is not very common for a simple heterocyclic derivative such as histamine. Biological assays to test the cytotoxicity of the compound 1b combined with electroporation were performed to determine its potential for future medical applications in cancer treatment.