Ecotoxicological effects of diuron and chlorotoluron nitrate-induced photodegradation products: monospecific and aquatic mesocosm-integrated studies

The ecotoxicological impact of nitrate-induced photodegradation products of diuron and chlorotoluron was studied through monospecific biotests conducted in conjunction with experiments in outdoor aquatic mesocosms. Organisms representing three trophic levels were used: two heterotrophic microorganisms, the luminescent bacterium Vibrio fischeri and the ciliated protozoa Tetrahymena pyriformis, and one metazoa, the gastropod Lymnaea stagnalis. Among the variety of the phenylurea photoproducts, the N-formylated ones appeared clearly more toxic than the parent compounds towards the microorganisms, whereas the nitroderivatives showed a similar toxicity. Using photodegraded solutions of diuron, toxicity was maintained or even increased during disappearance of the initial herbicide, demonstrating that some of the photoproducts may have an impact additively or in synergy. Enzymatic biomarker assays performed on Lymnaea stagnalis exposed under monospecific conditions showed significant effects, due to the combination of nitrate with the pesticide and its photoproducts. A positive impact on snail fecundity was observed with chlorotoluron both under monospecific laboratory and integrated mesocosm conditions. Oviposition stimulation took place when first- and second-generation photoproducts were predominant.

Localization of flavonoids in seeds by cluster time-of-flight secondary ion mass spectrometry imaging

Time-of-flight secondary ion mass spectrometry imaging has been used to map flavonoids in fresh seed sections of peas (Pisum sativum) and Arabidopsis thaliana. While for peas a very simple preparation method derived from mammalian tissue imaging could be utilized, several preparation methods had to be tested for the A. thaliana seeds before obtaining tissue sections on which the diagnostic ions were not delocalized. For such small and stiff biological material, none of the methods currently used in histology or scanning electron microscopy could be transferred to mass spectrometry imaging. Only the embedding of the fresh seeds in a polyester resin, followed by the analysis of the block after having obtained a flat surface section with a diamond blade, gave sensitive and reproducible results. Several flavonoid ions have been detected in the sections, showing increased concentrations of flavonoids in the seed coats. The method was finally applied to confirm the variations in the flavonoid content of seeds from different A. thaliana mutants.

Comorbidity and survival of hepatocellular carcinoma patients at a VA medical canter

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Background: To determine whether comorbidity indices predict survival in hepatocellular carcinoma (HCC) pts. Methods: In an IRB approved protocol, we reviewed the records of pts with tissue diagnosis of HCC seen at a VA Medical Center between 1/1/1999 to 12/31/2008. Comorbidity was assessed with four comorbidity indices, the Charlson Comorbidity Index (CMI), the Kaplan- Feinstein Index (KFI), the Cumulative Illness Rating Scale (CIRS), and VA Comorbidity Scale (VACS). Demographics, ECOG PS, stage, alpha-fetoprotein (AFP) at diagnosis, hepatitis B (HBV) and C (HCV) status, alcohol use, and iron overload were also reviewed. Cox survival regression analysis was performed. Results: There were 44 pts. All pts were men. The median (M) age at diagnosis was 60.5 years (range 35–86). The overall M survival was 230 days (4–2784). There were Stage I 12 (27%) pts, Stage II 7 (16%) pts, Stage III 14 (32%) pts, and Stage IV 11 (25%) pts. The M ECOG PS was 1.0 (0–4), stage 3 (1–4), CMI 5.75 (1–16), CIRS15 3.0 (1–5), CIRS16 6.0 (1–14), CIRS17 2.0 (0.83–5.0), CIRS18 0 (0–2), CIRS19 0 (0–1), KFI 3.0 (1–3), VACS 6.0 (2–9), and AFP 56.35 (1.1–379567). HBV was positive in 10 pts (23%), HCV 26 (59%) pts, alcohol use 37 (84%) pts, and iron overload 11 (25%) pts. In univariate survival analysis, stage (p<.038), ECOG PS (p<.001), AFP (p<.009), presence of iron overload (p<.006), and CMI (p<.019) were significant in predicting survival. However, age, HBV, HCV, alcohol use, CIRS15, CIRS16, CIRS17, CIRS18, KFI, and VACS were not significant for survival. In multivariate survival analyses that included stage and a comorbidity index, the CMI approaches significance (p<.077). Conclusions: In this sample, the CMI was a predictor for survival in pts with HCC. Further analysis in a larger sample is needed to provide a more definitive conclusion. This was supported by the New Jersey Commission for Cancer Research 09–1133-CCR-EO.

No significant financial relationships to disclose.

Comorbidity and survival in advanced non-small cell lung cancer (NSCLC) veteran patients

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Background: Prognostic value of comorbidity at diagnosis has received increasing attention. We studied whether the Charlson Comorbidity Index (CMI), Cumulative Illness Rating Scale (CIRS), Kaplan Feinstein Index (KFI), and/or VA Comorbidity Scale (VA) independently predicted survival for NSCLC patients Methods: In an IRB approved protocol, the charts of 101 patients with Stage IIIA, IIIB or IV Non small cell lung cancer seen from 2004 through 2006 at a VA medical center were reviewed of whom 94 have already died. Comorbidity scores ECOG performance status (PS), stage, number of treatments, serum LDH, and albumin levels were obtained or coded from medical records. Survival analyses were performed using proportional hazards models. Results: Median (M) patient age was 69 years (range 51–88), the M ECOG PS was 1 (range 0–4); 13 (13%) had stage IIIA, 27 (26%) IIB and 62 (61%) IV. The M number of treatments was 1 (range 0–6). Histologies were adenocarcinoma in 48 (48%) pts, squamous cell in 37 (37%) pts, and other 17 (15%) pts. The M survival was 207 days (range 4–1785 days). The Median (and ranges) were: 4.2 (1.2–12.8) for CMI, 3 (0–6) for CIRS15, 5(0–11) for CIRS16, 1.8 (0–4) for CIRS17, 0(0–1) for CIRS18, 2 (0–3) for KFI, and 4 (0–8) for VA. The M albumin was 3.7 (range 1.9–5.3) and LDH 201 (range 104–1036). In univariate survival analyses, the stage (p<0.001), ECOG PS (p<0.001), albumin (p<0.003), and the CIRS 17 (p <0.052) were predictive of survival; when, however, bisected by median values, the VA scale (p<0.027), ECOG PS (p<0.052) and albumin (p<.0017) were significantly related to survival but age, LDH, CMI, KFI and subscales of the CIRS (CIRS 16, CIRS 17, CIRS18) were not related to survival. In multivariate proportional hazards analyses that included stage and a comorbidity index, the CIRS16 (p<.032) was an independent predictor of survival; the combinations of stage (p<0.008), ECOG PS (p<.004), stage (p<.006) and albumin (p<.002) were independent predictors of survival. Conclusions: In this small sample, current comorbidity indices did not add to determinations of survival of veterans with advanced NSCLC. Further research is needed in a larger sample. Supported in part by the New Jersey Commission for Cancer Research 09–1133-CCR-EO and VA HSRD IIR 02–103.

No significant financial relationships to disclose.

Sunlight nitrate-induced photodegradation of chlorotoluron: evidence of the process in aquatic mesocosms

The nitrate-induced photodegradation of chlorotoluron was demonstrated to occur efficiently in natural water through two series of experiments in outdoor aquatic mesocosms. During the first campaign, it was shown that the pesticide degradation kinetics was clearly dependent on nitrate concentration. This parameter also influenced the accumulation of the first- and second-generation byproducts, including predominantly N-terminus oxidation products and nitro-derivatives of the phenyl ring. The latter compounds, specific to the NO3- -induced photoprocess, appeared particularly abundant as compared to laboratory-simulated sunlight irradiation conditions. During the second campaign, a dual day-night sampling was achieved, which demonstrated the almost exclusive role of photodegradation versus biodegradation.

Metabolism of fungicidal cyanooximes, cymoxanil and analogues in various strains of Botrytis cinerea

BACKGROUND

The metabolism of cymoxanil [1-(2-cyano-2-methoxyiminoacetyl)-3-ethylurea] and fungicidal cyanooxime analogues was monitored on three phenotypes of Botrytis cinerea Pers. ex Fr. differing in their sensitivity towards cymoxanil. For this purpose, labelled [2-(14)C]cymoxanil was added either to the culture medium of these strains or to its cell-free extract.

RESULTS

In the culture medium of the most sensitive strain, four main metabolites were detected. Three were isolated and identified. Cymoxanil was quickly metabolised by at least three concurrent enzymatic pathways: (i) cyclisation leading, after hydrolysis, to ethylparabanic acid, (ii) reduction giving demethoxylated cymoxanil, (iii) hydrolysis followed by reduction and then acetylation leading to N-acetylcyanoglycine. In the cell-free extract of the same strain, only the first and the second of these enzymatic reactions occurred. By comparing the metabolic profile of the most sensitive strain with that of the less sensitive ones, it was shown that the decrease in sensitivity to cymoxanil correlates with a reduced acetylcyanoglycine formation. Among all metabolites, only N-acetylcyanoglycine is active against the most sensitive strain. Moreover, in a culture of this strain, two other fungicidal cyanooximes were also metabolised into this metabolite.

CONCLUSION

The formation of N-acetylcyanoglycine may play an important role in the fungitoxicity of cymoxanil and cyanooxime derivatives.

Characterization of metabolites of fungicidal cymoxanil in a sensitive strain of Botrytis cinerea

The metabolism of cymoxanil [1-(2-cyano-2-methoxyiminoacetyl)-3-ethyl urea] by a very sensitive strain of Botrytis cinerea toward this fungicide was studied by using [2-(14)C]-cymoxanil. Labeled cymoxanil was added either in a culture of this strain or in its enzymatic extract. The main metabolites, detected in biological samples, were isolated and identified by mass and NMR spectrometry. Their identification allowed us to show that this strain quickly metabolized cymoxanil according to at least three enzymatic pathways: (i) cyclization leading, after hydrolysis, to ethyl parabanic acid, (ii) reduction giving demethoxylated cymoxanil, and (iii) hydrolysis and reduction followed by acetylation leading to N-acetylcyanoglycine. In a cell-free extract of the same strain, only the first and the second enzymatic reactions, quoted above, occurred. Biological tests showed that, among all the metabolites, only N-acetylcyanoglycine is fungitoxic toward this sensitive strain.

Expanding the chemical diversity of CK2 inhibitors

None of the already described CK2 inhibitors did fulfill the requirements for successful clinical settings. In order to find innovative CK2 inhibitors based on new scaffolds, we have performed a high-throughput screening of diverse chemical libraries. We report here the identification and characterization of several classes of new inhibitors. Whereas some share characteristics of previously known CK2 inhibitors, others are chemically unrelated and may represent new opportunities for the development of better CK2 inhibitors. By combining structure-activity relationships with a docking procedure, we were able to determine the binding mode of these inhibitors. Interestingly, beside the identification of several nanomolar ATP-competitive inhibitors, one class of chemical inhibitors displays a non-ATP competitive mode of inhibition, a feature that suggests that CK2 possess distinct druggable binding sites. For the most promising inhibitors, selectivity profiling was performed. We also provide evidence that some chemical compounds are inhibiting CK2 in living cells. Finally, the collected data allowed us to draw the rules about the chemical requirements for CK2 inhibition both in vitro and in a cellular context.

Evaluation of glycosylation and malonylation patterns in flavonoid glycosides during LC/MS/MS metabolite profiling

Flavonoid conjugates constitute several classes of plant phenolic secondary metabolites including many isomeric compounds differing in the hydroxylation pattern and substitution of their rings with different groups such as alkyls, acyls or sugars. These compounds occur in plant tissues mainly as glycosides and in many cases it is necessary to have reliable and detailed information concerning the structure of these natural products. Our results were obtained using leaf extracts of Arabidopsis thaliana and Lupinus angustifolius in which different glycosides of flavones, flavonols and isoflavones are present. Analysis of collision-induced dissociation (CID)/MS/MS spectra of protonated [M + H](+), sodiated [M + Na](+) or deprotonated [M - H](-) molecules recorded during HPLC runs may bring needed information in this respect. However, registration of mass spectra of [M + Na](+) ions with a good efficiency is possible only after post-column addition of a sodium acetate solution to the LC column eluate. The retention of sodium cation on the saccharidic parts of the molecule is observed after the CID fragmentation. In many cases, the location of this cation on the glycan attached to C-3 hydroxyl group of flavonol led to assignment of its structure. Additionally, the determination of the structure of the aglycone and of the sequence of the glycan part was made possible through the CID data obtained from the [M + H](+) and [M - H](-) ions. CID spectra show a different order of sugar elimination from hydroxyl groups at C-3 and C-7 in flavonol glycosides isolated from A. thaliana leaves and give sufficient information to discriminate flavonoid O-diglycosides from flavonoid di-O-glycosides.

Natural sunlight NO(3)(-)/NO(2)(-)-induced photo-degradation of phenylurea herbicides in water

The nitrate-induced photodegradation of phenylureas in water was demonstrated to occur efficiently using natural sunlight irradiation. The kinetics of disappearance was found to be dependent on the inducer and substrate concentrations, the phenylurea structure and the origin and composition of the aqueous matrix including the presence of nitrite. The measured effects under sunlight were of the same order of those measured previously in the lab using our solar light simulated system. However, by-product distribution might differ substantially particularly considering the nitration pathway.

Concentrations and specific loads of glyphosate, diuron, atrazine, nonylphenol and metabolites thereof in French urban sewage sludge

Indirect soil pollution by heavy metals and organics may occur when sewage sludge is used as fertilizer. It is essential to define the nature and amounts of pollutants contained in sewage sludge in order to assess environmental risk. Here, we present results from a one-year monitoring of herbicides (glyphosate, diuron and atrazine) and their major degradates in sewage sludge sampled from three wastewater treatment plants and one composting unit in the vicinity of Versailles, France. The concentrations of these compounds were determined, as well as these of the surfactant nonylphenol. We demonstrated the presence of glyphosate and aminomethylphosphonic acid at the mg kg(-1) (dry matter) level in all samples. Diuron was detected at the microg kg(-1) (d.m.) level, whereas its degradate and triazine compounds were below the limits of quantification. Nonylphenol amounts were higher than the future European limit value of 50 mg kg(-1) (d.m.).

Trace analysis of sulfonylurea herbicides and their metabolites in water using a combination of off-line or on-line solid-phase extraction and liquid chromatography–tandem mass spectrometry

Two alternatives for the rapid simultaneous quantification of six sulfonylurea herbicides and five of their main degradation products in natural water are proposed. For concentration, the compounds were extracted on a polystyrene-divinylbenzene solid phase under pH and elution conditions that suppressed any hydrolysis. The eluates were analysed by liquid chromatography coupled to electrospray tandem mass spectrometry within 20 min. The whole method was validated and shown to give no hydrolysis artefacts. The application of off-line and on-line SPE of sulfonylureas enabled the 0.1 microg L(-1) and 1 ng L(-1) LOQ levels to be reached, respectively. The on-line SPE-LC-MS-MS method allowed the accurate quantitation of all sulfonylureas and three degradation products at 0.1 microg L(-1) or below in natural water, with an average repeatability of 8%.

Glyphosate and AMPA analysis in sewage sludge by LC-ESI-MS/MS after FMOC derivatization on strong anion-exchange resin as solid support

An innovative analytical method has been developed for the determination of glyphosate and aminomethylphosphonic acid (AMPA), its major metabolite, in sewage sludge. This method involved an alkaline extraction from sludge and purification on a strong anion-exchange resin. While the analytes remained fixed by ionic interactions, an "on-solid support" derivatization by FMOC-Cl was carried out. This versatile approach allowed a 10 min reaction and simple elimination of the excess of reagent. The resulting derivatives remained retained by ionic and hydrophobic interactions with the resin until being eluted by a mixed NaCl water/acetonitrile, 70/30, v/v, solution. After an appropriate dilution and adjustment of the pH, the sample was concentrated on an Oasis HLB solid-phase cartridge. For quality analysis of traces in complex matrixes, LC-ESI-MS/MS in the multiple reaction monitoring positive mode was used fulfilling the European Union requirements (Decision 2002/657/CE). To overcome the matrix effects, stable isotopically labeled standards were added to the sludge extracts as internal standards and were thus derivatized during the procedure in parallel to the analytes. Mean recovery values were 70% +/- 7% for glyphosate and 63% +/- 3% for AMPA. Limits of detection (20 and 30 ppb dw) and limits of quantification (35 and 50 ppb dw) for glyphosate and AMPA, respectively, were sufficient to monitor samples taken from Ile-de-France wastewater treatment plants where contamination currently reached 0.1-3 ppm and 2-35 ppm dw for glyphosate and AMPA, respectively.

Photo-induced degradation of diuron in aqueous solution by nitrites and nitrates: kinetics and pathways

The photo-induced degradation of diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) in aqueous solution under simulated solar irradiation has been investigated in the presence of NO3-/NO2- ions. The degradation rates were compared by varying environmental parameters including substrate and inducer concentrations, oxygen content and pH. The photoproducts were identified by extensive LC-ESI-MS and LC-ESI-MS-MS studies after SPE preconcentration on prepacked cartridges. In both NO3- and NO2- conditions, oxidation of the N-(CH3)2 terminus group is the main process leading to the N-monodemethylated (NHCH3), N-formyl (N(CH3)CHO) and the uncommon and unstable carbinolamine (N(CH3)CH2OH) by-products. Cl/OH substituted and nitrated phenylureas are formed minorily. Degradation pathways involving OH* and NO2* (or dimer) radicals as reactive species are proposed.

Structural characterization of the major flavonoid glycosides from Arabidopsis thaliana seeds

Information gains from the seed of the model plant Arabidopsis thaliana (Brassicaceae) have greatly contributed to a better understanding of flavonoid synthesis and may be used for crop improvement. However, exhaustive identification of the flavonoid accumulated in Arabidopsis seed was still lacking. Complementary investigations of seed flavonoids by LC-ESI-MS, LC-ESI-MS-MS, and NMR spectroscopy in Arabidopsis led to full characterization of monoglycosides, namely, quercetin 3-O-alpha-rhamnopyranoside and kaempferol 3-O-alpha-rhamnopyranoside, and diglycosides, namely, quercetin and kaempferol 3-O-beta-glucopyranoside-7-O-alpha-rhamnopyranoside and quercetin and kaempferol 3,7-di-O-alpha-rhamnopyranoside. Interestingly, the tt7 mutant that lacks flavonoid-3'-hydroxylase and consequently accumulates only kaempferol derivatives was shown to contain three additional products, kaempferol 3-O-beta-glucopyranoside, kaempferol 3-O-alpha-rhamnopyranoside-7-O-beta-glucopyranoside, and the triglycoside kaempferol 3-O-beta-[alpha-rhamnopyranosyl(1-->2)-glucopyranoside]-7-O-alpha-rhamnopyranoside. Taken together these results allow a scheme for flavonol glycosylation to be proposed.

Determination of frequently detected herbicides in water by solid-phase microextraction and gas chromatography coupled to ion-trap tandem mass spectrometry

A method based on solid-phase microextraction (SPME) coupled with GC and ion trap tandem mass spectrometry has been developed for the analysis of nine herbicides and degradation products, among the most frequently found in natural water. A polydimethylsiloxane-divinylbenzene (PDMS-DVB)-coated fiber was selected to extract the analytes directly from the samples over the 0.01-1 microg L(-1) concentration range. Optimization of manual and automated SPME was performed on the basis of desorbed amounts, via various factorial experiment designs. Of the two modes, the automated one was found to be the most efficient. Memory effect was avoided owing to the 10-min fiber desorption time. Limits of detection reached down to below 0.01 microg L(-1) and repeatability ranged from 3 to 15% in natural water. A validation study was conducted involving the quantitation of the target compounds in Seine water with SPME/GC-MS-MS external calibration.

Flavonoid diversity and biosynthesis in seed of Arabidopsis thaliana

Functional characterization of genes involved in the flavonoid metabolism and its regulation requires in-depth analysis of flavonoid structure and composition of seed from the model plant Arabidopsis thaliana. Here, we report an analysis of the diverse and specific flavonoids that accumulate during seed development and maturation in wild types and mutants. Wild type seed contained more than 26 different flavonoids belonging to flavonols (mono and diglycosylated quercetin, kaempferol and isorhamnetin derivatives) and flavan-3-ols (epicatechin monomers and soluble procyanidin polymers with degrees of polymerization up to 9). Most of them are described for the first time in Arabidopsis. Interestingly, a novel group of four biflavonols that are dimers of quercetin-rhamnoside was also detected. Quercetin-3-O-rhamnoside (the major flavonoid), biflavonols, epicatechin and procyanidins accumulated in the seed coat in contrast to diglycosylated flavonols that were essentially observed in the embryo. Epicatechin, procyanidins and an additional quercetin-rhamnoside-hexoside derivative were synthesized in large quantities during seed development, whereas quercetin-3-O-rhamnoside displayed two peaks of accumulation. Finally, 11 mutants affected in known structural or regulatory functions of the pathway and their three corresponding wild types were also studied. Flavonoid profiles of the mutants were consistent with previous predictions based on genetic and molecular data. In addition, they also revealed the presence of new products in seed and underlined the plasticity of this metabolic pathway in the mutants.

Profiling isoflavone conjugates in root extracts of lupine species with LC/ESI/MSn systems

Extracts obtained from roots of three lupine species (Lupinus albus, L. angustifolius, L. luteus) were analysed using LC/UV and LC/ESI/MS(n). The experiments were performed using two mass spectrometric systems, equipped with the triple quadrupole or ion trap analysers. Thirteen to twenty isomeric isoflavone conjugates were identified in roots of the investigated lupine species. These were di- and monoglycosides of genistein and 2'-hydroxygenistein with different patterns of glycosylation, both at oxygen and carbon atoms; some glycosides were acylated with malonic acid. It was not possible to establish the glycosylation sites of the aglycone only on the basis of the registered mass spectra; however, it was possible to differentiate C- and O-glucosides of isoflavones. Only comparison of retention times with those of standard compounds permitted to indicate the correct glycosylation pattern. In the case of diglycosides, the glycosylation pattern (O-diglucoside or O-glucosylglucoside) was distinguishable on the basis of the relative intensities of daughter ions in the mass spectra of protonated molecular ions. It was not possible to elucidate the site of malonylation on the sugar moiety from mass spectra, however, protonated molecules [M + H](+) of isoflavone glucosides with different placement of the malonyl group on the sugar ring were recognized in the extracts. In addition to the isoflavone glycosides, some flavone or flavonol glycosides were identified in the samples on the basis of collision-induced daughter ion spectra of the aglycone ions. A comparison of results obtained with the triple quadrupole and ion trap analysers was done in the course of the investigations.