Metabolism of ibuprofen in higher plants: A model Arabidopsis thaliana cell suspension culture system.

The uptake and metabolism of ibuprofen (IBU) by plants at the cellular level was investigated using a suspension culture of A. thaliana. Almost all IBU added to the medium (200 µM) was metabolized or bound to insoluble structures in 5 days. More than 300 metabolites were determined by liquid chromatography-high resolution mass spectrometry (LC-HRMS) analysis, and most of these are first reported for plants here. Although hydroxylated derivatives formed by oxidation on the isobutyl side chain were the main first-step products of IBU degradation, conjugates of these products with sugar, methyl and amino acid groups were the dominant metabolites in the culture. The main portion of total added IBU (81%) was accumulated in the extractable intracellular pool, whereas the cultivation medium fraction contained only 19%. The amount of the insoluble cell-wall-bound IBU was negligible (0.005% of total IBU).

Lorazepam photofate under photolysis and TiO2-assisted photocatalysis: identification and evolution profiles of by-products formed during phototreatment of a WWTP effluent.

This manuscript reports on the study of Lorazepam (LZP) phototransformation pathways under artificial UV and natural solar irradiation, through photolytic and TiO2-assisted photocatalytic processes. Three experimental set-ups were employed: two lab-scale photoreactors, each provided with an UV lamp (one medium pressure mercury lamp and one blacklight blue lamp), and a pilot-scale Solar Plant with Compound Parabolic Collectors (CPCs). Samples collected along the different phototreatment experiments were analyzed by ultra-high performance liquid chromatography-quadrupole-time-of-flight-mass spectrometry (UHPLC/QqToF-MS). The key assumption of the analytical approach was that related compounds (LZP and its by-products (LBPs)) provide identical "diagnostic fragment ions". Identification was also based on the chlorine atoms specific isotopic pattern, as well as accurate masses. Six major LBPs were identified and elucidated, with nominal [M + H](+) masses of 337, 303, 319, 275, 291 and 293 Da. The proposed LZP photodegradation mechanism included the initial opening of the diazepinone seven-membered ring, followed by a rearrangement into a highly stabilized six-membered aromatic ring and subsequent cleavage and/or hydroxylation reactions. The evolution profiles of LBPs were described for each of the three experimental prototypes and the CPCs Solar Pilot Plant proved to be the most efficient one. Finally, LZP photocatalytic degradation was further assessed on a municipal effluent, where the photoproducts generated showed to be more persistent than LZP itself.

In vitro susceptibility of Plasmodium falciparum isolates from Abidjan, Côte d'Ivoire, to artemisinin, chloroquine, dihydroartemisinin and pyronaridine.

Côte d'Ivoire is an endemic area for Plasmodium falciparum malaria, with perennial transmission in the southern forest and seasonal transmission in the northern savannah. Change of first-line treatment of uncomplicated malaria to artemisinin-combination therapy (ACT) is widespread in the country as elsewhere in Africa. The present study was conducted to assess the in vitro response of Plasmodium falciparum to antimalarial drugs currently used in the country (chloroquine, artemisinin and dihydroartemisinin) and new drugs that could be used in the near future (pyronaridine) and to analyse the pattern of cross-resistance between these drugs. The standard in vitro drug sensitivity microtechnique recommended by the World Health Organization was used to assess the sensitivity of Plasmodium falciparum isolates collected in Abidjan (Côte d'Ivoire) between April and December 2006. Of 128 in vitro tests performed, 112 (87.5%) were successful. Among them, 32, 27, 25, and 28 P. falciparum isolates grew satisfactorily and yield interpretable results for chloroquine, pyronaridine, artemisinin, and dihydroartemisinin respectively. The proportions of resistant isolates were 56.2% for chloroquine, 48% for pyronaridine, 36% for artemisinin and 3.6% for dihydroartemisinin. The most potent drug was dihydroartemisinin with a geometric mean IC50 of 2.72 nM ranged from 1.45 to 3.99 nM. No multi-resistant isolates (showing resistance to more than three drugs) were found. A positive correlation was found between the IC50 values for the following drugs: chloroquine and pyronaridine (r=0.45), pyronaridine and dihydroartemisinin (r=0.40), chloroquine and artemisinin (r=0.68), artemisinin and dihydroartemisinin (r=0.62). Data suggested cross-resistance between these drugs and warrant an improved surveillance programme for drug resistance to malaria in Côte d'Ivoire.

Novel approaches in analysis of Fusarium mycotoxins in cereals employing ultra performance liquid chromatography coupled with high resolution mass spectrometry.

Rapid, simple and cost-effective analytical methods with performance characteristics matching regulatory requirements are needed for effective control of occurrence of Fusarium toxins in cereals and cereal-based products to which they might be transferred during processing. Within this study, two alternative approaches enabling retrospective data analysis and identification of unknown signals in sample extracts have been implemented and validated for determination of 11 major Fusarium toxins. In both cases, ultra-high performance liquid chromatography (U-HPLC) coupled with high resolution mass spectrometry (HR MS) was employed. (13)C isotopically labeled surrogates as well as matrix-matched standards were employed for quantification. As far as time of flight mass analyzer (TOF-MS) was a detection tool, the use of modified QuEChERS (quick easy cheap effective rugged and safe) sample preparation procedure, widely employed in multi-pesticides residue analysis, was shown as an optimal approach to obtain low detection limits. The second challenging alternative, enabling direct analysis of crude extract, was the use of mass analyzer based on Orbitrap technology. In addition to demonstration of full compliance of the new methods with Commission Regulation (EC) No. 401/2006, also their potential to be used for confirmatory purposes according to Commission Decision 2002/657/EC has been critically assessed.

Novel approach to fast determination of multiple pesticide residues using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

A rapid, high-throughput method employing ultra-performance liquid chromatography with tandem quadrupole mass spectrometry (UPLC-MS/MS) was developed and optimized for simultaneous quantification and confirmation of 64 pesticide residues and their toxic metabolites in fruit extracts prepared by a buffered QuEChERS procedure. The total time required for UPLC-MS/MS analysis was 8 min plus 2 min for re-equilibration to the initial UPLC conditions. Performance characteristics were determined for apple extracts spiked at 10 microg kg(-1). The repeatability of measurements expressed as relative standard deviations was in the range 1.5-13% at this level for most analytes. Thanks to very low limits of quantification (<10 microg kg(-1)for the majority of pesticides), an optimized method allows for the reliable control of not only common maximum residue limits (MRLs) set by European Union regulation for various pesticides/fruit combinations, but also of a uniform MRL of 10 microg kg(-1)endorsed for baby food.