This work set out the laboratory calibration of the passive samplers such as polar organic chemical integrative samplers (POCISs) which preconcentrate hydrophilic organic contaminants in aqueous medium. We compared the two different configurations available (i.e. pesticide and pharmaceutical POCISs) for sampling different classes of herbicides representative of a wide range of polarity (5.34>of=log Kow>or=-1.70). The results showed that pharmaceutical configuration was probably more convenient for sampling basic, neutral or acidic herbicides. Afterward, we performed a kinetic study with the pharmaceutical POCIS only. This calibration revealed linear and integrative uptakes of several herbicides for 21 days. For some compounds like sulcotrione, mesotrione, deisopropylatrazine (DIA) and deethylatrazine (DEA), the linear uptake model was only valid for 10 days. Lastly, we observed an increase of the sampling rates with the hydrophobicity of the herbicides.
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http://dx.doi.org/10.1016/j.chroma.2007.03.087 | DOI Listing |
Sci Adv
January 2025
PSI Center for Energy and Environmental Sciences, Paul Scherrer Institute, 5232 Villigen, Switzerland.
Glaciers serve as natural archives for reconstructing past changes of atmospheric aerosol concentration and composition. While most ice-core studies have focused on inorganic species, organic compounds, which can constitute up to 90% of the submicrometer aerosol mass, have been largely overlooked. To our knowledge, this study presents the first nontarget screening record of secondary organic aerosol species preserved in a Belukha ice core (Siberia, Russian Federation), ranging from the pre-industrial to the industrial period (1800-1980 CE).
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 München, Germany.
Free ions in organic solvents of low polarity would be valuable tools for the activation of low-reactivity substrates. However, the formation of unreactive ion pairs at concentrations relevant for synthesis has prevented the success of this concept so far. On the example of highly nucleophilic pyridinamide phosphonium salts in dichloromethane, we show that asymmetric aggregation offers a solution to this general problem.
View Article and Find Full Text PDFMar Drugs
December 2024
G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, Pr. 100-let Vladivostoku 159, 690022 Vladivostok, Russia.
In their shapes, molecules of some bipolar metabolites resemble the so-called bola, a hunting weapon of the South American inhabitants, consisting of two heavy balls connected to each other by a long flexible cord. Herein, we discuss the structures and properties of these natural products (bola-like compounds or bolaamphiphiles), containing two polar terminal fragments and a non-polar chain (or chains) between them, from archaea, bacteria, and marine invertebrates. Additional modifications of core compounds of this class, for example, interchain and intrachain cyclization, hydroxylation, methylation, etc.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
Modulation of optical properties through smart protein matrices is exemplified by a few examples in nature such as rhodopsin (absorption wavelength tuning) and the green fluorescence protein (emission), but in general, the scope found in nature for the matrix-controlled photofunctions remains rather limited. In this review, we present cyclophane-based supramolecular host-guest complexes for which electronic interactions between the cyclophane host and mostly planar aromatic guest molecules can actively modulate excited-state properties in a more advanced way involving both singlet and triplet excited states. We begin by highlighting photofunctional host-guest systems for on-off fluorescence switching and chiroptical functions using bay-functionalized perylene bisimide cyclophanes.
View Article and Find Full Text PDFJ Med Chem
January 2025
Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic v.v.i., Prague 160 00, Czech Republic.
Itaconate, an endogenous immunomodulator from the tricarboxylic acid (TCA) cycle, shows therapeutic effects in various disease models, but is highly polar with poor cellular permeability. We previously reported a novel, topical itaconate derivative, SCD-153, for the treatment of alopecia areata. Here, we present the discovery of orally available itaconate derivatives for systemic and skin disorders.
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