This study was undertaken to characterize the mechanism of toxicokinetic interaction between toluene (TOL) and m-xylene (XYL) in the rat using physiologically-based toxicokinetic (PBTK) modeling approach. First, the metabolic rate constants were determined by conducting closed-chamber inhalation exposures with individual solvents (Vmax: TOL = 4.8, XYL = 8.4 mg/hr/kg; Km: TOL = 0.55, XYL = 0.2 mg/l). Then, using the same experimental set-up, rats were exposed to different binary mixtures of TOL and XYL. PBTK analysis of the data showed competitive inhibition as the plausible mechanism of TOL/XYL interaction. This mechanistic modeling study suggests that the interaction between TOL and XYL is likely to be observed when the exposure concentration exceeds 50 ppm of each solvent.
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http://dx.doi.org/10.1007/BF00381325 | DOI Listing |
J Chem Theory Comput
December 2024
Advanced Computing, Mathematics and Data Division, Pacific Northwest National Laboratory, P.O. Box 999, MS J7-10, Richland, Washington 99352, United States.
Iron-sulfur clusters are crucial for biological electron transport and catalysis. Obtaining accurate geometries, energetics, manifolds of their excited electronic states, and reduction energies is important to understand their role in these processes. Using a [2Fe-2S] model complex with Fe and Fe oxidation states, which leads to different charges, i.
View Article and Find Full Text PDFAcc Chem Res
September 2023
College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, China.
ConspectusAtropisomers bearing a rotation-restricted axis are common structural units in natural products, chiral ligands, and drugs; thus, the prevalence of asymmetric synthesis has increased in recent decades. Research into atropisomers featuring an N-containing axis (N-X atropisomers) remains in its infancy compared with the well-developed C-C atropisomer analogue. Notably, N-X atropisomers could offer divergent scaffolds, which are extremely important in bioactive molecules.
View Article and Find Full Text PDFMaterials (Basel)
October 2021
Faculty of Chemistry, Nicolaus Copernicus University in Toruń, Gagarina 7, 87-100 Toruń, Poland.
This article discusses the properties of as many as 30 carbene-ZnX2 (X = H, Me, Et) complexes featuring a zinc bond C⋯Zn. The group of carbenes is represented by imidazol-2-ylidene and its nine derivatives (labeled as IR), in which both hydrogen atoms of N-H bonds have been substituted by R groups with various spatial hindrances, from the smallest Me, iPr, tBu through Ph, Tol, and Xyl to the bulkiest Mes, Dipp, and Ad. The main goal is to study the relationship between type and size of R and X and both the strength of C⋯Zn and the torsional angle of the ZnX2 plane with respect to the plane of the imidazol-2-ylidene ring.
View Article and Find Full Text PDFEven though homoatomic nine-atom germanium clusters are known for two decades, their chemical properties are still rarely investigated. We now discovered that Zintl ion main group-element clusters possess a reactive lone pair of electrons, and we show a new pathway to bind ligands with functional groups to the [Ge] cluster core through Ge-C bond formation. We report on the reactivity of [Ge{Si(TMS)}] (TMS = trimethylsilyl) towards a series of Lewis acidic bromo-boranes.
View Article and Find Full Text PDFmBio
February 2021
Systems Biology Department, Centro Nacional de Biotecnología-CSIC, Campus de Cantoblanco, Madrid, Spain
Despite intensive research on the biochemical and regulatory features of the archetypal catabolic TOL system borne by pWW0 of strain mt-2, the physical arrangement and tridimensional logic of the gene expression flow remains unknown. In this work, the spatial distribution of specific mRNAs with respect to the host nucleoid, the TOL plasmid, and the ribosomal pool has been investigated. hybridization of target transcripts with fluorescent oligonucleotide probes revealed that mRNAs cluster in discrete foci, adjacent but clearly separated from the TOL plasmid and the cell nucleoid.
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