The mutagenicity of nitroarenes for Salmonella typhimurium strains with adenine-thymine base pairs at the mutational site is dependent upon enzymic reduction of the nitro function. Although the electrophilic metabolites of nitroarenes are capable of mutating adenine-thymine base pairs, they show a marked preference for guanine-cytosine pairs when given a choice. Quantum chemical calculations indicate the reactivity order for nucleophilic sites in an AT run of base pairs to be the N-7 of adenine (N7(A)) first, followed by an approximately equal reactivity for C-8 of adenine (C8(A)) and O4 of thymine (O4(T)). Given the low probability of reaction of electrophilic metabolites of nitroarenes with adenine-thymine base pairs, the mutagenic potency of nitroarenes for strains with adenine-thymine base pairs at the mutational site is remarkable.
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http://dx.doi.org/10.1016/0027-5107(85)90146-0 | DOI Listing |
J Pharm Sci
January 2025
Ionis Pharmaceuticals, Inc., 2855 Gazelle Ct., Carlsbad, CA 92010. Electronic address:
Complexes formed between aluminum cluster molecules that adopt a Ɛ-Al-Keggin structure and antisense oligonucleotides were observed as new impurity peaks during drug product stability testing. The Ɛ-Al-Keggin molecules were determined to be artifacts of the analysis, originating from contact between antisense oligonucleotide drug product solution and aluminum weigh boats used to prepare the analytical sample solutions The presence of the Ɛ-Al-Keggin molecules was confirmed through synthesis of the Keggin molecule through an established route and subsequent spiking studies. Binding affinity studies revealed that the Ɛ-Al-Keggin bound to oligonucleotide sequences of various lengths (10 to 20 bases) and base compositions, though there is some evidence for preferential binding to 5-methylcytosine-containing sequences.
View Article and Find Full Text PDFMol Genet Genomic Med
February 2025
Department of Chemistry and Molecular Biology, Gothenburg University, Gothenburg, Sweden.
Background: SYNGAP1 encodes a Ras/Rap GTPase-activating protein that is predominantly expressed in the brain with the functional roles in regulating synaptic plasticity, spine morphogenesis, and cognition function. Pathogenic variants in SYNGAP1 have been associated with a spectrum of neurodevelopmental disorders characterized by developmental delays, intellectual disabilities, epilepsy, hypotonia, and the features of autism spectrum disorder. The aim of this study was to identify a novel SYNGAP1 gene variant linked to neurodevelopmental disorders and to evaluate the pathogenicity of the detected variant.
View Article and Find Full Text PDFAcc Chem Res
January 2025
The Wolfson Catalysis Centre, Department of Chemistry, University of Oxford, Oxford OX1 3QR, U.K.
ConspectusThe discovery of reversible hydrogenation using metal-free phosphoborate species in 2006 marked the official advent of frustrated Lewis pair (FLP) chemistry. This breakthrough revolutionized homogeneous catalysis approaches and paved the way for innovative catalytic strategies. The unique reactivity of FLPs is attributed to the Lewis base (LB) and Lewis acid (LA) sites either in spatial separation or in equilibrium, which actively react with molecules.
View Article and Find Full Text PDFChem Asian J
January 2025
Indian Institute of Science Education and Research Bhopa;, Chemistry, IISER Bhopal, Chemistry, #229,, Academic Building #2, Bhopal bypass road, Bhauri, 462066, Bhopal, INDIA.
Polymerases erroneously incorporate Guanine-Thymine (dG•dT) mismatches in genomic DNA that further evades repair by transient sampling of tautomeric/ionic states compromising fidelity of repairing dG•dT mismatches. In conjunction, significant frequency of ribose (mis)incorporation in duplex DNA permits for misincorporated-mismatch in the genome. Ribose incorporated G(rG) mismatched with T(rG•dT) is the most stable across all misincorporated-mismatch calling into question the conformational consequences of the ribose sugar in addition to the mismatch.
View Article and Find Full Text PDFActa Parasitol
January 2025
Laboratory of Morpho-Molecular Integration and Technologies, Federal Rural University of the Amazon (UFRA), Belém, State of Pará, Brazil.
Purpose: This work described a new species of Ceratomyxa, based on morphological and phylogenetic analyzes of myxospores collected from the gallbladder of the fish Astyanax mexicanus.
Methods: Sixty-two specimens were captured, between December 2022 and February 2024, in the Flexal River, in the community of Tessalônica, state of Amapá. The specimens were transported alive to the Laboratory of Morphophysiology and Animal Health, at the State University of Amapá, where the studies were carried out.
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