During investigations on the peroxidase-catalysed oxidation of polyhydroxylated monoaromatic substrates such as 5-methylpyrogallol, we observed a spectacular dimerisation proceeding by dearomatisation in contrast with most common reaction patterns involving phenolics oxidation and dimerization. A tetracyclic fused product featuring an unusual 2-oxatetracyclo [6.3.1.0.0] dodecan-3-one core was obtained and characterized by combined NMR techniques and high resolution mass spectroscopy (HRMS). This is an example of a spontaneous cascade triggered by a simple enzymatic reaction that could provide new options for biosynthetic hypothesis and a synthetic method to access this complex core in one operation.
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http://dx.doi.org/10.3390/molecules23102619 | DOI Listing |
Nat Commun
December 2024
National Key Laboratory of Green Pesticide, International Joint Research Center for Intelligent Biosensor Technology and Health, College of Chemistry, Central China Normal University, Wuhan, P.R. China.
Skeleton editing for heteroarenes, especially pyrazoles, is challenging and remains scarce because these non-strained aromatics exhibit inert reactivities, making them relatively inactive for performing a dearomatization/cleavage sequence. Here, we disclose a cycloaddition-induced scaffold hopping of 5-hydroxypyrazoles to access the pyrazolopyridopyridazin-6-one skeleton through a single-operation protocol. By converting a five-membered aza-arene into a five-unit spine of a 6/6 fused-bicyclic, this work unlocks a ring-opening reactivity of the pyrazole core that involves a formal C = N bond cleavage while retaining the highly reactive N-N bond in the resulting product.
View Article and Find Full Text PDFNat Commun
December 2024
Department of Biochemistry, McGill University, Montreal, QC, Canada.
Proteostasis is maintained through regulated protein synthesis and degradation and chaperone-assisted protein folding. However, this is challenging in neuronal projections because of their polarized morphology and constant synaptic proteome remodeling. Using high-resolution fluorescence microscopy, we discover that hippocampal and spinal cord motor neurons of mouse and human origin localize a subset of chaperone mRNAs to their dendrites and use microtubule-based transport to increase this asymmetric localization following proteotoxic stress.
View Article and Find Full Text PDFArch Pharm (Weinheim)
January 2025
School of Chemistry and Pharmaceutical Engineering, Huanghuai University, Zhumadian, Henan, China.
Cancer, characterized by uncontrolled growth and spread of abnormal cells potentially influencing almost all tissues in the body, is one of the most devastating and lethal diseases throughout the world. Chemotherapy is one of the principal approaches for cancer treatment, but multidrug resistance and severe side effects represent the main barriers to the success of therapy, creating a vital need to develop novel chemotherapeutic agents. The 1,2,3-triazole moiety can be conveniently constructed by "click chemistry" and could exert diverse noncovalent interactions with various enzymes in cancer cells.
View Article and Find Full Text PDFJACS Au
December 2024
Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060, United States.
Red-light absorbing photoredox catalysts offer potential advantages for large-scale reactions, expanding the range of usable substrates and facilitating bio-orthogonal applications. While many red-light absorbing/emitting fluorophores have been developed recently, functional red-light absorbing photoredox catalysts are scarce. Many photoredox catalysts rely on long-lived triplet excited states (triplets), which can efficiently engage in single electron transfer (SET) reactions with substrates.
View Article and Find Full Text PDFOptica
December 2024
Department of Medical Physics and Biomedical Engineering, University College London, London, WC1E 6BT, UK.
X-ray dark-field imaging highlights sample structures through contrast generated by sub-resolution features within the inspected volume. Quantifying dark-field signals generally involves multiple exposures for phase retrieval, separating contributions from scattering, refraction, and attenuation. Here, we introduce an approach for non-interferometric X-ray dark-field imaging that presents a single-parameter representation of the sample.
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