Ruthenium-catalysis enabled the C-5 selective C-H oxygenation of naphthoquinones, and also sets the stage for the site-selective introduction of a hydroxyl group into anthraquinones. A-ring modified naphthoquinoidal compounds represent an important class of bioactive quinones for which the present study encompasses the first C-H oxygenation strategy by weak O-coordination.
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http://dx.doi.org/10.1039/c8cc07572g | DOI Listing |
Chembiochem
January 2025
Renmin University of China, Chemistry, No.59 Zhongguangcun Street, Haidian District, 100872, Beijing, CHINA.
BTG13, a non-heme iron-dependent enzyme with a distinctive coordination environment of four histidines and a carboxylated lysine, has been found to catalyze the cleavage of the C4a-C10 bond in anthraquinone. Contrary to typical dioxygenase mechanisms, our quantum mechanical/molecular mechanical (QM/MM) calculations reveal that BTG13 functions more like a monooxygenase. It selectively inserts an oxygen atom into the C10-C4a bond, creating a lactone species that subsequently hydrolyzes, leading to the formation of a ring-opened product.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States.
Photochemistry-based silica formation offers a pathway toward energy-efficient and controlled fabrication processes. While the transformation of poly(dimethylsiloxane) (PDMS) to silica (often referred to as SiO due to incomplete conversion) under deep ultraviolet (DUV) irradiation in the presence of oxygen/ozone has experimentally been validated, the detailed mechanism remains elusive. This study demonstrates the underlying molecular-level mechanism of PDMS-to-silica conversion using density functional theory (DFT) calculations.
View Article and Find Full Text PDFMolecules
December 2024
School of Electrical Engineering, Shandong University, Jinan 250061, China.
In recent years, plasma medicine has developed rapidly as a new interdisciplinary discipline. However, the key mechanisms of interactions between cold atmospheric plasma (CAP) and biological tissue are still in the exploration stage. In this study, by introducing the reactive molecular dynamics (MD) simulation, the capsid protein (CA) molecule of HIV was selected as the model to investigate the reaction process upon impact by reactive oxygen species (ROS) from CAP and protein molecules at the atomic level.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720.
Polysaccharide monooxygenase (PMO) catalysis involves the chemically difficult hydroxylation of unactivated C-H bonds in carbohydrates. The reaction requires reducing equivalents and will utilize either oxygen or hydrogen peroxide as a cosubstrate. Two key mechanistic questions are addressed here: 1) How does the enzyme regulate the timely and tightly controlled electron delivery to the mononuclear copper active site, especially when bound substrate occludes the active site? and 2) How does this electron delivery differ when utilizing oxygen or hydrogen peroxide as a cosubstrate? Using a computational approach, potential paths of electron transfer (ET) to the active site copper ion were identified in a representative AA9 family PMO from (PMO9E).
View Article and Find Full Text PDFChemistry
January 2025
Boreskov Institute of Catalysis SB RAS, Siberian Branch of Russian Academy of Sciences, RUSSIAN FEDERATION.
Cu-modified zeolites provide methane conversion to methanol with high selectivity under mild conditions. The activity of different possible Cu-sites for methane transformation is still under discussion. Herein, ZSM-5 zeolite has been loaded with Cu2+ cations (1.
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