It has been found that flavonoids (FL) are able to reduce, add or oxidize alpha-hydroxyethyl radicals (HER). The probability of these processes to occur depends on the structure of the FL under study. Namely, to cause reduction of HER, the presence of hydroxyl groups is necessary, and to effect oxidation or addition of HER, the presence of a carbonyl group at C4 and a C2-C3 double bond in the C ring is required.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.bmcl.2005.06.065 | DOI Listing |
J Chem Phys
January 2024
MTA-ELTE Lendület Laboratory Astrochemistry Research Group, Institute of Chemistry, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest, Hungary.
The α-hydroxyethyl radical (CH3·CHOH, 2A) is a key intermediate in ethanol biochemistry, combustion, atmospheric chemistry, radiation chemistry, and astrochemistry. Experimental data on the vibrational spectrum of this radical are crucially important for reliable detection and understanding of the chemical dynamics of this species. This study represents the first detailed experimental report on the infrared absorption bands of the α-hydroxyethyl radical complemented by ab initio computations.
View Article and Find Full Text PDFPhys Chem Chem Phys
February 2023
Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.
This paper addresses the basic question of the impact of a chemically inert environment on the radiation-induced transformations of isolated organic molecules in icy media at cryogenic temperatures with possible implications for astrochemical issues. The radicals produced by X-ray irradiation of isolated ethanol molecules (CHOH and CHCDOH) in solid argon and xenon matrices at 7 K were characterized by electron paramagnetic resonance (EPR) spectroscopy. It was shown that methyl (CH˙) and formyl (HCO˙) radicals resulting from the C-C bond cleavage were mainly produced in the case of solid argon, which was attributed to the significant role of "hot" ionic fragmentation and inefficient energy dissipation to medium.
View Article and Find Full Text PDFJ Am Chem Soc
October 2022
State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian116023, China.
Photocatalytic C-C bond formation coupled with H production provides a sustainable approach to producing carbon-chain-prolonged chemicals and hydrogen energy. However, the involved radical intermediates with open-shell electronic structures are highly reactive, experiencing predominant oxidative or reductive side reactions in semiconductors. Herein, we demonstrate that hydrogen bonding on the catalyst surface and in the bulk solution can inhibit oxidation and reverse reaction of α-hydroxyethyl radicals (αHRs) in photocatalytic dehydrocoupling of ethanol over Au/CdS.
View Article and Find Full Text PDFJ Phys Chem A
June 2021
College of Chemical Engineering, Sichuan University, Chengdu 610065, P. R. China.
α-Site alcohol radicals are the most important products of H-abstract reactions from alcohols since the hydroxyl moiety weakens the α-site C-H bond. Reactions between α-site alcohol radicals and O play an important role in combustion of alcohols, especially at relatively low temperatures. However, reliable reaction pathways and rate constants for these reactions are still lacking.
View Article and Find Full Text PDFPhys Chem Chem Phys
May 2021
Division of Physical Chemistry, Ruđer Bošković Institute, Bijenička cesta 54, HR-10000, Zagreb, Croatia.
We measured and computed the rate constants of the reaction between the α-hydroxyethyl radical (˙CH(CH3)OH) and bromoacetate (BrCH2CO2-) in the non-buffered (NB), as well as in the bicarbonate (HCO3-) and hydrogen phosphate (HPO42-) buffered aqueous solutions in the presence of ethanol. These complex multistep reactions are initiated by the proton-coupled electron transfer (PCET) which reduces BrCH2CO2- and incites its debromination. The PCET is followed by the step in which the resulting carboxymethyl radical propagates a radical chain reaction thus recovering ˙CH(CH3)OH and enhancing the debromination yields.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!