Search results for "radical"
showing 10 items of 1401 documents
A Vastly Increased Chemical Variety of RNA Modifications Containing a Thioacetal Structure
2018
International audience; Recently discovered new chemical entities in RNA modifications have involved surprising functional groups that enlarge the chemical space of RNA. Using LC-MS, we found over 100 signals of RNA constituents that contained a ribose moiety in tRNAs from E. coli. Feeding experiments with variegated stable isotope labeled compounds identified 37 compounds that are new structures of RNA modifications. One structure was elucidated by deuterium exchange and high-resolution mass spectrometry. The structure of msms2 i6 A (2-methylthiomethylenethio-N6-isopentenyl-adenosine) was confirmed by methione-D3 feeding experiments and by synthesis of the nucleobase. The msms2 i6 A contai…
Identification and Quantification of Valuable Compounds in Red Grape Seeds
2021
Grape seeds are a by-product of the wine industry. They represent 38–52% of grape pomace and about 5% of the weight of grapes. The main objective of this study is to establish some important characteristics of grape seeds from red varieties cultivated in Romania. The analyzed grape varieties were Cabernet Sauvignon, Merlot, Pinot noir, Burgund Mare, Cadarcă, Syrah, Novac. The grape seeds were dried and ground and the following determinations were made: determination of total polyphenol content, antioxidant capacity, antiradical capacity and determination of phenolic compounds. The analyses were performed on the first day after obtaining the grape extract, on the 14th day and the 30th day. T…
Training session intensity affects plasma redox status in amateur rhythmic gymnasts
2016
Purpose: The aim of this study was to examine systemic responses of oxidant/antioxidant status following 2 training sessions of different intensity in amateur rhythmic gymnasts. Methods: Before the experimental training, 10 female gymnasts performed a gradually increased exercise test to assess maximal heart rate, maximal oxygen consumption, and anaerobic threshold. They executed 2 intermittent training sessions separated by 48 h of recovery (48 h-post R): the first was performed at low-moderate intensity (LMI) and the second at high intensity (HI). Blood samples were collected immediately pre- and post-training and 48 h-post R. Hydroperoxide level (OxL) and total antioxidant capacity (TAC)…
Modern diversification of the amino acid repertoire driven by oxygen
2017
All extant life employs the same 20 amino acids for protein biosynthesis. Studies on the number of amino acids necessary to produce a foldable and catalytically active polypeptide have shown that a basis set of 7-13 amino acids is sufficient to build major structural elements of modern proteins. Hence, the reasons for the evolutionary selection of the current 20 amino acids out of a much larger available pool have remained elusive. Here, we have analyzed the quantum chemistry of all proteinogenic and various prebiotic amino acids. We find that the energetic HOMO-LUMO gap, a correlate of chemical reactivity, becomes incrementally closer in modern amino acids, reaching the level of specialize…
The unusual structure of Ruminococcin C1 antimicrobial peptide confers clinical properties.
2020
The emergence of superbugs developing resistance to antibiotics and the resurgence of microbial infections have led scientists to start an antimicrobial arms race. In this context, we have previously identified an active RiPP, the Ruminococcin C1, naturally produced by Ruminococcus gnavus E1, a symbiont of the healthy human intestinal microbiota. This RiPP, subclassified as a sactipeptide, requires the host digestive system to become active against pathogenic Clostridia and multidrug-resistant strains. Here, we report its unique compact structure on the basis of four intramolecular thioether bridges introduced post-translationally by a specific radical-SAM sactisynthase. This structure con…
The Burden of Respiratory Syncytial Virus Disease in Pre-Term Infants
2015
This mini-review summarises the risk factors for acquiring Respiratory Syncitial Virus (RSV) infection, and describes the harmful effects of the infection in pre-term infants. Moreover, theoretical considerations are discussed for the prevention of RSV infection in high-risk infant categories, such as pre-term infants. Background: Neonates positive for RSV are more prone to severe infection than neonates infected with other common respiratory viruses. Despite RSV infection being more common in late neonates than in early ones, pre-term infants ≤ 35 wk gestational age (GA) are at high risk for developing severe RSV disease. Efforts to prevent infection include case management, vaccination an…
The Importance of Developing Electrochemical Sensors Based on Molecularly Imprinted Polymers for a Rapid Detection of Antioxidants
2021
International audience; This review aims to pin out the importance of developing a technique for rapid detection of antioxidants, based on molecular imprinting techniques. It covers three major areas that have made great progress over the years in the field of research, namely: antioxidants characterization, molecular imprinting and electrochemistry, alone or combined. It also reveals the importance of bringing these three areas together for a good evaluation of antioxidants in a simple or complex medium, based on selectivity and specificity. Although numerous studies have associated antioxidants with molecular imprinting, or antioxidants with electrochemistry, but even electrochemistry wit…
CCDC 2090126: Experimental Crystal Structure Determination
2021
Related Article: Chris Gendy, J. Mikko Rautiainen, Aaron Mailman, Heikki M. Tuononen|2021|Chem.-Eur.J.|27|14405|doi:10.1002/chem.202102804
CCDC 2090120: Experimental Crystal Structure Determination
2021
Related Article: Chris Gendy, J. Mikko Rautiainen, Aaron Mailman, Heikki M. Tuononen|2021|Chem.-Eur.J.|27|14405|doi:10.1002/chem.202102804
CCDC 957913: Experimental Crystal Structure Determination
2014
Related Article: I. S. Morgan, A. Peuronen, M. M. Hanninen, R. Clerac, H. M. Tuononen|2014|Inorg.Chem.|53|33|doi:10.1021/ic402954p