Oxidative Damage of Thymidines by the Atmospheric Free-Radical Oxidant NO3•

2011 ◽  
Vol 64 (6) ◽  
pp. 833 ◽  
Author(s):  
Uta Wille ◽  
Catrin Goeschen
Keyword(s):  
Free Radical ◽  
Building Blocks ◽  
Pyrimidine Ring ◽  
Initial Reaction ◽  
Irreversible Damage ◽  
Methyl Group ◽  
Rapid Hydrolysis ◽  
Experimental Findings ◽  
Work Up ◽  
First Time

Analysis of the products formed in the reaction of nitrate radicals, NO3 •, with the N- and O-methylated and acetylated thymidines 1a and 1b revealed, for the first time, insight regarding how this important atmospheric free-radical oxidant can cause irreversible damage to DNA building blocks. Mechanistic studies indicated that the initial reaction step likely proceeds via NO3 • induced electron transfer at the pyrimidine ring, followed by deprotonation of the methyl group at C5. The oxidation ultimately leads to formation of nitrates 2, aldehydes 4 and, in the case of high [NO3 •], also to carboxylic acids 5. In addition to this, through a very minor pathway, loss of the methyl group at C5 also occurred to give the respective 2′-deoxyuridines 6. The nitrates 2 are highly labile compounds that undergo rapid hydrolysis during work-up and purification of the reaction mixtures, which could lead to serious misinterpretation of the experimental findings and reaction mechanism. Products resulting from NO3 • addition to the C5=C6 double bond in the pyrimidine ring were not observed. Also, no reaction of NO3 • with the 2′-deoxyribose moiety was detected.

Probing the Substrate Promiscuity of Isopentenyl Phosphate Kinase as a Platform for Hemiterpene Analogue Production

2019 ◽  
Author(s):  
Sean Lund ◽  
Taylor Courtney ◽  
Gavin Williams
Keyword(s):  
Synthetic Biology ◽  
Building Blocks ◽  
Isoprenoid Biosynthesis ◽  
Thermoplasma Acidophilum ◽  
Substrate Promiscuity ◽  
Enzymatic Pathways ◽  
First Time ◽  
Rate Limiting ◽  
Alcohol Dependent ◽  
Isopentenyl Phosphate

Isoprenoids are a large class of natural products with wide-ranging applications. Synthetic biology approaches to the manufacture of isoprenoids and their new-to-nature derivatives are limited due to the provision in Nature of just two hemiterpene building blocks for isoprenoid biosynthesis. To address this limitation, artificial chemo-enzymatic pathways such as the alcohol-dependent hemiterpene pathway (ADH) serve to leverage consecutive kinases to convert exogenous alcohols to pyrophosphates that could be coupled to downstream isoprenoid biosynthesis. To be successful, each kinase in this pathway should be permissive of a broad range of substrates. For the first time, we have probed the promiscuity of the second enzyme in the ADH pathway, isopentenyl phosphate kinase from Thermoplasma acidophilum, towards a broad range of acceptor monophosphates. Subsequently, we evaluate the suitability of this enzyme to provide non-natural pyrophosphates and provide a critical first step in characterizing the rate limiting steps in the artificial ADH pathway.<br>

scholarly journals A Sustainable Improvement of ω-Bromoalkylphosphonates Synthesis to Access Novel KuQuinones

Organics ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 107-117
Author(s):  
Mattia Forchetta ◽  
Valeria Conte ◽  
Giulia Fiorani ◽  
Pierluca Galloni ◽  
Federica Sabuzi
Keyword(s):  
Metal Oxides ◽  
Phosphonic Acid ◽  
Organic Molecules ◽  
Building Blocks ◽  
Reaction Conditions ◽  
Phosphonic Acids ◽  
Sustainable Improvement ◽  
Phosphonate Esters ◽  
First Time ◽  
Complex Organic

Owing to the attractiveness of organic phosphonic acids and esters in the pharmacological field and in the functionalization of conductive metal-oxides, the research of effective synthetic protocols is pivotal. Among the others, ω-bromoalkylphosphonates are gaining particular attention because they are useful building blocks for the tailored functionalization of complex organic molecules. Hence, in this work, the optimization of Michaelis–Arbuzov reaction conditions for ω-bromoalkylphosphonates has been performed, to improve process sustainability while maintaining good yields. Synthesized ω-bromoalkylphosphonates have been successfully adopted for the synthesis of new KuQuinone phosphonate esters and, by hydrolysis, phosphonic acid KuQuinone derivatives have been obtained for the first time. Considering the high affinity with metal-oxides, KuQuinones bearing phosphonic acid terminal groups are promising candidates for biomedical and photo(electro)chemical applications.

scholarly journals Bacterial cellulose spheroids as building blocks for 3D and patterned living materials and for regeneration

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Joaquin Caro-Astorga ◽  
Kenneth T. Walker ◽  
Natalia Herrera ◽  
Koon-Yang Lee ◽  
Tom Ellis
Keyword(s):  
Bacterial Cellulose ◽  
Building Blocks ◽  
Genetically Engineered ◽  
High Yield ◽  
Synthetic Materials ◽  
Chemical Inputs ◽  
First Time ◽  
3D Shapes ◽  
Promising Avenue ◽  
Living Materials

AbstractEngineered living materials (ELMs) based on bacterial cellulose (BC) offer a promising avenue for cheap-to-produce materials that can be programmed with genetically encoded functionalities. Here we explore how ELMs can be fabricated in a modular fashion from millimetre-scale biofilm spheroids grown from shaking cultures of Komagataeibacter rhaeticus. Here we define a reproducible protocol to produce BC spheroids with the high yield bacterial cellulose producer K. rhaeticus and demonstrate for the first time their potential for their use as building blocks to grow ELMs in 3D shapes. Using genetically engineered K. rhaeticus, we produce functionalized BC spheroids and use these to make and grow patterned BC-based ELMs that signal within a material and can sense and report on chemical inputs. We also investigate the use of BC spheroids as a method to regenerate damaged BC materials and as a way to fuse together smaller material sections of cellulose and synthetic materials into a larger piece. This work improves our understanding of BC spheroid formation and showcases their great potential for fabricating, patterning and repairing ELMs based on the promising biomaterial of bacterial cellulose.

The initial reaction mechanism and thermal sensitivity of a fluoropolymer-containing energetic molecular system: the coupling effect of interfacial interactions and free radical reactions

CrystEngComm ◽  
2021 ◽  
Vol 23 (16) ◽  
pp. 3006-3014
Author(s):  
Wen Qian
Keyword(s):  
Free Radical ◽  
Coupling Effect ◽  
Molecular System ◽  
Thermal Sensitivity ◽  
Radical Reactions ◽  
Initial Reaction ◽  
Interfacial Interactions ◽  
Free Radical Reactions ◽  
Molecular Systems ◽  
Reactive Molecular Dynamics

A strategy combining classic and reactive molecular dynamics is applied to find the coupling effect of interfacial interactions and free radical reactions during the initial thermal decomposition of fluoropolymer-containing molecular systems.

scholarly journals Cubane Cu4I4(phosphine)4 Complexes as New Co-initiator for Free Radical Photopolymerization: Towards Aromatic Amine-Free Systems

2021 ◽  
Author(s):  
Jacques Lalevée ◽  
Fatima Hammoud ◽  
Mahmoud Rahal ◽  
Julien Egly ◽  
Fabrice Morlet-Savary ◽  
...  
Keyword(s):  
Free Radical ◽  
Radical Polymerization ◽  
Aromatic Amine ◽  
Free Radical Polymerization ◽  
Copper Iodide ◽  
Free Radical Photopolymerization ◽  
Acrylate Monomers ◽  
First Time

The investigation of copper-iodide cubane derivatives as new co-initiators for the free radical polymerization (FRP) of acrylate monomers under mild irradiation conditions is described for the first time here. These...

scholarly journals Intriguing C–H⋯Cu interactions in bis-(phenanthroline)Cu(i) redox mediators for dye-sensitized solar cells

2018 ◽  
Vol 47 (4) ◽  
pp. 1018-1022 ◽  
Author(s):  
Alessia Colombo ◽  
Rachele Ossola ◽  
Mirko Magni ◽  
Dominique Roberto ◽  
Denis Jacquemin ◽  
...  
Keyword(s):  
Solar Cells ◽  
Dye Sensitized Solar Cells ◽  
Redox Mediators ◽  
Methyl Group ◽  
Dye Sensitized ◽  
Copper Site ◽  
First Time ◽  
Sensitized Solar Cells

For the first time, an anagostic interaction is found between a H atom of a methyl group and a copper site in the bis-2-tertbutyl(phenanthroline)Cu(i) complex.

Design, synthesis and evaluation of structurally diverse ortho-acylphenol-diindolylmethane hybrids as anticancer agents

2022 ◽  
Author(s):  
Zhi-Gang Yin ◽  
Xiong-Wei Liu ◽  
Hui-Juan Wang ◽  
Min Zhang ◽  
Xiong-Li Liu ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Anticancer Agents ◽  
Nucleophilic Addition ◽  
Ring Opening ◽  
Building Blocks ◽  
Efficient Synthesis ◽  
Design Synthesis ◽  
Pyrone Ring ◽  
Ring Opening Reaction ◽  
First Time

A highly efficient synthesis of structurally diverse ortho-acylphenol–diindolylmethane hybrids 3 using carboxylic acid-activated chromones as versatile synthetic building blocks is reported here for the first time, through 1,4-nucleophilic addition and followed by a decarboxylation and pyrone ring opening reaction process.

scholarly journals APASL Single Topic Conference DELTA HEPATITIS, 27-28 June 2019, Baku, Azerbaijan

2019 ◽  
Vol 2 (2) ◽  
pp. 1-46
Author(s):  
Gulnara Aghayeva
Keyword(s):  
Hepatitis B ◽  
Current Treatment ◽  
Hbv Infection ◽  
Good Chance ◽  
Hepatitis Delta ◽  
New Horizons ◽  
History Of ◽  
Pharmaceutical Agents ◽  
Work Up ◽  
First Time

As Delta problem moved from the shadow up on the stage, becoming one of the most crucial disease in Hepatology area, our STC 2019 is dedicated to hepat itis D, for the first time in the history of APASL STC topics. As hepatitis Delta occurs only with HBV infection, we will discuss hepatitis B, its epidemiology, work - up, current treatment and new horizons in the developing pharmaceutical agents. The scient ific program will include the topics presented by the best speakers and the experts in Delta and B hepatitis. This conference is a good chance to meet and interact with leading clinical professionals and researches and to obtain latest information for hepa tologists.

scholarly journals Straightforward Preparation of Supramolecular Janus Nanorods by Hydrogen Bonding of End-Functionalized Polymers

2020 ◽  
Author(s):  
Shuaiyuan Han ◽  
Sandrine Pensec ◽  
Cédric Lorthioir ◽  
Jacques Jestin ◽  
Jean-Michel Guigner ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Self Assembly ◽  
Functional Materials ◽  
Phase Segregation ◽  
Building Blocks ◽  
Functionalized Polymers ◽  
Nanometer Range ◽  
One Dimensional ◽  
Oil In Water ◽  
First Time

Janus cylinders are one-dimensional colloids that have two faces with different compositions and functionalities and are useful as building blocks for advanced functional materials. Such anisotropic objects are difficult to prepare with nanometric dimensions. Here we describe a robust and versatile strategy to form micrometer long Janus nanorods with diameters in the 10-nanometer range, by self-assembly in water of end-functionalized polymers. For the first time, the Janus topology is not a result of the phase segregation of incompatible polymer arms, but is driven by the interactions between unsymmetrical and complementary hydrogen bonded stickers. It is therefore independent of the actual polymers used and works even for compatible polymers. To illustrate their applicative potential, we show that these Janus nanorods can efficiently stabilize oil-in-water emulsions.

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