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International Journal of Molecular... Jul 2022The redox equilibrium is important in preserving the correct functionality of vital cellular functions [...].
The redox equilibrium is important in preserving the correct functionality of vital cellular functions [...].
Topics: Oxidation-Reduction; Oxidative Stress; Reactive Oxygen Species
PubMed: 35887362
DOI: 10.3390/ijms23148017 -
Chemical & Pharmaceutical Bulletin 2024The first enantioselective total synthesis of kopsiyunnanine B, which has a unique folded and complex pentacyclic structure containing six contiguous chiral centers, has...
The first enantioselective total synthesis of kopsiyunnanine B, which has a unique folded and complex pentacyclic structure containing six contiguous chiral centers, has been achieved along our originally proposed biosynthetic pathway. The key reaction of this synthesis includes a bioinspired cascade that builds three ring structures and three chiral centers in one step and features the stereoselective reduction of a β-acrylate and oxidation to an oxindole.
Topics: Stereoisomerism; Oxidation-Reduction
PubMed: 38233133
DOI: 10.1248/cpb.c23-00654 -
Molecular Microbiology Oct 2021Bacterial respiration of diverse substrates is a primary contributor to the diversity of life. Respiration also drives alterations in the geosphere and tethers... (Review)
Review
Bacterial respiration of diverse substrates is a primary contributor to the diversity of life. Respiration also drives alterations in the geosphere and tethers ecological nodes together. It provides organisms with a means to dissipate reductants and generate potential energy in the form of an electrochemical gradient. Mechanisms have evolved to sense flux through respiratory pathways and sense the altered concentrations of respiration substrates or byproducts. These genetic regulatory systems promote efficient utilization of respiration substrates, as well as fine-tune metabolism to promote cellular fitness and negate the accumulation of toxic byproducts. Many bacteria can respire one or more chemicals, and these regulatory systems promote the prioritization of high-energy metabolites. Herein, we focus on regulatory paradigms and discuss systems that sense the concentrations of respiration substrates and flux through respiratory pathways. This is a broad field of study, and therefore we focus on key fundamental and recent developments and highlight specific systems that capture the diversity of sensing mechanisms.
Topics: Bacterial Physiological Phenomena; Energy Metabolism; Gene Expression Regulation, Bacterial; Genetic Fitness; Oxidation-Reduction; Quinones; Respiration; Transcription, Genetic
PubMed: 34387370
DOI: 10.1111/mmi.14795 -
Seminars in Radiation Oncology Jan 2019Since the recognition during the 20 century that cancer cells demonstrated fundamental alterations in the regulation of oxidative and glycolytic metabolism, many basic...
Since the recognition during the 20 century that cancer cells demonstrated fundamental alterations in the regulation of oxidative and glycolytic metabolism, many basic as well as translational scientists have proposed that targeting metabolic differences in cancer versus normal cells could be exploited to improve cancer therapy outcomes. With the recognition that dysregulation of mitochondrial redox metabolism leads to the increased steady-state levels of superoxide and hydrogen peroxide which could contribute to both aging and cancer; radiation biologists have pursued many avenues of targeting oxidative metabolic pathways to both selectively radiosensitive cancer cells as well as protect normal tissues during cancer therapy. Recent advances in exploiting redox metabolism for improving radiochemotherapy both from a basic and translational science point of view are the focus of the papers in this current issue of . The historical perspective underlying these areas of research as well as a unifying hypothesis for further advancing this research into clinical trials will be presented in this overview.
Topics: Antioxidants; Chemoradiotherapy; Gene Expression Regulation, Neoplastic; Humans; Neoplasms; Oxidation-Reduction; Oxidative Stress; Signal Transduction
PubMed: 30573179
DOI: 10.1016/j.semradonc.2018.10.010 -
Angewandte Chemie (International Ed. in... Jan 2023Alcohols and their derivatives are ubiquitous and versatile motifs in organic synthesis. Deoxygenative transformations of these compounds are often challenging due to... (Review)
Review
Alcohols and their derivatives are ubiquitous and versatile motifs in organic synthesis. Deoxygenative transformations of these compounds are often challenging due to the thermodynamic penalty associated with the cleavage of the C-O bond. However, electrochemically driven redox events have been shown to facilitate the C-O bond cleavage in alcohols and their derivatives either through direct electron transfer or through the use of electron transfer mediators and electroactive catalysts. Herein, a comprehensive overview of preparative electrochemically mediated protocols for C-O bond activation and functionalization is detailed, including direct and indirect electrosynthetic methods, as well as photoelectrochemical strategies.
Topics: Alcohols; Oxidation-Reduction; Electron Transport; Catalysis
PubMed: 36278406
DOI: 10.1002/anie.202211952 -
Molecules (Basel, Switzerland) Oct 2020The process of reduction (by hydrogen and ethanol) and oxidation (by oxygen and NO) of Cu sites in dealuminated faujasite-type zeolites (of Si/Al = 31) was studied by...
The process of reduction (by hydrogen and ethanol) and oxidation (by oxygen and NO) of Cu sites in dealuminated faujasite-type zeolites (of Si/Al = 31) was studied by infrared (IR) spectroscopy with CO (for Cu) and NO (for Cu) as probe molecules. Two zeolites were studied: one of them contained mostly Cu, whereas another one contained mostly Cu and Cu The susceptibility of various forms of Cu for reduction were investigated. IR experiments of CO sorption evidenced that Cu was more prone for the reduction than Cu According to NO sorption studies, Cu was reduced in the first order before Cu Ethanol reduced mostly Cu and, also, some amounts of Cu. The treatment with oxygen caused the oxidation of Cu (both Cu and Cu) to Cu. The adsorption of NO at 190K produced Cu(NO) dinitrosyls, but heating to room temperature transformed dinitrosyls to mononitrosyls and increased the Cu content.
Topics: Adsorption; Copper; Hydrogen; Oxidation-Reduction; Oxygen; Spectroscopy, Fourier Transform Infrared; Zeolites
PubMed: 33081409
DOI: 10.3390/molecules25204765 -
FEBS Letters Jan 2023Biological redox reactions often use a set-up in which final redox partners are localized in different compartments and electron transfer (ET) among them is mediated by... (Review)
Review
Biological redox reactions often use a set-up in which final redox partners are localized in different compartments and electron transfer (ET) among them is mediated by redox-active molecules. In enzymes, these ET processes occur over nm distances, whereas multi-protein filaments bridge μm ranges. Electrons are transported over cm ranges in cable bacteria, which are formed by thousands of cells. In this review, we describe molecular mechanisms that explain how respiration in a compartmentalized set-up ensures redox homeostasis. We highlight mechanistic studies on ET through metal-free peptides and proteins demonstrating that long-distance ET is possible because amino acids Tyr, Trp, Phe, and Met can act as relay stations. This cuts one long ET into several short reaction steps. The chances and challenges of long-distance ET for cellular redox reactions are then discussed.
Topics: Electrons; Electron Transport; Oxidation-Reduction; Peptides; Geobacter
PubMed: 36114008
DOI: 10.1002/1873-3468.14493 -
Drug Discovery Today Jan 2021Apurinic/apyrimidinic (AP) endonuclease-reduction/oxidation factor 1 (APE1/Ref-1, also called APE1) is a multifunctional enzyme with crucial roles in DNA repair and... (Review)
Review
Apurinic/apyrimidinic (AP) endonuclease-reduction/oxidation factor 1 (APE1/Ref-1, also called APE1) is a multifunctional enzyme with crucial roles in DNA repair and reduction/oxidation (redox) signaling. APE1 was originally described as an endonuclease in the Base Excision Repair (BER) pathway. Further study revealed it to be a redox signaling hub regulating critical transcription factors (TFs). Although a significant amount of focus has been on the role of APE1 in cancer, recent findings support APE1 as a target in other indications, including ocular diseases [diabetic retinopathy (DR), diabetic macular edema (DME), and age-related macular degeneration (AMD)], inflammatory bowel disease (IBD) and others, where APE1 regulation of crucial TFs impacts important pathways in these diseases. The central responsibilities of APE1 in DNA repair and redox signaling make it an attractive therapeutic target for cancer and other diseases.
Topics: DNA Repair; DNA-(Apurinic or Apyrimidinic Site) Lyase; Drug Discovery; Humans; Molecular Targeted Therapy; Oxidation-Reduction; Signal Transduction; Transcription Factors
PubMed: 33148489
DOI: 10.1016/j.drudis.2020.10.015 -
International Journal of Molecular... Aug 2015Photodynamic therapy (PDT) is a clinical modality used to treat cancer and infectious diseases. The main agent is the photosensitizer (PS), which is excited by light and... (Review)
Review
Photodynamic therapy (PDT) is a clinical modality used to treat cancer and infectious diseases. The main agent is the photosensitizer (PS), which is excited by light and converted to a triplet excited state. This latter species leads to the formation of singlet oxygen and radicals that oxidize biomolecules. The main motivation for this review is to suggest alternatives for achieving high-efficiency PDT protocols, by taking advantage of knowledge on the chemical and biological processes taking place during and after photosensitization. We defend that in order to obtain specific mechanisms of cell death and maximize PDT efficiency, PSes should oxidize specific molecular targets. We consider the role of subcellular localization, how PS photochemistry and photophysics can change according to its nanoenvironment, and how can all these trigger specific cell death mechanisms. We propose that in order to develop PSes that will cause a breakthrough enhancement in the efficiency of PDT, researchers should first consider tissue and intracellular localization, instead of trying to maximize singlet oxygen quantum yields in in vitro tests. In addition to this, we also indicate many open questions and challenges remaining in this field, hoping to encourage future research.
Topics: Animals; Cell Death; Humans; Oxidation-Reduction; Photochemistry; Photochemotherapy; Photosensitizing Agents
PubMed: 26334268
DOI: 10.3390/ijms160920523 -
Oncotarget Dec 2016
Topics: Glutamine; Octamer Transcription Factor-3; Oxidation-Reduction; Transcription Factors
PubMed: 27876699
DOI: 10.18632/oncotarget.13459