Search results for "Phosphor"
showing 10 items of 1952 documents
Reactions of Piperazin-2-one, Morpholin-3-one, and Thiomorpholin-3-one with Triethyl Phosphite Prompted by Phosphoryl Chloride: Scope and Limitations
2019
The reaction of the title lactams with triethyl phosphite prompted by phosphoryl chloride provided six-membered ring heterocyclic phosphonates or bisphosphonates. These novel scaffolds might be of interest as building blocks in medicinal chemistry. The course of the reaction was dependent on the structure of the used substrate. Thus, morpholin-3-one and thiomorpholin-3-one readily provided the corresponding 1,1-bisphosphonates (compounds 1, 2, 7, 14 and 16), whereas the protection of their nitrogen atom resulted in the formation of dehydrophosphonates (compounds 5, 6, and 8). Piperazin-2-one reacted differently yielding mixture of cis- and trans- piperazine-2,3-diyl-bisphosphonates (compoun…
Nucleotide, Nucleoside, Purine, Pyrimidine, Pteridine
1952
Die Organe erwachsener Tiere enthalten zumeist mehr Ribonucleotide als Desoxyribonucleotide (Tabelle 159). Der Quotient RN : DRN ist in fetalen Geweben kleiner als in erwachsenen. J. Geschwind und C. H. Li fanden ihn in der fetalen Rattenleber zu 0,9, in der Leber neugeborener Ratten zu 1,9 und in der Leber 40 Tage alter Ratten zu 2,8.
Serum antinuclear autoantibodies are associated with measures of oxidative stress and lifestyle factors - analysis of LIPIDOGRAM2015 and LIPIDOGEN201…
2021
IntroductionOxidative stress is one of many factors suspected to promote antinuclear autoantibody (ANA) formation. Reactive oxygen species can induce changes in the antigenic structure of macromolecules, causing the immune system to treat them as “neo-antigens” and start production of autoantibodies. This study was designed to evaluate the relationship between oxidative stress markers, lifestyle factors and the detection of ANA.Material and methodsWe examined measures of oxidative stress indices of free-radical damage to lipids and proteins, such as total oxidant status (TOS), concentration of protein thiol groups (PSH), and malondialdehyde (MDA), activity of superoxide dismutase (SOD) in i…
Antioxidation and the Hypoxic Ventilatory Response
2012
Reactive oxygen species favor the reductive state of iron. Antioxidation, by depleting biologically active ferrous iron, could then have a stabilizing effect, akin to hypoxia, on HIF-1α; the process which controls the genetic responses to hypoxia. However, the influence of antioxidation on the hypoxic ventilatory responses (HVR) is unclear. In this study we set out to determine the influence of mangiferin, a natural polyphenolic compound present in mango trees, with strong antioxidant and iron chelating properties, on the HVR. The study was performed in awake Wistar rats. Acute HVR to 12% and 8% FiO2 before and 40 min after mangiferin (300 mg/kg, i.p.) pretreatment were recorded plethysmogr…
The Role of Mitochondrial Reactive Oxygen Species Formation for Age-Induced Vascular Dysfunction
2010
Aging is an important risk factor for the development of cardiovascular diseases, which can be accelerated by atherosclerosis, diabetes, hypercholesterolemia, or obesity. Vascular aging is mainly characterized by endothelial dysfunction, an alteration of endothelium-dependent signaling processes, and vascular remodeling. The underlying mechanisms include increased production of reactive oxygen species (ROS), inactivation of nitric oxide (•NO), and subsequent formation of reactive nitrogen and oxygen species (RNOS). Elevated RNOS may exhibit new messenger functions by posttranslational oxidative modification of intracellular regulatory proteins or lead to irreversible alterations of biologic…
Exercise-Induced Activation and Translocation of αB-Crystallin in Skeletal Muscle Depends upon Fiber Type and Oxidative Stress
2016
Alpha B-crystallin (CRYAB) is a member of the small heat shock proteins implicated in various biological functions, particularly in skeletal muscle tissue [1], where it results to be modulated following exercise-induced reactive oxygen species (ROS) [2]. In this work we aimed to analyse the CRYAB response to acute exercise with respect muscle fiber composition and to identify the underlying molecular mechanism by the utilization of the C2C12 “in vitro” cellular model. Our results highlighted as acute exercise determines a specific increase of phospho-CRYAB both in the red, but not white, gastrocnemius (GS), with an higher amount of oxidative and oxidative-glycolytic fibers, and in soleus (S…
Formation of covalent di-tyrosine dimers in recombinant α-synuclein
2015
Parkinson's disease is associated with fibril deposition in the diseased brain. Misfolding events of the intrinsically disordered synaptic protein α-synuclein are suggested to lead to the formation of transient oligomeric and cytotoxic species. The etiology of Parkinson's disease is further associated with mitochondrial dysfunction and formation of reactive oxygen species. Oxidative stress causes chemical modification of native α-synuclein, plausibly further influencing misfolding events. Here, we present evidence for the spontaneous formation of covalent di-tyrosine α-synuclein dimers in standard recombinant protein preparations, induced without extrinsic oxidative or nitrative agents. The…
Oxidative stress in diabetic retinopathy
2020
Diabetic retinopathy (DR) is the leading cause of acquired blindness in working adults worldwide. Biochemical changes in DR contribute to both the microscopic structural and functional changes in the retina. All these alterations result in retinal damage that can be assessed by funduscopy, optical coherence tomography (OCT), and angioOCT. Reactive oxygen species (ROS) overproduction in the mitochondria is considered a causal link between elevated glucose and biochemical abnormalities in the pathophysiology of DR. Moreover, oxidative-induced pathways also seem to provide positive feedback to ROS production, resulting in a vicious cycle. ROS can directly damage lipids, proteins, and DNA, lead…
Epigenetics, oxidative states and diabetes
2020
Abstract Although controlling a wide range of physiological cell functions, redox states unbalance during inflammation toward oxidative stress. Specific regions of our genome are extremely sensitive to both oxygen and reactive oxygen species, therefore modulating gene transcription in response to this specific epigenetic effect. Additional epigenetic mechanisms may include the alteration of the methylation states of DNA, protein and lipid nitration or modulation of specific microRNAs. A crucial role in finely tuning redox states is also played by mitochondria, where oxidative phosphorylation is epigenetically controlled. Diabetes, the most considerable “epigenetic” clinical disorder, exacer…
Electrochemical sensor for evaluating oxidative stress in airway epithelial cells
2021
Cigarette smoke exposure induces oxidative stress within the airways. Increased oxidative burden contributes to the pathogenesis of chronic lung disorders and is associated with aging and chronic inflammation. Airway epithelial cells highly contribute to Reactive Oxygen Species (ROS) generation within injured and inflamed lung tissues. Among ROS, hydrogen peroxide (H2O2) can be monitored in the extracellular space. Herein, we present an amperometric/voltammetric sensor based on gold nanoparticles and graphene oxide able to detect H2O2 with good sensitivity and selectivity. Using this sensor, H2O2 release was measured in conditioned medium from primary bronchial epithelial cells (PBEC), bron…