Redox modulation of curcumin stability: Redox active antioxidants increase chemical stability of curcumin

2015 ◽  
Vol 60 (3) ◽  
pp. 487-494 ◽  
Author(s):  
Yoshiki Nimiya ◽  
Weicang Wang ◽  
Zheyuan Du ◽  
Elvira Sukamtoh ◽  
Julia Zhu ◽  
...  
Keyword(s):  
Chemical Stability ◽  
Redox Modulation ◽  
Redox Active

scholarly journals Front cover: Redox modulation of curcumin stability: Redox active antioxidants increase chemical stability of curcumin

2016 ◽  
Vol 60 (3) ◽  
pp. NA-NA
Author(s):  
Yoshiki Nimiya ◽  
Weicang Wang ◽  
Zheyuan Du ◽  
Elvira Sukamtoh ◽  
Julia Zhu ◽  
...  
Keyword(s):  
Chemical Stability ◽  
Redox Modulation ◽  
Front Cover ◽  
Redox Active

scholarly journals Cross talk between Ca 2+ and redox signalling cascades in muscle and neurons through the combined activation of ryanodine receptors/Ca 2+ release channels

2005 ◽  
Vol 360 (1464) ◽  
pp. 2237-2246 ◽  
Author(s):  
Cecilia Hidalgo
Keyword(s):  
Skeletal Muscle ◽  
Neuronal Plasticity ◽  
Calcium Release ◽  
Ryanodine Receptors ◽  
Nitrogen Species ◽  
Redox Modulation ◽  
Redox Active ◽  
Signalling Cascades ◽  
Sequential Activation ◽  
Redox Molecules

Calcium release mediated by the ryanodine receptors (RyR) Ca 2+ release channels is required for muscle contraction and contributes to neuronal plasticity. In particular, Ca 2+ activation of RyR-mediated Ca 2+ release can amplify and propagate Ca 2+ signals initially generated by Ca 2+ entry into cells. Redox modulation of RyR function by a variety of non-physiological or endogenous redox molecules has been reported. The effects of RyR redox modification on Ca 2+ release in skeletal muscle as well as the activation of signalling cascades and transcription factors in neurons will be reviewed here. Specifically, the different effects of S -nitrosylation or S -glutathionylation of RyR cysteines by endogenous redox-active agents on the properties of skeletal muscle RyRs will be discussed. Results will be presented indicating that these cysteine modifications change the activity of skeletal muscle RyRs, modify their behaviour towards both activators and inhibitors and affect their interactions with FKBP12 and calmodulin. In the hippocampus, sequential activation of ERK1/2 and CREB is a requisite for Ca 2+ -dependent gene expression associated with long-lasting synaptic plasticity. The effects of reactive oxygen/nitrogen species on RyR channels from neurons and RyR-mediated sequential activation of neuronal ERK1/2 and CREB produced by hydrogen peroxide and other stimuli will be discussed as well.

scholarly journals Correction to: Redox Modulation at Work: Natural Phytoprotective Polysulfanes From Alliums Based on Redox-Active Sulfur

2019 ◽  
Vol 5 (5) ◽  
pp. 400-400
Author(s):  
Awais Anwar ◽  
Emma Gould ◽  
Ryan Tinson ◽  
Javaid Iqbal ◽  
Chris Hamilton
Keyword(s):  
Redox Modulation ◽  
Redox Active

Common modifications of selenocysteine in selenoproteins

2019 ◽  
Vol 64 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Elias S.J. Arnér
Keyword(s):  
Amino Acids ◽  
Covalent Binding ◽  
Physicochemical Characteristics ◽  
Redox Active

Abstract Selenocysteine (Sec), the sulfur-to-selenium substituted variant of cysteine (Cys), is the defining entity of selenoproteins. These are naturally expressed in many diverse organisms and constitute a unique class of proteins. As a result of the physicochemical characteristics of selenium when compared with sulfur, Sec is typically more reactive than Cys while participating in similar reactions, and there are also some qualitative differences in the reactivities between the two amino acids. This minireview discusses the types of modifications of Sec in selenoproteins that have thus far been experimentally validated. These modifications include direct covalent binding through the Se atom of Sec to other chalcogen atoms (S, O and Se) as present in redox active molecular motifs, derivatization of Sec via the direct covalent binding to non-chalcogen elements (Ni, Mb, N, Au and C), and the loss of Se from Sec resulting in formation of dehydroalanine. To understand the nature of these Sec modifications is crucial for an understanding of selenoprotein reactivities in biological, physiological and pathophysiological contexts.

On the Crystal Chemistry of Inorganic Nitrides: Crystal-Chemical Parameters and Opportunities in the Exploration of Their Compositional Space

2020 ◽  
Author(s):  
Olivier Charles Gagné
Keyword(s):  
Functional Properties ◽  
A Priori ◽  
Lone Pair ◽  
Length Variation ◽  
Electronic Effects ◽  
Statistical Knowledge ◽  
Redox Active ◽  
Multiply Bonded ◽  
Jahn Teller ◽  
Compositional Space

The scarcity of nitrogen in Earth’s crust, combined with challenging synthesis, have made inorganic nitrides a relatively-unexplored class of compounds compared to their naturally-abundant oxide counterparts. To facilitate exploration of their compositional space via <i>a priori</i> modeling, and to help <i>a posteriori</i> structure verification not limited to inferring the oxidation state of redox-active cations, we derive a suite of bond-valence parameters and Lewis-acid strength values for 76 cations observed bonding to N<sup>3-</sup>, and further outline a baseline statistical knowledge of bond lengths for these compounds. We examine structural and electronic effects responsible for the functional properties and anomalous bonding behavior of inorganic nitrides, and identify promising venues for exploring uncharted compositional spaces beyond the reach of high-throughput computational methods. We find that many mechanisms of bond-length variation ubiquitous to oxide and oxysalt compounds (e.g., lone-pair stereoactivity, the Jahn-Teller and pseudo Jahn-Teller effects) are similarly pervasive in inorganic nitrides, and are occasionally observed to result in greater distortion magnitude than their oxide counterparts. We identify inorganic nitrides with multiply-bonded metal ions as a promising venue in heterogeneous catalysis, e.g. in the development of a post-Haber-Bosch process proceeding at milder reaction conditions, thus representing further opportunity in the thriving exploration of the functional properties of this emerging class of materials.<br>

Energetic Control of Redox-Active Polymers Towards Safe Organic Bioelectronic Materials

2019 ◽  
Author(s):  
Alexander Giovannitti ◽  
Reem B. Rashid ◽  
Quentin Thiburce ◽  
Bryan D. Paulsen ◽  
Camila Cendra ◽  
...  
Keyword(s):  
Molecular Oxygen ◽  
Organic Semiconductors ◽  
Side Reaction ◽  
Semiconducting Polymers ◽  
Side Reactions ◽  
Redox Active ◽  
Donor Acceptor ◽  
Electrochemical Devices ◽  
Biological Environment ◽  
Device Operation

<p>Avoiding faradaic side reactions during the operation of electrochemical devices is important to enhance the device stability, to achieve low power consumption, and to prevent the formation of reactive side‑products. This is particularly important for bioelectronic devices which are designed to operate in biological systems. While redox‑active materials based on conducting and semiconducting polymers represent an exciting class of materials for bioelectronic devices, they are susceptible to electrochemical side‑reactions with molecular oxygen during device operation. We show that this electrochemical side reaction yields hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>), a reactive side‑product, which may be harmful to the local biological environment and may also accelerate device degradation. We report a design strategy for the development of redox-active organic semiconductors based on donor-acceptor copolymers that prevent the formation of H<sub>2</sub>O<sub>2</sub> during device operation. This study elucidates the previously overlooked side-reactions between redox-active conjugated polymers and molecular oxygen in electrochemical devices for bioelectronics, which is critical for the operation of electrolyte‑gated devices in application-relevant environments.</p>

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