scholarly journals Autocatalytic Photodegradation of [Ru(II)(2,2’-bipyridine)2DAD]+ (DADH = 1,2-dihydroxyanthracene-9,10-dione) by Hydrogen Peroxide under Acidic Aqueous Conditions

2021 ◽  
Author(s):  
Lingli Zeng ◽  
Dumitru Sirbu ◽  
Nikolai V Tkachenko ◽  
A. C. Benniston

As part of a continuing effort to identify ruthenium agents capable of the photorelease of anthraquinone-based ligands the complexes Δ/Λ-[Ru(bpy)2DAD]+ (bpy = 2,2’-bipyridine) were produced by the reaction of 1,2-dihydoxyanthracene-9,10-dione...

ChemInform ◽  
2012 ◽  
Vol 43 (15) ◽  
pp. no-no
Author(s):  
Houjin Hachiya ◽  
Yoshihiro Kon ◽  
Yutaka Ono ◽  
Kiyoshi Takumi ◽  
Naoki Sasagawa ◽  
...  

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 943 ◽  
Author(s):  
Jinlong Wang ◽  
Xusheng Li ◽  
Jianxiao Song ◽  
Kunze Wu ◽  
Yichun Xue ◽  
...  

Separating the fibers, deconstructing both the interlamellar structures and the intermicrofibrils structures in the cell wall, and cleaving the amorphous regions of cellulose (all reached in one bath chemical-assisted treatment), then extracting cellulose nanofibers (CNFs) from biomass, is both challenging and imperative. A simple, cost-effective and green strategy for extracting CNFs from bamboo using nitric acid and hydrogen peroxide (NCHP), to enable fibrillation via a cooperative mechanism, is demonstrated herein. NCHP-CNFs 13.1 ± 2.0 nm wide, with a high aspect ratio, 74% crystallinity, excellent UV resistance and high thermal stability, were successfully extracted by treatment in HNO3 aqueous solution, at a concentration of 3.2 mol/L, and treatment with 60.00 mmol/g H2O2 at 50 °C for 48 h. The yields of NCHP-CNFs reached 73% and 99% based on biomass and cellulose, respectively, due to the high delignification selectivity of OH+ and the mild aqueous conditions during the NCHP treatment. These NCHP-CNFs with excellent UV resistance can potentially be applied in the field of UV-resistant coatings, to replace organic and inorganic materials.


Synlett ◽  
2011 ◽  
Vol 2011 (19) ◽  
pp. 2819-2822 ◽  
Author(s):  
Yoshihiro Kon ◽  
Kazuhiko Sato ◽  
Houjin Hachiya ◽  
Yutaka Ono ◽  
Kiyoshi Takumi ◽  
...  

Author(s):  
George E. Childs ◽  
Joseph H. Miller

Biochemical and differential centrifugation studies have demonstrated that the oxidative enzymes of Acanthamoeba sp. are localized in mitochondria and peroxisomes (microbodies). Although hartmanellid amoebae have been the subject of several electron microscopic studies, peroxisomes have not been described from these organisms or other protozoa. Cytochemical tests employing diaminobenzidine-tetra HCl (DAB) and hydrogen peroxide were used for the ultrastructural localization of peroxidases of trophozoites of Hartmanella sp. (A-l, Culbertson), a pathogenic strain grown in axenic cultures of trypticase soy broth.


2020 ◽  
Vol 48 (6) ◽  
pp. 2657-2667
Author(s):  
Felipe Montecinos-Franjola ◽  
John Y. Lin ◽  
Erik A. Rodriguez

Noninvasive fluorescent imaging requires far-red and near-infrared fluorescent proteins for deeper imaging. Near-infrared light penetrates biological tissue with blood vessels due to low absorbance, scattering, and reflection of light and has a greater signal-to-noise due to less autofluorescence. Far-red and near-infrared fluorescent proteins absorb light >600 nm to expand the color palette for imaging multiple biosensors and noninvasive in vivo imaging. The ideal fluorescent proteins are bright, photobleach minimally, express well in the desired cells, do not oligomerize, and generate or incorporate exogenous fluorophores efficiently. Coral-derived red fluorescent proteins require oxygen for fluorophore formation and release two hydrogen peroxide molecules. New fluorescent proteins based on phytochrome and phycobiliproteins use biliverdin IXα as fluorophores, do not require oxygen for maturation to image anaerobic organisms and tumor core, and do not generate hydrogen peroxide. The small Ultra-Red Fluorescent Protein (smURFP) was evolved from a cyanobacterial phycobiliprotein to covalently attach biliverdin as an exogenous fluorophore. The small Ultra-Red Fluorescent Protein is biophysically as bright as the enhanced green fluorescent protein, is exceptionally photostable, used for biosensor development, and visible in living mice. Novel applications of smURFP include in vitro protein diagnostics with attomolar (10−18 M) sensitivity, encapsulation in viral particles, and fluorescent protein nanoparticles. However, the availability of biliverdin limits the fluorescence of biliverdin-attaching fluorescent proteins; hence, extra biliverdin is needed to enhance brightness. New methods for improved biliverdin bioavailability are necessary to develop improved bright far-red and near-infrared fluorescent proteins for noninvasive imaging in vivo.


2010 ◽  
Vol 34 (8) ◽  
pp. S27-S27
Author(s):  
Xueling Dai ◽  
Ping Chang ◽  
Ke Xu ◽  
Changjun Lin ◽  
Hanchang Huang ◽  
...  

2020 ◽  
Vol 48 (2) ◽  
pp. 613-620
Author(s):  
Clara Ortegón Salas ◽  
Katharina Schneider ◽  
Christopher Horst Lillig ◽  
Manuela Gellert

Processing of and responding to various signals is an essential cellular function that influences survival, homeostasis, development, and cell death. Extra- or intracellular signals are perceived via specific receptors and transduced in a particular signalling pathway that results in a precise response. Reversible post-translational redox modifications of cysteinyl and methionyl residues have been characterised in countless signal transduction pathways. Due to the low reactivity of most sulfur-containing amino acid side chains with hydrogen peroxide, for instance, and also to ensure specificity, redox signalling requires catalysis, just like phosphorylation signalling requires kinases and phosphatases. While reducing enzymes of both cysteinyl- and methionyl-derivates have been characterised in great detail before, the discovery and characterisation of MICAL proteins evinced the first examples of specific oxidases in signal transduction. This article provides an overview of the functions of MICAL proteins in the redox regulation of cellular functions.


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