Decoloration of Azo Dyes by Hydrogen Peroxide Catalyzed by Water-Soluble Manganese Porphyrins

1999 ◽  
Vol 69 (12) ◽  
pp. 956-960 ◽  
Author(s):  
J. Tokuda ◽  
R. Ohura ◽  
T. Iwasaki ◽  
Y. Takeuchi ◽  
A. Kashiwada ◽  
...  
2011 ◽  
Vol 8 (2) ◽  
pp. 33
Author(s):  
Norfaezah Mazalan ◽  
Mazatulikhma Mat Zain ◽  
Nor Saliyana Jumali ◽  
Norhanim Mohalid ◽  
Zurina Shaameri ◽  
...  

Recently, research and development in the field of drug delivery systems (DDS) facilitating site-specific therapy has reached significant progression. DDS based on polymer micelles, coated micro- and nanoparticles, and various prodrug systems including water-soluble polymer have been prepared and extensively studied as novel drugs designed for cancer chemotherapy and brain delivery. Since polymers are going to be used in human, this study has the interest of testing two types of polymer, polyimides (PI) and polyphenylenevinylene (PPV) on neuronal cells. The objective of this study was to determine the possible neurotoxicity and potential neuroprotective effects of PI and PPV towards SH-SY5Y neuronal cells challenged by hydrogen peroxide (H2O2) as an oxidant. Cells were pretreated with either PI or PPV for 1 hour followed by incubation for 24 hour with 100 µM of H2O2. MTS assay was used to assess cell viability. Results show that PI and PPV are not harmful within the concentration up to 10 µM and 100 µM, respectively. However, PI and PPV do not protect neuronal cells against toxicity induced by H2O2 or further up the cell death.


2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Jeanette M. Cardamone ◽  
Alberto Nuñez ◽  
Rafael A. Garcia ◽  
Mila Aldema-Ramos

Keratin from wool is a reactive, biocompatible, and biodegradable material. As the biological structural component of skin (soft keratins) and of nails, claws, hair, horn, feathers, and scales (hard keratins) pure keratin comprises up to 90% by weight of wool. Wool was treated in alkaline solutions to extract from 68% to 82% keratin within 2 to 5 hours of exposure at . The keratin products were water-soluble and were confirmed to contain intermediate filament and microfibrillar component-proteins of fractured, residual cuticle, and cortical cells. Oxidation of wool by peroxycarboximidic acid in alkaline hydrogen peroxide produced keratin products with distinct microcrystalline structures: descaled fibers, fibrous matrices, and lyophilized powders. Morphology and confirmation of peptide functionality were documented by SEM, Amino Acid Analysis, SDS-PAGE gel electrophoresis, MALDI-TOF/TOF, and FTIR analyses. The reactivity of keratin from wool models the reactivity of keratin from low-value sources such as cattle hair.


2017 ◽  
Vol 5 (1) ◽  
pp. 61
Author(s):  
Weon-Bae Ko ◽  
Hong-Seok Jeong ◽  
Sung-Ho Hwang

<p>The water-soluble fullerenes [C<sub>60</sub>, C<sub>70</sub>] are prepared with fullerenes [C<sub>60</sub>, C<sub>70</sub>] and a mixture of oxidants (v/v) at the ratio of 3:1 under ultrasonic condition at room temperature. The MALDI-TOF MS confirmed that the water-soluble compounds were C<sub>60</sub> and C<sub>70</sub>. The antioxidant effect of water-soluble fullerenes [C<sub>60</sub>, C<sub>70</sub>] in the PC 12 cells (Rat pheochromocytoma) line following exposure to hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) was investigated.</p>


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Siddhesh Umesh Mestry ◽  
Umesh Ratan Mahajan ◽  
Aswathy M. ◽  
Shashank T. Mhaske

Purpose The purpose of this paper is to use the bio-based resource as the starting material for the synthesis of azo dye. Cardanol is one of the most used bio-based resources for carrying out the synthesis of various compounds having numerous end applications. The study presents an attempt to develop an azo dye from Cardanol having end applications in pH-responsive dyes. Design/methodology/approach The cardanol was sulfonated to block the para position by which ortho positioned hydroxyl group after diazotization and coupling will provide necessary pH-sensitivity. The diazotization of two naphthalene derivatives, i.e. 1-naphthol-8-amino-3,6-disulfonic acid (H-acid) and 7-amino-4-hydroxy-2-naphthalene sulfonic acid (J-acid) was carried out using the standard practice, and the diazotized compounds were coupled with the sulfonated cardanol. The obtained dyes were characterized by Fourier transform infrared, nuclear magnetic resonance, carbon-hydrogen-nitrogen-sulfur analysis and hydroxyl value. The colour properties were checked using UV-vis spectrophotometry and density functional theory, while thermogravimetric analysis was used for the thermal degradation studies of both the dyes. Findings Water-soluble cardanol-based azo dyes were prepared successfully having good thermal stability, and the obtained results are being presented in this paper. Originality/value The originality lies between the use of cardanol as a bio-based resource for the synthesis of azo-dye and the obtained azo-dye has the pH-sensitivity.


Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1078
Author(s):  
Hang Zhang ◽  
Zhipeng Ma ◽  
Yunpeng Min ◽  
Huiru Wang ◽  
Ru Zhang ◽  
...  

Several kinds of composite materials with phosphotungstic acid (PTA) as the catalyst were prepared with activated carbon as support, and their structures were characterized. According to the Box–Behnken central combination principle, the mathematical model of the heterogeneous system is established. Based on the single-factor experiments, the reaction temperature, the reaction time, the amount of hydrogen peroxide and the loading capacity of PTA were selected as the influencing factors to study the catalyzed oxidation of hydrogen peroxide and degradation of high molecular weight chitosan. The results of IR showed that the catalyst had a Keggin structure. The results of the mercury intrusion test showed that the pore structure of the supported PTA catalyst did not change significantly, and with the increase of PTA loading, the porosity and pore volume decreased regularly, which indicated that PTA molecules had been absorbed and filled into the pore of activated carbon. The results of Response Surface Design (RSD) showed that the optimum reaction conditions of supported PTA catalysts for oxidative degradation of high molecular weight chitosan by hydrogen peroxide were as follows: reaction temperature was 70 ℃, reaction time was 3.0 h, the ratio of hydrogen peroxide to chitosan was 2.4 and the catalyst loading was 30%. Under these conditions, the yield and molecular weight of water-soluble chitosan were 62.8% and 1290 Da, respectively. The supported PTA catalyst maintained high catalytic activity after three reuses, which indicated that the supported PTA catalyst had excellent catalytic activity and stable performance compared with the PTA catalyst.


1962 ◽  
Vol 40 (1) ◽  
pp. 459-469 ◽  
Author(s):  
P. H. Jellinck ◽  
Louise Irwin

Aerobic incubation of estrone-16-C14with peroxidase in the presence of serum albumin and other proteins resulted in the formation of water-soluble, ether-insoluble metabolites in high percentage yields. Similar products were formed when protein was replaced by cysteine or tryptophan but none of the other amino acids tested had any effect. The evidence points to an initial generation of hydrogen peroxide from these nitrogenous compounds by the enzyme acting as an aerobic oxidase, and the subsequent peroxidation of estrone to highly reactive products. These then combine with the protein or amino acid or else undergo alternative reactions. A strong chemical bond is formed with albumin and attempts to release the estrone metabolites from it were unsuccessful. Uterine homogenates from estrogen-treated rats showing high DPNH oxidase activity contained no "peroxidase" as measured by the formation of water-soluble products from estrone in the presence of protein.


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