Oxidative Degradation ofin Situand Isolated Spruce Lignins by Water-Soluble Hydrogen Peroxide Resistant Pentafluorophenylporphyrin

1996 ◽  
Vol 44 (7) ◽  
pp. 1953-1959 ◽  
Author(s):  
Bernard Kurek ◽  
Isabelle Artaud ◽  
Brigitte Pollet ◽  
Catherine Lapierre ◽  
Bernard Monties
Keyword(s):  
Hydrogen Peroxide ◽  
Oxidative Degradation ◽  
Water Soluble

Neurotoxicity and Neuroprotective Effects of Polyimides (PI) and Polyphenylenevinylene (PPV) against Hydrogen Peroxide (H2O2)

2011 ◽  
Vol 8 (2) ◽  
pp. 33
Author(s):  
Norfaezah Mazalan ◽  
Mazatulikhma Mat Zain ◽  
Nor Saliyana Jumali ◽  
Norhanim Mohalid ◽  
Zurina Shaameri ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Drug Delivery Systems ◽  
Neuronal Cells ◽  
Water Soluble ◽  
Brain Delivery ◽  
Specific Therapy ◽  
Neuroprotective Effects ◽  
Water Soluble Polymer ◽  
Site Specific ◽  
Novel Drugs

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.

A review of lignin hydrogen peroxide oxidation chemistry with emphasis on aromatic aldehydes and acids

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ajinkya More ◽  
Thomas Elder ◽  
Zhihua Jiang
Keyword(s):  
Hydrogen Peroxide ◽  
Oxidative Degradation ◽  
Reaction Medium ◽  
Dicarboxylic Acids ◽  
Aromatic Aldehydes ◽  
Product Distribution ◽  
Reaction Conditions ◽  
Alkaline Conditions ◽  
The Stability ◽  
Oxidation Chemistry

Abstract This review discusses the main factors that govern the oxidation processes of lignins into aromatic aldehydes and acids using hydrogen peroxide. Aromatic aldehydes and acids are produced in the oxidative degradation of lignin whereas mono and dicarboxylic acids are the main products. The stability of hydrogen peroxide under the reaction conditions is an important factor that needs to be addressed for selectively improving the yield of aromatic aldehydes. Hydrogen peroxide in the presence of heavy metal ions readily decomposes, leading to minor degradation of lignin. This degradation results in quinones which are highly reactive towards peroxide. Under these reaction conditions, the pH of the reaction medium defines the reaction mechanism and the product distribution. Under acidic conditions, hydrogen peroxide reacts electrophilically with electron rich aromatic and olefinic structures at comparatively higher temperatures. In contrast, under alkaline conditions it reacts nucleophilically with electron deficient carbonyl and conjugated carbonyl structures in lignin. The reaction pattern in the oxidation of lignin usually involves cleavage of the aromatic ring, the aliphatic side chain or other linkages which will be discussed in this review.

Oxidative Degradation of Toxic Organic Pollutants by Water Soluble Nonheme Iron(IV)-Oxo Complexes of Polydentate Nitrogen Donor Ligands

2021 ◽  
Author(s):  
Sandip Munshi ◽  
Rahul Dev Jana ◽  
Tapan Kanti Paine
Keyword(s):  
Organic Pollutants ◽  
Oxidative Degradation ◽  
Heme Iron ◽  
Water Soluble ◽  
Donor Ligands ◽  
Nitrogen Donor Ligands ◽  
Polydentate Ligands ◽  
Oxo Complexes ◽  
Non Heme Iron ◽  
Nitrogen Donor

The ability of four mononuclear non-heme iron(IV)-oxo complexes supported by nitrogen donor polydentate ligands in degrading organic pollutants has been investigated. The water soluble iron(II) complexes upon treatment with ceric...

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 ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Azo Dyes ◽  
Water Soluble ◽  
Manganese Porphyrins

scholarly journals Characterizing Wool Keratin

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Jeanette M. Cardamone ◽  
Alberto Nuñez ◽  
Rafael A. Garcia ◽  
Mila Aldema-Ramos
Keyword(s):  
Hydrogen Peroxide ◽  
Gel Electrophoresis ◽  
Water Soluble ◽  
Alkaline Solutions ◽  
Biodegradable Material ◽  
Alkaline Hydrogen Peroxide ◽  
Cortical Cells ◽  
Sds Page ◽  
Fibrous Matrices ◽  
Wool Keratin

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.

scholarly journals Formation of Water-Soluble Fullerenes [C60,C70] under Ultrasonication and Antioxidant Effect

2017 ◽  
Vol 5 (1) ◽  
pp. 61
Author(s):  
Weon-Bae Ko ◽  
Hong-Seok Jeong ◽  
Sung-Ho Hwang
Keyword(s):  
Hydrogen Peroxide ◽  
Room Temperature ◽  
Antioxidant Effect ◽  
Water Soluble ◽  
Maldi Tof Ms ◽  
Pc 12 Cells ◽  
Effect Of Water ◽  
Maldi Tof ◽  
Line Following ◽  
Tof Ms

<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>

scholarly journals Catalytic Degradation of Chitosan by Supported Heteropoly Acids in Heterogeneous Systems

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1078
Author(s):  
Hang Zhang ◽  
Zhipeng Ma ◽  
Yunpeng Min ◽  
Huiru Wang ◽  
Ru Zhang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Molecular Weight ◽  
Catalytic Activity ◽  
Activated Carbon ◽  
Reaction Time ◽  
High Molecular Weight ◽  
Reaction Temperature ◽  
Water Soluble ◽  
High Catalytic Activity ◽  
High Molecular Weight Chitosan

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.

Combinative dyebath treatment with activated carbon and UV/H2O2: a case study on Everzol Black-GSP®

2002 ◽  
Vol 46 (4-5) ◽  
pp. 51-58 ◽  
Author(s):  
N.H. Ince ◽  
D.A. Hasan ◽  
B. Üstün ◽  
G. Tezcanli
Keyword(s):  
Hydrogen Peroxide ◽  
Activated Carbon ◽  
Carbon Mineralization ◽  
Oxidative Degradation ◽  
Advanced Oxidation ◽  
Color Removal ◽  
Operating Parameters ◽  
Cost Reductions ◽  
H2o2 System

Treatability of textile dyebath effluents by two simultaneously operated processes comprising adsorption and advanced oxidation was investigated using a reactive dyestuff, Everzol Black-GSP® (EBG). The method was comprised of contacting aqueous solutions of the dye with hydrogen peroxide and granules of activated carbon (GAC) during irradiation of the reactor with ultraviolet light (UV). Control experiments were run separately with each individual process (advanced oxidation with UV/H2O2 and adsorption on GAC) to select the operating parameters on the basis of maximum color removal. The effectiveness of the combined scheme was tested by monitoring the rate of decolorization and the degree of carbon mineralization in effluent samples. It was found that in a combined medium of advanced oxidation and adsorption, color was principally removed by oxidative degradation, while adsorption contributed to the longer process of dye mineralization. Economic evaluation of the system based on total color removal and 50% mineralization showed that in the case of Everzol Black-GSP®, which adsorbs relatively poorly on GAC, the proposed combination provides 25% and 35% reduction in hydrogen peroxide and energy consumption relative to the UV/H2O2 system. Higher cost reductions are expected in cases with well adsorbing dyes and/or with less costly adsorbents.

Sign in / Sign up

Export Citation Format

Share Document