scholarly journals Hydrogen peroxide disproportionation with manganese macrocyclic complexes of cyclen and pyclen

2020 ◽  
Vol 7 (7) ◽  
pp. 1573-1582 ◽  
Author(s):  
David M. Freire ◽  
Debora Beeri ◽  
Kristof Pota ◽  
Hannah M. Johnston ◽  
Philip Palacios ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Spectroscopic Investigation ◽  
Catalase Activity ◽  
Macrocyclic Complexes ◽  
Ph Dependent

Pyclen and cylen complexes of manganese show pH dependent catalase activity with improved TOF and TON for the more rigid pyclen derivative. Spectroscopic investigation shows O2 evolution corresponds with the presence of a μ-O bridged species.

scholarly journals Microbial resistance in relation to catalase activity to oxidative stress induced by photolysis of hydrogen peroxide

2012 ◽  
Vol 56 (1) ◽  
pp. 48-55 ◽  
Author(s):  
Keisuke Nakamura ◽  
Taro Kanno ◽  
Takayuki Mokudai ◽  
Atsuo Iwasawa ◽  
Yoshimi Niwano ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Catalase Activity ◽  
Microbial Resistance

scholarly journals Phosphate-Catalyzed Hydrogen Peroxide Formation from Agar, Gellan, and κ-Carrageenan and Recovery of Microbial Cultivability via Catalase and Pyruvate

2017 ◽  
Vol 83 (21) ◽  
Author(s):  
Kosei Kawasaki ◽  
Yoichi Kamagata
Keyword(s):  
Hydrogen Peroxide ◽  
Phosphate Buffer ◽  
Laboratory Culture ◽  
Colony Count ◽  
Natural Environments ◽  
Ammonium Ions ◽  
Factors Affecting ◽  
Culture Techniques ◽  
Ph Dependent ◽  
Growth Inhibiting

ABSTRACTPreviously, we reported that when agar is autoclaved with phosphate buffer, hydrogen peroxide (H2O2) is formed in the resulting medium (PT medium), and the colony count on the medium inoculated with environmental samples becomes much lower than that on a medium in which agar and phosphate are autoclaved separately (PS medium) (T. Tanaka et al., Appl Environ Microbiol 80:7659–7666, 2014,https://doi.org/10.1128/AEM.02741-14). However, the physicochemical mechanisms underlying this observation remain largely unknown. Here, we determined the factors affecting H2O2formation in agar. The H2O2formation was pH dependent: H2O2was formed at high concentrations in an alkaline or neutral phosphate buffer but not in an acidic buffer. Ammonium ions enhanced H2O2formation, implying the involvement of the Maillard reaction catalyzed by phosphate. We found that other gelling agents (e.g., gellan and κ-carrageenan) also produced H2O2after being autoclaved with phosphate. We then examined the cultivability of microorganisms from a fresh-water sample to test whether catalase and pyruvate, known as H2O2scavengers, are effective in yielding high colony counts. The colony count on PT medium was only 5.7% of that on PS medium. Catalase treatment effectively restored the colony count of PT medium (to 106% of that on PS medium). In contrast, pyruvate was not as effective as catalase: the colony count on sodium pyruvate-supplemented PT medium was 58% of that on PS medium. Given that both catalase and pyruvate can remove H2O2from PT medium, these observations indicate that although H2O2is the main cause of reduced colony count on PT medium, other unknown growth-inhibiting substances that cannot be removed by pyruvate (but can be by catalase) may also be involved.IMPORTANCEThe majority of bacteria in natural environments are recalcitrant to laboratory culture techniques. Previously, we demonstrated that one reason for this is the formation of high H2O2levels in media prepared by autoclaving agar and phosphate buffer together (PT medium). In this study, we investigated the factors affecting H2O2formation from agar. H2O2formation is pH dependent, and ammonium ions promote this phosphate-catalyzed H2O2formation. Amendment of catalase or pyruvate, a well-known H2O2-scavenging agent, effectively eliminated H2O2. Yet results suggest that growth-inhibiting factor(s) that cannot be eliminated by pyruvate (but can be by catalase) are present in PT medium.

scholarly journals Tumor-acidity activated surface charge conversion of two-photon fluorescent nanoprobe for enhanced cellular uptake and targeted imaging of intracellular hydrogen peroxide

2019 ◽  
Vol 10 (40) ◽  
pp. 9351-9357 ◽  
Author(s):  
Lanlan Chen ◽  
Shuai Xu ◽  
Wei Li ◽  
Tianbing Ren ◽  
Lin Yuan ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Surface Charge ◽  
Cellular Uptake ◽  
Targeted Imaging ◽  
Two Photon ◽  
Fluorescent Nanoprobe ◽  
Tumor Acidity ◽  
Ph Dependent ◽  
Intracellular Hydrogen Peroxide ◽  
Activated Surface

A smart, two-photon fluorescent GC–NABP nanoprobe with pH-dependent surface charge conversion was developed for tumor-targeted visualization of H2O2.

pH-Dependent response of a hydrogen peroxide sensing probe

2016 ◽  
Vol 237 ◽  
pp. 113-119 ◽  
Author(s):  
Hamed Akbari Khorami ◽  
Peter Wild ◽  
Alexandre G. Brolo ◽  
Ned Djilali
Keyword(s):  
Hydrogen Peroxide ◽  
Ph Dependent

Colorimetric detection of catalase and catalase-positive bacteria (E. coli) using silver nanoprisms

2016 ◽  
Vol 8 (36) ◽  
pp. 6625-6630 ◽  
Author(s):  
Lili Zhao ◽  
Julia Wiebe ◽  
Rabia Zahoor ◽  
Sladjana Slavkovic ◽  
Brian Malile ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Catalase Activity ◽  
Colorimetric Detection ◽  
E Coli ◽  
Silver Nanoprisms

The sensitivity of the formation of plasmonic silver nanoprisms to hydrogen peroxide is explored for the colorimetric detection of catalase activity in bacteria.

The formation of choleglobin and the role of catalase in the erythrocyte

1949 ◽  
Vol 136 (884) ◽  
pp. 435-448 ◽  
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Amino Acid ◽  
Catalase Activity ◽  
Acid Oxidase ◽  
Small Decrease ◽  
Amino Acid Oxidase ◽  
Oxidase System ◽  
Inverse Proportion

In haemolysates of non-nucleated erythrocytes there is an inverse proportion between catalase activity and rate of choleglobin formation on addition of ascorbic acid. In the intact erythrocytes catalase protects haemoglobin against oxidation and further destruction by the hydrogen peroxide generated by the D-amino-acid oxidase system or by physiological concentrations of ascorbic acid and glutathione. Acid destromatization of haemolyzed horse erythrocytes causes a small decrease in the catalase activity and an increased rate of inactivation of the remaining catalase by ascorbic acid. The liberation of copper from haemocuprein is quantitatively insufficient to explain the decreased stability of the catalase. Exposing duck oxyhaemoglobin, but not reduced haemoglobin, to a pH of 5⋅5 to 5⋅8, causes an alteration which is apparent from the increase of the rate of choleglobin formation. The mechanism of this alteration is discussed. It partly explains the 'stroma effect', at least in duck erythrocytes. In addition, in the latter, there is a true stroma effect. Choleglobin formation in the presence of ascorbic acid is accelerated by a variety of substances. Some of these perturb haemoglobin, while others increase the formation of hydrogen peroxide from ascorbic acid. The implications of our findings on the mechanism of choleglobin formation and on the role of catalase in the erythrocyte are discussed.

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