scholarly journals A Novel Thiosemicarbazide-Based Fluorescent Chemosensor for Hypochlorite in Near-Perfect Aqueous Solution and Zebrafish

Chemosensors ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 65
Author(s):  
Minji Lee ◽  
Donghwan Choe ◽  
Soyoung Park ◽  
Hyeongjin Kim ◽  
Soomin Jeong ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Reactive Oxygen Species ◽  
Aqueous Solution ◽  
Fluorescence Quenching ◽  
Limit Of Detection ◽  
Fluorescent Sensor ◽  
Ionization Mass ◽  
Oxygen Species ◽  
Marked Selectivity ◽  
Uv Visible

A novel thiosemicarbazide-based fluorescent sensor (AFC) was developed. It was successfully applied to detect hypochlorite (ClO−) with fluorescence quenching in bis-tris buffer. The limit of detection of AFC for ClO− was analyzed to be 58.7 μM. Importantly, AFC could be employed as an efficient and practical fluorescent sensor for ClO− in water sample and zebrafish. Moreover, AFC showed a marked selectivity to ClO− over varied competitive analytes with reactive oxygen species. The detection process of AFC to ClO− was illustrated by UV–visible and fluorescent spectroscopy and electrospray ionization–mass spectrometry (ESI–MS).

scholarly journals Generation of reactive oxygen species by promoting the Cu(II)/Cu(I) redox cycle with reducing agents in aerobic aqueous solution

2018 ◽  
Vol 78 (6) ◽  
pp. 1390-1399 ◽  
Author(s):  
Wenshu Li ◽  
Peng Zhou ◽  
Jing Zhang ◽  
Yongli Zhang ◽  
Gucheng Zhang ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Aqueous Solution ◽  
Superoxide Radical ◽  
Reactive Oxygen ◽  
Reducing Agents ◽  
Oxygen Species ◽  
Redox Cycle ◽  
Copper Species ◽  
Chain Reactions ◽  
H2o2 Generation

Abstract This study investigated the generation of reactive oxygen species (ROS) (O2−•, H2O2, and HO•) by promoting the Cu(II)/Cu(I) redox cycle with certain reducing agents (RAs) in aerobic aqueous solution, and benzoic acid (BA) was employed as indicator for the hydroxyl radical (HO•). Hydroxylamine (HA) can reduce Cu(II) to Cu(I) to induce chain reactions of copper species resulting in the generation of the superoxide radical (O2−•) and hydrogen peroxide (H2O2), and the intermediate Cu(I) can further activate H2O2 via a Fenton-like reaction to produce HO•, creating the remarkable BA degradation. O2 is indispensable, and unprotonated HA is the motive power in the O2/Cu/HA system. Moreover, pH is a crucial factor of the O2/Cu/HA system due to the protonated HA not being able to reduce Cu(II) into Cu(I). The oxidation of HA can be effectively induced by trace amounts of Cu(II), and both a higher HA dosage and a higher Cu(II) dosage can enhance H2O2 generation and BA degradation. In addition, some other RAs that can reduce Cu(II) into Cu(I) could replace HA in the O2/Cu/HA system to induce the generation of these ROS in aerobic aqueous solution.

Colorimetric and Fluorescent Probe for Hypochlorite with High Selectivity

2013 ◽  
Vol 295-298 ◽  
pp. 475-478 ◽  
Author(s):  
Zhi Xiang Han ◽  
Ming Hui Du ◽  
Guo Xi Liang ◽  
Xiang Yang Wu
Keyword(s):  
Reactive Oxygen Species ◽  
Aqueous Solution ◽  
Detection Limit ◽  
Fluorescent Probe ◽  
Rhodamine B ◽  
High Selectivity ◽  
Reactive Oxygen ◽  
Living Cells ◽  
Oxygen Species ◽  
Turn On

Rhodamine B thiohydrazide (RBS) was firstly employed as turn-on fluorescent probe for hypochlorite in aqueous solution and living cells. It exhibits a stable response to hypochlorite from 1.0×10-6to 1.0×10-5M with a detection limit of 3.3×10-7M. The response of this probe to hypochlorite is fast and highly selective compared with other reactive oxygen species (such as.OH,1O2, H2O2) and other common anions (such as X-, ClO2-, ClO4-, NO3-, NO2-, OH-, Ac-, CO32-, SO42-).

scholarly journals Stabilisation of Natural Colourants and Lignocellulosic Textiles

2021 ◽  
Author(s):  
◽  
Ying Tang
Keyword(s):  
Reactive Oxygen Species ◽  
Aqueous Solution ◽  
Textile Fibre ◽  
Oxygen Species ◽  
Blue Fluorescence ◽  
Esi Ms ◽  
Naturally Occurring ◽  
Antifungal Effects ◽  
Fluorescent Whitening Agents ◽  
Cyclobutane Ring

<p>The lignocellulosic fibres extracted from the leaves of New Zealand flax, Phormium tenax, have been used as the principal textile fibre by Maori since pre- European times. Variations of antifungal activity were observed in Phormium fibres of different cultivars. The most resistant cultivars of P. tenax in an aqueous antifungal assay also possessed the greatest variety of naturally-occurring 7-hydroxycoumarins as identified by mass spectroscopy, ESI-MS. In addition to antifungal effects, coumarins function as fluorescent whitening agents in Phormium fibres and play a role in the fibre’s photodegradation. Ultraviolet irradiation (350 – 400 nm) of the fibre resulted in a substantial loss of the blue fluorescence originating from a number of 7-hydroxycoumarins present, together with the formation of new fluorophores absorbing and emitting at longer wavelengths, which contribute to the photoyellowing of the fibre. The photolysis of two standard 7-hydroxycoumarins in aqueous solution was examined and two primary photoproducts were elucidated by ESI-MS: a photodimer containing a linking cyclobutane ring and a monomeric photooxidation product. The formation of at least some of the photoproducts is associated with the coumarin-sensitised generation of reactive oxygen species, hydrogen peroxide and superoxide. The fluorescence properties and photodegradation of Chinese handmade papers were also investigated. Papers manufactured by traditional methods were found to be more photostable than that produced from chemically-facilitated techniques.</p>

scholarly journals Fengycins, Cyclic Lipopeptides from MarineBacillus subtilisStrains, Kill the Plant-Pathogenic FungusMagnaporthe griseaby Inducing Reactive Oxygen Species Production and Chromatin Condensation

2018 ◽  
Vol 84 (18) ◽  
Author(s):  
Linlin Zhang ◽  
Chaomin Sun
Keyword(s):  
Mass Spectrometry ◽  
Reactive Oxygen Species ◽  
Biological Control ◽  
Bacillus Subtilis ◽  
Rice Blast ◽  
Marine Bacterium ◽  
Magnaporthe Grisea ◽  
Chromatin Condensation ◽  
Oxygen Species ◽  
Content Type

ABSTRACTRice blast caused by the phytopathogenMagnaporthe griseaposes a serious threat to global food security and is difficult to control.Bacillusspecies have been extensively explored for the biological control of many fungal diseases. In the present study, the marine bacteriumBacillus subtilisBS155 showed a strong antifungal activity againstM. grisea. The active metabolites were isolated and identified as cyclic lipopeptides (CLPs) of the fengycin family, named fengycin BS155, by the combination of high-performance liquid chromatography (HPLC) and electrospray ionization mass spectrometry (ESI-MS) and tandem mass spectrometry (ESI-MS/MS). Analyses using scanning and transmission electron microscopy revealed that fengycin BS155 caused morphological changes in the plasma membrane and cell wall ofM. griseahyphae. Using comparative proteomic and biochemical assays, fengycin BS155 was demonstrated to reduce the mitochondrial membrane potential (MMP), induce bursts of reactive oxygen species (ROS), and downregulate the expression level of ROS-scavenging enzymes. Simultaneously, fengycin BS155 caused chromatin condensation in fungal hyphal cells, which led to the upregulation of DNA repair-related protein expression and the cleavage of poly(ADP-ribose) polymerase (PARP). Altogether, our results indicate that fengycin BS155 acts by inducing membrane damage and dysfunction of organelles, disrupting MMP, oxidative stress, and chromatin condensation, resulting inM. griseahyphal cell death. Therefore, fengycin BS155 and its parent bacterium are very promising candidates for the biological control ofM. griseaand the associated rice blast and should be further investigated as such.IMPORTANCERice (Oryza sativaL.) is the most important crop and a primary food source for more than half of the world's population. Notably, scientists in China have developed several types of rice that can be grown in seawater, avoiding the use of precious freshwater resources and potentially creating enough food for 200 million people. The plant-affecting fungusMagnaporthe griseais the causal agent of rice blast disease, and biological rather than chemical control of this threatening disease is highly desirable. In this work, we discovered fengycin BS155, a cyclic lipopeptide material produced by the marine bacteriumBacillus subtilisBS155, which showed strong activity againstM. grisea. Our results elucidate the mechanism of fengycin BS155-mediatedM. griseagrowth inhibition and highlight the potential ofB. subtilisBS155 as a biocontrol agent againstM. griseain rice cultivation under both fresh- and saltwater conditions.

scholarly journals Elevated serum matrix metalloprotease (MMP-2) as a candidate biomarker for stable COPD

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Durga Mahor ◽  
Vandana Kumari ◽  
Kapil Vashisht ◽  
Ruma Galgalekar ◽  
Ravindra M. Samarth ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Reactive Oxygen Species ◽  
Neutrophil Elastase ◽  
Elevated Serum ◽  
Reactive Oxygen ◽  
Mass Spectrometry Analysis ◽  
Oxygen Species ◽  
Matrix Metalloprotease ◽  
Copd Patients ◽  
Asthma Patients

Abstract Background The increasing trend of Chronic Obstructive Pulmonary Disease (COPD) in becoming the third leading cause of deaths by 2020 is of great concern, globally as well as in India. Dysregulation of protease/anti-protease balance in COPD has been reported to cause tissue destruction, inflammation and airway remodelling; which are peculiar characteristics of COPD. Therefore, it is imperative to explore various serum proteases involved in COPD pathogenesis, as candidate biomarkers. COPD and Asthma often have overlapping symptoms and therefore involvement of certain proteases in their pathogenesis would render accurate diagnosis of COPD to be difficult. Methods Serum samples from controls, COPD and Asthma patients were collected after requisite institutional ethics committee approvals. The preliminary analysis qualitatively and quantitatively analyzed various serum proteases by ELISA and mass spectrometry techniques. In order to identify a distinct biomarker of COPD, serum neutrophil elastase (NE) and matrix metalloprotease-2 (MMP-2) from COPD and Asthma patients were compared; as these proteases tend to have overlapping activities in both the diseases. A quantitative analysis of the reactive oxygen species (ROS) in the serum of controls and COPD patients was also performed. Statistical analysis for estimation of p-values was performed using unpaired t-test with 95% confidence interval. Results Amongst the significantly elevated proteases in COPD patients vs the controls- neutrophil elastase (NE) [P < 0.0241], caspase-7 [P < 0.0001] and matrix metalloprotease-2 (MMP-2) [P < 0.0001] were observed, along with increased levels of reactive oxygen species (ROS) [P < 0.0001]. The serum dipeptidyl peptidase-IV (DPP-IV) [P < 0.0010) concentration was found to be decreased in COPD patients as compared to controls. Interestingly, a distinct elevation of MMP-2 was observed only in COPD patients, but not in Asthma, as compared to controls. Mass spectrometry analysis further identified significant alterations (fold-change) in various proteases (carboxy peptidase, MMP-2 and human leukocyte elastase), anti-proteases (Preg. zone protein, α-2 macroglobulin, peptidase inhibitor) and signalling mediators (cytokine suppressor- SOCS-3). Conclusion The preliminary study of various serum proteases in stable COPD patients distinctly identified elevated MMP-2 as a candidate biomarker for COPD, subject to its validation in large cohort studies.

scholarly journals Development and testing of an online method to measure ambient fine particulate Reactive Oxygen Species (ROS) based on the 2',7'-dichlorofluorescin (DCFH) assay

2013 ◽  
Vol 6 (2) ◽  
pp. 3279-3315
Author(s):  
L. E. King ◽  
R. J. Weber
Keyword(s):  
Reactive Oxygen Species ◽  
Limit Of Detection ◽  
Reactive Oxygen ◽  
Rural Site ◽  
Oxygen Species ◽  
Optimal Method ◽  
Mist Chamber ◽  
Filter Particle ◽  
Urban Sites ◽  
Probe Response

Abstract. An online, semi-continuous instrument to measure fine particle (PM2.5) reactive oxygen species (ROS) was developed based on the fluorescent probe 2'7'-dichlorofluorescin (DCFH). Parameters that influence probe response were first characterized to develop an optimal method for use in a field instrument. The online method used a mist chamber scrubber to collect total (gas plus particle) ROS components (ROSt) alternating with gas phase ROS (ROSg) by means of an inline filter. Particle phase ROS (ROSp) was determined by difference between ROSt and ROSg. The instrument was deployed in urban Atlanta, Georgia, and at a rural site during various seasons. Concentrations from the online instrument generally agreed well with those from an intensive filter measurement of ROSp. Concentrations of the ROSp measurements made with this instrument were lower than reported in other studies, often below the instrument's average limit of detection (0.15 nmol H2O2 equivalents m−3). Mean ROSp concentrations were 0.26 nmol H2O2 equivalents m−3 at the Atlanta urban sites compared to 0.14 nmol H2O2 equivalents m−3 at the rural site.

scholarly journals Development and testing of an online method to measure ambient fine particulate reactive oxygen species (ROS) based on the 2',7'-dichlorofluorescin (DCFH) assay

2013 ◽  
Vol 6 (7) ◽  
pp. 1647-1658 ◽  
Author(s):  
L. E. King ◽  
R. J. Weber
Keyword(s):  
Reactive Oxygen Species ◽  
Limit Of Detection ◽  
Reactive Oxygen ◽  
Rural Site ◽  
Oxygen Species ◽  
Optimal Method ◽  
The Difference ◽  
Mist Chamber ◽  
Filter Particle ◽  
Urban Sites

Abstract. An online, semi-continuous instrument to measure fine particle (PM2.5) reactive oxygen species (ROS) was developed based on the fluorescent probe 2'7'-dichlorofluorescin (DCFH). Parameters that influence probe response were first characterized to develop an optimal method for use in a field instrument. The online method used a mist chamber scrubber to collect total (gas plus particle) ROS components (ROSt) alternating with gas phase ROS (ROSg) by means of an inline filter. Particle phase ROS (ROSp) was determined by the difference between ROSt and ROSg. The instrument was deployed in urban Atlanta, Georgia, USA, and at a rural site during various seasons. Concentrations from the online instrument generally agreed well with those from an intensive filter measurement of ROSp. Concentrations of the ROSp measurements made with this instrument were lower than reported in other studies, often below the instrument's average limit of detection (0.15 nmol H2O2 equivalents m−3). Mean ROSp concentrations were 0.26 nmol H2O2 equivalents m−3 at the Atlanta urban sites compared to 0.14 nmol H2O2 equivalents m−3 at the rural site.

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