Sonolytic degradation of chlorophene enhanced by Fenton-mediated oxidation and H -scavenging effect

2017 ◽  
Vol 328 ◽  
pp. 904-914 ◽  
Author(s):  
J. Bolobajev ◽  
A. Goi
Keyword(s):  
Scavenging Effect ◽  
Sonolytic Degradation ◽  
Mediated Oxidation

Chemical Constituents Isolated from Rhododendron ungernii with Antioxidant Profile

2019 ◽  
Vol 9 (3) ◽  
pp. 238-243 ◽  
Author(s):  
Emine Dede ◽  
Nusret Genc ◽  
Mahfuz Elmastas ◽  
Huseyin Aksit ◽  
Ramazan Erenler
Keyword(s):  
Antioxidant Activities ◽  
Biological Activities ◽  
Chemical Constituents ◽  
Reducing Power ◽  
Scavenging Activity ◽  
Isolation And Identification ◽  
Reduced Pressure ◽  
Scavenging Effect ◽  
Pharmaceutical Industries ◽  
Dpph Scavenging

Background: Plant in Rhododendron genus that contains phenolic compounds has been used in traditional medicine and revealed considerable biological activities. Objective: Isolation and identification of antioxidant natural products from Rhododendron ungernii. Methods: Rhododendron ungernii Trautv. flowers were collected and dried in shade. The dried flowers were extracted with methanol for 3 days. The solvent was removed by reduced pressure to yield the extract which was subjected to column chromatography (Sephadex LH-20, C18 reversed phase column) to isolate catechin-7-O-glucoside (1), quercetin-3-O-β-galactoside (2), quercetin-3-O- β-xyloside (3), farrerol (4), myricetin (5), and quercetin (6). The structures of isolated compounds were elucidated by spectroscopic methods such as 1D-NMR, 2D-NMR, and LC-TOF/MS. DPPH scavenging effect, ABTS+ scavenging activity, and reducing power (FRAP) were performed for antioxidant assays of isolated natural compounds. Results: Isolated flavonoids displayed the outstanding antioxidant activities. Catechin-7-O-glucoside (1) and quercetin-3-O-β-galactoside (2) (IC50, 3.66 µg/mL) had the most DPPH• scavenging effect among the compounds. The highest ABTS•+ scavenging activity (IC50, 1.41 µg/mL) and reducing power effect (6.05 mmol TE/g comp) were observed for myricetin (5). Conclusion: R. ungernii extract and isolated compounds could be a promising antioxidant for food and pharmaceutical industries.

scholarly journals Antibacterial, Antioxidant and Cytotoxic Properties of Crinum asiaticum Bulb Extract

2012 ◽  
Vol 28 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Md Atiar Rahman ◽  
Rumana Sharmin ◽  
Md Nazim Uddin ◽  
Md Sohel Rana ◽  
Nazim Uddin Ahmed
Keyword(s):  
Radical Scavenging ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Scavenging Effect ◽  
Ic50 Value ◽  
Radical Scavenging Effect ◽  
Dpph Scavenging ◽  
Crinum Asiaticum

Antibacterial effect of Crinum asiaticum bulb extract (1mg/disc) was tested on four Gram- positive and six Gram-negative bacteria by disc diffusion method using kanamycin (30 ìg/disc) as standard antibiotic disc. The bulb extract (250-1000mg/disc) showed significant zone of inhibition against all Gram-positive and Gram-negative bacteria ranging from 12-14 mm in diameter. Antioxidant potential of the same extract was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging method. The extract showed remarkable free radical scavenging effect (95.96%) providing the IC50 value of 5.62 for the bulb extract and 5.46 for ascorbic acid (standard antioxidant) at the concentration of 1000 ìg/ml. The bulb extract was found to be (LC50 value 94.06 ?g/ml) in Brine-Shrimp lethality test. DOI: http://dx.doi.org/10.3329/bjm.v28i1.11801 Bangladesh J Microbiol, Volume 28, Number 1, June 2011, pp 1-5

Effect of Polyethylene Glycol in Nanocellulose/PLA Composites

2019 ◽  
Vol 821 ◽  
pp. 89-95
Author(s):  
Wanasorn Somphol ◽  
Thipjak Na Lampang ◽  
Paweena Prapainainar ◽  
Pongdhorn Sae-Oui ◽  
Surapich Loykulnant ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Lactic Acid ◽  
Polyethylene Glycol ◽  
Aspect Ratio ◽  
Mechanical Performance ◽  
Tensile Modulus ◽  
Poly Lactic Acid ◽  
Solvent Casting ◽  
Casting Method ◽  
Mediated Oxidation

Poly (lactic acid) or PLA was reinforced by nanocellulose and polyethylene glycol (PEG), which were introduced into PLA matrix from 0 to 3 wt.% to enhance compatibility and strength of the PLA. The nanocellulose was prepared by TEMPO-mediated oxidation from microcrystalline cellulose (MCC) powder and characterized by TEM, AFM, and XRD to reveal rod-like shaped nanocellulose with nanosized dimensions, high aspect ratio and high crystallinity. Films of nanocellulose/PEG/PLA nanocomposites were prepared by solvent casting method to evaluate the mechanical performance. It was found that the addition of PEG in nanocellulose-containing PLA films resulted in an increase in tensile modulus with only 1 wt% of PEG, where higher PEG concentrations negatively impacted the tensile strength. Furthermore, the tensile strength and modulus of nanocellulose/PEG/PLA nanocomposites were higher than the PLA/PEG composites due to the existence of nanocellulose chains. Visual traces of crazing were detailed to describe the deformation mechanism.

scholarly journals Plasmon-Mediated Oxidation Reaction on Au/p-Cu2O: The Origin of Hot Holes

Physchem ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 163-175
Author(s):  
Philipp Hawe ◽  
Vitor R. R. Silveira ◽  
Robert Bericat Vadell ◽  
Erik Lewin ◽  
Jacinto Sá
Keyword(s):  
Optical Absorption ◽  
Small Molecules ◽  
Photocatalytic Efficiency ◽  
Sustainable Solutions ◽  
Hot Carrier ◽  
Mitigate Climate Change ◽  
Underlying Processes ◽  
Direct Use ◽  
Mediated Oxidation ◽  
High Optical Absorption

More sustainable solutions are needed to produce chemicals and fuels, mainly to face rising demands and mitigate climate change. Light, as a reagent, has emerged as a route to activate small molecules, e.g., H2O, CO2, N2, and make complex chemicals in a process called photocatalysis. Several photosystems have been proposed, with plasmonic technology emerging as one the most promising technologies due to its high optical absorption and hot-carrier formation. However, the lifetime of hot carriers is unsuitable for direct use; therefore, they are normally coupled with suitable charge-accepting materials, such as semiconductors. Herein, a system is reported consisting of Au supported in p-Cu2O. The combination of p-Cu2O intrinsic photoactivity with the plasmonic properties of Au extended the system’s optical absorption range, increasing photocatalytic efficiency. More importantly, the system enabled us to study the underlying processes responsible for hot-hole transfer to p-Cu2O. Based on photocatalytic studies, it was concluded that most of the holes involved in aniline photo-oxidation come from hot-carrier injections, not from the PIRET process.

scholarly journals Phytochemical Analysis, Antioxidant and Anticancer Potential of Sideritis niveotomentosa: Endemic Wild Species of Turkey

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2420
Author(s):  
Ela Nur Şimşek Şimşek Sezer ◽  
Tuna Uysal
Keyword(s):  
Cell Lines ◽  
Phenolic Content ◽  
Radical Scavenging ◽  
Total Phenolic ◽  
Phytochemical Analysis ◽  
Expression Levels ◽  
Phenolic Contents ◽  
Scavenging Effect ◽  
Methanolic Extracts ◽  
Total Antioxidant

Sideritis niveotomentosa Hub. -Mor. is a local endemic species belonging to the Lamiaceae family. In this study, GC/MS analysis, total antioxidant capacity and anticancer effects of different extracts obtained from S. niveotomentosa were investigated comparatively. Total phenolic contents of extracts were determined by the Folin–Ciocalteu method, total flavonoid contents by aluminum chloride method, and also the free radical scavenging activities of the extracts by DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) assay. The cytotoxic effect of the extracts was studied via MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay on DLD1, HL60 and ARH77 cell lines. Pro-apoptotic gene expression levels were also tested in the most sensitive cell line ARH77 by Real-Time PCR. The expression levels of 4 pro-apoptotic genes, APAF, BAX, CASP3, and HRK were found to be upregulated in ARH77 cells that were treated extracts. Results showed that methanolic extracts contain more phenolic content than acetone extracts, consistent with DPPH results. As a result, Sideritis niveotomentosa extracts, especially methanolic extracts, are rich in phenolic content and have a strong radical scavenging effect. In addition, the extracts showed selective effects on cell lines. This study is pioneering in terms of future studies, and the findings provide hope for future experimentation.

scholarly journals Effect of Salinity on UVA-Vis Light Driven Photo-Fenton Process at Acidic and Circumneutral pH

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1315
Author(s):  
Iván Vallés ◽  
Lucas Santos-Juanes ◽  
Ana M. Amat ◽  
Javier Moreno-Andrés ◽  
Antonio Arques
Keyword(s):  
Hydroxyl Radicals ◽  
Acidic Medium ◽  
Emerging Pollutants ◽  
Clofibric Acid ◽  
Fenton Process ◽  
Simulated Sunlight ◽  
Scavenging Effect ◽  
Aqueous Matrices ◽  
Ph Dependent ◽  
Pollutants Removal

In the present work, the treatment of a mixture of six emerging pollutants (acetamiprid, acetaminophen, caffeine, amoxicillin, clofibric acid and carbamazepine) by means of photo-Fenton process has been studied, using simulated sunlight as an irradiation source. Removal of these pollutants has been investigated in three different aqueous matrices distinguished by the amount of chlorides (distilled water, 1 g L−1 of NaCl and 30 g L−1 of NaCl) at a pH of 2.8 and 5.0. Interestingly, the presence of 1 g L−1 was able to slightly accelerate the pollutants removal at pH = 5, although the reverse was true at pH = 2.8. This is attributed to the pH-dependent interference of chlorides on photo-Fenton process, that is more acute in an acidic medium. As a matter of fact, the fastest reaction was obtained at pH = 3.5, in agreement with literature results. Monitoring of hydrogen peroxide consumption and iron in solution indicates that interference with chlorides is due to changes in the interaction between iron and the peroxide, rather than a scavenging effect of chloride for hydroxyl radicals. Experiments were also carried out with real seawater and showed higher inhibition than in the NaCl experiments, probably due to the effect of different dissolved salts present in natural water.

scholarly journals Carbamate intermediates over mesoporous carbon nitrides in CO2 mediated oxidation reaction

2021 ◽  
Vol 6 ◽  
pp. 100102
Author(s):  
Mohd Bismillah Ansari ◽  
Ram Sambhar Shukla ◽  
Yong-Hwan Mo ◽  
Sang-Eon Park
Keyword(s):  
Mesoporous Carbon ◽  
Oxidation Reaction ◽  
Carbon Nitrides ◽  
Mediated Oxidation
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