Unraveling the Mechanism of Remote Scavenging Effect at the InP/Al 2 O 3 Interface Induced by Titanium Layer

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.

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Antibacterial, Antioxidant and Cytotoxic Properties of Crinum asiaticum Bulb Extract

Bangladesh Journal of Microbiology ◽

10.3329/bjm.v28i1.11801 ◽

2012 ◽

Vol 28 (1) ◽

pp. 1-5 ◽

Cited By ~ 6

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

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Molecular structures of nonvolatile components in the Haihong fruit wine and their free radical scavenging effect

Food Chemistry ◽

10.1016/j.foodchem.2021.129298 ◽

2021 ◽

Vol 353 ◽

pp. 129298

Author(s):

Yang Hui ◽

Su Wen ◽

Wang Lihong ◽

Wang Chuang ◽

Wang Chaoyun

Keyword(s):

Free Radical ◽

Radical Scavenging ◽

Free Radical Scavenging ◽

Molecular Structures ◽

Scavenging Effect ◽

Fruit Wine ◽

Radical Scavenging Effect ◽

Free Radical Scavenging Effect

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

Molecules ◽

10.3390/molecules26092420 ◽

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.

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

Water ◽

10.3390/w13091315 ◽

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.

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The Interface and Fabrication Process of Diamond/Cu Composites with Nanocoated Diamond for Heat Sink Applications

Metals ◽

10.3390/met11020196 ◽

2021 ◽

Vol 11 (2) ◽

pp. 196

Author(s):

Yaqiang Li ◽

Hongyu Zhou ◽

Chunjing Wu ◽

Zheng Yin ◽

Chang Liu ◽

...

Keyword(s):

Heat Sink ◽

Copper Matrix ◽

Interfacial Bonding ◽

Diamond Surface ◽

Interfacial Thermal Resistance ◽

Titanium Layer ◽

High Tc ◽

Interface Reactions ◽

Diamond Particles ◽

Measurement Results

The coefficients of thermal expansion (CTE) and thermal conductivity (TC) are important for heat sink applications, as they can minimize stress between heat sink substrates and chips and prevent failure from thermal accumulation in electronics. We investigated the interface behavior and manufacturing of diamond/Cu composites and found that they have much lower TCs than copper due to their low densities. Most defects, such as cavities, form around diamond particles, substantially decreasing the high TC of diamond reinforcements. However, the measurement results for the Cu-coated diamond/Cu composites are unsatisfactory because the nanosized copper layer on the diamond surface grew and spheroidized at elevated sintering temperatures. Realizing ideal interfacial bonding between a copper matrix and diamond particles is difficult. The TC of the 40 vol.% Ti-coated diamond/Cu composite is 475.01 W m−1 K−1, much higher than that of diamond/Cu and Cu-coated diamond/Cu composites under equivalent manufacturing conditions. The minimally grown titanium layer retained its nanosized and was consistent with the sintering temperature. Depositing a nanosized titanium layer on a diamond surface will strengthen interfacial bonding through interface reactions among the copper matrix, nanosized titanium layer and diamond particles, reducing the interfacial thermal resistance and exploiting the high TC of diamond particles, even if defects from powder metallurgy remain. These results provide an important experimental and theoretical basis for manufacturing diamond/Cu composites for heat sink applications.

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The scavenging effect of curcumin, piperine and their combination against physiological relevant reactive pro-oxidant species using in vitro non-cellular and cellular models

Chemical Papers ◽

10.1007/s11696-021-01710-y ◽

2021 ◽

Author(s):

Mariana Lucas ◽

Marisa Freitas ◽

Jadriane A. Xavier ◽

Fabiana A. Moura ◽

Marília O. F. Goulart ◽

...

Keyword(s):

Scavenging Effect ◽

Cellular Models

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Anti-oxidative and antimicrobial activities of Hieracium pilosella L. extracts

Journal of the Serbian Chemical Society ◽

10.2298/jsc0805531s ◽

2008 ◽

Vol 73 (5) ◽

pp. 531-540 ◽

Cited By ~ 16

Author(s):

Ljiljana Stanojevic ◽

Mihajlo Stankovic ◽

Vesna Nikolic ◽

Ljubisa Nikolic

Keyword(s):

Salmonella Enteritidis ◽

Radical Scavenging ◽

Antimicrobial Activities ◽

Diffusion Method ◽

Quantitative Composition ◽

Minimal Inhibitory Concentrations ◽

Qualitative And Quantitative ◽

Scavenging Effect ◽

Hieracium Pilosella ◽

Radical Scavenging Effect

The anti-oxidative and antimicrobial activities of different extracts from Hieracium pilosella L. (Asteraceae) whole plant were investigated. The total dry extracts were determined for all the investigated solvents: methanol, dichloromethane, ethyl acetate and dichloromethane: methanol (9:1). It was found that the highest yield was obtained by extraction with methanol (12.9 g/100 g of dry plant material). Qualitative and quantitative analysis were performed by the HPLC method, using external standards. Chlorogenic acid, apigenin-7-O-glucoside and umbelliferone were detected in the highest quantity in the extracts. The qualitative and quantitative composition of the extracts depends on the solvent used. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging effect of the extracts was determined spectrophotometrically. The highest radical scavenging effect was observed in the methanolic extract, both with and without incubation, EC50 = 0.012 and EC50 = 0.015 mg ml-1, respectively. The antimicrobial activities of the extracts towards the bacteria (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Salmonella enteritidis and Klebsiella pneumoniae) and the fungi (Aspergillus niger and Candida albicans) were determined by the disc diffusion method. The minimal inhibitory concentrations were determined for all the investigated extracts against all the mentioned microorganisms.

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