Phenols as probes of chemical composition of graphene oxide

2016 ◽  
Vol 18 (44) ◽  
pp. 30515-30519 ◽  
Author(s):  
Thi Mai Huong Tran ◽  
Adriano Ambrosi ◽  
Martin Pumera
Keyword(s):  
Graphene Oxide ◽  
Chemical Composition ◽  
Phenolic Compounds ◽  
Electrochemical Properties ◽  
Oxidation State

Phenolic compounds are used to test the graphene oxide oxidation state and the electrochemical properties.

scholarly journals Synthesis of Polypyrrole/Reduced Graphene Oxide Hybrids via Hydrothermal Treatment for Energy Storage Applications

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2273 ◽  
Author(s):  
Adam Moyseowicz ◽  
Krzysztof Pająk ◽  
Katarzyna Gajewska ◽  
Grażyna Gryglewicz
Keyword(s):  
Graphene Oxide ◽  
Chemical Composition ◽  
Electrochemical Properties ◽  
Reduced Graphene Oxide ◽  
Hydrothermal Treatment ◽  
Hybrid Materials ◽  
Electrode Materials ◽  
Conductive Polymer ◽  
Surface Areas ◽  
Reduced Graphene

Herein, we propose hydrothermal treatment as a facile and environmentally friendly approach for the synthesis of polypyrrole/reduced graphene oxide hybrids. A series of self-assembled hybrid materials with different component mass ratios of conductive polymer to graphene oxide was prepared. The morphology, porous structure, chemical composition and electrochemical performance of the synthesized hybrids as electrode materials for supercapacitors were investigated. Nitrogen sorption analysis at 77 K revealed significant changes in the textural development of the synthesized materials, presenting specific surface areas ranging from 25 to 199 m2 g−1. The combination of the pseudocapacitive polypyrrole and robust graphene material resulted in hybrids with excellent electrochemical properties, which achieved specific capacitances as high as 198 F g−1 at a current density of 20 A g−1 and retained up to 92% of their initial capacitance after 3000 charge–discharge cycles. We found that a suitable morphology and chemical composition are key factors that determine the electrochemical properties of polypyrrole/reduced graphene oxide hybrid materials.

Microwave Pretreatment of Vegetable Materials to Increase the Extraction Yield of Natural Products

2018 ◽  
Vol 69 (8) ◽  
pp. 1976-1979
Author(s):  
Ioana Asofiei ◽  
Ioan Calinescu ◽  
Adina Ionuta Gavrila ◽  
Daniel Ighigeanu ◽  
Diana Martin
Keyword(s):  
Natural Products ◽  
Chemical Composition ◽  
Phenolic Compounds ◽  
Total Phenolic Content ◽  
Phenolic Content ◽  
Extraction Yield ◽  
Total Phenolic ◽  
Microwave Pretreatment ◽  
Pretreatment Time ◽  
Conventional Extraction

It was designed and built a laboratory experimental installation (LEI) for the microwave pretreatment of vegetable materials. To study the influence of microwave pretreatment on the total phenolic content (TPC), a conventional extraction of polyphenols from treated and untreated fresh sea buckthorn leaves was performed. For short extraction times, the amount of phenolic compounds was higher for the extracts obtained from treated leaves, but a long pretreatment time (28 s) led to a decrease in TPC. The qualitative analysis showed that the chemical composition is not affected by the microwave pretreatment.

scholarly journals Effect of Deposition Parameters on Electrochemical Properties of Polypyrrole-Graphene Oxide Films

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 624 ◽  
Author(s):  
Alina Iuliana Pruna ◽  
Nelly Ma. Rosas-Laverde ◽  
David Busquets Mataix
Keyword(s):  
Cyclic Voltammetry ◽  
Graphene Oxide ◽  
Electrochemical Properties ◽  
Sodium Dodecyl ◽  
Hybrid Coatings ◽  
Deposition Parameters ◽  
Structure Morphology ◽  
Energy Storage Applications ◽  
Improved Performance ◽  
Sds Surfactant

Graphene oxide (GO)-modified polypyrrole (PPy) coatings were obtained by electrochemical methods in the presence of the anionic surfactant, sodium dodecyl sulfate (SDS). The structure, morphology, and electrochemical properties of the coatings were assessed by Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM) and cyclic voltammetry at varying scan rates, respectively. The properties of the obtained coatings were analyzed with the GO and PPy loadings and electrodeposition mode. The hybrid coatings obtained galvanostatically showed a coarser appearance than those deposited by cyclic voltammetry CV mode and improved performance, respectively, which was further enhanced by GO and PPy loading. The capacitance enhancement can be attributed to the SDS surfactant that well dispersed the GO sheets, thus allowing the use of lower GO content for improved contribution, while the choice of suitable electrodeposition parameters is highly important for improving the applicability of GO-modified PPy coatings in energy storage applications.

scholarly journals By-Products of Camu-Camu [Myrciaria dubia (Kunth) McVaugh] as Promising Sources of Bioactive High Added-Value Food Ingredients: Functionalization of Yogurts

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 70 ◽  
Author(s):  
Natália Conceição ◽  
Bianca R. Albuquerque ◽  
Carla Pereira ◽  
Rúbia C. G. Corrêa ◽  
Camila B. Lopes ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Phenolic Compounds ◽  
Food System ◽  
Food Additives ◽  
Added Value ◽  
Phenolic Profile ◽  
Food Ingredients ◽  
Myrciaria Dubia ◽  
By Products ◽  
Fruit Part

Camu-camu (Myrciaria dubia (Kunth) McVaugh) is a fruit economically relevant to the Amazon region, mostly consumed in the form of processed pulp. Our aim was to perform an unprecedented comparative study on the chemical composition and bioactivities of the camu-camu pulp and industrial bio-residues (peel and seed), and then the most promising fruit part was further explored as a functionalized ingredient in yogurt. A total of twenty-three phenolic compounds were identified, with myricetin-O-pentoside and cyanindin-3-O-glucoside being the main compounds in peels, followed by p-coumaroyl hexoside in the pulp, and ellagic acid in the seeds. The peel displayed the richest phenolic profile among samples, as well as the most significant antibacterial (MICs = 0.625–10 mg/mL) and anti-proliferative (GI50 = 180 µg/mL against HeLa cells) activities. For this reason, it was selected to be introduced in a food system (yogurt). Taken together, our results suggest the possibility of using the camu-camu peel as a source of food additives.

scholarly journals Comparative Evaluation of Chemical Composition, Phenolic Compounds, and Antioxidant and Antimicrobial Activities of Tropical Black Bolete Mushroom Using Different Preservation Methods

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 781
Author(s):  
Jaturong Kumla ◽  
Nakarin Suwannarach ◽  
Keerati Tanruean ◽  
Saisamorn Lumyong
Keyword(s):  
Chemical Composition ◽  
Phenolic Compounds ◽  
Natural Antioxidants ◽  
Antimicrobial Activities ◽  
Fresh Sample ◽  
Antioxidant Power ◽  
Preservation Methods ◽  
Ferric Reducing Antioxidant Power ◽  
Nutritional Benefits ◽  
Antioxidant And Antimicrobial Activities

Tropical black bolete, Phlebopus portentosus, provides various nutritional benefits and natural antioxidants to humans. In this study, the chemical composition, phenolic compounds, and antioxidant and antimicrobial activities of fresh mushroom samples and samples stored for a period of one year using different preservation methods (drying, brining, and frozen) were investigated. The results indicated that the brining method significantly reduced the protein and fat contents of the mushrooms. The polyphenol and flavonoid contents of the frozen sample were not significantly different from that of the fresh sample. The results revealed that an inhibition value of 50% (IC50) for the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay of the extract of the dried and frozen samples was not statistically different from that of the fresh sample. The IC50 value of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assay and ferric reducing antioxidant power (FRAP) value in the extract of the frozen sample were not found to be significantly different from those of the fresh sample. Furthermore, the lowest degree of antioxidant activity was found in the extract of the brined sample. Additionally, the antimicrobial activities of the extracts of the fresh and frozen samples were not significantly different and both extracts could have inhibited the growth of all tested Gram-positive bacteria and Pseudomonas aeruginosa.

scholarly journals Phytochemical and Psychotropic Research of Motherwort (Leonurus cardiaca L.) Modified Dry Extracts

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 230
Author(s):  
Oleh Koshovyi ◽  
Ain Raal ◽  
Igor Kireyev ◽  
Nadiya Tryshchuk ◽  
Tetiana Ilina ◽  
...  
Keyword(s):  
Amino Acids ◽  
Chemical Composition ◽  
Phenolic Compounds ◽  
Pharmacological Activity ◽  
Ellagic Acid ◽  
Hydroxycinnamic Acids ◽  
Psychotropic Activity ◽  
Phytochemical Analysis ◽  
Phenolic Substances ◽  
Leonurus Cardiaca

The prospect of creating a new medicine with psychotropic activity is shown as a result of studying the chemical composition and pharmacological activity of modified dry extracts of motherwort (Leonurus cardiaca L.) tincture. The most promising substances were the dry extracts, modified by adding small amounts of arginine, valine, phenylalanine, glycine, lysine, and alanine. A total of 15 main phenolic substances were found in the extracts, and eight of them were identified. There were also 10 hydroxycinnamic acids in these extracts, three of which were identified (chlorogenic, caffeic, and rosmarinic acids). The dominant hydroxycinnamic acids were chlorogenic and caffeic acids. Among flavonoids, catechin, hyperoside, and rutin were identified. It should be noted that the extracts had a significant content of ellagic acid. On the basis of the results of the phytochemical analysis of the extracts, it can be concluded that the composition of phenolic compounds does not differ significantly, and the main differences are related to amino acids, which obviously have an impact on the overall pharmacological effect. The results obtained indicate the presence of anxiolytic activity in the motherwort extracts studied in complex with amino acids. The extracts with glycine, valine, and arginine were more effective in reducing anxiety in animals.

scholarly journals Impact of in vitro gastrointestinal digestion on the chemical composition, bioactive properties, and cytotoxicity of Vitis vinifera L. cv. Syrah grape pomace extract

2019 ◽  
Vol 10 (4) ◽  
pp. 1856-1869 ◽  
Author(s):  
Joana R. Costa ◽  
Manuela Amorim ◽  
Ana Vilas-Boas ◽  
Renata V. Tonon ◽  
Lourdes M. C. Cabral ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Phenolic Compounds ◽  
Vitis Vinifera ◽  
Human Health ◽  
Grape Pomace ◽  
Vitis Vinifera L ◽  
Gastrointestinal Digestion ◽  
Gastrointestinal Health ◽  
Bioactive Properties

Grape pomace (GP) is a major byproduct worldwide, and it is well known for its bioactive compounds, such as fibers and phenolic compounds, that are popular for their impact upon human health, including in gastrointestinal health.

Sign in / Sign up

Export Citation Format

Share Document