Publications related to Naturally occurring phenols

Electrospun zein incorporating phycocyanin and Spirulina extract: Fabrication, characterization, and potential application

Electrospinning was used to develop zein fibers containing phycocyanin and aqueous-ethanolic extract of Spirulina (AEES) for elucidating the potent packaging properties of phycocyanin and AEES on walnut samples. Morphological results revealed that using th ...

Elsevier2023

Reactivity of Bromine Radical with Dissolved Organic Matter Moieties and Monochloramine: Effect on Bromate Formation during Ozonation

Urs von Gunten, Sung Eun Lim

Bromine radical (Br center dot) has been hypothesized to be a key intermediate of bromate formation during ozonation. Once formed, Br center dot further reacts with ozone to eventually form bromate. However, this reaction competes with the reaction of Br c ...

AMER CHEMICAL SOC2023

Hypervalent Iodine: New Reagents and Functionalization of Peptides

Eliott Hugo Joran Le Du

Alkynes are found in a multitude of natural or synthetic bioactive compounds. In addition to the capacity of these chemical motifs to impact the physicochemical properties of a molecule of interest, the well-established reactivity of alkynes makes them ide ...

EPFL2023

Photochemical oxidation of phenols and anilines mediated by phenoxyl radicals in aqueous solution

Urs von Gunten, Silvio Canonica, Stephanie Christa Remke

Reactive intermediates formed upon irradiation of chromophoric dissolved organic matter (CDOM) contribute to the degradation of various organic contaminants in surface waters. Besides well-studied "short-lived" photo oxidants, such as triplet state CDOM (3 ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Phototransformation of Organic Contaminants in Aquatic Systems: Characterization of Long-Lived Photooxidants Derived from Dissolved Organic Matter

Stephanie Christa Remke

The increasing interest in the fate of organic contaminants in the aquatic environment requires the elucidation of relevant abiotic transformation processes. These processes often involve the ubiquitous dissolved organic matter (DOM), a complex mixture of ...

EPFL2021

Impact of the Natural Compound Urolithin A on Health, Disease, and Aging

Johan Auwerx, Pénélope Andreux, Davide D'Amico, Pamela Solange Valdés Undurraga, Anurag Singh

Urolithin A (UA) is a natural compound produced by gut bacteria from ingested ellagitannins (ETs) and ellagic acid (EA), complex polyphenols abundant in foods such as pomegranate, berries, and nuts. UA was discovered 40 years ago, but only recently has its ...

2021

Guidelines for performing lignin-first biorefining

Jeremy Luterbacher, Feng Wang

The valorisation of the plant biopolymer lignin is now recognised as essential to enabling the economic viability of the lignocellulosic biorefining industry. In this context, the "lignin-first" biorefining approach, in which lignin valorisation is conside ...

2021

Catechin reduces phototoxic effects induced by protoporphyrin IX-based photodynamic therapy in the chick embryo chorioallantoic membrane

Georges Wagnières, Jaroslava Joniová

Significance: Side effects of many cancer treatments are associated with the production of reactive oxygen species (ROS) in normal tissues. This explains why patients treated by photodynamic therapy (PDT) often suffer from skin photosensitization, whereas ...

SPIE Society of Photo-optical Instrumentation Engineers2020

Efficiency of pre-oxidation of natural organic matter for the mitigation of disinfection byproducts: Electron donating capacity and UV absorbance as surrogate parameters

Urs von Gunten

Pre-oxidation is often used before disinfection with chlorine to decrease the reactivity of the water matrix and mitigate the formation of regulated disinfection byproducts (DBPs). This study provides insights on the impact of oxidative pre-treatment with ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Enhanced transformation of sulfonamide antibiotics by manganese(IV) oxide in the presence of model humic constituents

Urs von Gunten, Jun Ma, Jin Jiang, Yang Song, Yang Zhou

In this study, a manganese(IV) oxide-mediator (MnO2-mediator) system for the abatement of sulfonamide antibiotics was evaluated. Two simple model humic constituents, syringaldehyde (SA) and acetosyringone (AS), could promote the transformation of sulfonami ...

PERGAMON-ELSEVIER SCIENCE LTD2019

Species-species interactions modulate copper toxicity under different visible light conditions

Valérie Gagnaux

Combination of biotic and abiotic factors influences the effects of naturally occurring or anthropogenic chemicals on photosynthetic microorganisms in the aquatic environment. Nonetheless, the combined effects of physical stressors and species-species inte ...

ACADEMIC PRESS INC ELSEVIER SCIENCE2019

Exploring the Sources of Unexpected High Methane Concentrations and Fluxes From Alpine Headwater Streams

Amber Joy Ulseth, Sabine Flury McGinnis

The dynamics of methane generation and evasion from well-oxygenated, oligotrophic streams have been traditionally neglected. We estimated evasion of methane and assessed its sources and production pathways using a stable isotope approach in 16 oxygen-rich ...

AMER GEOPHYSICAL UNION2019

Ozonation of Para-Substituted Phenolic Compounds Yields p-Benzoquinones, Other Cyclic α,β-Unsaturated Ketones, and Substituted Catechols

Urs von Gunten, Peter Rudolf Tentscher

Phenolic moieties are common functional groups in organic micropollutants and in dissolved organic matter, and are exposed to ozone during drinking water and wastewater ozonation. Although unsubstituted phenol is known to yield potentially genotoxic p-benz ...

2018

Ozone and chlorine reactions with dissolved organic matter - Assessment of oxidant-reactive moieties by optical measurements and the electron donating capacities

Urs von Gunten

Oxidation processes are impacted by the type, concentration and reactivity of the dissolved organic matter (DOM). In this study, the reactions between various types of DOM (Suwannee River fulvic acid (SRFA), Nordic Reservoir NOM (NNOM) and Pony Lake fulvic ...

2018

Two analytical approaches quantifying the electron donating capacities of dissolved organic matter to monitor its oxidation during chlorination and ozonation

Urs von Gunten

Electron-donating activated aromatic moieties, including phenols, in dissolved organic matter (DOM) partially control its reactivity with the chemical oxidants ozone and chlorine. This comparative study introduces two sensitive analytical systems to direct ...

2018

Sphagnum Species Modulate their Phenolic Profiles and Mycorrhizal Colonization of Surrounding Andromeda polifolia along Peatland Microhabitats

Alexandre Buttler, Vincent Eric Jules Jassey

Sphagnum mosses mediate long-term carbon accumulation in peatlands. Given their functional role as keystone species, it is important to consider their responses to ecological gradients and environmental changes through the production of phenolics. We compa ...

SPRINGER2018

Oxidative stability and microstructure of 5% fish-oil-enriched granola bars added natural antioxidants derived from brown alga Fucus vesiculosus

Louise Helene Soegaard Jensen

The aims of this study were to (i) investigate the ability of Icelandic brown algae Fucus vesiculosus extracts to inhibit lipid oxidation in granola bars fortified with fish oil-in-water emulsion; (ii) investigate whether addition of the seaweed extracts a ...

Wiley-Blackwell2017

Influence of Ablation on Vacuum-Ultraviolet Radiation in a Plasma Wind Tunnel Flow

Pénélope Leyland

Plasma wind tunnel experiments have been performed simulating a Hayabusa reentry trajectory point at 78.8km altitude with a velocity of 11.7km/s corresponding to a local mass-specific enthalpy of 68.4MJ/kg and a stagnation pressure of 2.44kPa. Ablation-rad ...

American Institute of Aeronautics and Astronautics2017

Economical Analysis of a Pressurized Fluid-Based Process Applied for Phytochemicals Recovery in a Sustainable Biorefinery Concept for Brazilian Ginseng Roots

François Maréchal

A growing number of technologies are being developed in order to produce different high added value products, such as phytochemicals, ethanol and other chemicals from biomass, representing an important trend that needs to be evaluated. The use of pressuriz ...

Aidic Servizi Srl2016

Antioxidant Assay Based on Quenching of Photocatalytically Generated Reactive Oxygen Species

Hubert Girault, Mohamad Hojeij, Qifeng Zhang

A method based on photogeneration of OH radicals in water from TiO2 nanoparticles was developed to study the kinetics of oxidation of organic molecules which were used as biological antioxidants. The kinetics of oxidation of terephthalic acid as a referenc ...

Elsevier Science Inc2016