Phytyl Phenolipids: Structurally Modified Antioxidants with Superior Lipid Membrane Interaction.

A set of procedures was developed for the simple synthesis of phytyl phenolipids, which resulted in high yields (70-95%) of phytyl esters of caffeic, protocatechuic, homoprotocatechuic, and dihydrocaffeic acids. Initial characterization revealed that these new compounds exhibited similar radical scavenging activity and liposolubility to α-tocopherol, a key antioxidant present in membranes. Cyclic voltammetry analysis indicated that the phytyl derivatives had lower anodic peak potentials compared to the original phenolic acids, with electron transfer following an adsorption-controlled mechanism.

A Correlation-Based Approach for Predicting Humic Substance Bioactivity from Direct Compost Characterization.

The efficient characterization of compost quality is essential for optimizing its application in agriculture and soil improvement. In this study, a correlation-based approach was employed to evaluate relationships between physicochemical properties, structural features, and reactivity indicators of compost extracts-fulvic acid-like (FA-L), humic acid-like (HA-L), and dissolved organic matter (DOM)-and their respective bulk composts. The goal was to identify key compost parameters that can serve as reliable predictors of humic substance composition and bioactivity, thereby reducing reliance on labor-intensive humic substance extractions.

Electrochemical Magnetic Immunoassay for the Determination of the Fish Allergen β-Parvalbumin.

β-parvalbumin (β-PV) is the primary fish allergen responsible for most allergic reactions in individuals sensitive to fish. To ensure food safety, a sandwich-based magnetic immunoassay was developed using maleimide-functionalized magnetic beads (NH-MBs). Specific anti-β-PV antibodies were immobilized on these MBs, and a screen-printed carbon electrode was employed as the electrochemical transducer.

Evaluation of Performance and Longevity of Ti-Cu Dry Electrodes: Degradation Analysis Using Anodic Stripping Voltammetry.

This study aimed to investigate the degradation of dry biopotential electrodes using the anodic stripping voltammetry (ASV) technique. The electrodes were based on Ti-Cu thin films deposited on different polymeric substrates (polyurethane, polylactic acid, and cellulose) by Direct Current (DC) magnetron sputtering. TiCu thin films (chemical composition of 25.

Cholesteryl Phenolipids as Potential Biomembrane Antioxidants.

The lipophilization of polyphenols (phenolipids) may increase their affinity for membranes, leading to better antioxidant protection. Cholesteryl esters of caffeic, dihydrocaffeic, homoprotocatechuic and protocatechuic acids were synthetized in a one-step procedure with good to excellent yields of ~50-95%. After evaluation of their radical scavenging capacity by the DPPH method and establishing the anodic peak potential by cyclic voltammetry, their antioxidant capacity against AAPH-induced oxidative stress in soybean PC liposomes was determined.

Seafood product safety: A hybrid graphene/gold-based electrochemical immunosensor for fish allergen analysis.

Seafood product labels with accurate allergen contents can avoid and/or minimize allergic reactions. Therefore, an electrochemical immunosensor for the analysis of β-parvalbumin (β-PV, a major fish allergen) was developed. Screen-printed carbon electrodes were nanostructured with reduced graphene oxide and gold nanoparticles.

Enhancing the Longevity and Functionality of Ti-Ag Dry Electrodes for Remote Biomedical Applications: A Comprehensive Study.

This study aims to evaluate the lifespan of Ti-Ag dry electrodes prepared using flexible polytetrafluoroethylene (PTFE) substrates. Following previous studies, the electrodes were designed to be integrated into wearables for remote electromyography (EMG) monitoring and electrical stimulation (FES) therapy. Four types of Ti-Ag electrodes were prepared by DC magnetron sputtering, using a pure-Ti target doped with a growing number of Ag pellets.

Developing a Compost Quality Index (CQI) Based on the Electrochemical Quantification of Cd (HA) Reactivity.

The present work demonstrates the use of Cd as a reactivity probe of the fulvic acids (FAs), humic acids (HAs) and dissolved organic matter (DOM) compost extracts. Significant differences were observed between the extracts, with the HA extract showing the highest reactivity. Comparing the different composts, the largest reactivity variation was again observed for HA then FA and finally DOM extracts.

Photosynthetic pigments in acid mine drainage: Seasonal patterns and associations with stressful abiotic characteristics.

Acid mine drainage represents an extreme type of water pollution. The environments develop especial hydrochemical and ecological characteristics, such as high concentrations of acidity and low biodiversity, with dominance of acidophilic organisms. Ecological criteria are assuming increasing relevance for assessing water quality, including in acid mine drainage-affected systems.

Evaluation of total polyphenol content of wines by means of voltammetric techniques: Cyclic voltammetry vs differential pulse voltammetry.

Taking advantage of the low oxidation potential of polyphenolic compounds, voltammetric techniques, such as cyclic voltammetry (CV) and differential pulse voltammetry (DPV) are used rather indiscriminately. In this work, we report Total Polyphenols results (TPP) obtained by these two techniques from a set of nine samples of red and Tawny Port wine. The CV and DPV voltammograms display significant correlations with the physical-chemical parameters used to characterize red and Tawny Port wines, particularly with polyphenols.

Radical scavenging activity of antioxidants evaluated by means of electrogenerated HO radical.

A method is proposed and tested concerning the characterization of antioxidants by means of their reaction with electrogenerated HO radicals in galvanostatic assays with simultaneous O2 evolution, using a Pt anode fairly oxidized. The consumption of a set of species with antioxidant activity, ascorbic acid (AA), caffeic acid (CA), gallic acid (GA) and trolox (T), is described by a first order kinetics. The rate of the processes is limited by the kinetics of reaction with HO radicals and by the kinetics of charge transfer.

Simplified 2,4-dinitrophenylhydrazine spectrophotometric assay for quantification of carbonyls in oxidized proteins.

This work proposes a modification of the 2,4-dinitrophenylhydrazine (DNPH) spectrophotometric assay commonly used to evaluate the concentration of carbonyl groups in oxidized proteins. In this approach NaOH is added to the protein solution after the addition of DNPH, shifting the maximum absorbance wavelength of the derivatized protein from 370 to 450nm. This reduces the interference of DNPH and allows the direct quantification in the sample solution without the need for the precipitation, washing, and resuspension steps that are carried out in the traditional DNPH method.

Oxidation management of white wines using cyclic voltammetry and multivariate process monitoring.

The development of a fingerprinting strategy capable to evaluate the "oxidation status" of white wines based on cyclic voltammetry is proposed here. It is known that the levels of specific antioxidants and redox mechanisms may be evaluated by cyclic voltammetry. This electrochemical technique was applied on two sets of samples.

Resistance to oxidation of white wines assessed by voltammetric means.

This work concerns the development of a methodology suited to measure the resistance to oxidation of white wines by cyclic voltammetry. The voltammetric responses of several white wines of different origin and age were analyzed in the oxidation potential range (0.2-1.