oxidative process
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2021 ◽  
Author(s):  
Israel Ehizuelen Ebhohimen ◽  
Taiwo Stephen Okanlawon ◽  
Augustine Ododo Osagie ◽  
Owen Norma Izevbigie

Oxidative stress characterized by an imbalance in the production and degradation of radical species has been implicated in the onset and progression of several diseases. The efficacy of antioxidants acting via the inhibition of radical chain reactions, scavenging of free radicals, direct donation of electrons to radical species and chelation of metal ions have been reported to attenuate the oxidative process. Vitamin E is an effective antioxidant and its hydrophobic nature and membrane permeability offer some benefits to application and bioavailability. This chapter highlights the following; structural differences in the vitamin family, biosynthesis in plants and the native biological role, antioxidant mechanisms of vitamin E, an overview of the prophylactic action of vitamin E as well as the effect on the oxidative process in some diseases.


Separations ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 96
Author(s):  
Olga Yakimenko ◽  
Andrey Stepanov ◽  
Svetlana Patsaeva ◽  
Daria Khundzhua ◽  
Olesya Osipova ◽  
...  

The composition, structure, and biological activity of humic-like substances (HLS) synthesized in the process of lignosulfonate conversion for the production of the humic product Lignohumate® (LH) were examined. It is shown that during the hydrolytic-oxidative process, the transformation of raw material and accumulation of HLS occur. Data on the chemical (elemental content, functional groups, FTIR) and spectral (absorbance and fluorescence) parameters and biological activity (in phytotest) combined with PCA show that the LH samples can be divided into three groups, depending on the duration of synthesis: initial raw material (0-time sample); “young” HLS (15–30 min), and “mature” HLS in 45–120 min of treatment. During the first 30 min, reactions similar to the ones that occur during lignin humification in nature take place: depolymerization, oxidative carboxylation, and further polycondensation with the formation and accumulation of HLS. After 45–60 min, the share of HLS reaches a maximum, and its composition stabilizes. Biological activity reaches a maximum after 45–60 min of treatment, and at that stage, the further synthesis process can be stopped. Further processing (up to 2 h and more) does not provide any added value to the humic product.


Author(s):  
Yasmin Saegusa Tadayozzi ◽  
Felipe André dos Santos ◽  
Eduardo Festozo Vicente ◽  
Juliane Cristina Forti
Keyword(s):  

2021 ◽  
Vol 42 (1) ◽  
pp. 75
Author(s):  
Ana Gabriela da Silva Freitas ◽  
Gizelle Kupac Vianna ◽  
Claudia Mazza Dias

Degenerative neurological diseases, although common in the population, are difficult to diagnose. However, it is known that most of them are directly related to the so-called oxidative stress. Understanding and evaluating how this process takes place is of great interest and, in this sense, this work extends the existing mathematical and computational models for the oxidative stress process (REIS, 2005; REIS et al., 2006; VIANNA, 2005; VIANNA; REIS; CARVALHO, 2012), incorporating an aspect not previously evaluated, the influence of homocysteine indices on the oxidants present in this process. The results indicate that hyperhomocysteinemia can in fact cause oxidative stress and consequent neuronal death, leading to the appearance of neurodegenerative diseases.


Author(s):  
Bemgba B. Nyakuma

This study presents a preliminary analysis of the chemical and thermal fuel properties of Afuze (AFZ) coal extracted from coalfields in Owan East Local Government Area of Edo State, Nigeria. The chemical properties of AFZ were examined by combined scanning electron microscopy-energy dispersive X-ray (EDX), whereas the thermal properties were deduced by thermogravimetric analysis (TGA) under flash (50 °C/min heating rate) oxidative (combustion) and non-oxidative (pyrolysis) conditions. The microstructure and morphology analysis of AFZ revealed has a compact structure comprising small-to-large, irregular shaped and exfoliated grains with a vitreous appearance typically ascribed to metal elements (Ti and Fe) kaolinite, quartz, and other clay minerals. Chemical analysis revealed carbon, oxygen, aluminium, silicon, sulphur, calcium, titanium, and iron in major and minor (trace) quantities. Thermal analysis under oxidative and non-oxidative conditions revealed degradation occurs in three stages, namely; drying or demineralisation, devolatilization or maceral degradation and the formation of char/coke or ash. Lastly, the findings showed that the temperature range for the oxidative thermal degradation process (338.58 - 756.76 °C) was higher than the non-oxidative process (378.43 - 615.34 °C). This observation can be explained by the exothermic nature of the oxidative (combustion) process, which ensures greater heat supply required to thermally soften or degrade the maceral coal components. Overall, the oxidative process yielded the residual mass (RM = 21.97%) and mass loss (ML = 78.03%). The lower ML (49.03%) but higher RM (50.97%) observed during non-oxidative degradation of AFZ could be ascribed to the largely endothermic nature of the process.


2021 ◽  
Vol 259 ◽  
pp. 117755
Author(s):  
Liangyi Song ◽  
Xiaran Miao ◽  
Xiuhong Li ◽  
Fenggang Bian ◽  
Jinyou Lin ◽  
...  

2021 ◽  
Vol 11 (9) ◽  
pp. 4067
Author(s):  
Linda-Lucila Landeros-Martínez ◽  
Néstor Gutiérrez-Méndez ◽  
Juan Pedro Palomares-Báez ◽  
Nora-Aydeé Sánchez-Bojorge ◽  
Juan Pablo Flores-De los Ríos ◽  
...  

Type 2 diabetes mellitus has been classified as the epidemic of the XXI century, making it a global health challenge. Currently, the commonly used treatment for this disease is acarbose, however, the high cost of this medicine has motivated the search for new alternatives. In this work, the maysin, a characteristic flavonoid from maize inflorescences, and its aglycon version, luteolin, are proposed as acarbose substitutes. For this, a theoretical comparative analysis was conducted on the molecular interactions of acarbose, maysin, and luteolin with human maltase-glucoamylase (NtMGAM), as well as their oxidative process. The binding energies in the active site of NtMGAM with acarbose, maysin, and luteolin molecules were predicted using a molecular docking approach applying the Lamarckian genetic algorithm method. Theoretical chemical reactivity parameters such as chemical hardness (η) and chemical potential (µ) of the acarbose, maysin, and luteolin molecules, as well as of the amino acids involved in the active site, were calculated using the electronic structure method called Density Functional Theory (DFT), employing the M06 meta-GGA functional in combination with the 6-31G(d) basis set. Furthermore, a possible oxidative process has been proposed from quantum-chemical calculations of the electronic charge transfer values (ΔN), between the amino acids of the active site and the acarbose, maysin, and luteolin. Molecular docking predictions were complemented with molecular dynamics simulations. Hence, it was demonstrated that the solvation of the protein affects the affinity order between NtMGAM and ligands.


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