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The shape parameters: A1, A2, B1, and B2 in the model first‐derivative electron paramagnetic resonance spectrum
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Electron paramagnetic resonance (EPR) spectroscopy, UV‐Vis spectrophotometry, and colorimetric analysis, were used to examine nonirradiated and UV‐irradiated caffeic acid. In this work free radical formation during UV‐irradiation of caffeic acid and the effect of UV‐irradiation on its radical scavenging ability, were studied. The influence of time...
Citations
... UVA radiation increases the risk of skin cancer [41]. In this work, it was assumed that the interactions of antioxidants with free radicals not only depend on their type [42][43][44][45], but also the physical factors in the environment, including UV radiation, which affect these interactions [46,47]. We searched for answers to the question of whether the tested plant raw materials can be stored with access to UVA radiation. ...
An X-band (9.3 GHz) electron paramagnetic resonance (EPR) spectroscopy was used to examine the free radical scavenging activity of the following infusions, which were nonirradiated and exposed to UVA: root of Asparagus racemosus and herbs of Mitchella repens, Cnicus benedictus L., Galega officinalis L., and Eupatorium cannabinum L. The plant materials for obstetrics applications were chosen for analysis. The aims of these studies were to compare the free radical scavenging ability of the tested infusions and to determine the influence of UVA irradiation of the plant materials on interactions of these infusions with free radicals. Both the magnitude and kinetics of the interactions of the infusions with the model DPPH free radicals were examined. The ability to quench the free radicals for the examined plant infusions increases in the following order: Asparagus racemosus (root) < Mitchella repens (herb) < Cnicus benedictus L. (herb) < Galega officinalis L. (herb) < Eupatorium cannabinum L. (herb). The analyzed infusions differ in the kinetics of the interactions with free radicals. The fastest interactions with free radicals characterize the infusions of Galega officinalis L. herb and Eupatorium cannabinum L. herb. The infusion of Mitchella repens herb interacts with free radicals in the slowest way. UVA radiation reduces the antioxidant interactions of all tested infusions, especially the infusion of Eupatorium cannabinum L. herb, which should be protected against UVA radiation during storage. The weakest decrease of free radical scavenging activity was observed for the infusion of the root of Asparagus racemosus exposed to UVA radiation. UVA radiation affected the speed of the free radical interactions of the infusions, depending on the type of plant materials. EPR spectroscopy is useful to examine the free radical scavenging activity of plant infusions, which is helpful to find effective antioxidants for applications in obstetrics and their optimal storage conditions.
Electron paramagnetic resonance (EPR) is a non-invasive and highly sensitive technique that has been extensively used for detecting free radicals and reactive oxygen species (ROS) in biological systems. In plant biology, ROS are highly reactive and play a critical role in regulating various cellular processes. However, detecting ROS in plant systems is challenging due to their short half-life and low concentrations. This review presents a comprehensive overview of the application of EPR for the detection of free radicals and ROS in plant systems, including a comparison with other methods. Furthermore, it explores the utilization of the spin trapping method in combination with EPR for ROS detection, providing spectroscopic parameters for numerous spin trap compounds. We highlight some of the relevant studies that used EPR spectroscopy to detect ROS, as well as stable radicals, in plant systems. This review serves as a valuable resource for researchers interested in using EPR spectroscopy for free radicals and ROS detection in plant systems and provides insights into the current state of the field and future research trends.
Alternariol (AOH) and alternariol monomethyl ether (AME) are two Alternaria mycotoxins with high occurrence rates in food systems. This study aimed to investigate the photodegradation of AOH and AME by ultraviolet-C (UV-C) irradiation. The effect of UV-C intensity, pH, treatment time, solvents and the exposure of food components were evaluated. After treated by UV-C irradiation at 3500 μW/cm2 for 90 min, AOH samples in methanol, aqueous solution and solid state were degraded by 89.1%, 72.9% and 53.2%, respectively, while the degradation percentages of AME were 86.6%, 50.1% and 11.1%, respectively. Increasing irradiation intensity and prolonging irradiation time could significantly facilitate the degradation of AOH and AME. An alkaline environment (pH = 11) was more conducive to the degradation of toxins. In addition, 2.5 mg mL-1 citric acid or malic acid increased the photodegradation of AOH and AME to 94.6% and 95.3%, 93.2% and 70.5%, respectively. However, protein, polyphenols and vitamin C exerted inhibitory effects on the degradation, while 10% glucose or sucrose reduced the photodegradation of AOH and AME to 65.9% and 40.3%. UV-C treatment could effectively reduce the content of AOH and AME, with the highest efficiency achieved in methanol and alkaline environment. By contrast, UV-C irradiation is more effective in degrading toxins in some liquid foods rich in organic acids but lacking in protein. The utilization of UV-C radiation appears to be a potentially useful approach for decreasing the underlying risk of Alternaria mycotoxin contamination in foods.
