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Chemosphere Apr 2019The mechanism of direct UV photolysis of p-arsanilic acid (p-ASA), a widely used veterinary drug, was revised by means of laser flash photolysis coupled with high...
The mechanism of direct UV photolysis of p-arsanilic acid (p-ASA), a widely used veterinary drug, was revised by means of laser flash photolysis coupled with high resolution liquid chromatography - mass spectrometry (LC-MS). None of p-ASA triplet state or singlet oxygen was found to directly participate in the photodegradation of p-ASA as it was assumed in previous works. Here we demonstrate that the main primary photoprocess is a monophotonic ionization (ϕ = 0.032) leading to the formation of hydrated electron and corresponding anilinyl cation radical. These primary species react with dissolved oxygen yielding secondary reactive oxygen species. The final organic photoproducts, such as aminophenol and different dimeric products, originate from various reactions between these secondary species. The generation of inorganic arsenic, both As(V) and As(III), was also observed in agreement with previous works. For the first time we report the quantum yield of p-ASA photodegradation, which decreases from 0.058 to 0.035 with the excitation wavelength from 222 to 308 nm.
Topics: Arsanilic Acid; Lasers; Oxygen; Photolysis; Reactive Oxygen Species; Ultraviolet Rays
PubMed: 30597365
DOI: 10.1016/j.chemosphere.2018.12.179 -
Molecular Biology Reports Feb 2019Anthocyanin is a natural plant pigment that acts as an antioxidant and scavenges free radicals. This study aimed to investigate the potential protective role of...
Anthocyanin is a natural plant pigment that acts as an antioxidant and scavenges free radicals. This study aimed to investigate the potential protective role of nightshade anthocyanin (NA), a natural flavonoid compound, against the arsanilic acid (ASA)-induced cell death of DF-1 cells. DF-1 cells were initially exposed to ASA, and then NA was applied to the treated cells. Cell viability, intracellular reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and apoptosis were examined. Results showed that NA inhibited the ASA-induced decrease in cell viability, increase in ROS, and loss of MMP in DF-1 cells. Moreover, caspase-3 activation was inhibited by ASA supplementation and NA attenuated the ASA-induced increase in the percentage of apoptotic cells. In summary, our study suggested that NA can enhance ASA-induced cytotoxicity and apoptosis, thereby providing a basis for the molecular mechanisms of NA-mediated protection.
Topics: Animals; Anthocyanins; Antioxidants; Apoptosis; Arsanilic Acid; Caspase 3; Cell Line; Cell Survival; Chick Embryo; Flavonoids; Hydrogen Peroxide; Membrane Potential, Mitochondrial; Oxidative Stress; Reactive Oxygen Species
PubMed: 30488373
DOI: 10.1007/s11033-018-4472-5 -
The Journal of Physical Chemistry. A Dec 2018In this study, a three-dimensional surface enhanced Raman scattering (SERS) substrate comprised of silver coated gold nanorods (Ag/AuNRs) decorated on electrospun...
In this study, a three-dimensional surface enhanced Raman scattering (SERS) substrate comprised of silver coated gold nanorods (Ag/AuNRs) decorated on electrospun polycaprolactone (PCL) fibers has been applied, for the first time, to quantitative analytical measurements on various arsenic species: p-arsanilic acid ( pAsA), roxarsone (Rox), and arsenate (As), with a demonstrated sensitivity below 5 ppb. As detection in a solution of common salt ions has been demonstrated, showing the tolerance of the substrate to more complex environments. pAsA adsorption behavior on the substrate surface has been investigated in detail using these unique SERS substrates. Calculations based on density functional theory (DFT) support the spectral observation for pAsA. This substrate also has been shown to serve as a platform for in situ studies of arsenic desorption and reduction. This SERS substrate is potentially an excellent environmental sensor for both fundamental studies and practical applications.
PubMed: 30418025
DOI: 10.1021/acs.jpca.8b09104 -
Removal of Organoarsenic with Ferrate and Ferrate Resultant Nanoparticles: Oxidation and Adsorption.Environmental Science & Technology Nov 2018Many investigations focused on the capacity of ferrate for the oxidation of organic pollutant or adsorption of hazardous species, while little attention has been paid on...
Many investigations focused on the capacity of ferrate for the oxidation of organic pollutant or adsorption of hazardous species, while little attention has been paid on the effect of ferrate resultant nanoparticles for the removal of organics. Removing organics could improve microbiological stability of treated water and control the formation of disinfection byproducts in following treatment procedures. Herein, we studied ferrate oxidation of p-arsanilic acid ( p-ASA), an extensively used organoarsenic feed additive. p-ASA was oxidized into As(V), p-aminophenol ( p-AP), and nitarsone in the reaction process. The released As(V) could be eliminated by in situ formed ferric (oxyhydr) oxides through surface adsorption, while p-AP can be further oxidized into 4,4'-(diazene-1,2-diyl) diphenol, p-nitrophenol, and NO. Nitarsone is resistant to ferrate oxidation, but mostly adsorbed (>85%) by ferrate resultant ferric (oxyhydr) oxides. Ferrate oxidation (ferrate/ p-ASA = 20:1) eliminated 18% of total organic carbon (TOC), while ferrate resultant particles removed 40% of TOC in the system. TOC removal efficiency is 1.6 to 38 times higher in ferrate treatment group than those in O, HClO, and permanganate treatment groups. Besides ferrate oxidation, adsorption of organic pollutants with ferrate resultant nanoparticles could also be an effective method for water treatment and environmental remediation.
Topics: Adsorption; Iron; Nanoparticles; Oxidation-Reduction; Water Pollutants, Chemical; Water Purification
PubMed: 30346162
DOI: 10.1021/acs.est.8b01718 -
Chemosphere Dec 2018The effects of co-existing nitrogen species in surface water on the phototransformation of organoarsenical p-arsanilic acid (p-ASA) have been investigated using a xenon...
The effects of co-existing nitrogen species in surface water on the phototransformation of organoarsenical p-arsanilic acid (p-ASA) have been investigated using a xenon lamp as a simulated solar light source. Significant enhancements of p-ASA phototransformation efficiency were observed in the presence of nitrate and nitrite, increasing with the concentration of these species and pH, whereas ammonia showed no obvious effect. The products, including inorganic arsenic species and organic derivatives, have been analyzed in order to reveal the phototransformation pathways. In the nitrate and nitrite systems, only small proportions of inorganic arsenic species were generated, with the majority of p-ASA being converted into other organoarsenical derivatives through hydroxylation, nitration, and nitrosation. Phototransformation of p-ASA in collected natural surface water was also observed. This work has implications for the phototransformation of p-ASA in nitrogen-contaminated surface water.
Topics: Arsanilic Acid; Arsenic; Nitrates; Nitrites; Nitrogen; Ultraviolet Rays; Water; Water Pollutants, Chemical
PubMed: 30179842
DOI: 10.1016/j.chemosphere.2018.08.104 -
Chemosphere Sep 2018Many researchers at home and abroad have made a body of researches and have gained great achievements on the environmental occurrence, fate, and toxicity of inorganic... (Review)
Review
Many researchers at home and abroad have made a body of researches and have gained great achievements on the environmental occurrence, fate, and toxicity of inorganic arsenic. But there is less research on the use of aromatic organoarsenic compounds (AOCs), which are common feed additives for livestock in the poultry industry. In this review, we outline the current state of knowledge acquired on the occurrence and remediation of AOCs, respectively. We also identify knowledge gaps and research needs, including the elucidation of the environmental fate of AOCs, metabolic pathway, the impact of metabolic modification on toxicity, and advanced analytical or repaired methods that allows for monitoring, identification or removal of the degradation products.
Topics: Arsenic; Environmental Restoration and Remediation
PubMed: 29857198
DOI: 10.1016/j.chemosphere.2018.05.145 -
Cold Spring Harbor Protocols May 2018Many compounds on their own do not have all of the properties needed to induce a strong antibody response. However, small changes in the structure of an antigen can...
Many compounds on their own do not have all of the properties needed to induce a strong antibody response. However, small changes in the structure of an antigen can often greatly alter the immunogenicity of a compound. Common methods for doing so include the addition of small modifying groups such as dinitrophenol or arsenate to the molecules. These techniques either alter regions of the immunogen to provide better sites for T-cell binding or expose new epitopes for B-cell binding. The techniques are rapid and easy, and have been used extensively as a general procedure to increase the chances of raising antisera, particularly against well-conserved antigens.
Topics: Animals; Antigens; Arsanilic Acid; Dinitrophenols; Immunologic Techniques; T-Lymphocytes
PubMed: 29717054
DOI: 10.1101/pdb.prot099952 -
Ecotoxicology and Environmental Safety Aug 2018Organoarsenic arsanilic acid (ASA) contamination of paddy soil is a serious but less concerned hazard to agriculture and health of people consuming rice as staple food,...
Silicon improves growth and alleviates oxidative stress in rice seedlings (Oryza sativa L.) by strengthening antioxidant defense and enhancing protein metabolism under arsanilic acid exposure.
Organoarsenic arsanilic acid (ASA) contamination of paddy soil is a serious but less concerned hazard to agriculture and health of people consuming rice as staple food, for rice is one major pathway of arsenic (As) exposure to human food. To date little research has studied the effect of ASA on biochemical process of rice. Silicon (Si) application is able to reduce the toxicities of heavy metals in numerous plants, but little information about ASA. This work investigated whether and how Si influenced alleviation of ASA toxicity in rice at biochemical level to have a better understanding of defense mechanism by Si against ASA stress. Results showed that ASA reduced rice growth, disturbed protein metabolism, increased lipid peroxidation but decreased the efficiencies of antioxidant activities compared to control plants, more severe in roots than in shoots. The addition of Si in ASA-stressed rice plants noticeably increased growth and development as well as soluble protein contents, but decreased malondialdehyde (MDA) contents in ASA-stressed rice plants, suggesting that Si did have critical roles in ASA detoxification in rice. Furthermore, increased superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activities along with elevated glutathione (GSH) and ascorbic acid (AsA) contents implied the active involvement of ROS scavenging and played, at least in part, to Si-mediated alleviation of ASA toxicity in rice, and these changes were related to rice genotypes and tissues. The study provided physio-chemical mechanistic evidence on the beneficial effect of Si on organoarsenic ASA toxicity in rice seedlings.
Topics: Antioxidants; Arsanilic Acid; Ascorbic Acid; Catalase; Chemical Phenomena; Glutathione; Lipid Peroxidation; Oryza; Oxidative Stress; Peroxidase; Plant Roots; Reactive Oxygen Species; Seedlings; Silicon; Soil; Superoxide Dismutase
PubMed: 29715631
DOI: 10.1016/j.ecoenv.2018.03.050 -
Environmental Science & Technology Mar 2018p-Arsanilic acid ( p-ASA) is an emerging organoarsenic pollutant comprising both inorganic and organic moieties. For the efficient removal of p-ASA, adsorbents with high...
Enhanced Adsorption of p-Arsanilic Acid from Water by Amine-Modified UiO-67 as Examined Using Extended X-ray Absorption Fine Structure, X-ray Photoelectron Spectroscopy, and Density Functional Theory Calculations.
p-Arsanilic acid ( p-ASA) is an emerging organoarsenic pollutant comprising both inorganic and organic moieties. For the efficient removal of p-ASA, adsorbents with high adsorption affinity are urgently needed. Herein, amine-modified UiO-67 (UiO-67-NH) metal-organic frameworks (MOFs) were synthesized, and their adsorption affinities toward p-ASA were 2 times higher than that of the pristine UiO-67. Extended X-ray absorption fine structure (EXAFS), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculation results revealed adsorption through a combination of As-O-Zr coordination, hydrogen bonding, and π-π stacking, among which As-O-Zr coordination was the dominant force. Amine groups played a significant role in enhancing the adsorption affinity through strengthening the As-O-Zr coordination and π-π stacking, as well as forming new adsorption sites via hydrogen bonding. UiO-67-NHs could remove p-ASA at low concentrations (<5 mg L) in simulated natural and wastewaters to an arsenic level lower than that of the drinking water standard of World Health Organization (WHO) and the surface water standard of China, respectively. This work provided an emerging and promising method to increase the adsorption affinity of MOFs toward pollutants containing both organic and inorganic moieties, via modifying functional groups based on the pollutant structure to achieve synergistic adsorption effect.
Topics: Adsorption; Amines; Arsanilic Acid; China; Density Functional Theory; Photoelectron Spectroscopy; Water; X-Rays
PubMed: 29385347
DOI: 10.1021/acs.est.7b05761 -
Journal of Neuroscience Methods Feb 2018The vestibular lesion (VL) is required to examine the physiological function of the vestibular system in animals. Toxic chemicals or electrical apparatus have been used... (Comparative Study)
Comparative Study
BACKGROUND
The vestibular lesion (VL) is required to examine the physiological function of the vestibular system in animals. Toxic chemicals or electrical apparatus have been used for the VL, however, they are not ideal as they have low specificity, and can result in unintended damage, and systemic toxic effect.
NEW METHOD
Localized vibration-induced VL, using an ultrasonicator, is expected to overcome the problems associated with chemical and electrical lesions. Thus, we examined the effect of the ultrasonication on the VL from the aspects of both the physiological function and histology in the present study.
RESULTS
and Comparison with Existing Method(s) Complete VL, which was evaluated by deterioration of swimming skills, righting reflex, and body stability, was induced using an ultrasonicator or electrical apparatus. Histological evaluation shows that hair cell layers in the saccule and utricle were completely destroyed in both methods Furthermore, significant drop in body mass was observed in VL. However, abscess at the cranial base was observed in VL induced by the electrical apparatus in ICR mice. Complete chemically-induced VL was observed in C57BL/6J but not ICR mice, and systemic leakage of the toxic chemicals (arsenic) was not detectable even 1day after surgery.
CONCLUSIONS
Compared to the electrical apparatus, the ultrasonicator is useful for inducing VL in ICR and C57BL/6J mice, as it results in less non-specific damage. Toxic chemicals can be used for inducing VL in C57BL/6J mice; however, this method does not ensure complete disruption of the hair cells in the saccule and utricle.
Topics: Animals; Arsanilic Acid; Body Size; Disease Models, Animal; Male; Mice, Inbred C57BL; Mice, Inbred ICR; Physical Stimulation; Species Specificity; Ultrasonics; Vestibular Diseases; Vestibular Function Tests; Vestibule, Labyrinth; Vibration
PubMed: 29198950
DOI: 10.1016/j.jneumeth.2017.11.021