Pivotal role of water molecules in the photodegradation of pymetrozine: New insights for developing green pesticides

Liang, Ximei; Guan, Fangling; Ling, Zhiyou; Wang, Honghong; Tao, Peng; Kraka, Elfi; Huang, Huajun; Yu, Changming; Li, Danping; He, Jinbao; Fang, Hansun

doi:10.1016/j.jhazmat.2021.127197

Cited by 12 publications

(5 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous studies also indicated that the proton transfer process of the hydrolysis reaction could be mediated by additional water molecules or hydroxyl groups of residues that are present in the active site to reduce the tension of the transition state. 13,33 Thus, we further examined the possibility that an additional water molecule (W2) is involved in C6–N1 bond hydrolysis. Because the reaction cannot continue from INT2a due to the high barrier of TS3a, a water molecule (W2) can enter into the active site to locate between C6–OH and N1 in this stage and forms the intermediate (INT2b).…”

Section: Resultsmentioning

confidence: 99%

“…Previous studies also indicated that the proton transfer process of the hydrolysis reaction could be mediated by additional water molecules or hydroxyl groups of residues that are present in the active site to reduce the tension of the transition state. 13,33 , respectively; it is therefore not surprising that the energy barrier is decreased by 17.7 kcal mol À1 compared to the pathway without the assistance of the additional water. To confirm that the bridge water molecule can stably bind in the active site to participate in the reaction, we estimated the energetic effect for introducing W2 into the complex of UrcA and the reaction intermediate.…”

Section: W1 and The Acceptor O E2mentioning

confidence: 99%

See 1 more Smart Citation

Theoretical investigation on the reaction mechanism of UTP cyclohydrolase

Ouyang

Pang

Chang

et al. 2022

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

show abstract

Section: Resultsmentioning

confidence: 99%

“…Previous studies also indicated that the proton transfer process of the hydrolysis reaction could be mediated by additional water molecules or hydroxyl groups of residues that are present in the active site to reduce the tension of the transition state. 13,33 , respectively; it is therefore not surprising that the energy barrier is decreased by 17.7 kcal mol À1 compared to the pathway without the assistance of the additional water. To confirm that the bridge water molecule can stably bind in the active site to participate in the reaction, we estimated the energetic effect for introducing W2 into the complex of UrcA and the reaction intermediate.…”

Section: W1 and The Acceptor O E2mentioning

confidence: 99%

Theoretical investigation on the reaction mechanism of UTP cyclohydrolase

Ouyang

Pang

Chang

et al. 2022

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

show abstract

“…Pesticides have been extensively applied to protect crops against pests, pathogens, and weeds, thereby increasing the crop yield and improving crop quality. , An estimated more than 3.47 million tons of pesticides are used annually in agricultural production, and the usage of pesticides is expected to increase during the next decade . However, once applied, residual pesticides are often detected in water, soils, crops, and foodstuffs.…”

Section: Introductionmentioning

confidence: 99%

“…1,2 An estimated more than 3.47 million tons of pesticides are used annually in agricultural production, and the usage of pesticides is expected to increase during the next decade. 3 However, once applied, residual pesticides are often detected in water, soils, crops, and foodstuffs. The widespread occurrence of this large group of xenobiotic chemicals in the environment may pose a potential risk to nontargeted organisms and human health, and has been raising great public concern.…”

Section: Introductionmentioning

confidence: 99%

Degradation of the Novel Heterocyclic Insecticide Pyraquinil in Water: Kinetics, Degradation Pathways, Transformation Products Identification, and Toxicity Assessment

Jiang

Xiao

Chen

et al. 2023

J. Agric. Food Chem.

View full text Add to dashboard Cite

As new pesticides are continuously introduced into agricultural systems, it is essential to investigate their environmental behavior and toxicity effects to better evaluate their potential risks. In this study, the degradation kinetics, pathways, and aquatic toxicity of the new fused heterocyclic insecticide pyraquinil in water under different conditions were investigated for the first time. Pyraquinil was classified as an easily degradable pesticide in natural water, and hydrolyzes faster in alkaline conditions and at higher temperatures. The formation trends of the main transformation products (TPs) of pyraquinil were also quantified. Fifteen TPs were identified in water using ultrahigh-performance liquid chromatography coupled to quadrupole Orbitrap high-resolution mass spectrometry (UHPLC-Orbitrap-HRMS) and Compound Discoverer software, which adopted suspect and nontarget screening strategies. Among them, twelve TPs were reported for the first time and 11 TPs were confirmed by synthesis of their standards. The proposed degradation pathways have demonstrated that the 4,5-dihydropyrazolo[1,5-a]quinazoline skeleton of pyraquinil is stable enough to retain in its TPs. ECOSAR prediction and laboratory tests showed that pyraquinil was “very toxic” or “toxic” to aquatic organisms, while the toxicities of all of the TPs are substantially lower than that of pyraquinil except for TP484, which was predicted to pose a higher toxicity. The results are important for elucidating the fate and assessing the environmental risks of pyraquinil, and provide guidance for scientific and reasonable use.

show abstract

“…These features are also an obstacle to the biological attenuation of the same CECs in natural water bodies. In these cases, photochemistry can play a key role in natural decontamination [ 1 , 2 , 9 , 10 ].…”

Section: Introductionmentioning

confidence: 99%

Photochemical Implications of Changes in the Spectral Properties of Chromophoric Dissolved Organic Matter: A Model Assessment for Surface Waters

Altare

Vione

2023

Molecules

View full text Add to dashboard Cite

Chromophoric dissolved organic matter (CDOM) is the main sunlight absorber in surface waters and a very important photosensitiser towards the generation of photochemically produced reactive intermediates (PPRIs), which take part in pollutant degradation. The absorption spectrum of CDOM (ACDOM(λ), unitless) can be described by an exponential function that decays with increasing wavelength: ACDOM(λ) = 100 d DOC Ao e− Sλ, where d [m] is water depth, DOC [mgC L−1] is dissolved organic carbon, Ao [L mgC−1 cm−1] is a pre-exponential factor, and S [nm−1] is the spectral slope. Sunlight absorption by CDOM is higher when Ao and DOC are higher and S is lower, and vice versa. By the use of models, here we investigate the impact of changes in CDOM spectral parameters (Ao and S) on the steady-state concentrations of three PPRIs: the hydroxyl radical (•OH), the carbonate radical (CO3•−), and CDOM excited triplet states (3CDOM*). A first finding is that variations in both Ao and S have impacts comparable to DOC variations on the photochemistry of CDOM, when reasonable parameter values are considered. Therefore, natural variability of the spectral parameters or their modifications cannot be neglected. In the natural environment, spectral parameters could, for instance, change because of photobleaching (prolonged exposure of CDOM to sunlight, which decreases Ao and increases S) or of the complex and still poorly predictable effects of climate change. A second finding is that, while the steady-state [3CDOM*] would increase with increasing ACDOM (increasing Ao, decreasing S), the effect of spectral parameters on [•OH] and [CO3•−] depends on the relative roles of CDOM vs. NO3− and NO2− as photochemical •OH sources.

show abstract

Pivotal role of water molecules in the photodegradation of pymetrozine: New insights for developing green pesticides

Cited by 12 publications

References 65 publications

Theoretical investigation on the reaction mechanism of UTP cyclohydrolase

Theoretical investigation on the reaction mechanism of UTP cyclohydrolase

Degradation of the Novel Heterocyclic Insecticide Pyraquinil in Water: Kinetics, Degradation Pathways, Transformation Products Identification, and Toxicity Assessment

Photochemical Implications of Changes in the Spectral Properties of Chromophoric Dissolved Organic Matter: A Model Assessment for Surface Waters

Contact Info

Product

Resources

About