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1.
Food Chem ; 375: 131859, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34933234

RESUMO

The effects of different kinds of chitosan, oligomer (ChiO) and monomer (Gluco), and the combinations of polymer (Chi) or ChiO with flavonoid aglycones and glycosides against the formation of major HAs were investigated to find out potential combination partners for enhanced suppression of HA formation. Results in roast beef patties showed ChiO and Gluco significantly inhibited PhIP and MeIQx formation by 43-80% and 31-57%, respectively. Of which, ChiO was the most effective. In combinations with flavonoid glycosides (phloridzin, rutin and hesperidzin, respectively), Chi, but not ChiO, generated enhanced inhibitory effects. Further analysis showed Chi and phloridzin combined at a ratio of 1:1 was the most promising, especially in inhibiting PhIP, and the mechanism behind involved: 1) water retention by Chi, and 2) reduction of phenylalanine availability by phloridzin. These findings suggest that appropriate combination of Chi and flavonoid glycosides contributes to significant improvement in the safety of meat products.


Assuntos
Quitosana , Compostos Heterocíclicos , Aminas/análise , Animais , Bovinos , Culinária , Flavonoides , Glicosídeos , Compostos Heterocíclicos/análise , Carne/análise
2.
Food Chem ; : 131677, 2021 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-34865928

RESUMO

The existence of microwave non-thermal effects in food processing is still debated. In this study, molecular dynamics (MD) simulations were performed to investigate the conformation, electrostatic profiles, and intramolecular hydrogen bonds (intra-HB) of glucose in aqueous solution under alternating electric fields of microwaves ranging from 0 to 109 V/m at 2.45 GHz. The results showed a field-induced threshold of 109 V/m. At the threshold, alternating microwaves reoriented the flexible moieties and thus enhanced the intra-HB. The conformational transition among gg, gt, and tg conformers at 109 V/m possibly resulted from the uneven electrostatic potential and the increased intra-HB. In practice, the maximum electric field of microwaves is several times weaker than the threshold, verifying the absence of microwave non-thermal effects for glucose molecules in food processing. This study provides a novel strategy to evaluate the potential non-thermal effects of microwaves in food processing and the related underlying food safety issues.

3.
Front Endocrinol (Lausanne) ; 12: 774997, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34867824

RESUMO

Objective: Supraphysiological hormone exposure, in vitro culture and embryo transfer throughout the in vitro fertilization-embryo transfer (IVF-ET) procedures may affect placental development. The present study aimed to identify differences in genomic expression profiles between IVF-ET and naturally conceived placentals and to use this as a basis for understanding the underlying effects of IVF-ET on placental function. Methods: Full-term human placental tissues were subjected to next-generation sequencing to determine differentially expressed miRNAs (DEmiRs) and genes (DEGs) between uncomplicated IVF-ET assisted and naturally conceived pregnancies. Gene ontology (GO) enrichment analysis and transcription factor enrichment analysis were used for DEmiRs. MiRNA-mRNA interaction and protein-protein interaction (PPI) networks were constructed. In addition, hub genes were obtained by using the STRING database and Cytoscape. DEGs were analyzed using GO and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Differentially expressed miRNAs were validated through qRT-PCR. Results: Compared against natural pregnancies, 12 DEmiRs and 258 DEGs were identified in IVF-ET placental tissues. In a validation cohort, it was confirmed that hsa-miR-204-5p, hsa-miR-1269a, and hsa-miR-941 were downregulation, while hsa-miR-4286, hsa-miR-31-5p and hsa-miR-125b-5p were upregulation in IVF-ET placentas. Functional analysis suggested that these differentially expressed genes were significantly enriched in angiogenesis, pregnancy, PI3K-Akt and Ras signaling pathways. The miRNA-mRNA regulatory network revealed the contribution of 10 miRNAs and 109 mRNAs while EGFR was the most highly connected gene among ten hub genes in the PPI network. Conclusion: Even in uncomplicated IVF-ET pregnancies, differences exist in the placental transcriptome relative to natural pregnancies. Many of the differentially expressed genes in IVF-ET are involved in essential placental functions, and moreover, they provide a ready resource of molecular markers to assess the association between placental function and safety in IVF-ET offspring.

5.
Signal Transduct Target Ther ; 6(1): 438, 2021 12 24.
Artigo em Inglês | MEDLINE | ID: mdl-34952914

RESUMO

Messenger RNA (mRNA) vaccine technology has shown its power in preventing the ongoing COVID-19 pandemic. Two mRNA vaccines targeting the full-length S protein of SARS-CoV-2 have been authorized for emergency use. Recently, we have developed a lipid nanoparticle-encapsulated mRNA (mRNA-LNP) encoding the receptor-binding domain (RBD) of SARS-CoV-2 (termed ARCoV), which confers complete protection in mouse model. Herein, we further characterized the protection efficacy of ARCoV in nonhuman primates and the long-term stability under normal refrigerator temperature. Intramuscular immunization of two doses of ARCoV elicited robust neutralizing antibodies as well as cellular response against SARS-CoV-2 in cynomolgus macaques. More importantly, ARCoV vaccination in macaques significantly protected animals from acute lung lesions caused by SARS-CoV-2, and viral replication in lungs and secretion in nasal swabs were completely cleared in all animals immunized with low or high doses of ARCoV. No evidence of antibody-dependent enhancement of infection was observed throughout the study. Finally, extensive stability assays showed that ARCoV can be stored at 2-8 °C for at least 6 months without decrease of immunogenicity. All these promising results strongly support the ongoing clinical trial.


Assuntos
Vacinas contra COVID-19/farmacologia , COVID-19/imunologia , Imunogenicidade da Vacina , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , /farmacologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/prevenção & controle , Vacinas contra COVID-19/imunologia , Chlorocebus aethiops , Humanos , Macaca fascicularis , Células Vero , /imunologia
6.
Eur J Med Chem ; 229: 114055, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34971874

RESUMO

The development of inhibitors targeting the PI3K-Akt-mTOR signaling pathway has been greatly hindered by the on-target AEs, such as hyperglycemia and hepatotoxicities. In this study, a series of diaryl urea derivatives has been designed and synthesized based on clinical candidate gedatolisib (6aa), and most of the newly synthesized derivatives showed kinase inhibitory and antiproliferative activities within nanomolar and submicromolar level, respectively. The terminal l-prolineamide substituted derivative 6 ab showed 8.6-fold more potent PI3Kα inhibitory activity (0.7 nM) and 4.6-fold more potent antiproliferative effect against HCT116 cell lines (0.11 µM) compared with control 6aa. The potential antitumor mechanism and efficacy of 6 ab in HCT116 xenograft models have also been evaluated, and found 6 ab showed comparable in vivo antitumor activity with 6aa. The safety investigations revealed that compound 6 ab exhibited more safer profiles in the selectivity of liver cells (selectivity index: >6.6 vs 1.85) and blood glucose regulation than 6aa. In addition, the in vitro stability assays also indicated our developed compound 6 ab possessed good metabolic stabilities.

7.
PLoS One ; 16(12): e0261168, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34910742

RESUMO

BACKGROUND: Acute aortic dissection (AAD) is very fatal without surgical treatment. Higher serum sodium can increase in-hospital mortality of many diseases; however, the effect of serum sodium on postoperative in-hospital mortality in AAD patients remains unknown. METHODS: We collected a total of 415 AAD patients from January 2015 to December 2019. Patients were classified into four categories (Q1-Q4) according to the admission serum sodium quartile. The cox proportional hazards model evaluated the association between serum sodium and in-hospital mortality. All-cause in-hospital mortality was set as the endpoint. RESULTS: By adjusting many covariates, cox proportional hazards model revealed the in-hospital mortality risk of both Q3 and Q4 groups was 3.086 (1.242-7.671, P = 0.015) and 3.370 (1.384-8.204, P = 0.007) respectively, whereas the risk of Q2 group was not significantly increased. Univariate and multiple Cox analysis revealed that Stanford type A, serum glucose, α-hydroxybutyrate dehydrogenase and serum sodium were risk factors correlated with in-hospital death in AAD patients. CONCLUSION: The study indicates that the admission serum sodium of AAD patients has a vital impact on postoperative hospital mortality.


Assuntos
Aneurisma Dissecante/mortalidade , Mortalidade Hospitalar/tendências , Hospitalização/estatística & dados numéricos , Sódio/sangue , Aneurisma Dissecante/sangue , Aneurisma Dissecante/patologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida
8.
Front Mol Biosci ; 8: 756085, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34950700

RESUMO

Gastric cancer (GC) is rampant around the world. Most of the GC cases are detected in advanced stages with poor prognosis. The identification of marker genes for early diagnosis is of great significance. Studying the tumor environment is helpful to acknowledge the process of tumorigenesis, development, and metastasis. Twenty-two kinds of immune cells were calculated by CIBERSORT from Gene Expression Omnibus (GEO) database. Subsequently, higher infiltration of macrophages M0 was discovered in GC compared with normal tissues. WGCNA was utilized to construct the network and then identify key modules and genes related to macrophages in TCGA. Finally, 18 hub genes were verified. In the PPI bar chart, the top 3 genes were chosen as hub genes involved in most pathways. On the TIMER and THPA websites, it is verified that the expression levels of CYBB, CD86, and C3AR1 genes in tumor tissues were higher than those in normal tissues. These genes may work as biomarkers or targets for accurate diagnosis and treatment of GC in the future. Our findings may be a new strategy for the treatment of GC.

9.
J Texture Stud ; 2021 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-34921420

RESUMO

Frozen-stored fish mince tend to have poor gelling ability due to significant myosin denaturation caused by freezing. In this study, microbial transglutaminase (MTGase) was used to improve the quality of fish mince gel products made from frozen-stored longtail southern cod (LSC). The gel strength of the gel product increased with the addition of MTGase and reached a plateau value of ~19 N·mm beyond 300 U/kg of MTGase, at the same condition, T22 was reduced from 57.22 ms to 49.77 ms, T23 was reduced from 1273.88 ms to 1072.27 ms. As the MTGase addition increased from 0 U/kg to 400 U/kg, the hardness of the fish surimi gel increased from 14.52 N to 21.36 N, and the microstructure changed from loose to dense, respectively. This study showed that MTGase could promote gelation to improve the quality of frozen-stored LSC fish mince gel, especially at 300 U/kg which potentially can be utilized to produce good surimi gel products out of frozen-stored fish. This article is protected by copyright. All rights reserved.

10.
Ann Diagn Pathol ; 56: 151859, 2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34844099

RESUMO

Erythropoietic protoporphyria (EPP) is a rare inherited disease whose morbidity is about 1:75,000 to 1:200,000. It is caused by the deficiency of porphyrin ferrochelatase (FECH). Liver involvement in EPP is even rarer. The diagnosis of EPP with liver involvement mainly relies on clinical manifestations, laboratory examinations, histopathological examinations and genetic testing, which is still a huge challenge for both clinicians and pathologists. Here, 5 cases of EPP with liver injury were collected, and the clinicopathological features of these patients were analyzed. The clinical manifestations and laboratory examinations varied from person to person, whereas the liver biopsies showed that there were dark brown deposits within the hepatocytes, Kupffer cells, bile canaliculi and the lumen of bile ducts, which was a constant finding by histopathological examination. Gene tests were conducted in two of the five cases, and the results confirmed the diagnosis. Fully understanding of the diseases can help us reduce the rate of missed diagnosis and provide proper treatment as early as possible.

11.
Nutrients ; 13(11)2021 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-34836184

RESUMO

Armillaria luteo-virens Sacc (ALS) is a rare wild Chinese medicinal and edible basidiomycete. However, its protective effect on intestinal functions and the underlying mechanism is still unknown. This work explored the improvement of dextran sulfate sodium (DSS)-induced colitis by ALS. ALS supplementation markedly improved colitis symptoms, gut barrier integrity, and goblet loss in DSS-treated mice. In addition, ALS inhibited colonic inflammation through the inhibition/activation of the mitogen-activated protein kinases/NF-κB signaling pathway. The 16S rRNA gene-based microbiota analysis revealed that ALS altered the gut microbiota composition, decreasing the richness of Enterobacteriaceae and increasing the abundance of Lactobacillaceae. The bile-acid-targeted metabolomic analysis showed that ALS recovered the microbial bile acid metabolism in the gut, enabling the activation of the farnesoid X receptor signaling by these acids, thus maintaining the intestinal homeostasis. Importantly, broad-spectrum antibiotic treatment reduced the efficacy of ALS-induced protection from colitis. Overall, our findings suggest that ALS may represent a novel approach in the nutritional intervention to prevent colitis.

13.
Sci China Life Sci ; 2021 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-34783996

RESUMO

The biased ligands in G protein-coupled receptors (GPCRs) have opened new avenues for developing safer and more effective drugs. However, the identification of such biased ligands as drug candidates is highly desirable. Here, we report that Higenamine, a compound isolated from a Chinese herb, functions as a novel ß-arrestin-biased ligand of the ß2-adrenergic receptor (ß2-AR). The radioligand binding assays demonstrated that Higenamine was the ligand of ß2-AR. Higenamine induced phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), which can be blocked by propranolol, an inhibitor of ß2-AR. The Gi protein inhibitor, pertussis toxin, had no effect on the phosphorylation of ERK1/2 induced by Higenamine. Furthermore, Higenamine induced ERK1/2 phosphorylation through transactivation of Epithelial growth factor receptor (EGFR). We also found that Higenamine-induced-ERK1/2 phosphorylation is dependent on ß-arrestin1/2, and HG inhibits Doxorubicin-induced cardiomyocyte apoptosis. Our results identify Higenamine as a novel biased ligand via the ß-arrestin-dependent pathway. These findings give us a better understanding of Higenamine's potential role in designing diagnostic and therapeutic strategies.

14.
Technol Cancer Res Treat ; 20: 15330338211057982, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34806478

RESUMO

Objectives: Thyroid nodules are common in adults, but only some of them are malignant. Ultrasound-guided fine-needle aspiration (FNA) is widely applied as a reliable and minimally invasive technique for evaluating thyroid nodules. However, the scarcity of FNA biopsy specimens poses a challenge to molecular diagnosis. This study aimed to evaluate the feasibility of FNA washout precipitation specimens as an effective supplement to the thyroid genetic test. Methods: A total of 115 patients with thyroid nodules were enrolled in our study. The BRAF V600E mutation status was detected in all FNA washout precipitation specimens and biopsy formalin-fixed paraffin-embedded (FFPE) specimens using an amplification refractory mutation system PCR (ARMS-PCR). All patients underwent cytological diagnoses; 79 patients also underwent surgery for histopathological analysis. Results: All the 115 samples were successfully analyzed using both FNA washout precipitation and biopsy FFPE specimens. The results showed that the BRAF V600E status detected in 96 FNA washout precipitation specimens were consistent with that in FNA biopsy FFPE specimens, including 41 BRAF V600E positive and 55 BRAF V600E negative, achieving a concordance rate of 84.4% (kappa = 0.689). Furthermore, the BRAF V600E mutation status using FNA washout precipitation specimens provided a 100.0% positive predictive value for diagnosing papillary thyroid carcinoma in patients with The Bethesda system for reporting thyroid cytopathology (TBSRTC) V. Besides, the BRAF V600E mutation status was positive in 90.9% (10/11) FNA washout precipitation specimens from patients with capsule invasion, achieving a higher overall sensitivity of 100.0%, compared with 57.1% of FNA washout precipitation specimens from patients without capsule invasion. Conclusion: These results suggested that FNA washout precipitation specimens might be a valuable supplementary sample type for detecting the BRAF V600E mutation in patients with thyroid nodules, especially with thyroid capsule invasion.

15.
J Agric Food Chem ; 69(46): 13933-13941, 2021 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-34756022

RESUMO

The effects of the deacetylation degree (DD) of chitosan on heterocyclic aromatic amine formation were investigated in chemical models and beef patties. The results in model systems showed that at lower addition levels (10 mg), chitosan with 85% DD showed the strongest inhibitory effect against 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) formation, while chitosan with a higher DD (95%) or a lower DD (72 and 50%) did not show any significantly inhibitory effect. Further mechanism study showed that chitosan addition reduced the content of Maillard reaction intermediates including phenylacetaldehyde and the aldol condensation product but increased the PhIP precursor creatinine residue in the chemical model, indicating that chitosan at least partially competed with creatinine to react with phenylacetaldehyde to inhibit PhIP formation. In roast beef patties, 0.15% (w/w) chitosan (85% DD) significantly reduced the formation of PhIP, MeIQx, 4,8-DiMeIQx, Harman, and Norharman by 56.21, 33.32, 31.35, 25.14, and 28.12%, respectively. Moreover, chitosan significantly inhibited the formation of aldehydes in roast beef patties, further confirming the above-mentioned inhibition mechanism. However, the addition of chitosan might promote fatty acid oxidation. In addition, chitosan addition below 0.15% (w/w) had no significant effect on the textural properties of the roast samples.


Assuntos
Quitosana , Modelos Químicos , Animais , Bovinos , Culinária , Imidazóis , Carne/análise , Piridinas
16.
Cell Death Differ ; 2021 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-34635817

RESUMO

Many integral membrane proteins might act as indispensable coordinators in specific functional microdomains to maintain the normal operation of known receptors, such as Notch. Gm364 is a multi-pass transmembrane protein that has been screened as a potential female fertility factor. However, there have been no reports to date about its function in female fertility. Here, we found that global knockout of Gm364 decreased the numbers of primordial follicles and growing follicles, impaired oocyte quality as indicated by increased ROS and γ-H2AX, decreased mitochondrial membrane potential, decreased oocyte maturation, and increased aneuploidy. Mechanistically, Gm364 directly binds and anchors MIB2, a ubiquitin ligase, on the membrane. Subsequently, membrane MIB2 ubiquitinates and activates DLL3. Next, the activated DLL3 binds and activates Notch2, which is subsequently cleaved within the cytoplasm to produce NICD2, the intracellular active domain of Notch2. Finally, NICD2 can directly activate AKT within the cytoplasm to regulate oocyte meiosis and quality.

17.
Cancer Cell Int ; 21(1): 536, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34654433

RESUMO

BACKGROUND: Tertiary lymphoid structures (TLSs), organizationally resemble lymph nodes, are frequently present in breast cancer (BCa). It is usually, but not always, associated with a positive prognosis or immunotherapy response in cancer patients. This meta-analysis was performed to assess the prognostic and clinical impact of TLSs in BCa. METHODS: We conducted a systematic search in PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, and WanFang Database to obtain eligible research data up to May 30, 2021. This meta-analysis is focusing on the studies evaluated the prognostic value of TLSs and the associated clinicopathologic indicators, related gene expression and survival. STATA software 16.0 software was used to assess the prognostic significance and clinical impact of TLSs. RESULTS: Nine studies involved with 2281 cases were incorporated in this meta-analysis, in which four of them evaluated the prognostic value of TLSs. There are 6 studies assessed the relationship of TLSs and 4 studies investigated the clinicopathologic parameters as well as the key gene expression, respectively. The results showed the presence of TLSs were predicting a better OS (HR = 0.61, 95% CI: 0.51-0.73, p < 0.001) and DFS (HR = 0.40, 95% CI: 0.17-0.93, p < 0.001) of BCa patients. It also revealed that the presence of TLSs was significantly correlated with tumor differentiation (p < 0.001), pTNM stage (p < 0.001), lymph node metastasis (p < 0.001), and TILs density (p < 0.001) of BCa, and the expression of Her2 (p < 0.001), ER (p < 0.001), PR (p < 0.001) and Ki67 (p = 0.009) of the tumor cell. CONCLUSION: Our results indicated that high levels of TLSs could predict a favorable prognosis for BCa. Moreover, the TLSs were significantly correlated with the clinicopathological indicators and the critical gene expression of BCa, indicating its potential clinical impact on BCa patients.

18.
Int J Mol Sci ; 22(19)2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34638946

RESUMO

Floccularia luteovirens is a rare wild edible and medicinal fungus endemic to the Qinghai-Tibet Plateau. In this study, the hollow fiber membranes with molecular weights of 50 kDa, 6 kDa and 3 kDa were used to extract different fractions of F. luteovirens, which were named as #1, #2 and #3. Then the antitumor activity of these fractions on NSCLC cell lines, PC9 and NCI-H460, were investigated by using MTT assay, flow cytometry analysis and Western blot assay. The results indicated that the #2 and #3 fractions showed obviously inhibitory activities on PC9 and NCI-H460 tumor cells and proved that these small molecule fractions induced apoptosis of NSCLC cells by activating caspase-3. Finally, a total of 15 components, including six amino acids, two nucleosides, two glycosides, two terpenoids, one phenylpropanoid, one ester and one alkaloid, were identified in #2 and #3 fractions. This is the first evidence that the small molecule components of F. luteovirens were able to inhibit lung cancer by inducing apoptosis in a caspase-3 manner. The present study indicated the benefits of F. luteovirens in lung cancer treatment, which might be a potential resource of functional food and drugs.


Assuntos
Agaricales/química , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Caspase 3/metabolismo , Neoplasias Pulmonares/metabolismo , Transdução de Sinais/efeitos dos fármacos , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Carpóforos/química , Humanos , Neoplasias Pulmonares/patologia
19.
Natl Sci Rev ; 8(3): nwaa297, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34676096

RESUMO

Receptor recognition and subsequent membrane fusion are essential for the establishment of successful infection by SARS-CoV-2. Halting these steps can cure COVID-19. Here we have identified and characterized a potent human monoclonal antibody, HB27, that blocks SARS-CoV-2 attachment to its cellular receptor at sub-nM concentrations. Remarkably, HB27 can also prevent SARS-CoV-2 membrane fusion. Consequently, a single dose of HB27 conferred effective protection against SARS-CoV-2 in two established mouse models. Rhesus macaques showed no obvious adverse events when administrated with 10 times the effective dose of HB27. Cryo-EM studies on complex of SARS-CoV-2 trimeric S with HB27 Fab reveal that three Fab fragments work synergistically to occlude SARS-CoV-2 from binding to the ACE2 receptor. Binding of the antibody also restrains any further conformational changes of the receptor binding domain, possibly interfering with progression from the prefusion to the postfusion stage. These results suggest that HB27 is a promising candidate for immuno-therapies against COVID-19.

20.
Ecotoxicol Environ Saf ; 224: 112655, 2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34418856

RESUMO

Organophosphorus pesticides (OPs) are posing great threat to the environment and human health, due to their overuse and persistence in the environment. Photolysis has been established as an effective method to degrade OPs. The influence of pH value, the initial concentration of pesticides and the light source on the photolysis of two OPs, including chlorpyrifos and dimethoate, was investigated. The optimal reaction condition for OPs degradation was under pH 9, with xenon lamp as the light source, in which the photodegradation efficiencies of chlorpyrifos and dimethoate (500 mg/L) were 75.12% and 94.31%, respectively. The photodegradation products of chlorpyrifos and dimethoate were identified by GC-MS. Also, density functional theory (DFT) calculations were used to characterize the molecular properties of chlorpyrifos and dimethoate, as well as predicting potential photolysis reactions. Photodegradation mechanisms of chlorpyrifos and dimethoate were proposed, in which 3,5,6-trichloropyridinol (TCP), O,O-diethyl thiophosphate (DETP), 2,3,5-Trichloro-6-methoxypyridine (TMP) and O,O,S-trimethyl phosphorothioate were identified as the main products of chlorpyrifos degradation. Omethoate, O,O,S-trimethyl thiophosphorothioate, N-methyl-2-sulfanylacetamide, O,O,O-trimethyl thiophosphate, O,O,S-trimethylphosphorothiate, and O,O,O-trimethyl phosphoric ester as the main photodegradation products for dimethoate. The main degradation mechanisms included ring opening, cleavage, oxidation and demethylation. This work demonstrated the feasibility of combining chemical analysis with quantum chemical calculation in unraveling degradation mechanisms of OPs. Also, it is of great significance for evaluating the environmental fate of OPs in aquatic system and further environmental risk assessment.

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