Saffron Petal, an Edible Byproduct of Saffron, Alleviates Dextran Sulfate Sodium-Induced Colitis by Inhibiting Macrophage Activation and Regulating Gut Microbiota.

Saffron petal (SP) is an agricultural byproduct in the process of the crude drug saffron, accounting for 90% of the dry weight of saffron flowers. To promote the utilization of SP in the food and pharmaceutical industries, its anti-inflammatory activities were evaluated on LPS-activated RAW 264.7 cells and DSS-challenged colitic mice. The results indicated that the SP extract had a notable effect in alleviating the clinical manifestations of colitis, such as reduction in body weight, improvement in disease activity index, mitigation of colon shortening, and alleviation of colon tissue damage. Moreover, SP extract significantly suppressed macrophage infiltration and activation, evidenced by a decrease in colonic F4/80 macrophages and suppression of the transcription and secretion of colonic tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) in DSS-challenged colitic mice. In vitro, SP extract also significantly suppressed nitric oxide production, COX-2 and iNOS expressions, and TNF-α and IL-1ß transcription of activated RAW 264.7 cells. Network pharmacology-guided research identified that SP extract significantly downregulated Akt, p38, ERK, and JNK phosphorylation in vivo and in vitro. In parallel, SP extract also effectively corrected microbial dysbiosis by increasing the abundance of Bacteroides acidifaciens, Bacteroides vulgatus, Lactobacillus murinus, and Lactobacillus gasseri. These findings indicate that the effectiveness of SP extract in treating colitis is demonstrated by its ability to reduce macrophage activation, inhibit the PI3K/Akt and MAPK pathways, and regulate gut microbiota, suggesting that SP extract holds great potential as a therapeutic option for colitis.

Aspirin Ameliorates Pancreatic Inflammation and Fibrosis by Inhibiting COX-2 Expression in Experimental Chronic Pancreatitis.

Aim: Chronic pancreatitis (CP) is a complex and intractable disease mainly manifested as chronic inflammation and fibrosis. Aspirin(acetylsalicylic acid, ASA) has been reported to be used in the treatment of acute pancreatitis (AP), but its effectiveness on CP is unclear. This study aimed to investigate the therapeutic effects of ASA in CP mice. Methods: A murine model of CP was induced by intraperitoneal injection with 20% L-arginine. After one week of L-arginine administration, mice in the ASA treatment group were administered aspirin (100mg/kg/d) by intragastric gavage. At two, four, and six weeks after the first injection of L-arginine, mice were euthanized and the pancreas was collected for histological and molecular analysis. A second model of CP (caeruelin-induced) was used as a validation experiment to test the effect of ASA. Results: L-arginine-induced CP resulted in over-expression of the inflammatory enzyme cyclooxygenase (COX)-2. COX-2 expression decreased after ASA treatment. Pancreatic-injury inflammatory response (measured by changes in amylase, CK-19, F4/80, CD3, MCP-1, IL-6) and fibrosis degree (measured by expression of COL1A1, MMP-1 and TIMP-1) was reduce in ASA -treated mice model. The therapeutic effect of ASA was also observed in caeruelin-induced CP. Conclusion: ASA has an ameliorating effect in murine models of CP through inhibition of pancreatic inflammation and fibrosis, which may be a promising option for clinical treatment.

Ban-Lan-Gen Granule Alleviates Dextran Sulfate Sodium-Induced Chronic Relapsing Colitis in Mice via Regulating Gut Microbiota and Restoring Gut SCFA Derived-GLP-1 Production.

PURPOSE: GLP-1 based therapy represents a new treatment option for inflammatory bowel disease. Ban-Lan-Gen (BLG) granule, a known anti-viral TCM formulation, exhibits potential anti-inflammatory activities in treating various kinds of inflammation. However, its anti-inflammatory effect on colitis and the underlying mechanisms remain unknown. METHODS: Dextran sulfate sodium (DSS)-induced chronic relapsing colitis in mice was established. The disease activity index, histological sign of damage, and levels of proinflammatory cytokines were performed to assess the protective effects of BLG. Serum GLP-1 level and colonic Gcg, GPR41 and GRP43 expression, the community compositions of gut microbiota, the levels of SCFAs in the feces and GLP-1 release from primary murine colon epithelial cells were performed to characterize the effects of BLG on gut microbiota and gut SCFA derived-GLP-1 production. RESULTS: BLG treatment significantly alleviated body weight loss, DAI, colon shortening, colon tissue damage, and pro-inflammatory cytokine levels of TNF-α, IL-1ß and IL-6 in the colon tissues. Moreover, BLG treatment could observably restore colonic Gcg, GPR41 and GRP43 expression and serum GLP-1 level of colitic mice, as well as correct the alteration of gut microbiota in colitic mice by increasing the abundances of SCFA-producing bacteria, eg, Akkermansia and Prevotellaceae_UCG-001, and decreasing the abundances of bacteria, eg, Eubacterium_xylanophilum_group, Ruminococcaceae_UCG-014, Intestinimonas, and Oscillibacter. Furthermore, BLG treatment could markedly increase the levels of SCFAs in feces of colitic mice. In parallel, ex vivo assay also showed that and the extract of feces from BLG-treatment mice could greatly stimulate the secretion of GLP-1 from primary murine colon epithelial cells. CONCLUSION: These findings suggest that the anti-colitis effects of BLG are achieved at least partly by regulating gut microbiota and restoring gut SCFA derived-GLP-1 production, and BLG has the potential to be developed as a promising agent for the treatment of chronic relapsing colitis.

Residual levels of five pesticides in peanut oil processing and chips frying.

BACKGROUND: Pesticide contamination in oil crops and processed products is an important food safety concern. The study was aimed to investigate the pesticide residue changes in press processing of peanut oil and frying of chips. RESULTS: Five pesticides - chlorpyrifos, deltamethrin, methoxyfenozide, azoxystrobin and propargite - which are often applied during growth period in peanut plants, were selected to investigate their residue changes in cold press processing of peanut oil and frying of potato chips. Results showed that the residues of the five pesticides were decreased by 3.1-42.6% during air-drying before oil pressing. The residues of chlorpyrifos, deltamethrin, methoxyfenozide and propargite in peanut oil were 2.05-3.63 times higher than that in peanut meal after cold pressing of the oil, except for azoxystrobin having a slightly lower residue in peanut oil, with 0.92 times that in peanut meal. The processing factors of the five pesticides in peanut oil ranged from 1.17 to 2.73 and were highly related to the log Kow of the pesticides. The higher the log Kow , the more easily was the pesticide partitioned in the peanut oil. Besides, as frying time increase during preparation of chips, the concentration of pesticides in peanut oil decreased gradually by 6.7-22.1% compared to the first frying. In addition, 0.47-11.06% of the pesticides were transferred to the chips through frying with contaminated oil. CONCLUSION: This is first report showing that pesticides can transfer from contaminated oil to chips. There exists a potential dietary health risk by using pesticide-contaminated oil for frying chips. This work could provide basic data for accurate dietary risk assessment of pesticide residues in peanut oil and its frying products. © 2021 Society of Chemical Industry.

Model prediction of herbicide residues in soybean oil: Relationship between physicochemical properties and processing factors.

The distribution and processing factors (PFs) of herbicides in cold-/hot-pressed soybean samples (n = 3) were studied on the laboratory scale. The hot-pressing process was found to have a significant effect on herbicide degradation in soybean samples. Specifically, for highly water-soluble pesticides with pKow > 2 in soybean oil, the PF values were generally > 1. Nonlinear curve fitting revealed that the PFs of herbicides in soybean oil were positively correlated with their octanol-water partition coefficients, but negatively correlated with their water solubility and melting points. A principal component analysis confirmed the dominant parameters among the herbicide PFs during soybean oil production. Using the physicochemical parameters of pesticides, the developed multiple linear regression model gave a fitting accuracy of ≥0.80 for predicting the theoretical PF values of pesticides in soybean oil products (0.39 < RMSE < 0.58). Thus, this model may be applicable for safety risk assessments and establishing maximum residue limits for pesticides in processed products.

[Impact of high-fat diet on gene expression in mouse prostate tissue].

OBJECTIVE: To analyze the effects of high-fat diet on the biological network regulation of gene expression microarray data and key proteins in mouse prostate tissue, and provide some new theoretical evidence for the mechanism of obesity inducing PCa. METHODS: From the Gene Expression Omnibus (GEO), we obtained RNAs in the prostate tissue from two groups of C57BL / 6J mice, the normal diet group (n = 5) and high-fat diet group (n = 4). Using the Gene Cloud, Gene-Cloud of Biotechnology Informs (GCBI), GenClip2.0, and Sytoscape 3.5.1, we screened differentially expressed genes, investigated protein interaction networks and biological pathways of differential genes and, from the perspective of transcriptome, explored the effects of high-fat diet on the changes of the molecular network of prostate tissue genes and the molecular biological functions possibly involved. RESULTS: A total of 134 differentially expressed genes were identified, 130 up-regulated and 4 down-regulated, mainly involved in biological functions such as chromosome organization, cell-cell signaling, small molecule biosynthesis and leukocyte activation. The Lck, Prkcb and Cd28 genes in the gene network were of high value, indicating an important relationship with protein synthesis and biological functions, the core node of the protein-protein network, and a high predictive ability of Lck and Cd28. CONCLUSIONS: The high-fat diet can induce changes in prostate tissue genes, leading to tumorigenesis.

CRISPR/Cas9-based generation of a recombinant double-reporter pseudorabies virus and its characterization in vitro and in vivo.

Pseudorabies, caused by pseudorabies virus (PRV) variants, has broken out among commercial PRV vaccine-immunized swine herds and resulted in major economic losses to the pig industry in China since late 2011. However, the mechanism of virulence enhancement of variant PRV is currently unclear. Here, a recombinant PRV (rPRV HN1201-EGFP-Luc) with stable expression of enhanced green fluorescent protein (EGFP) and firefly luciferase as a double reporter virus was constructed on the basis of the PRV variant HN1201 through CRISPR/Cas9 gene-editing technology coupled with two sgRNAs. The biological characteristics of the recombinant virus and its lethality to mice were similar to those of the parental strain and displayed a stable viral titre and luciferase activity through 20 passages. Moreover, bioluminescence signals were detected in mice at 12 h after rPRV HN1201-EGFP-Luc infection. Using the double reporter PRV, we also found that 25-hydroxycholesterol had a significant inhibitory effect on PRV both in vivo and in vitro. These results suggested that the double reporter PRV based on PRV variant HN1201 should be an excellent tool for basic virology studies and evaluating antiviral agents.

The effects of nuclear factor-kappa B in pancreatic stellate cells on inflammation and fibrosis of chronic pancreatitis.

The activation of pancreatic stellate cells (PSCs) plays a critical role in the progression of pancreatic fibrosis. Nuclear factor-kappa B (NF-κB) is associated with chronic pancreatitis (CP). Previous evidence indicated that NF-κB in acinar cells played a double-edged role upon pancreatic injury, whereas NF-κB in inflammatory cells promoted the progression of CP. However, the effects of NF-κB in PSCs have not been studied. In the present study, using two CP models and RNAi strategy of p65 in cultured PSCs, we found that the macrophage infiltration and MCP-1 expression were increased, and the NF-κBp65 protein level was elevated. NF-κBp65 was co-expressed with PSCs. In vitro, TGF-ß1 induced overexpression of the TGF-ß receptor 1, phosphorylated TGF-ß1-activated kinase 1 (p-TAK1) and NF-κB in the PSCs. Moreover, the concentration of MCP-1 in the supernatant of activated PSCs was elevated. The migration of BMDMs was promoted by the supernatant of activated PSCs. Further knockdown of NF-κBp65 in PSCs resulted in a decline of BMDM migration, accompanied by a lower production of MCP-1. These findings indicate that TGF-ß1 can induce the activation of NF-κB pathway in PSCs by regulating p-TAK1, and the NF-κB pathway in PSCs may be a target of chronic inflammation and fibrosis.

Study on the relationship between hepatic fibrosis and epithelial-mesenchymal transition in intrahepatic cells.

Hepatic fibrosis is a pathophysiological process, which causes excessive extracellular matrix (ECM) deposition resulting from persistent liver damage. Myofibroblasts are the core cells that produce ECM. It is known that epithelial-mesenchymal transition (EMT) is not a simple transition of cells from the epithelial to mesenchymal state. Instead, it is a process, in which epithelial cells temporarily lose cell polarity, transform into interstitial cell-like morphology, and acquire migration ability. Hepatocytes, hepatic stellate cells, and bile duct cells are the types of intrahepatic cells found in the liver. They can be transformed into myofibroblasts via EMT and play important roles in the development of hepatic fibrosis through a maze of regulations involving various pathways. The aim of the present study is to explore the relationship between the relevant regulatory factors and the EMT signaling pathways in the various intrahepatic cells.

Baicalin Ameliorates Pancreatic Fibrosis by Inhibiting the Activation of Pancreatic Stellate Cells in Mice with Chronic Pancreatitis.

Pancreatic inflammation and fibrosis are typical pathological features in chronic pancreatitis (CP). Activated pancreatic stellate cells (PSCs) have been regarded as the core event in the development of pancreatic fibrosis and are considered to be the key target for treatment of CP. Baicalin (C21H18O11), the main chemical composition of Baikal skullcap in the traditional Chinese medicines Dachaihu decoction (DCHD) and Xiaochaihu decoction (XCHD), has shown significant effects in the treatment of pancreatic fibrosis in CP mice; however, whether baicalin can inhibit the activation of PSCs and its underlying mechanism remain unclear. In this study, the influence of baicalin on activated PSCs in vitro and in vivo was investigated, and the results showed that Baicalin could significantly ameliorate the degree of pancreatic inflammation and fibrosis, while decreasing the levels of alpha-smooth muscle actin (α-SMA), F4/80 (surface markers of mouse macrophages), nuclear factor kappa-B (NF-κB), monocyte chemotactic protein 1 (MCP-1), and collagen type I alpha 1 (COL1A1)in the pancreas. Moreover, NF-κB and α-SMA were co-expressed in the pancreas of CP mice. Baicalin treatment markedly reduced the expression of co-location of α-SMA and NF-κB. In vitro, the protein expression levels of transforming growth factor-ß receptor 1 (TGF-ßR1), phosphorylated TGF-ß activated kinase 1 p-TAK 1, and NF-κBp65 in PSCs were all remarkably reduced after treatment with baicalin. In addition, baicalin could inhibit MCP-1 mRNA expression in supernatant of activated PSCs, as well as the excessive migration of macrophages. Taken together, our findings indicated that baicalin could inhibit the TGF-ß1/TGF-ßR1/TAK1/NF-κB signaling pathway of activated PSCs, reduce the secretion of MCP-1, and further decrease the infiltration of macrophages and inflammation cells of the local microenvironment of the pancreas. Thus, this study provides a reliable experimental basis for baicalin in the prevention and treatment of CP.

[Gene expression profiles in normal human prostate epithelial cells exposed to low-dose cadmium: A bioinformatics analysis].

OBJECTIVE: To analyze the biological network regulation and key proteins of gene expression microarray in human normal prostate epithelial cells after treated with low-dose cadmium, and provide some new theoretical evidence for the pathogenesis of cadmium-related prostate cancer. METHODS: We downloaded 19 copies of gene chip data from the Gene Expression Omnibus (GEO), involving 9 samples of prostate epithelial cells exposed to low-dose cadmium and 10 cases of normal control. Using the Gene-Cloud of Biotechnology Informs platform, GenClip2.0 and Sytoscape 3.5.1, we screened differentially expressed genes, explored their protein interaction networks and biological pathways and, from the perspective of transcriptome, analyzed the changes in the genetic network of normal human prostate epithelial cells and their possible molecular biological functions after low-dose cadmium treatment. RESULTS: Totally, 1 050 (1.92%) differentially expressed genes were found in the prostate epithelial cells treated with low-dose cadmium, involved in such biological functions as the cell physiological process, MAPK regulation, regulation of intracellular signal transduction, and immunological effect. The HSP90AB1, BUB3 and PRKAR1A genes were the core nodes of the protein network, which showed statistically significant differences in their expressions and a correlation with the malignant transformation of normal cells. CONCLUSIONS: Low-dose cadmium can cause genetic changes in normal human prostate epithelial cells and the differentially expressed genes are mainly involved in such biological functions as the cell physiological process, MAPK regulation, regulation of intracellular signal transduction, and immunological effect.

p-Coumaric Acid Protects Human Lens Epithelial Cells against Oxidative Stress-Induced Apoptosis by MAPK Signaling.

To protect against oxidative stress-induced apoptosis in lens epithelial cells is a potential strategy in preventing cataract formation. The present study aimed at studying the protective effect and underlying mechanisms of p-coumaric acid (p-CA) on hydrogen peroxide- (H2O2-) induced apoptosis in human lens epithelial (HLE) cells (SRA 01-04). Cells were pretreated with p-CA at a concentration of 3, 10, and 30 µM before the treatment of H2O2 (275 µM). Results showed that pretreatment with p-CA significantly protected against H2O2-induced cell death in a dose-dependent manner, as well as downregulating the expressions of both cleaved caspase-3 and cleaved caspase-9 in HLE cells. Moreover, p-CA also greatly suppressed H2O2-induced intracellular ROS production and mitochondrial membrane potential loss and elevated the activities of T-SOD, CAT, and GSH-Px of H2O2-treated cells. As well, in vitro study showed that p-CA also suppressed H2O2-induced phosphorylation of p-38, ERK, and JNK in HLE cells. These findings demonstrate that p-CA suppresses H2O2-induced HLE cell apoptosis through modulating MAPK signaling pathways and suggest that p-CA has a potential therapeutic role in the prevention of cataract.

Evaluation of the safe application of copper nonylphenolsulfonate and hexaconazole in wax gourd under field conditions.

Wax gourd is a popular vegetable and the new organic copper pesticide product of copper nonylphenolsulfonate and hexaconazole was firstly recommended to control the serious disease powdery mildew frequently occurred in wax gourd. However, it is still a concern for data deficiency of residue amounts of these two pesticides in edible portion of wax gourd and the persistence in environment. In this study, the dissipation and residue of copper nonylphenolsulfonate and hexaconazole in wax gourd and soil were investigated. The experiment results demonstrated that the dissipation half-lives of copper nonylphenolsulfonate and hexaconazole in wax gourd and soil were 4.6-5.8 days and 7.1-21.7 days, respectively. After 3 days from the last treatment, the residues of copper nonylphenolsulfonate were below 0.38 mg kg-1 in wax gourd and were below 0.21 mg kg-1 in soil, and the residues of hexaconazole ranged from < 0.01 to 0.19 mg kg-1 in wax gourd and from 0.01 to 0.63 mg kg-1 in soil. The long-term dietary risk assessment was done based on the supervised trial median residue and Chinese dietary pattern combining corresponding standards, by comparing with national estimated daily intake, the results showed that it was safe to use copper nonylphenolsulfonate·hexaconazole 20% microemulsion (ME) at the dosage of 420 g a.i. ha-1 with the pre-harvest interval of 3 days in China. And it also supplied authorities with important data for establishing MRL standards of copper nonylphenolsulfonate and hexaconazole in wax gourd in China.

Respective roles of the mitogen-activated protein kinase (MAPK) family members in pancreatic stellate cell activation induced by transforming growth factor-ß1 (TGF-ß1).

Activated pancreatic stellate cells (PSCs) play a crucial role in the progression of pancreatic fibrosis. Transforming growth factor-ß (TGF-ß) is one of the strongest stimulator inducing fibrosis. The mitogen-activated protein kinase (MAPK) proteins (including ERK, JNK and p38 MAPK) are known to contribute to PSC activation and pancreatic fibrosis. Previous studies have identified PSC activation induced by TGF-ß1 is related to MAPK pathway, but the respective role of MAPK family members in PSC activation still unclear, and which family member may be the key mediator in mice PSC activation still controversial. In this study, we investigated the influence of different MAPK family member (JNK, ERK, and p38 MAPK) on mice PSC activation using an in vivo and in vitro model. The results showed p-JNK, p-ERK and p-p38 MAPK were all over-expressed in CP group, and p-JNK, p-ERK, and p-p38 MAPK were co-expressed with activated PSC. In vitro, TGF-ß1 induced JNK and ERK over-expression in PSCs. In contrast, p38 MAPK expression in PSC showed only a very weak increase. JNK- and ERK-specific inhibitors inhibited FN and α-SMA mRNA expression in PSCs, and a p38 MAPK inhibitor had no effect on PSC activation. These findings indicate that JNK and ERK were directly involved in the PSCs activation induced by TGF-ß1 and the development of pancreatic fibrosis. p38 MAPK participate in the progression of CP, but it does not respond to TGF-ß1 directly and may not be regarded as the target of TGF-ß1 induced PSC activation.

Dachaihu decoction ameliorates pancreatic fibrosis by inhibiting macrophage infiltration in chronic pancreatitis.

AIM: To explore the role of macrophages in chronic pancreatitis (CP) and the effect of Dachaihu decoction (DCHD) on pancreatic fibrosis in mice. METHODS: KunMing mice were randomly divided into a control group, CP group, and DCHD group. In the CP and DCHD groups, mice were intraperitoneally injected with 20% L-arginine (3 g/kg twice 1 d/wk for 6 wk). Mice in the DCHD group were administered DCHD intragastrically at a dose of 14 g/kg/d 1 wk after CP induction. At 2 wk, 4 wk and 6 wk post-modeling, the morphology of the pancreas was observed using hematoxylin and eosin, and Masson staining. Interleukin-6 (IL-6) serum levels were assayed using an enzyme-linked immunosorbent assay. Double immunofluorescence staining was performed to observe the co-expression of F4/80 and IL-6 in the pancreas. Inflammatory factors including monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-1α (MIP-1α) and IL-6 were determined using real time-polymerase chain reaction. Western blot analysis was used to detect fibronectin levels in the pancreas. RESULTS: Compared with the control group, mice with 20% L-arginine-induced CP had obvious macrophage infiltration and a higher level of fibrosis. IL-6 serum concentrations were significantly increased. Double immunofluorescence staining showed that IL-6 and F4/80 were co-expressed in the pancreas. With the administration of DCHD, the infiltration of macrophages and degree of fibrosis in the pancreas were significantly attenuated; IL-6, MCP-1 and MIP-1α mRNA, and fibronectin levels were reduced. CONCLUSION: The dominant role of macrophages in the development of CP was mainly related to IL-6 production. DCHD was effective in ameliorating pancreatic fibrosis by inhibiting macrophage infiltration and inflammatory factor secretion in the pancreas.

Residue behavior and dietary intake risk assessment of three fungicides in tomatoes (Lycopersicon esculentum Mill.) under greenhouse conditions.

The residue behavior and dietary intake risk of three fungicides (pyrimethanil, iprodione, kresoxim-methyl) in tomatoes (Lycopersicon esculentum Mill.) grown in greenhouse were investigated. A simple, rapid analytical method for the quantification of fungicide residues in tomatoes was developed using gas chromatography coupled with mass spectrum detection (GC-MSD). The fortified recoveries were ranged from 87% to 103% with relative standard deviations (RSDs) varied from 4.7% to 12.1%. The results indicated that the dissipation rate of the studied fungicides in tomatoes followed first order kinetics with half lives in the range of 8.6-11.5 days. The final residues of all the fungicides in tomatoes were varied from 0.241 to 0.944 mg/kg. The results of dietary intake assessment indicated that the dietary intake of the three fungicides from tomatoes consumption for Chinese consumers were acceptable. This study would provide more understanding of residue behavior and dietary intake risk by these fungicides used under greenhouse conditions.

Distribution behaviour of acaricide cyflumetofen in tomato during home canning.

The distribution behaviour of cyflumetofen in tomatoes during home canning was studied. The targeted compound cyflumetofen was determined by ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) after each process step, which included washing, peeling, homogenisation, simmering and sterilisation. Results indicated that more cyflumetofen was removed by washing with detergent solution compared with tap water, 2% NaCl solution and 2% CH3COOH solution. Peeling resulted in 90.2% loss of cyflumetofen and was the most effective step at removing pesticide residues from tomatoes. The processing factors (PFs) of tomato samples after each step were generally less than 1; in particular, the PF of the peeling process for cyflumetofen was 0.28.

Simultaneous determination of spirotetramat and its four metabolites in fruits and vegetables using a modified quick, easy, cheap, effective, rugged, and safe method and liquid chromatography/tandem mass spectrometry.

A modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method for the simultaneous determination of spirotetramat and its four metabolites in fruits (apple, peach) and vegetables (cabbage, tomato, potato, cucumber), based on the use of liquid extraction/partition and dispersive solid phase extraction (dispersive-SPE) followed by ultrahigh-performance chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS), was established. Acidified acetonitrile (containing 1% (v/v) acetic acid) as the extraction solvent and simultaneous liquid-liquid partitioning formed by adding anhydrous magnesium sulfate (MgSO4) and anhydrous sodium acetate (NaOAc). The extract was then cleaned up by dispersive-SPE using graphitized carbon black (GCB) as selective sorbent. Further optimization of sample preparation and determination achieved recoveries of between 82 and 110% for all analytes with RSD values lower than 14% in apple, peach, cabbage, tomato, potato and cucumber at three levels (10, 100 and 1000µg/kg). The method showed excellent linearity (R(2)≥0.9895) for all studied analytes. The determination of the target compounds was achieved in less than 6.0min using an electrospray ionization source in positive mode (ESI+). The method is demonstrated to be convenient and reliable for the routine monitoring of spirotetramat and its metabolites in fruits and vegetables.

[Determination of meptyldinocap residues in vegetable and fruit by liquid chromatography-tandem mass spectrometry].

A method was developed for the determination of the residues of meptyldinocap (2,4-dinitro-6-(1-methylheptyl) phenyl crotonate, 2,4-DNOPC) as 2, 4-dinitrooctylphenol (2,4-dinitro-6-(1-methylheptyl) phenol, 2,4-DNOP), which is a hydrolysate of 2,4-DNOPC, in six vegetable and fruit by using liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The residues of 2,4-DNOPC in vegetable and fruit samples were extracted by the mixture of acetone, methanol and hydrochloric acid, then extracted by liquid-liquid partitioning, hydrolyzed under alkaline condition with ultrasonication, and extracted again by liquid-liquid partitioning, then analyzed by using LC-MS/MS in multiple reaction monitoring (MRM) mode via negative electrospray ionization with an Agilent ZORBAX SB-C, column. The method was validated at four fortification levels in vegetable and fruit. The validation results were as follows: the recoveries of 2,4-DNOPC in cabbages were from 89.7% to 93.3% (the relative standard deviations (RSD) of 6. 3% - 8.5%), in cucumbers from 87.7% to 95.1% (RSD of 5.8% -10.4%), in tomatoes from 89.3% to 96.0% (RSD of 6.8% -9.2%), in apples from 92.0% to 98.3% (RSD of 5.1% - 10.3%), in pears from 89.0% to 95.0% (RSD of 5.3% -10.2%), in grapes from 81.2% to 95.8% (RSD of 5.8% - 10.4%). The limits of quantification of 2,4-DNOPC in all the test samples were 0. 01 mg/kg. The results showed that the method is simple, rapid, and is characterized with acceptable sensitivity and accuracy to meet the requirements of the pesticide residue analysis. This method is applicable to confirm the residues of meptyldinocap in vegetable and fruit samples.