Co-reporter:He Zhang, Liyang Zhang, Xue Diao, Na Li, Chenglan Liu
Toxicon 2017 Volume 129(Volume 129) pp:
Publication Date(Web):1 April 2017
DOI:10.1016/j.toxicon.2017.01.018
•For the first time, this study examines the toxicity of fumonisin B1 (FB1) and its mechanism of action in the Spodoptera frugiperda Sf9 cell line.•Our studies try to provide a possible for FB1 as a precursor compounds of biological insecticide.•Our test could provide a reference for other kinds of insect cells studies on FB1 stress.Fumonisins are a type of mycotoxin produced by Fusarium spp., mainly F. proliferatum and F. vertieilliodes, and represent a potential hazard to the health of animals and human beings. The toxicity and mechanism of action of fumonisins is ambiguous, and it is unclear whether fumonisins are toxic to insect cells. This study examines the toxicity of fumonisin B1 (FB1) and its mechanism of action in the Spodoptera frugiperda Sf9 cell line. We found that FB1 inhibited Sf9 cellular proliferation and arrested cell growth at the G2/M phase. Morphological observation showed that FB1 induced swelling, vacuole formation, and loss of adhesion in Sf9 cells. Flow cytometry analysis showed that FB1 caused depolarization of the cell membrane potential and hyperpolarization of the mitochondrial membrane potential. To uncover potential genes associated with the molecular mechanisms of FB1, 41 differentially expressed genes were identified by transcriptome analyses after FB1 treatment. These genes are putatively involved in detoxification metabolism, insect hormone regulation, cell apoptosis, and other related processes. Finally, six differentially expressed genes were chosen and validated by quantitative real-time PCR (QRT-PCR). Our test could provide a reference for other kinds of insect cells studies on FB1 stress. At the same time, our studies try to provide a possible for FB1 as a precursor compounds of biological insecticide.Download high-res image (171KB)Download full-size image
Co-reporter:Chunqiang Ruan, Xue Diao, Na Li, He Zhang, Yan Pang and Chenglan Liu
Analytical Methods 2016 vol. 8(Issue 7) pp:1586-1594
Publication Date(Web):22 Jan 2016
DOI:10.1039/C5AY03219A
A novel analytical method was developed for simultaneous determination of ochratoxin A and citrinin in fruit samples using ultrasound-assisted extraction (USAE) combined with dispersive liquid–liquid microextraction (DLLME), followed by high-performance liquid chromatography with fluorescence detection (FLD). Fruit samples were first extracted with 1% acetic acid in acetonitrile by USAE, and after centrifugation, the upper phase (acetonitrile) was used as the dispersant solvent in the subsequent DLLME step. CHCl3 was used as the extraction solvent in the DLLME procedure. The experimental parameters controlling the performance of DLLME (sodium chloride percentage, sample pH, and volume of extraction and disperser solvents) were optimized by means of an experimental design. To determine the presence of a matrix effect, calibration curves of standards and fortified fruit extracts (matrix matched calibration) were studied. Under optimum conditions, the mean recovery values of ochratoxin A and citrinin from three fruit samples were in the range of 75.0–103.0% (except for citrinin in apples), with relative standard deviations lower than 5.3%. Limits of detections (LODs) were in the range 0.06–0.16 μg kg−1. The proposed method was also applied for the analysis of ochratoxin A and citrinin in fifteen fruit samples purchased from markets in Guangzhou, China and no samples were contaminated with the two mycotoxins. The results show that UASE-DLLME combined with HPLC-FLD is a fast and simple method for determining ochratoxin A and citrinin in fruit samples.
Co-reporter:Chunqiang Ruan;Xiang Zhao
Journal of Separation Science 2015 Volume 38( Issue 17) pp:2931-2937
Publication Date(Web):
DOI:10.1002/jssc.201401162
In this study, a simple and low-organic-solvent-consuming method combining an acetonitrile-partitioning extraction procedure followed by “quick, easy, cheap, effective, rugged and safe” cleanup with ionic-liquid-based dispersive liquid–liquid microextraction and high-performance liquid chromatography with diode array detection was developed for the determination of diflubenzuron and chlorbenzuron in grapes and pears. Ionic-liquid-based dispersive liquid–liquid microextraction was performed using the ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate as the extractive solvent and acetonitrile extract as the dispersive solvent. The main factors influencing the efficiency of the dispersive liquid–liquid microextraction were evaluated, including the extractive solvent type and volume and the dispersive solvent volume. The validation parameters indicated the suitability of the method for routine analyses of benzoylurea insecticides in a large number of samples. The relative recoveries at three spiked levels ranged between 98.6 and 109.3% with relative standard deviations of less than 5.2%. The limit of detection was 0.005 mg/kg for the two insecticides. The proposed method was successfully used for the rapid determination of diflubenzuron and chlorbenzuron residues in real fruit samples.
Co-reporter:Xianwen Lai, Chunqiang Ruan, Ruicen Liu, Chenglan Liu
Food Chemistry 2014 Volume 161() pp:317-322
Publication Date(Web):15 October 2014
DOI:10.1016/j.foodchem.2014.04.033
•We establish IL-DLLME method for the detection of OTA in rice wine.•Ionic liquid based DLLME is used as rapid green sample treatment.•Several IL-DLLME parameters were optimized to select optimum conditions.•Various rice wine samples were analysed by IL-DLLME coupled with HPLC-FLD.A novel and rapid ionic liquid-based dispersive liquid–liquid microextraction (IL-DLLME) method combined with liquid chromatography and a fluorescence detector for the analysis of ochratoxin A in rice wines is presented. The following parameters were systematically investigated: type and volume of ionic liquid, volume of dispersive solvent, salt addition, sample pH, and vortex time. Rice wine samples were first diluted to 18% alcohol with deionized water, and the pH was adjusted to 3.0. A DLLME procedure was followed that included IL ([HMIM][PF6]) and ethanol as the extraction and dispersive solvents, respectively. Under the optimized experimental conditions, good linearity was obtained with a correlation coefficient (r) of 0.9998 and a limit of detection (LOD) of 0.04 μg L−1. The recoveries ranged from 75.9% to 82.1% with an RSD below 10.4%. The proposed method was successfully applied to analyse OTA samples from several rice wine brands collected in Guangdong province, China.
Co-reporter:Xian-Wen Lai;Dai-Li Sun;Chun-Qiang Ruan;He Zhang;Cheng-Lan Liu
Journal of Separation Science 2014 Volume 37( Issue 1-2) pp:92-98
Publication Date(Web):
DOI:10.1002/jssc.201300970
A novel, simple, and rapid method is presented for the analysis of aflatoxin B1, aflatoxin B2, and ochratoxin A in rice samples by dispersive liquid–liquid microextraction combined with LC and fluorescence detection. After extraction of the rice samples with a mixture of acetonitrile/water/acetic acid, mycotoxins were rapidly partitioned into a small volume of organic solvent (chloroform) by dispersive liquid–liquid microextraction. The three mycotoxins were simultaneously determined by LC with fluorescence detection after precolumn derivatization for aflatoxin B1 and B2. Parameters affecting both extraction and dispersive liquid–liquid microextraction procedures, including the extraction solvent, the type and volume of extractant, the volume of dispersive solvent, the addition of salt, the pH and the extraction time, were optimized. The optimized protocol provided an enrichment factor of approximately 1.25 and with detection of limits (0.06–0.5 μg/kg) below the maximum levels imposed by current regulations for aflatoxins and ochratoxin A. The mean recovery of three mycotoxins ranged from 82.9–112%, with a RSD less than 7.9% in all cases. The method was successfully applied to measure mycotoxins in commercial rice samples collected from local supermarkets in China.
Co-reporter:Dali Sun, Junxiao Pang, Jing Qiu, Li Li, Chenglan Liu, and Bining Jiao
Journal of Agricultural and Food Chemistry 2013 Volume 61(Issue 47) pp:11273-11277
Publication Date(Web):October 25, 2013
DOI:10.1021/jf4045952
In this study, the enantioselective degradation and enantiomerizaton of indoxacarb were investigated in two soils under nonsterilized and sterilized conditions using a chiral OD-RH column on a reversed-phase HPLC. Under nonsterilized conditions, the degradation of indoxacarb in two soils was enantioselective. In acidic soil, the half-lives of R-(−)- and S-(+)-indoxacarb were 10.43 and 14.00 days, respectively. Acidic soil was preferential to the degradation of R-(−)-indoxacarb. In alkaline soil, the half-lives of R-(−)- and S-(+)-indoxacarb were 12.14 and 4.88 days, respectively. S-(+)-Indoxacarb was preferentially degraded. Under sterilized conditions, approximately 5–10% of the initial concentration degraded after 75 days of incubation in acidic soil, whereas in alkaline soil, approximately half of the initial concentration degraded due to chemical hydrolysis under alkaline conditions. Enantiomerization was also discovered in acidic and alkaline soils. The results showed that mutual transformation existed between two enantiomers and that S-(+)-indoxacarb had a significantly higher inversion rate to R-(−)-indoxacarb than its antipode.
Co-reporter:Dali Sun;Li Li;Ran Ji;Wei Li;Huochun Ye
Bulletin of Environmental Contamination and Toxicology 2011 Volume 87( Issue 6) pp:653-656
Publication Date(Web):2011 December
DOI:10.1007/s00128-011-0421-x
A sensitive and effective analytical method for the determination of hymexazol in cucumber and soil samples by gas chromatography with a flame photometric detector was developed. This method was validated with fortified at three different levels of 0.2, 1.0 and 5.0 mg/kg. Average recoveries obtained from cucumber and soil samples at three fortified levels were 94.0%–107.8% with relative standard deviations (RSDs) of less than 11.4%. Limits of quantification (LOQ) in cucumber and soil were 0.2 mg/kg. The method was successfully applied to determine hymexazol in real samples of cucumber and soil under open fields.
Co-reporter:Xianwen Lai, He Zhang, Ruicen Liu, Chenglan Liu
Saudi Journal of Biological Sciences (March 2015) Volume 22(Issue 2) pp:176-180
Publication Date(Web):1 March 2015
DOI:10.1016/j.sjbs.2014.09.013
In this study, we investigated the potential for aflatoxin B1 (AFB1) and B2 (AFB2) production in rice grain by 127 strains of Aspergillus flavus isolated from rice grains collected from China. These strains were inoculated onto rice grains and incubated at 28 °C for 21 days. AFB1 and AFB2 were extracted and quantified by high-performance liquid chromatography coupled with fluorescence detection. Among the tested strains, 37% produced AFB1 and AFB2 with levels ranging from 175 to 124 101 μg kg−1 for AFB1 and from not detected to 10 329 μg kg−1 for AFB2. The mean yields of these isolates were 5884 μg kg−1 for AFB1 and 1968 μg kg−1 for AFB2. Overall, most of the aflatoxigenic strains produced higher levels of AFB1 than AFB2 in rice. The obtained information is useful for assessing the risk of aflatoxin contamination in rice samples.
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