4.Determination of glyphosate in air of workplaces by ion chromatography.
Ren-nan ZHANG ; Hua-liang LIU ; Zong-li HUO ; Feng ZHANG ; Yong-jian MA ; Bao-li ZHU ; Jian-rui DOU ; Yi-yang MAO
Chinese Journal of Industrial Hygiene and Occupational Diseases 2013;31(10):779-782
OBJECTIVETo establish a method for determining glyphosate in the air of workplaces by ion chromatography.
METHODSUltra-fine glass fiber filter paper was used to collect glyphosate from the workplace air. After being ultrasonically eluted with deionized water, samples were determined by ion chromatography using a conductivity detector.
RESULTSWithin the range of 0.05-1.00 mg/L, a linear relationship was found with a limit of detection of 0.003 mg/m(3). The minimum detectable concentration was 0.000 41 mg/m(3) (calculated by sampling 75 L of air). For three different concentrations of glyphosate, the intra-batch relative standard deviations (RSDs) were 1.8%, 1.6%, and 0.8%, respectively, and the inter-batch RSDs were 1.9%, 2.1%, and 2.2%, respectively. The recovery rate ranged from 94.8% to 97.4%. The elution efficiency ranged from 94.5% to 96.7%. The sampling efficiency was 100%. Samples could be stored at room temperature for at least 7 days.
CONCLUSIONThis presented method meets the requirements of Guide for establishing occupational health standards-Part 4: Determination methods of air chemicals in workplace and is feasible for determination of glyphosate in the air of workplaces.
Air Pollutants, Occupational ; analysis ; Chromatography, Gas ; Glycine ; analogs & derivatives ; analysis ; Workplace
5.Discussion of the application of three-point interaction principle to the phenylglycine racemic compound in IR spectrometry and its enantiomers separation in HPLC.
Yi SHEN ; Da-nian YI ; Ji-ning LIU
Acta Pharmaceutica Sinica 2002;37(8):636-638
AIMTo discuss the relationship between the three-point interaction principle in the stereoselective separation of chromatography and applying this principle to survey the infrared spectrometry of racemate.
METHODSIn proving the applicability of the three-point interaction principal in IR spectrometry, a special case was found that phenylglycine did not obtain enantioselective separation on the chiral column but its IR spectrometry still obey this principle and explained such special case by experiment.
RESULTSAfter an equal quantity of solid crystal of d-phenylglycine and l-phenylglycine were mixed and ground for several minutes, they transformed to racemic compound. X-powder diffraction also confirmed this fact.
CONCLUSIONThe three-point principle was relatively reliable when it was used in the enantioselective chromatography separation and the IR spectrometric analysis. The reason of the fact that phenylglycine was not separated by chiral column can be explained by the fact that the acting force between the three polarity groups in the enantiomers is so strong that they can not form the instantaneous diastereoisomer with the chiral column, it was agreeable with the phenomenon that racemic mixture easily became racemic compound only by simply grinding the mixture in IR spectrometric experiment.
Chromatography, High Pressure Liquid ; Glycine ; analogs & derivatives ; analysis ; chemistry ; Orosomucoid ; chemistry ; Spectrophotometry, Infrared ; Stereoisomerism
6.Synthesis of (S)-4-fluorophenylglycine by using immobilized amidase based on metal-organic framework.
Chaoping LIN ; Jiangtao TANG ; Renchao ZHENG ; Yuguo ZHENG
Chinese Journal of Biotechnology 2021;37(8):2936-2946
A stable Zr-based metal-organic framework (MOF, UiO-66-NH2) synthesized via micro-water solvothermal method was used to immobilize amidase by using the glutaraldehyde crosslinking method. The effect of immoblization conditions on enzyme immoblization efficiency was studied. An activity recovery rate of 86.4% and an enzyme loading of 115.3 mg/g were achieved under the optimal conditions: glutaraldehyde concentration of 1.0%, cross-linking time of 180 min, and the weight ratio of MOF to enzyme of 8:1. The optimal temperature and optimal pH of the immobilized amidase were determined to be 40 °C and 9.0, respectively, and the Km, Vmax and kcat of the immoblized amidase were 58.32 mmol/L, 16.23 μmol/(min·mg), and 1 670 s⁻¹, respectively. The immobilized enzyme was used for (S)-4-fluorophenylglycine synthesis and the optimal reaction conditions were 300 mmol/L of N-phenylacetyl-4-fluorophenylglycine, 10 g/L of immobilized enzyme loading, and reacting for 180 min at pH 9.0 and 40 °C. A conversion rate of 49.9% was achieved under the optimal conditions, and the conversion rate can be increased to 99.9% under the conditions of enantiomeric excess. The immobilized enzyme can be repeatedly used, 95.8% of its original activity can be retained after 20 cycles.
Amidohydrolases
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Enzyme Stability
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Enzymes, Immobilized/metabolism*
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Glycine/analogs & derivatives*
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Hydrogen-Ion Concentration
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Metal-Organic Frameworks
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Temperature
7.Cellular delivery of modified peptide nucleic acids: a review.
Chundong LIU ; Jianhua WANG ; Fang ZENG
Chinese Journal of Biotechnology 2016;32(3):292-305
Peptide nucleic acid (PNA) is a DNA surrogate in which the phosphate deoxyribose backbone of DNA is replaced by repeating N-(2-aminoethyl)glycine units. PNA can hybridize to the complementary DNA and RNA with higher affinity than their oligonucleotide counterparts. This character of PNA not only makes it a new tool for the studies of molecular biology but also the potential candidate for gene-targeting drugs. The non-ionic backbone of PNA leads to stable hybrids with the nucleic acids, but at the same time, the neutral backbone results in poor cellular uptake. To address this problem, studies on modified PNA progress rapidly in recent years. We reviewed literature reports combined with our study about the delivery methods, including backbone modified PNA and PNA-ligand conjugates, and the cellular uptake of modified PNA. In addition, we summarized the problems and future prospect of the cellular delivery of modified PNA.
DNA, Complementary
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Drug Delivery Systems
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Glycine
;
analogs & derivatives
;
Humans
;
Nucleic Acid Hybridization
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Oligonucleotides
;
Peptide Nucleic Acids
;
chemistry
;
RNA
8.In Vitro Cytotoxic Effect of Glyphosate Mixture Containing Surfactants.
Ho Yeon SONG ; Young Hee KIM ; Su Jin SEOK ; Hyo Wook GIL ; Sae Yong HONG
Journal of Korean Medical Science 2012;27(7):711-715
We investigated whether glyphosate influences the cellular toxicity of the surfactants TN-20 and LN-10 on the mouse fibroblast-like cells, alveolar epithelial cells, and a heart cell line. The cytotoxicity of TN-20 and LN-10 (0.4-100 microM), in the presence or absence of glyphosate was determined by assessing membrane integrity. TN-20 toxicity was significantly lower in the presence of 50 microM glyphosate for the fibroblast-like cell (6.25 microM; 3.9% +/- 3.4% vs -4.8% +/- 0.7%), for the alveolar cells (0.78 microM; 5.7% +/- 0.9% vs 0.1% +/- 0.6%), and for the heart cell line (25.0 microM; 7.9% +/- 3.0% vs 19.4% +/- 0.7%) compared to that of TN-20 alone. The cellular toxicity of LN-10 towards the fibroblast-like cells was found to be increased in the presence of 50 microM glyphosate when LN-10 concentrations of 50 microM (31.3% +/- 3.9% vs 19.2% +/- 0.9%) and 100 microM (62.1% +/- 3.4% vs 39.0% +/- 0.7%) were compared to that of LN-10 alone. These results suggest that the mixture toxicity may be a factor in glyphosate-surfactant toxicity in patients with acute glyphosate herbicide intoxication.
Animals
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Cell Line
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Cell Survival/drug effects
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Glycine/*analogs & derivatives/chemistry/toxicity
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Herbicides/chemistry/*toxicity
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Mice
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Polyethylene Glycols/*chemistry
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Surface-Active Agents/*chemistry
9.Lipase-catalyzed enantioselective ammonolysis of racemic phenylglycine methyl ester in organic solvent.
Wei DU ; Min-Hua ZONG ; Yong GUO ; Jun HE ; Yuan-Yuan ZHANG ; Zhao-Lin XIE ; Wen-Yong LOU
Chinese Journal of Biotechnology 2002;18(2):242-245
A novel reaction-enzymatic ammonolysis discovered in the mid of 1990s has been demonstrated to be a very promising alternative in the preparation of optically pure compounds. The effects of organic solvent, initial water activity, temperature and additives on lipase Novozym435-catalyzed enantioselective ammonolysis of racemic phenylglycine methyl ester were investigated systematically in this paper. Enzymatic reaction of ammonolysis showed higher activity and enantioselectivity than the corresponding reaction of hydrolysis and alcoholysis.
Alcohols
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Ammonia
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Catalysis
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Dimethylformamide
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pharmacology
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Esters
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Glycine
;
analogs & derivatives
;
metabolism
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Hexoses
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pharmacology
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Hydrolysis
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Lipase
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drug effects
;
metabolism
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Organic Chemicals
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Solvents
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Surface-Active Agents
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pharmacology
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Temperature
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Water
10.Metabotropic glutamate receptor 8 activation promotes the apoptosis of lung carcinoma A549 cells in vitro.
Tian-Jiao LI ; Yan-Hong HUANG ; Xi CHEN ; Zhou ZHOU ; Si-Wei LUO ; Dan-Dan FENG ; Jian-Zhong HAN ; Zi-Qiang LUO
Acta Physiologica Sinica 2015;67(5):513-520
This study aims to detect the expression of metabotropic glutamate receptors (mGluRs) in lung carcinoma A549 cells, and to investigate the effects of mGluR8 and mGluR4 activation on the growth of A549 cells in vitro. The mRNA expression levels of the 8 subtypes of mGluRs in A549 cells were determined by real-time PCR. Immunohistochemistry was used to analyze the protein expression of mGluR4 and mGluR8 in A549 cells and lung tissue sections obtained from lung adenocarcinoma patients. To observe the effects of mGluR8 and mGluR4 activation on the growth of A549 cells, the cultured cells were treated with (S)-3,4-DCPG (an agonist of mGluR8) and VU0155041 (an agonist of mGluR4), respectively, and then the cell viability was analyzed by CCK-8 kit, the percentage of DNA synthesis was detected by EdU incorporation, and the apoptosis of the cells was measured by hoechst 33258 staining and flow cytometry. The results showed that there were low expressions of mGluR1, mGluR5, mGluR6, mGluR7 mRNA, no expression of mGluR2 and mGluR3 mRNA, and high expressions of mGluR8 and mGluR4 mRNA in A549 cells. Accordingly, there were also mGluR4 and mGluR8 protein expressions in the A549 cells and the lung adenocarcinoma tissue sections. VU0155041 had no effect on the growth of A549 cells, but (S)-3,4-DCPG significantly decreased the cells' growth in a dose-dependent manner and increased the apoptosis of the cells. The results revealed a role of mGluR8 in the growth and apoptosis of A549 cells and suggested a potential target for clinical treatment of lung cancer.
Anilides
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pharmacology
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Apoptosis
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Benzoates
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pharmacology
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Cell Cycle
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Cell Line, Tumor
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Cell Proliferation
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Cyclohexanecarboxylic Acids
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pharmacology
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Glycine
;
analogs & derivatives
;
pharmacology
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Humans
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Lung Neoplasms
;
pathology
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Receptors, Metabotropic Glutamate
;
physiology