3.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
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
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
;
Enzyme Stability
;
Enzymes, Immobilized/metabolism*
;
Glycine/analogs & derivatives*
;
Hydrogen-Ion Concentration
;
Metal-Organic Frameworks
;
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
;
Drug Delivery Systems
;
Glycine
;
analogs & derivatives
;
Humans
;
Nucleic Acid Hybridization
;
Oligonucleotides
;
Peptide Nucleic Acids
;
chemistry
;
RNA
8.Analysis of exogenous gene and protein digestion and absorption of SD rats (Rattus norvegicus) fed roundup ready soybean meal.
Jianqin YUAN ; Hong CHANG ; Jianghe ZHAO ; Zongyong SHI ; Jundong WANG
Chinese Journal of Biotechnology 2016;32(5):657-668
Metabolism and deposition of exogenous gene and protein from transgenic glyphosate herbicide-tolerant soybean meal in SD rats were studied in the experiment. The transgenic soybean GTS40-3-2 meal and its non-transgenic counterpart (parent A5403) were fed to the generation and the second generation Sprague-Dawley (SD) rats (Rattus norvegicus). The study added the genetically modified (GM) soybean meal and its non-transgenic control soybean meal (parent A5403) in a ratio of 20% respectively to the feeds. By using qualitative, quantitative PCR and ELISA methods to detect transgenic soybean residues of metabolism ingredients in rats, the safety and influence of GM soybean were evaluated. The results showed that the intestinal fecal and cecum contents of rats were detected with residues of GM ingredients, intestinal flora and organs were not found related genes and protein. These results indicated that transgenic glyphosate herbicide-tolerant soybean GTS40-3-2 meal was as safe as its non-GM soybean meal in long-term feeding study.
Animal Feed
;
Animal Nutritional Physiological Phenomena
;
Animals
;
Digestion
;
Glycine
;
analogs & derivatives
;
Herbicide Resistance
;
Herbicides
;
Plants, Genetically Modified
;
Proteolysis
;
Rats
;
Rats, Sprague-Dawley
;
Soybean Proteins
;
Soybeans
9.Molecular mechanisms of the protection of SNMC in HepG2 cell apoptosis.
Yan WANG ; Ying-Ji MA ; Bao-Shan YANG ; Man-Ru BI ; Li-Yan CHEN
Chinese Journal of Hepatology 2005;13(2):132-135
OBJECTIVEApoptosis of the cells of liver cancer cell line HepG2 could be induced by TNF alpha and actinomycin D (Act D). In the current study, the molecular mechanism of the apoptosis protection of stronger neo-minophagen C (SNMC) to HepG2 cells was investigated.
METHODSSNMC was added to the HepG2 cell culture medium when the cell concentration reached 0, 2, 20, 100, 200, 800 microg/ml 30 min before their apoptosis were inducted with TNF alpha and Act D. A flow cytometry assay was performed to detect the cell apoptosis rate; electromicroscopy was employed to visualize the subcellular structure after apoptosis. DNA ladder formation was checked with genomic DNA agarose electrophoresis. The expression pattern of apoptosis related protein Caspase-3, Bcl-2 and Bax was detected by Western blot.
RESULTSAfter pretreatment with various concentrations of SNMC and 12 hours after treatment with TNF alpha and Act D, the HepG2 cell apoptosis rate and DNA ladder formation decreased dramatically when the SNMC concentration was higher in the media; the intracellular inactive form of Caspase-3 increased while the 17*10(3) active Caspase-3 decreased gradually. In addition, the expression of Bcl-2 increased and the expression of Bax decreased. Under the electromicroscope, the typical nucleolus condensation of HepG2 induced by TNF alpha and Act D was not seen among the 100 microg/ml SNMC treated cells.
CONCLUSIONSNMC inhibits TNF alpha and Act D induced HepG2 cell apoptosis. This protective action may be regulated by intracellular apoptosis related factors.
Apoptosis ; drug effects ; Carcinoma, Hepatocellular ; pathology ; Cell Line, Tumor ; Cysteine ; pharmacology ; Drug Combinations ; Glycine ; pharmacology ; Glycyrrhiza ; Humans ; Liver Neoplasms ; pathology ; Oleanolic Acid ; analogs & derivatives ; pharmacology
10.Simultaneous determination of sivelestat and its metabolite XW-IMP-A in human plasma using HPLC-MS/MS.
Jing WANG ; Xiao-jian DAI ; Yi-fan ZHANG ; Da-fang ZHONG ; Yu-lin WU ; Xiao-yan CHEN
Acta Pharmaceutica Sinica 2015;50(10):1318-1323
A simple and rapid method was developed based on high performance liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) to determine sivelestat and its metabolite XW-IMP-A in human plasma. After a simple protein precipitation, the samples and internal standards were analyzed on a C18 column by a gradient elution program. The mobile phase consisted of 30% acetonitrile in methanol and 5 mmol · L(-1) ammonium acetate at a flow rate of 0.7 mL · min(-1). The mass spectrometric data was collected in multiple reaction monitoring mode (MRM) in the negative electrospray ionization. The standard curves were linear in the range of 10.0-15,000 ng · mL(-1) for sivelestat, and 2.50-1000 ng · mL(-1) for XW-IMP-A. The low limits of quantitation were identified at 10.0 and 2.50 ng · mL for sivelestat and XW-IMP-A, respectively. The intra- and inter-day precision were within 11.3% and 13.1% for sivelestat and XW-IMP-A, and accuracy was 0.3% and 0.6% for sivelestat and XW-IMP-A, within the acceptable limits across all concentrations. The method was successfully validated in the pharmacokinetic study of sivelestat in healthy Chinese volunteers.
Chromatography, High Pressure Liquid
;
Chromatography, Liquid
;
Glycine
;
analogs & derivatives
;
blood
;
Humans
;
Inosine Monophosphate
;
blood
;
Reproducibility of Results
;
Sulfonamides
;
blood
;
Tandem Mass Spectrometry