Glycine ; analogs & derivatives ; toxicity ; Herbicides ; toxicity

Glycine/analogs & derivatives* ; Humans ; Vasculitis, Leukocytoclastic, Cutaneous

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

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

Air Pollution, Indoor ; analysis ; Chromatography, High Pressure Liquid ; Glycine ; analogs & derivatives ; analysis ; Humans ; Workplace

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

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

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 ; Cell Line ; Cell Survival/drug effects ; Glycine/*analogs & derivatives/chemistry/toxicity ; Herbicides/chemistry/*toxicity ; Mice ; Polyethylene Glycols/*chemistry ; Surface-Active Agents/*chemistry

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

BACKGROUNDIn vivo proton magnetic resonance spectroscopy (MRS) provides a noninvasive method of examining a wide variety of cerebral metabolites in both healthy subjects and patients with various brain diseases. Absolute metabolite concentrations have been determined using external and internal standards with known concentrations. When an external standard is placed beside the head, variations in signal amplitudes due to B1 field inhomogeneity and static field inhomogeneity may occur. Hence an internal standard is preferable. The purpose of this study was to quantitatively analyze the metabolite concentrations in normal adult brains and gliomas by in vivo proton MRS using the fully relaxed water signal as an internal standard.

METHODSBetween January 1998 and October 2001, 28 healthy volunteers and 16 patients with gliomas were examined by in vivo proton MRS. Single-voxel spectra were acquired using the point-resolved spectroscopic pulse sequence with a 1.5 T scanner (TR/TE/Ave = 3000 ms/30 ms/64).

RESULTSThe calculated concentrations of N-acetyl-asparatate (NAA), creatine (Cre), choline (Cho), and water (H2O) in the normal hemispheric white matter were (23.59 +/- 2.62) mmol/L, (13.06 +/- 1.8) mmol/L, (4.28 +/- 0.8) mmol/L, and (47,280.96 +/- 5414.85) mmol/L, respectively. The metabolite concentrations were not necessarily uniform in different parts of the brain. The concentrations of NAA and Cre decreased in all gliomas (P < 0.001). The ratios of NAA/Cho and NAA/H2O showed a significant difference between the normal brain and gliomas, and also between the high and low grades (P < 0.001).

CONCLUSIONSQuantitative analysis of in vivo proton MR spectra using the fully relaxed water signal as an internal standard is useful. The concentrations of NAA and the ratios of NAA/H2O and NAA/Cho conduce to discriminating between the glioma and normal brain, and also between the low-grade glioma and high-grade glioma.

Adult ; Aspartic Acid ; analogs & derivatives ; metabolism ; Brain ; metabolism ; Choline ; metabolism ; Creatine ; metabolism ; Female ; Glioma ; metabolism ; Glycine ; metabolism ; Humans ; Inositol ; metabolism ; Magnetic Resonance Spectroscopy ; Male