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Objective To investigate the characteristic volatile organic compounds(VOCs)in exhaled breath and their diagnostic value in mice with early stage radiation injury.Methods The thermal desorption gas chromatography-mass spectrometry(TD-GC/MS)technique was used to analyze VOCs in exhaled breath of irradiated mice by 60Coγ-ray with 800 cGy.The characteristic VOCs in the early stage of radiation injury were identified,and a diagnostic model was established.Results The 30-day survival rate of mice was 4.2%.There were significant differences in characteristic VOCs at 7 hours after radiation injury,and thirty characteristic VOCs related to early-stage radiation injury were identified.The diagnostic value of differential metabolites in mice after irradiation was evaluated via the ROC curve,and the area under the ROC curve(AUC)of a single compound exceeded 0.8.The diagnostic model was constructed by screening 9 potential biomarkers of exhalation through Fisher discriminant analysis,and its sensitivity and specificity were close to 100%.Conclusion Analysis of VOCs in exhaled breath is expected to provide a non-invasive diagnostic method for early screening and diagnosis of radiation injury.
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The content of endogenous anabolic steroids is extremely low in biological matrices.Its chemical structure contains polar functional groups such as hydroxyl and carbonyl, which limits their applicability in GC-MS.The lack of ionized groups in the chemical structure leads to poor sensitivity in LC-MS, which plays a significant role in various physiological activities analysis.It is an effective way to enhance the response of mass spectrometer by modifying the chemical structure of endogenous anabolic steroids through derivatization technology.This review summarizes various derivatization reagents and corresponding derivatization processes of endogenous anabolic steroids analysis in the methods based on different testing instruments and methodologies.The advantage and disadvantage of all kinds of derivatiaztion methods and the prospect of the endogenous anabolic steroids derivatiaztion techniques are also discussed.
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Objective To establish an high performance liquid chromatography method for determination of 2-indole ketone derivative and its related substances. Methods Agilent Eclipse XDB-C18(250 mm×4.6 mm,5 μm) column was adopted.The mobile phase was acetonitrile-water with gradient elution mode at a flow rate of 1. 0 mL?min-1; the column temperature was 35 ℃;the injection volume was 20 μL and the detection wavelength was set at 257 nm. Results 2-indole ketone derivative ID and related substances could be well separated. The 2-indole ketone derivative had good linear correlation ( r=0.999 4) within the range of 40-300 μg?mL-1 . It had a good precision ( RSD<1%) . The limit of detection was 8 ng. Conclusion The method is accurate,simple,sensitive and selective,which can be used for the quality control of 2-indole ketone derivative and related substances.
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Objective To establish a headspace gas chromatography method for determination of nine residual solvents in grape seed extract. Methods The residual solvents in grape seed extract were separated on DB-WAX column (30 m× 0.45 mm, 0.85 μm) with an FID detector; the injector temperature and the detector temperature was set at 220 ℃ and 250 ℃ , respectively; the chapiter pressure was 27.58 kPa; the containers of headspace injector were in equilibrium for 30 min at 80 ℃ ;the N, N-dimethylformamide was used as the solvent. Results The detected solvents were well separated. Good linear relationship of the benzene and ethanol was obtained within the range of 0.04-0.3,100-750 μg?mL-1 , respectively. Good linear relationships of the hexane, o-xylene, m-xylene, p-xylene, styrene, toluene and 1,2-diethyl benzene solvents were obtained within the range of 0.4-3.0 μg?mL-1 (r≥0.995 8), respectively. The average recoveries (n = 3) of the nine solvents were 96.35%,97.08%,97.31%,89.93%,92.35%,90.65%,88.56%,93.84%,86.51% and the RSDs were 4.38%,2.16%,3.49%, 4.19%,4.80%,4. 83%,4. 70%,5. 00%,4. 39%, respectively. Conclusion The established method is simple, rapid and accurate, which can be used for the determination of residual solvents in grape seed extract and can simultaneously provide scientific basic for quality control.
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Objective To further understand the natural metabolic characteristics of menopausal syndrome,and explore the role of biological pathways. Methods Our experiment adopted the HPLC-MS/MS technology of metabolomics researching methods, aiming at the comprehensive change characteristics in metabolism group level of menopausal rat and searching for age-related biomark?ers. The urine of 6 and 18 months rat was taken for HPLC-MS/MS metabolomics analysis. Besides,XCMS online analysis was used for positive and negative ion detection spectrum and the principal component analysis was used to identify biomarkers. Finally ,MetPA was used to implement a Google-map style interactive visualization system,which has analyzed the metabolic pathway. Pathway views were generated dynamically based on interactions with the visualized system. Results The TCA cycle,arginine and proline metabo?lism and aldehyde acid metabolism are related to aging rat metabolite pathways. Conclusion Age-related metabolic pathways are mainly related to the respiratory chain reaction and the urea cycle,which are influenced by liver mitochondrial function.
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Objective To establish an HPLC method for determination of the content of radiosensitizer YABQ and its related substances.Methods Diamonsil C18 column (250 mm ×4.6 mm,5 μm) was used.The mobile phase consisted of methanol-0.1%formic acid (22∶78) and isocratic elution at a flow rate of 1.0 ml/min.The detection wavelength was 266 nm,the temperature of the column was 30℃, and the injection volume was 10 μl.Results The linear range of YABQ was 7-84 μg/ml, r=0.9992.The detection limit was 8 ng (S/N≥3), and the quantitation limit was 24 ng (S/N≥10). According to destructive sample processing, the separation coefficient between the peaks was above 1.5, indicating that this chromatographic method could meet the YABQ monitoring requirements.Conclusion Method validation and destructive testing show that both the precision and specificity are fine with this method, which could be used for quality control of YABQ and its related substances.
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Objective To establish a RP-HPLC method for the determination of 3-amide-indole derivative and its related substances. Methods Diamonsil C18(250 mmí4. 6 mm,5 μm) column was adopted. The mobile phase consisted of a mixture of methanol-acetonitrile-water(431245) at the flow rate of 1. 0 mL·min-1 . The wavelength for ultraviolet detection was 224 nm. The injection volume was 20 μL and the column temperature was room temperature. Results 3-amide-indole derivative and related substances could be well separated. The linearity of the 3-amide-indole derivative curve was well correlated (r=0. 999 7) within the range of 0. 04-0. 16 mg·mL-1. The RSD was 0. 52%with good repeatability. The detection limit was 2. 65 ng. Conclusion The method is accurate,reliable,sensitive and specific,which could be used for the determination of 3-amide-indolederivative and related substances.
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Objective 1H NMR spectroscopy and principal component analysis(PCA) were used to investigate the mouse serum metabonomics and toxic mechanism after oral administration of Fructus Toosendan. Methods In this study, mice were orally administered with the ethyl acetate extract of Fructus Toosendan before collecting serum samples. Then 1H NMR was utilized to identify the metabolites with the PCA. After the experimental model of toxicity was established and the data were collected, NMR spectral regions and the metabolites were identified and ranked according to their weight aline with the loading plot. Results The scores plot for classification within groups was clear and showed a great difference from the control group. Combining the body weight and biochemical results, the elevated levels of glucose, lactate, taurine, arginine, glycine and decreased levels of betaine, creatine, amino and neurotransmitters were observed. Conclusion Our current study indicated that the ethyl acetate extract of Fructus Toosendan has liver and kidney toxicity.
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To investigate chemical constituents from Radix Pittospori, chloroform extract of the roots was subjected to column chromatography with various chromatographic techniques. The structures were elucidated on the basis of physico-chemical property and spectral analysis. Two triterpenoids were identified as 22-acetyl-21-(2-acetoxy-2-methylbutanoyl)-R1-barrigenol(1) and 3alpha-hydroxyl-20-demethylisoaleuritolic-14(15)-ene-28, 30-dioic acid (2). Compound 1 is a new triterpene and compound 2 is isolated from this plant for the first time.