17 results on '"Tao GJ"'
Search Results
2. Alleviating sleep disturbances and modulating neuronal activity after ischemia: Evidence for the benefits of zolpidem in stroke recovery.
- Author
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Zhong ZG, Tao GJ, Hao SM, Ben H, Qu WM, Sun FY, Huang ZL, and Qiu MH
- Subjects
- Humans, Male, Rats, Animals, Zolpidem pharmacology, Zolpidem therapeutic use, Pyridines pharmacology, Pyridines therapeutic use, Infarction, Middle Cerebral Artery drug therapy, Sleep, Stroke complications, Stroke drug therapy, Sleep Wake Disorders drug therapy, Sleep Wake Disorders etiology, Ischemic Stroke drug therapy
- Abstract
Aims: Sleep disorders are prevalent among stroke survivors and impede stroke recovery, yet they are still insufficiently considered in the management of stroke patients, and the mechanisms by which they occur remain unclear. There is evidence that boosting phasic GABA signaling with zolpidem during the repair phase improves stroke recovery by enhancing neural plasticity; however, as a non-benzodiazepine hypnotic, the effects of zolpidem on post-stroke sleep disorders remain unclear., Method: Transient ischemic stroke in male rats was induced with a 30-minute middle cerebral artery occlusion. Zolpidem or vehicle was intraperitoneally delivered once daily from 2 to 7 days after the stroke, and the electroencephalogram and electromyogram were recorded simultaneously. At 24 h after ischemia, c-Fos immunostaining was used to assess the effect of transient ischemic stroke and acute zolpidem treatment on neuronal activity., Results: In addition to the effects on reducing brain damage and mitigating behavioral deficits, repeated zolpidem treatment during the subacute phase of stroke quickly ameliorated circadian rhythm disruption, alleviated sleep fragmentation, and increased sleep depth in ischemic rats. Immunohistochemical staining showed that in contrast to robust activation in para-infarct and some remote areas by 24 h after the onset of focal ischemia, the activity of the ipsilateral suprachiasmatic nucleus, the biological rhythm center, was strongly suppressed. A single dose of zolpidem significantly upregulated c-Fos expression in the ipsilateral suprachiasmatic nucleus to levels comparable to the contralateral side., Conclusion: Stroke leads to suprachiasmatic nucleus dysfunction. Zolpidem restores suprachiasmatic nucleus activity and effectively alleviates post-stroke sleep disturbances, indicating its potential to promote stroke recovery., (© 2024 The Authors. CNS Neuroscience & Therapeutics published by John Wiley & Sons Ltd.)
- Published
- 2024
- Full Text
- View/download PDF
3. Whole-brain connectivity to the bed nucleus of the stria terminalis calretinin-expressing interneurons in male mice.
- Author
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Zhu KW, Tao GJ, Huang ZL, Qu WM, and Wang L
- Subjects
- Mice, Male, Animals, Calbindin 2, Brain metabolism, Interneurons metabolism, Septal Nuclei metabolism, Neuropeptides metabolism
- Abstract
The bed nucleus of the stria terminalis (BNST) is a neuropeptide-enriched brain region that modulates a wide variety of emotional behaviours and states, including stress, anxiety, reward and social interaction. The BNST consists of diverse subregions and neuronal ensembles; however, because of the high molecular heterogeneity within BNST neurons, the mechanisms through which the BNST regulates distinct emotional behaviours remain largely unclear. Prior studies have identified BNST calretinin (CR)-expressing neurons, which lack neuropeptides. Here, employing virus-based cell-type-specific retrograde and anterograde tracing systems, we mapped the whole-brain monosynaptic inputs and axonal projections of BNST CR-expressing neurons in male mice. We found that BNST CR-expressing neurons received inputs mainly from the amygdalopiriform transition area, central amygdala and hippocampus and moderately from the medial preoptic area, basolateral amygdala, paraventricular thalamus and lateral hypothalamus. Within the BNST, plenty of input neurons were primarily located in the oval and interfascicular subregions. Furthermore, numerous BNST CR-expressing neuronal boutons were observed within the BNST but not in other brain regions, thus suggesting that these neurons are a type of interneuron. These results will help further elucidate the neuronal circuits underlying the elaborate and distinct functions of the BNST., (© 2023 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.)
- Published
- 2023
- Full Text
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4. Characteristics of enhanced biological phosphorus removal (EBPR) process under the combined actions of intracellular and extracellular polyphosphate.
- Author
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Long XY, Tang R, Wang T, Tao GJ, Wang JY, Zhou HW, Xue M, and Yu YP
- Subjects
- Bioreactors, Extracellular Polymeric Substance Matrix, Fatty Acids, Volatile, Sewage, Phosphorus, Polyphosphates
- Abstract
The characteristics of enhanced biological phosphorus removal (EBPR) process under the combined actions of intracellular and extracellular polyphosphate (polyP) were investigated with the
31 P Nuclear Magnetic Resonance (NMR) and the fractionation extracting the loosely-bound and tightly-bound extracellular polymer substances (i.e., LB-EPS and TB-EPS) and bacterial cells in EBPR sludge. The hydrolysis/synthesis of extracellular and intracellular polyP was a key step of the phosphate migration and transformation in EBPR sludge. The orthophosphate (orthoP) produced from the intracellular and extracellular polyP anaerobic-hydrolysis was partially accumulated in the bacterial cells and TB-EPS, and then the accumulated orthoP was main composition for these polyP aerobic-synthesis. Importantly, the anaerobic-hydrolysis enhancement of intracellular and extracellular ployP could promote EBPR sludge to absorb volatile fatty acids (VFAs) followed by being transformed into intracellular poly-hydroxy-alkanoates (PHAs). The mechanism for VFAs passing through the LB-EPS and TB-EPS should be an anion-exchange action between orthoP and VFAs. The orthoP accumulation in the TB-EPS kept an orthoP concentration gradient among the TB-EPS, LB-EPS and bulk solution, driving orthoP and VFAs migrations. The orthoP accumulation in the bacterial cells could keep an orthoP concentration difference between the cell-membrane two sides of phosphorus accumulating organisms (PAOs) to promote VFAs passing through the cell membrane considered as an anion exchange membrane. The intracellular PHAs continuously hydrolyzed accompanied with the average chain-length increases of the extracellular and intracellular polyP during the whole aerobic stage. Additionally, the energy of the extracellular polyP synthesized in situ should came from the intracellular PHAs hydrolysis., (Copyright © 2021 Elsevier Ltd. All rights reserved.)- Published
- 2021
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5. Bladder-embedded ectopic intrauterine device with calculus.
- Author
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Xiong BJ, Tao GJ, and Jiang D
- Abstract
The present study aimed to analyze the data of embedded intrauterine device (IUD) in the bladder wall with the additional presence of calculus. This case series study included 11 female patients with partially or completely embedded IUD in the bladder wall. Their median age was 34 (range, 32-39) years. The median duration of IUD placement was 36 (range, 24-60) months. The median duration of symptoms was 9 (range, 3-12) months. Six patients underwent laparoscopy: the operation duration was 129 (range, 114-162) min, blood loss was 15 (range, 10-25) mL, the hospital stay was 4 (range, 4-4.5) days, the visual analog scale (VAS) for pain at 6 h after surgery was 3 (range, 2-6), and the time to removal of the urethral catheter was 7 (range, 7-8) days. Five patients underwent open surgery: the operation duration was 126 (range, 96-192) min, blood loss was 30 (range, 20-50) mL, the hospital stay was 7 (range, 7-15) days, the VAS was 6 (range, 4-9) at 6 h after surgery, and the time to removal of the urethral catheter was 9 (range, 8-17) days. The IUD and bladder stones were successfully removed in all 11 (100%) patients., (© 2020 Bing-Jian Xiong et al., published by De Gruyter.)
- Published
- 2020
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6. Comparison and optimization of extraction protocol for intracellular phosphorus and its polyphosphate in enhanced biological phosphorus removal (EBPR) sludge.
- Author
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Tao GJ, Long XY, Tang R, Wang JY, Fang ZD, Xie CX, Wang T, and Peng XH
- Subjects
- Bacteria, Biodegradation, Environmental, Bioreactors, Magnetic Resonance Spectroscopy, Sewage, Phosphorus, Polyphosphates, Waste Disposal, Fluid methods
- Abstract
Intracellular polyphosphate (poly-P) plays important roles in Enhanced biological phosphorus removal (EBPR) process, but an effective and reliable protocol for extracting intracellular P and its poly-P in EBPR sludge without hydrolysis of poly-P has not been setup yet. In the study, it was revealed that the severe hydrolysis of intracellular poly-P occurred during the different extraction processes, such as acid (i.e., HClO
4 , H2 SO4 and HCl), basic (i.e., NaOH and KOH) and freezing-grind (under different solid-liquid ratios), but it did not occur during ultrasonic extraction process. The optimal extraction process of the ultrasonic protocol was 10 w/mL of ultrasonic power density and 15 min of ultrasonic time, when the extraction efficiency of intracellular P was 88.24 ± 1.56%. In addition, the extraction efficiency of intracellular P could be furtherly improved by that the 0.75 mol/L LiCl solution was used to resuspend the bacterial cell before ultrasonic extraction (i.e., LiCl-ultrasonic protocol). The ultrasonic protocol was more suitable to extract the intracellular P and its poly-P of EBPR sludge than the other 4 protocols (i.e., PCA-NaOH, EDTA-NaOH, freezing-grind and LiCl-ultrasonic), which had the technical characteristics of (i) with relatively high extraction efficiency of intracellular P, (ii) without hydrolysis of intracellular poly-P, (iii) with weak noise signal in31 P NMR spectrum and (iv) with simple extraction process and short extraction time. It was founded by the ultrasonic protocol that there was the high content (82.88%-89.79% of intracellular P content) of intracellular poly-P with long average chain length (376.4-383.2) in the EBPR sludges. Importantly, it was confirmed that the EBPR process was related to the combined action of extracellular and intracellular poly-P using a new fractionation method of P in EBPR sludge, which included the ultrasonic protocol at high power density for extracting the intracellular P and its poly-P., (Copyright © 2019. Published by Elsevier B.V.)- Published
- 2020
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7. Acetonitrile extraction coupled with UHPLC-MS/MS for the accurate quantification of 17 heterocyclic aromatic amines in meat products.
- Author
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Yan Y, Zhang S, Tao GJ, You FH, Chen J, and Zeng MM
- Subjects
- Amines isolation & purification, Animals, Heterocyclic Compounds isolation & purification, Limit of Detection, Linear Models, Reproducibility of Results, Swine, Acetonitriles chemistry, Amines analysis, Chromatography, High Pressure Liquid methods, Heterocyclic Compounds analysis, Meat analysis, Tandem Mass Spectrometry methods
- Abstract
This study proposed a simple and accurate acetonitrile extraction pretreatment method coupled with ultrahigh-performance liquid chromatography with tandem mass spectrometry for the simultaneous determination of 17 heterocyclic aromatic amines (HAAs) in meat products. With this new method, all 17 HAAs, including 11 polar and 6 nonpolarHAAs, were simultaneously extracted by acetonitrile and purified by one-step Oasis MCX cartridge purification. Compared with two different improved reference methods, the acetonitrile method could obtain higher recoveries (in the range of 42.5% to 99.0%) and better repeatability (lower than 12.2%). The limits of quantification were calculated between 0.028ngg
-1 and0.648ngg-1 with high correlation coefficients (r>0.9976) in wide linear ranges. The proposed acetonitrile method was successfully applied to the analysis of the HAAs levels in 10 commercial meat products with satisfactory recoveries., (Copyright © 2017 Elsevier B.V. All rights reserved.)- Published
- 2017
- Full Text
- View/download PDF
8. Lidocaine alleviates morphine tolerance via AMPK-SOCS3-dependent neuroinflammation suppression in the spinal cord.
- Author
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Zhang Y, Tao GJ, Hu L, Qu J, Han Y, Zhang G, Qian Y, Jiang CY, and Liu WT
- Subjects
- AMP-Activated Protein Kinase Kinases, Analgesics, Opioid administration & dosage, Anesthetics, Local administration & dosage, Animals, Cell Line, Drug Therapy, Combination, Drug Tolerance physiology, Inflammation metabolism, Inflammation pathology, Inflammation prevention & control, Inflammation Mediators metabolism, Male, Mice, Microglia drug effects, Microglia metabolism, Spinal Cord metabolism, Spinal Cord pathology, Inflammation Mediators antagonists & inhibitors, Lidocaine administration & dosage, Morphine administration & dosage, Protein Kinases biosynthesis, Spinal Cord drug effects, Suppressor of Cytokine Signaling 3 Protein biosynthesis
- Abstract
Background: Morphine tolerance is a clinical challenge, and its pathogenesis is closely related to the neuroinflammation mediated by Toll-like receptor 4 (TLR4). In Chinese pain clinic, lidocaine is combined with morphine to treat chronic pain. We found that lidocaine sufficiently inhibited neuroinflammation induced by morphine and improved analgesic tolerance on the basis of non-affecting pain threshold., Methods: CD-1 mice were utilized for tail-flick test to evaluate morphine tolerance. The microglial cell line BV-2 was utilized to investigate the mechanism of lidocaine. Neuroinflammation-related cytokines were measured by western blotting and real-time PCR. The level of suppressor of cytokine signaling 3 (SOCS3) and adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)-related signaling pathway was evaluated by western blotting, real-time PCR, enzyme-linked immunosorbent assay (ELISA), and immunofluorescence staining., Results: Lidocaine potentiated an anti-nociceptive effect of morphine and attenuated the chronic analgesic tolerance. Lidocaine suppressed morphine-induced activation of microglia and downregulated inflammatory cytokines, interleukin-1β (IL-1β), and tumor necrosis factor-alpha (TNF-α) via upregulating SOCS3 by activating AMPK. Lidocaine enhanced AMPK phosphorylation in a calcium-dependent protein kinase kinase β (CaMKKβ)-dependent manner. Furthermore, lidocaine decreased the phosphorylation of p38 mitogen-activated protein kinase (MAPK) and inhibited the nuclear factor-κB (NF-κB) in accordance with the inhibitory effects to TLR4., Conclusions: Lidocaine as a prevalent local anesthetic suppresses morphine tolerance efficiently. AMPK-dependent upregulation of SOCS3 by lidocaine plays a crucial role in the improvement of analgesic tolerance.
- Published
- 2017
- Full Text
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9. Investigating the inhibitory activity and mechanism differences between norartocarpetin and luteolin for tyrosinase: A combinatory kinetic study and computational simulation analysis.
- Author
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Zhang L, Zhao X, Tao GJ, Chen J, and Zheng ZP
- Subjects
- Artocarpus enzymology, Computer Simulation, Dose-Response Relationship, Drug, Flavonoids chemistry, Kinetics, Luteolin chemistry, Monophenol Monooxygenase metabolism, Plant Extracts chemistry, Plant Extracts isolation & purification, Protein Structure, Secondary, Tandem Mass Spectrometry methods, Enzyme Inhibitors pharmacokinetics, Flavonoids pharmacokinetics, Luteolin pharmacokinetics, Molecular Docking Simulation methods, Monophenol Monooxygenase antagonists & inhibitors
- Abstract
Flavonoids are an important type of natural tyrosinase inhibitor, but their inhibitory activity and mechanism against tyrosinase are very different because of their different structures. In this study, the inhibitory activity and mechanism differences between norartocarpetin and luteolin for tyrosinase were investigated by a combination of kinetic studies and computational simulations. The kinetic analysis showed that norartocarpetin reversibly inhibited tyrosinase in a competitive manner, whereas luteolin caused reversible noncompetitive inhibition. Both norartocarpetin and luteolin showed a single type of quenching and a static-type quenching mechanism. A computational simulation indicated that the hydroxyl groups of the B ring of norartocarpetin interacted with tyrosinase residues Asn81 and His85 in the active pocket, while the hydroxyl groups of the B ring of luteolin bound residues Asn81 and Cys83. HPLC and UPLC-MS/MS further confirmed that luteolin acted as a substrate or a suicide inhibitor, yet norartocarpetin acted as an inhibitor., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
10. A novel isoflavone profiling method based on UPLC-PDA-ESI-MS.
- Author
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Zhang S, Zheng ZP, Zeng MM, He ZY, Tao GJ, Qin F, and Chen J
- Subjects
- Chromatography, High Pressure Liquid methods, Isoflavones chemistry, Spectrometry, Mass, Electrospray Ionization methods
- Abstract
A novel non-targeted isoflavone profiling method was developed using the diagnostic fragment-ion-based extension strategy, based on ultra-high performance liquid chromatography coupled with photo-diode array detector and electrospray ionization-mass spectrometry (UPLC-PDA-ESI-MS). 16 types of isoflavones were obtained in positive mode, but only 12 were obtained in negative mode due to the absence of precursor ions. Malonyldaidzin and malonylgenistin glycosylated at the 4'-O position or malonylated at the 4″-O position of glucose were indicated by their retention behavior and fragmentation pattern. Three possible quantification methods in one run based on UPLC-PDA and UPLC-ESI-MS were validated and compared, suggesting that methods based on UPLC-ESI-MS possess remarkable selectivity and sensitivity. Impermissible quantitative deviations induced by the linearity calibration with 400-fold dynamic range was observed for the first time and was recalibrated with a 20-fold dynamic range. These results suggest that isoflavones and their stereoisomers can be simultaneously determined by positive-ion UPLC-ESI-MS in soymilk., (Copyright © 2016. Published by Elsevier Ltd.)
- Published
- 2017
- Full Text
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11. Simultaneous analysis of PhIP, 4'-OH-PhIP, and their precursors using UHPLC-MS/MS.
- Author
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Yan Y, Zeng MM, Zheng ZP, He ZY, Tao GJ, Zhang S, Gao YH, and Chen J
- Subjects
- Animals, Cooking, Creatine analysis, Creatinine analysis, Glucose analysis, Hot Temperature, Phenylalanine analysis, Swine, Tyrosine analysis, Chromatography, High Pressure Liquid methods, Imidazoles analysis, Meat analysis, Tandem Mass Spectrometry methods
- Abstract
A novel method allowing simultaneous analysis of PhIP, 4'-OH-PhIP, and their precursors (phenylalanine, tyrosine, creatine, creatinine, glucose) has been developed as a robust kinetic study tool by using ultra high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). A direct hydrochloric acid (HCl) extraction was applied to achieve the simultaneous extraction of all seven analytes, with the mean recoveries ranging from 60% to 120% at two concentration levels. Then, an Atlantis dC18 column selected from four different chromatographic columns was ultimately used to separate these compounds within 15 min. The limits of detection range of allseven analytes were calculated as 0.14-325.00 μg L(-1). The intra- and interday precision of the proposed method were less than 15.4 and 19.9%, respectively. The proposed method was successfully applied to depict the kinetic profiles of PhIP, 4'-OH-PhIP, and their precursors in pork model, reducing the analysis time and cost in the kinetic study.
- Published
- 2014
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12. Preparation of human milk fat substitutes from palm stearin with arachidonic and docosahexaenoic acid: combination of enzymatic and physical methods.
- Author
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Zou XQ, Huang JH, Jin QZ, Liu YF, Tao GJ, Cheong LZ, and Wang XG
- Subjects
- Arachidonic Acid chemistry, Docosahexaenoic Acids chemistry, Fat Substitutes chemistry, Fatty Acids analysis, Fatty Acids, Monounsaturated, Humans, Lipase metabolism, Palm Oil, Palmitic Acid chemistry, Pancreatin metabolism, Plant Oils chemistry, Rapeseed Oil, Sunflower Oil, Triglycerides chemistry, Triglycerides metabolism, Arachidonic Acid metabolism, Docosahexaenoic Acids metabolism, Fat Substitutes chemical synthesis, Milk, Human chemistry, Palmitic Acid metabolism
- Abstract
Human milk fat substitutes (HMFSs) were prepared by a two-step process, namely, Lipozyme RM IM-catalyzed acidolysis of interesterified high-melting palm stearin with fatty acids from rapeseed oil and blending of the enzymatic product with the selected oils on the basis of the calculation model. The optimum conditions for the enzymatic reaction were a mole ratio of palm stearin/fatty acids 1:10, 60 °C, 8% enzyme load (wt % of substrates), 4 h, and 3.5% water content (wt % of enzyme); the enzymatic product contained 39.6% palmitic acid (PA), 83.7% of the fatty acids at sn-2 position were PA (sn-2 PA), and the distribution probability of PA at the sn-2 position among total PA (% sn-2 PA) was 70.5%. With the fatty acid profiles of human milk fat (HMF) as a preferable goal, a physical blending model was established for the second step to guarantee the maximum addition of selected oils. Based on the model prediction, a desirable formula constituted enzymatic product/rapeseed oil/sunflower oil/palm kernel oil/algal oil/microbial oil at a mole ratio of 1:0.28:0.40:0.36:0.015:0.017, and the final product had PA content, sn-2 PA, and %sn-2 PA at 23.5, 43.1, and 61.1%, respectively. The contents of arachidonic and docosahexaenoic acids were 0.4 and 0.3%, respectively. Relying on the total and sn-2 fatty acid compositions of HMF and "deducting score" principle, the score for the similarity between the final product and HMF was scaled as 89.2, indicating the potential as a fat substitute in infant formulas.
- Published
- 2012
- Full Text
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13. Detoxification and degradation of microcystin-LR and -RR by ozonation.
- Author
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Miao HF, Qin F, Tao GJ, Tao WY, and Ruan WQ
- Subjects
- Animals, Chromatography, High Pressure Liquid, Hydroxyl Radical metabolism, Male, Marine Toxins, Mice, Microcystins toxicity, Oxidation-Reduction, Phosphoprotein Phosphatases metabolism, Spectrometry, Mass, Electrospray Ionization, Water Pollutants toxicity, Microcystins chemistry, Ozone chemistry, Water Pollutants chemistry
- Abstract
In the present study, two Microsystins (MCs) of Microcystin-LR and Microcystin-RR were degraded with different dosages of ozone (O(3)). The possible degradation pathways were elucidated by analyzing their intermediates and end-products with liquid chromatography-mass spectrometry (LC-MS) method. The toxicity of the MCs ozonation products was also evaluated by assaying the protein phosphatase inhibition in vitro and acute toxicity in vivo. Results demonstrated that ozonation was a promising technology for removal and detoxification of the cyanotoxins. The MCs destruction was mainly involved in the attack of ozone on Adda side chain. First, the conjugated diene structure of Adda moiety was attacked by hydroxyl radical (OH()) to produce dihydroxylated products, then the hydroxylated 4-5 and/or 6-7 bond of Adda was cleaved into aldehyde or ketone peptide residues, and finally the residues were oxidized into the corresponding carboxylic acids. The fragmentation of the Mdha-Ala peptide bond of MCs also contributed positively to the oxidation process. Additionally, the attack on the benzene ring of Adda side chain was exclusively observed during MC-RR degradation. The toxicity evaluation of MCs ozonation products revealed that those end-products had no adverse effects in vivo and in vitro ozonation that could completely remove the MCs' toxicity., ((c) 2010. Published by Elsevier Ltd.)
- Published
- 2010
- Full Text
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14. A myxobacterium strain Sorangium cellulosum AHB125 producing epothilone B and other anticancer substances.
- Author
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Guo WJ, Tao GJ, Tao WY, Cui FJ, Jin XC, Bi F, Xu ZH, and Ao ZH
- Subjects
- Animals, Antineoplastic Agents chemistry, Antineoplastic Agents isolation & purification, Cell Line, Tumor, Cell Proliferation drug effects, Cell Survival drug effects, Chromatography, Liquid, Epothilones chemistry, Epothilones isolation & purification, Humans, Mice, Molecular Structure, Myxococcales chemistry, Spectrometry, Mass, Electrospray Ionization, Antineoplastic Agents pharmacology, Epothilones pharmacology, Myxococcales metabolism
- Abstract
A myxobacterium strain AHB125 belonging to genus Sorangium cellulosum was isolated from Anhui area in China and identified with morphological analysis by electron microscopy and phase contrast microscope according to Bergey's manual of systematic bacteriology (8th Ed.). Its high-antitumor bioactivity metabolites was evaluated by bioassay-directed screening technique with B16 tumor cell line etc. Research results showed that it exhibited not only strong antitumor ability bioactivities and broad-spectrum antitumor abilities to B16, Bel7402, H446, SGC7901 cell lines, but also has selectivity and pertinence to B16 and SGC7901 cell lines. The compound was confirmed as epothilone B by HPLC and LC/MS analysis, compared to the epothilone B standard sample. Bioassay indicated that there were other high-bioactive substances in the metabolites.
- Published
- 2007
- Full Text
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15. [Analysis of mannoligosaccharides by liquid chromatography-electrospray ionization mass spectrometry].
- Author
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Zhang YT, Tao GJ, Wang LX, Gu WY, and Gu QQ
- Subjects
- Mannans chemistry, Mannose analysis, Oligosaccharides chemistry, Saccharomyces cerevisiae chemistry, Spectrometry, Mass, Electrospray Ionization methods, Trisaccharides analysis, Chromatography, Liquid methods, Mannans analysis, Oligosaccharides analysis
- Abstract
Oligosaccharide characterization has been of utmost interest in various areas such as medicine, biochemistry, and food chemistry. These biologically relevant molecules are ideally suited for mass spectrometric investigation, because of the capability of this technique in offering structure and relative molecular mass information. Therefore, liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) was applied to characterize the acetolysis of mannan from Saccharomyces cerevisiae. The electrospray using Na+ as adducts proved to be superior to the LC-MS for the determination of mannoligosaccharides. LC separation was accomplished by the use of NH2 column and the elution by acetonitrile-water (70:30, volume ratio). The results showed that mannoligosaccharides side chain consisted of mannose, mannobiose, mannotriose and mannotetraose. The method developed is accurate, fast and convenient and can be used to characterize the relative molecular mass of the oligosaccharides.
- Published
- 2002
16. [Screening of steroidal saponins from the bulbs of Lilium brownii var. colchesteri by combination of high performance liquid chromatography-electrospray ionization mass spectrometry and electron impact mass spectrometry].
- Author
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Ji HW, Ding XL, and Tao GJ
- Subjects
- Chromatography, High Pressure Liquid methods, Spectrometry, Mass, Electrospray Ionization, Drugs, Chinese Herbal chemistry, Lilium chemistry, Sapogenins analysis, Spirostans analysis
- Abstract
With the combination of high performance liquid chromatography-electrospray ionization mass spectrometry (HPLC/ESI-MS) and electron impact mass spectrometry (EI-MS), two steroidal saponins, one compound containing three glycosyls and tigogenin and the other one containing three glycosyls and diosgenin, from the bulbs of Lilium brownii var. calchesteri in China have been screened. In the method, on-line HPLC/ESI-MS allows us to obtain rapidly useful information about the molecular weight and the glycosyl chain of glycoside without the necessity of isolating individual compounds, but little information about steroidal sapogenins. Just with 1 mg to 2 mg of pure sample, off-line EI-MS allows us to acquire useful information about a steroidal sapogenin of saponins, but it is difficult to obtain the molecular ion peak. The combination of HPLC/ESI-MS and EI-MS is well suitable for rapidly screening steroidal saponins from plants.
- Published
- 2001
17. [Separation, purification and identification of angiotensin converting enzyme inhibitory silk fibroin peptide].
- Author
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Ni L, Tao GJ, Dai J, Wang Z, and Xu SY
- Subjects
- Angiotensin-Converting Enzyme Inhibitors analysis, Animals, Bombyx chemistry, Chromatography, High Pressure Liquid, Dipeptides, Fibroins analysis, Fibroins chemistry, Mass Spectrometry, Peptides analysis, Peptides chemistry, Silk, Angiotensin-Converting Enzyme Inhibitors isolation & purification, Fibroins isolation & purification, Insect Proteins chemistry, Peptides isolation & purification
- Abstract
Silk fibroin peptides could be obtained from soluble silk fibroin by enzymatic hydrolysis. Its hydrolyzates produced with Alcalase showed significant inhibitory activity against the angiotensin I-converting enzyme (ACE). One inhibitory peptide from the hydrolyzate at a degree of hydrolysis of 20% (sample A20) was purified and identified. Sample A20 was first isolated by size exclusion chromatography(SEC), eluted with 0.01 mol/L hydrochloric acid solution on a Sephadex G-15 column (1.6 cm i.d. x 100 cm). The peak of No. 5 on the SEC chromatography was further purified by reversed-phase HPLC (mu Bondapak C18 P/N 84176 column, 7.8 mm i.d. x 300 mm), eluted with a linear gradient elution with acetonitrile from 0% to 15% at temperature (30 +/- 2) degrees C. Then the pure peptide with ACE inhibitory activity was obtained, the amino acid sequence of which was identified as Gly-Tyr by mass spectrometry.
- Published
- 2001
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