LncRNA Pulldown Combined with Mass Spectrometry to Identify the Novel LncRNA-Associated Proteins

2016 ◽  
pp. 1-9 ◽  
Author(s):  
Zhen Xing ◽  
Chunru Lin ◽  
Liuqing Yang
Keyword(s):  
Mass Spectrometry ◽  
The Novel ◽  
Associated Proteins

Selective reagent ionisation-time of flight-mass spectrometry: a rapid technology for the novel analysis of blends of new psychoactive substances

2015 ◽  
Vol 50 (2) ◽  
pp. 427-431 ◽  
Author(s):  
Matteo Lanza ◽  
W. Joe Acton ◽  
Philipp Sulzer ◽  
Kostiantyn Breiev ◽  
Simone Jürschik ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Time Of Flight ◽  
New Psychoactive Substances ◽  
The Novel ◽  
Psychoactive Substances ◽  
Flight Mass Spectrometry ◽  
Selective Reagent

Identification of nuclei associated proteins by 2D-gel electrophoresis and mass spectrometry

2001 ◽  
Vol 109 (1) ◽  
pp. 3-11 ◽  
Author(s):  
Jonas Bergquist ◽  
Johan Gobom ◽  
Anders Blomberg ◽  
Peter Roepstorff ◽  
Rolf Ekman
Keyword(s):  
Mass Spectrometry ◽  
Gel Electrophoresis ◽  
2D Gel Electrophoresis ◽  
Associated Proteins ◽  
2D Gel

Relationship between plasma and salivary melatonin and cortisol investigated by LC-MS/MS

2017 ◽  
Vol 55 (9) ◽  
Author(s):  
Martijn van Faassen ◽  
Rainer Bischoff ◽  
Ido P. Kema
Keyword(s):  
Mass Spectrometry ◽  
Equilibrium Dialysis ◽  
Added Value ◽  
The Novel ◽  
Plasma Melatonin ◽  
Disease States ◽  
Validation Criteria ◽  
Significant Difference ◽  
Salivary Melatonin ◽  
Free Plasma

AbstractBackground:Disturbance of the circadian rhythm has been associated with disease states, such as metabolic disorders, depression and cancer. Quantification of the circadian markers such as melatonin and cortisol critically depend on reliable and reproducible analytical methods. Previously, melatonin and cortisol were primarily analyzed separately, mainly using immunoassays.Methods:Here we describe the validation and application of a high-throughput liquid chromatography in combination with mass spectrometry (LC-MS/MS) method for the combined analysis of melatonin and cortisol in plasma and saliva. The LC-MS/MS method was validated according to international validation guidelines. We used this method to analyze total plasma, free plasma (as obtained by equilibrium dialysis) and saliva melatonin and cortisol in healthy adults.Results:Validation results for plasma and saliva melatonin and cortisol were well within the international validation criteria. We observed no difference between saliva collected by passive drooling or Salivette. Moreover, we noted a significant difference in saliva vs. free plasma melatonin. We observed on average 36% (95% CI: 4%–60%) higher salivary melatonin levels in comparison to free plasma melatonin, suggestive of local production of melatonin in the salivary glands.Conclusions:The novel outcome of this study is probably due to the high precision of our LC-MS/MS assay. These outcomes illustrate the added value of accurate and sensitive mass spectrometry based methods for the quantification of neuroendocrine biomarkers.

PRESERVATION OF FRUITS: A STUDY ON APPLES BASED ON MONITORING VOCS BY THE NOVEL PROTON TRANSFER MASS SPECTROMETRY METHOD (PTR-MS)

2005 ◽  
pp. 1489-1496
Author(s):  
A. Boschetti ◽  
M. Vescovi ◽  
D. Barbon ◽  
A. Tonini ◽  
A. Weber ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Proton Transfer ◽  
The Novel ◽  
Spectrometry Method ◽  
Mass Spectrometry Method

scholarly journals Qualitative analysis of 7- and 8-hydroxyzolpidem and discovery of novel zolpidem metabolites in postmortem urine using liquid chromatography–tandem mass spectrometry

2022 ◽  
Author(s):  
Koji Yamaguchi ◽  
Hajime Miyaguchi ◽  
Youkichi Ohno ◽  
Yoshimasa Kanawaku
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Pyridine Ring ◽  
Multiple Reaction Monitoring ◽  
Fragmentation Pattern ◽  
The Novel ◽  
Flight Mass Spectrometry ◽  
Urine Extract ◽  
Liquid Chromatography Tandem Mass ◽  
Characteristic Fragmentation

Abstract Purpose Zolpidem (ZOL) is a hypnotic sometimes used in drug-facilitated crimes. Understanding ZOL metabolism is important for proving ZOL intake. In this study, we synthesized standards of hydroxyzolpidems with a hydroxy group attached to the pyridine ring and analyzed them to prove their presence in postmortem urine. We also searched for novel ZOL metabolites in the urine sample using liquid chromatography–triple quadrupole mass spectrometry (LC-QqQMS) and liquid chromatography–quadrupole time-of-flight mass spectrometry (LC-QqTOFMS). Methods 7- and 8-Hydroxyzolpidem (7OHZ and 8OHZ, respectively) were synthesized and analyzed using LC-QqQMS. Retention times were compared between the synthetic standards and extracts of postmortem urine. To search for novel ZOL metabolites, first, the urine extract was analyzed with data-dependent acquisition, and the peaks showing the characteristic fragmentation pattern of ZOL were selected. Second, product ion spectra of these peaks at various collision energies were acquired and fragments that could be used for multiple reaction monitoring (MRM) were chosen. Finally, MRM parameters were optimized using the urine extract. These peaks were also analyzed using LC-QqTOFMS. Results The presence of 7OHZ and 8OHZ in urine was confirmed. The highest peak among hydroxyzolpidems was assigned to 7OHZ. The novel metabolites found were zolpidem dihydrodiol and its glucuronides, cysteine adducts of ZOL and dihydro(hydroxy)zolpidem, and glucuronides of hydroxyzolpidems. Conclusions The presence of novel metabolites revealed new metabolic pathways, which involve formation of an epoxide on the pyridine ring as an intermediate.

Synthesis, characterization, and structures of zircona- and boracyclosiloxanes with ferrocenyl substituents

2002 ◽  
Vol 80 (11) ◽  
pp. 1469-1480 ◽  
Author(s):  
Karena Thieme ◽  
Sara C Bourke ◽  
Juan Zheng ◽  
Mark J MacLachlan ◽  
Fojan Zamanian ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
The Novel ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Multinuclear Nmr Spectroscopy

The novel zirconatetraferrocenylcyclotrisiloxane Cp2Zr(OSiFc2)2O (6), dizirconatetraferrocenylcyclotetrasiloxane [Cp2Zr(OSiFc2)O]2 (7), boratetraferrocenylcyclotrisiloxane (C6H5)B(OSiFc2)2O (8), and diboratetraferrocenylcyclotetrasiloxane [(C6H5)B(OSiFc2)O]2 (9) with ferrocenyl (Fc = Fe(η-C5H4)(η-C5H5)) substituents at silicon have been prepared from the reactions of Cp2Zr(NMe2)2 and PhBCl2 with diferrocenylsilanediol Fc2Si(OH)2 (3) and tetraferrocenyldisiloxanediol [Fc2SiOH]2O (5). The compounds were characterized by mass spectrometry, elemental analysis, UV–vis, IR, Raman, and multinuclear NMR spectroscopy, as well as single crystal X-ray diffraction. Thermogravimetric analysis and differential scanning calorimetry investigation of 6–9 showed that the cycles decompose before they can undergo any thermal ring-opening polymerization. In addition, no polymerization was detected in the presence of either KOSiMe3 or HOTf. The bulky ferrocenyl substituents on the Si atoms are likely to be at least partially responsible for the inability of these heterocycles to undergo ring-opening polymerization. Key words: heterocyclosiloxanes, ferrocenyl.

Synthesis, characterization, and enzymic conversion of nonhydrolysable analogues of propionylcoenzyme A

1994 ◽  
Vol 72 (1) ◽  
pp. 164-169 ◽  
Author(s):  
Yimin Zhao ◽  
Martina Michenfelder ◽  
János Rétey
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Coenzyme A ◽  
The Novel ◽  
Mechanistic Studies ◽  
Preparative Scale ◽  
Propionibacterium Shermanii ◽  
Fab Mass Spectrometry ◽  
Michaelis Constants ◽  
Coenzyme B

We describe the synthesis of three novel analogues of propionyl-coenzyme A, in which the sulfur atom has been replaced by methylene, ethylene, and thiomethylene, respectively. All three analogues, propionyl-dethia(carba)-CoA (1), propionyl-dethia(dicarba)-CoA (2), and S-(2-oxobutanyl)-CoA (3) were characterized by 1H and 31P NMR spectroscopy and FAB mass spectrometry. Propionyl-CoA–oxaloacetate transcarboxylase from Propionibacterium shermanii accepted the novel analogues as substrates and carboxylated them to the corresponding methylmalonyl-CoA analogues (4–6). The latter were further converted into the succinyl-CoA analogues by the coenzyme-B12-dependent methylmalonyl-CoA mutase from the same organism. The succinyl-CoA analogues, succinyl-dethia(carba)-CoA (7), succinyl-dethia(dicarba)-CoA (8), and 4-carboxy(2-oxobutanyl)-CoA (9) were obtained on a preparative scale and their Michaelis constants (Km) with methylmalonyl-CoA mutase were determined to be 0.136, 2.20, and 0.132 mM, respectively (Km for succinyl-CoA is 0.025 mM). The Vmax values for 7, 8, and 9 are 1.1, 0.013, and 0.0047 µmol min−1 U−1, respectively (Vmax for succinyl CoA is 1.0). The utility of the novel coenzyme A analogues in enzyme mechanistic studies is discussed.

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