scholarly journals New Metabolites of Udenafil Identified through Liquid Chromatography– Quadrupole Time-of-flight Mass Spectrometry

2020 ◽  
Vol 17 ◽  
Author(s):  
Jaesung Pyo
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Solid Phase ◽  
Liver Microsomes ◽  
Time Of Flight ◽  
Rat Urine ◽  
Flight Mass Spectrometry ◽  
Tof Ms

Background: Udenafil, a recently discovered drug used for erectile dysfunction treatment, has been widely prescribed and its effect on human systems has been extensively studied. However, there is little research on the human metabolites of udenafil. Three metabolites have been identified in rats. Objective: Herein, highly sensitive and accurate liquid chromatography–quadrupole time-of-flight tandem mass spectrometry (LC-Q-TOF-MS/MS) was conducted to identify new udenafil metabolites. Methods: Human liver microsomes were incubated with udenafil for in vitro samples, and rat urine and faeces samples were collected from udenafil-administered rats for in vivo samples. Each sample was deproteinated with acetonitrile and extracted by solid phase extraction. The purified samples were separated and analyzed by LC-Q-TOF-MS, and some metabolite candidates were reanalyzed for further structural analysis using LC-Q-TOF-MS/MS. Results: Eleven and three metabolites were identified in the in vitro and in vivo samples, respectively, and were found to be hydrolyzed, oxidized, or demethylated forms of udenafil or its metabolites. The error of the metabolic analysis was −8.7 to 7.6 ppm, indicating the high accuracy of the method. Conclusion: These metabolic results could be useful for further investigation of udenafil and new phosphodiesterase-5 inhibitors.

scholarly journals In Vitro/In Vivo Metabolism of Ginsenoside Rg5 in Rat Using Ultra-Performance Liquid Chromatography/Quadrupole-Time-of-Flight Mass Spectrometry

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2113 ◽  
Author(s):  
Chao Hong ◽  
Ping Yang ◽  
Shuping Li ◽  
Yizhen Guo ◽  
Dan Wang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Time Of Flight ◽  
Ultra Performance Liquid Chromatography ◽  
In Vivo Metabolism ◽  
Rat Urine ◽  
Flight Mass Spectrometry ◽  
Ginsenoside Rg5

Background: Ginsenoside Rg5 has been proved to have a wide range of pharmacological activities. However, the in vitro and in vivo metabolism pathways of ginsenosides are still unclear, which impedes the understanding of their in vivo fate. In this paper, the possible metabolic process of Rg5 was studied and the metabolites are identified. Methods: Samples from rat liver microsomes (RLMs) in vitro and from rat urine, plasma and feces in vivo were collected for analysis after oral administration of Rg5. A rapid analysis technique using ultra-performance liquid chromatography (UPLC)/quadrupole-time-of-flight mass spectrometry (QTOF-MS) was applied for detecting metabolites of Rg5 both in vitro and in vivo. Results: A feasible metabolic pathway was proposed and described for ginsenoside Rg5. A total of 17 metabolic products were detected in biological samples, including the RLMs (four), rat urine (two), feces (13) and plasma (four). Fifteen of them have never been reported before. Oxidation, deglycosylation, deoxidation, glucuronidation, demethylation and dehydration were found to be the major metabolic reactions of Rg5. Conclusions: The present study utilized a reliable and quick analytical tool to explore the metabolism of Rg5 in rats and provided significant insights into the understanding of the metabolic pathways of Rg5 in vitro and in vivo. The results could be used to not only evaluate the efficacy and safety of Rg5, but also identify potential active drug candidates from the metabolites.

scholarly journals Studying in vitro metabolism of the first and second generation of antisense oligonucleotides with the use of ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry

2020 ◽  
Vol 412 (27) ◽  
pp. 7453-7467
Author(s):  
Anna Kilanowska ◽  
Łukasz Nuckowski ◽  
Sylwia Studzińska
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Liver Microsomes ◽  
Time Of Flight ◽  
Ion Pair ◽  
In Vitro Metabolism ◽  
Detection Methods ◽  
Ion Pair Chromatography ◽  
Flight Mass Spectrometry

Abstract The aim of the present investigation was the analysis and identification of antisense oligonucleotide metabolism products after incubation with human liver microsomes regarding four different oligonucleotide modifications. Separation and detection methods based on the use of liquid chromatography coupled with quadrupole time-of-flight mass spectrometry were developed for this purpose. Firstly, the optimization of mass spectrometer parameters was done to select those which ensure the highest possible sensitivity of oligonucleotide analysis. This step was conducted for two chromatographic modes—ion pair chromatography and hydrophilic interaction liquid chromatography—due to their common application in oligonucleotide analysis. Based on sensitivity results, ion pair chromatography coupled with mass spectrometry was selected for the separation of model oligonucleotide mixtures in order to verify its selectivity for N-deleted metabolite separation. Next, the developed method was applied in the examination of oligonucleotides in vitro metabolism. First, wide optimization of incubation parameters was conducted including the concentration of the reaction buffer components. Obtained results indicated that both 3′-exonucleases and 5′-exonucleases contributed to the biotransformation of oligonucleotides. Moreover, it may be concluded that the number of metabolites depends on oligonucleotide modification and consequently its resistance to enzymatic attack. Thus, the number of the oligonucleotide metabolites decreased with the decrease of the resultant polarity of oligonucleotide caused by chemical modification.

scholarly journals Metabolism studies of paeoniflorin in rat liver microsomes by ultra-performance liquid chromatography coupled with hybrid quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS)

2018 ◽  
Vol 5 (10) ◽  
pp. 180759
Author(s):  
L. J. Zhu ◽  
S. S. Sun ◽  
Y. X. Hu ◽  
Y. F. Liu
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Rat Liver ◽  
Metabolic Pathways ◽  
Liver Microsomes ◽  
Time Of Flight ◽  
Ultra Performance Liquid Chromatography ◽  
Rat Liver Microsomes ◽  
Flight Mass Spectrometry ◽  
Tof Ms

To explore metabolism mechanism of paeoniflorin in the liver and further understand intact metabolism process of paeoniflorin, a rapid, convenient and effective assay is described using ultra-performance liquid chromatography coupled with hybrid quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS). The strategy was confirmed in the following primary processes: firstly, different concentration of paeoniflorin, rat liver microsomes, coenzymes and different incubated conditions were optimized to build a biotransformation model of rat liver microsomes in vitro by high performance liquid chromatography with diode array detection (HPLC-DAD); secondly, the metabolites of paeoniflorin in rat liver microsomes were detected and screened using UPLC-Q-TOF-MS/MS by comparing the total ion chromatogram (TIC) of the experimental group with those of control groups; finally, the molecular formulae and corresponding chemical structures of paeoniflorin metabolites were identified by comparing the MS and MS/MS spectra with the self-constructed database and simulation software. Based on this analytical strategy, 20 metabolites of paeoniflorin were found and 6 metabolites (including four new compounds) were tentatively identified. It was shown that hydrolysis and oxidation were the major metabolic pathways of paeoniflorin in rat liver microsomes, and the main metabolic sites were the structures of pinane and the ester bond. These findings were significant for a better understanding of the metabolism of paeoniflorin in rat liver microsomes and the proposed metabolic pathways of paeoniflorin might provide fundamental support for the further research in the pharmacological mechanism of Paeoniae Radix Rubra (PRR).

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