Pharmaceutica Analytica Acta

Development of an lc-ms/ms method for quantification of methylthioadenosine using freshly prepared isotope-labelled internal standard

24^th Global Summit on Analytical and Bioanalytical Techniques

July 19-20, 2023 | Webinar

Dr. Makoto Tsuji

Japan

Scientific Tracks Abstracts: Pharm Anal Acta

Abstract:

Methylthioadenosine (MTA) is one of the oncometabolites, which is expected to be a potential biomarker for reflecting status of T-cell exhaustion in cancer. While MTA has been attracting much attention, accurate LC-MS/MS quantification method for MTA was not widely available yet. Although internal standard of stable isotope-labelled MTA was not commercially available at the beginning of this study, we found trace 2H3-MTA was included in 2H3-S-adenosylmethionine (SAM) solution as an impurity or a degradation product. We succeeded to increase peak intensity of 2H3-MTA by partial degradation of 2H3-SAM to 2H3- MTA in weak alkaline solution. The partially degraded 2H3-SAM solution was used as internal standard for the simultaneous and accurate quantitation of MTA and SAM. Chromatographic separation of MTA from structurally related metabolite such as SAM or S-adenosylhomocysteine was achieved using reversed phase column. Calibration standards for MTA and SAM were prepared separately due to the presence of MTA as an impurity in authentic SAM. Linear range of calibration of MTA and SAM were from 2 NM to 100 NM and 100 NM to 10000 NM, respectively. By monitoring M+1 isotopologue of MTA, we expanded the upper limit of calibration of MTA to 250 NM. Simultaneous quantitation of MTA and SAM in lysates from various cell lines revealed that MTA was accumulated in MTA phosphorylate-null cells, whereas concentrations of SAM did not show significant difference among the cell lines tested.

Biography :

Dr. Makoto Tsuji is an accomplished Scientist with a diverse background in virology, specifically focusing on hepatitis B virus (HBV) research, diagnostic techniques, and Analytical Chemistry and environmental research. With an unwavering passion for understanding infectious diseases and their impact on public health, Dr. Makoto Tsuji has made significant contributions to the field through his extensive research and expertise.