Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2024 Jan 2;10(1):2. doi: 10.1038/s41514-023-00133-1

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© The Author(s) 2024

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

PMC Copyright notice

Fig. 1 — a The structures of stable isotopic compounds used for LC-MS/MS analysis. Atoms in red, green, or purple are stable isotopes. b Chromatograms of regular (upper panel) and stable isotopic (bottom panel) compounds. These regular and isotopic compounds (200 nM for NR and M + 10 NR; 1000 nM for NMN, NA, NAM, NAD⁺, M + 5 NMN, M + 4 NA, M + 5 NAM, and M + 5 NAD⁺) were separated by an NMN-2 column newly developed by Shimadzu Corporation. Total Ion Counts (TICs) from the multiple reaction monitoring (MRM) of each compound are shown. c Chromatograms and mass spectra of regular and isotopic NMN. TICs and transitions were obtained as a chromatogram from the MRM of regular and isotopic NMN (left panels), and resultant product ions were displayed as mass spectra (right panels). d Calibration curves of NMN and other related compounds. The area under curves (AUCs) of each regular compound at different ranges of concentrations (0, 60, 200, 500, 1000, and 1500 nM for NMN, NAD⁺, and NA; 0, 84, 280, 700, 1400, and 2100 nM for NAM; 0, 2.4, 8, 20, 40, and 60 nM for NR) were measured by LC-MS/MS under the existence of a fixed amount (1000 nM for M + 5 NMN, M + 5 NAD+ and M + 4 NA; 2000 nM for M + 5 NAM; 200 nM for M + 10 NR) of each corresponding isotopic compound and normalized to the AUC of each isotopic internal standard.