Metabonomics in Traditional Chinese Medicine: Mass spectrum-based orthogonal projection method to eliminate the signals of exogenous metabolites

• A novel mass spectrum-based orthogonal projection (MSOP) method was proposed.
• The MSOP method could eliminate the exogenous metabolites effectively.
• Urine samples data is generated from acetaminophen-treated rats by UPLC/ESI-MS.
• The method aims to eliminate the exogenous metabolites generated from the TCM.

In this paper, a novel mass spectrum-based orthogonal projection (MSOP) method was proposed, aiming to eliminate the signals of exogenous metabolites generated from the Traditional Chinese Medicine (TCM) in metabonomics modeling. This method was tested by simulated data and standard sample data, respectively. Urinary sample data generated from control and acetaminophen (APAP)-treated rats by ultra-performance liquid chromatography/electrospray ionization mass spectrometry (UPLC/ESI-MS) were also used to investigate the feasibility of this method. All the results demonstrated that the MSOP method could eliminate the exogenous metabolites effectively. What's more, the metabolism peaks calculated from dosed group with MSOP method were identified to be the metabolites of APAP, which further indicated that the MSOP method was effective and reliable to eliminate the interfering signals of exogenous metabolites in real metabonomics research. Therefore, the MSOP method would be of great significance in metabonomics research especially for study in TCM.