CEU Mass Mediator is a tool for searching metabolites in different databases (Kegg, HMDB, LipidMaps, Metlin, NP Atlas, KNApSAcK, MINE and an in-house library). This is specially designed for searches through experimental masses obtained from mass spectrometry techniques.

CEU Mass Mediator unifies compounds from different sources based on the InChI Key. It will save time to researchers which have to find the compounds in the databases one by one and unifying them manually as well as it reduces the risk of a wrong manual unification.

The LC-MS batch advanced search calculates a scoring for the annotations based on three aspects:
1. Probability of the compound to form a specific adduct.
2. Presence of other adducts coming from the same signal in the same RT window.
3. RT of the lipids with the same head depending on the number of carbons and double bonds (and, consequently, the hydrophobicity of them).
A final score is calculated based on these three aspects (see manual for more information).

The CE-MS services allows to search compounds using experimental information from Capillary Electrophoresis in different set-ups (background electrolyte, polarity and ionization mode). It permits searches using the effective mobility, the experimental relative migration time and the predicted absolute or relative migration time.

Furthermore, it offers the next services:
1. A Lipid Annotation Service (LAS) for annotating lipids using a totally isolated docker implemented in Prolog and applying the same rules than the LC-MS batch advanced search.
2. A pathway displayer for sorting the most relevant pathways in a previous search from CMM.
3. Identification of oxidized glycerophosphocholines (oxPCs) based on the MS/MS spectrum of them.
4. A spectral quality controller to measure the reliability of a spectrum for identification purposes.

CEU Mass Mediator version 3.0.
Citing CMM:
  1. CMM 2.0: Gil-de-la-Fuente A., Godzien J. et al. Knowledge-based metabolite annotation tool: CEU Mass Mediator. Journal of Pharmaceutical and Biomedical Analysis, 2018, 154, 138-149.
  2. CMM 3.0: Gil-de-la-Fuente A., Godzien J. et al. CEU Mass Mediator 3.0: A Metabolite Annotation Tool Journal of Proteome Research 2019, 18 (2), 797-802
  3. CE-MS Database: Mamani-Huanca, M., Gil-de-la-Fuente A. et al. Enhancing confidence of metabolite annotation in Capillary Electrophoresis-Mass Spectrometry untargeted metabolomics with relative migration time and in-source fragmentation Journal of Chromatography A 2020, 1635 (4), 461758
  4. RT Pred search: García, C.A., Gil-de-la-Fuente, A., Barbas, C. et al. Probabilistic metabolite annotation using retention time prediction and meta-learned projections Journal of Cheminformatics 2022, 14, 33

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Last updated: 01/06/2022