Glossary

A step of the workflow where researcher will try to give a name to a compound using all available information (m/z, RT, MS/MS spectra). People usually use the terme identification but in fact a compound is only fully identified if a pur standard can be found and injected, in all other cases some doubs on the compound name still exists and here we talk of an annotated compound.

Each NMR signal is attributed to a group of protons of a metabolite

Method used to compare the means of more than 2 groups. It is based on the principle of variance decomposition (variability between groups and variability within groups)

A data processing step of multiplying the time signal obtained in NMR by a mathematical function to improve the signal-to-noise ratio.

A biomarker is a measurable biological characteristic related to a normal or abnormal process (e.g. biomarker of a disease, of the response to a treatment, etc.). It is a metabolite selected at the statistical processing stage that shares with metabolites duly listed in a metabolic database spectroscopic properties (chemical displacement(s), molecular weight, type of fragmentation). This a priori identification of the metabolite remains putative and needs to be confirmed with additional experiments (e.g. MS/MS fragmentation).

Correspond to samples supposed to be free of relevant metabolites. It usually corresponds to the injection solvent.

process aiming at, based on genome information, list all metabolic reactions which can occur in an organism.

Set of nodes connected by edges

Weighted path where weight is the sum of all node degrees along the path.

List of reactions and metabolites involved in the same metabolic function (anabolic and/or catabolic)

Character string allowing to identify a particular metabolite.

processing of MS ions in order to group in a single feature, ions of same m/z ratio and same retention time.

Establishing a correspondance between a metabolite in a fingerprint and a metabolite in a network.

Processing step applied to correct shifts between peaks that can occur across different spectra

Number of edges connected to a node.

Sequence of edges allowing to connect two nodes

Statistical approach aiming at identifying the significance of a metabolic pathway for a given metabolic fingerprint.

"Quality-control pooled samples" correspond to a mix of all the biological samples of a given analytical project. They are generally injected regularly all through the analytical sequence.

Systems Biology Markup Language format which allows describing metabolic network content in a single file.

Path with the minimum number of intermediary nodes.