Analyte Annotation and Marker Identification
Table S2 presents the annotated metabolite ions discussed in
this study. The metabolite ions of interest were first searched through
HMDB (http://hmdb.ca) and Metlin
(https://metlin.scripps.edu) with the 5.0 ppm mass tolerance. The
type of adduct ions included [M+H]+,
[M+Na]+, [M+K]+,
[M-H2O+H]+,
[M+2Na-H]+, [M+2K-H]+, and
[M+NH4]+. Only those candidates
with a reported presence in humans were given consideration. For those
unknown significantly changed ions, MS/MS experiments were performed to
match the collision-induced dissociation (CID) fragmentation patterns
either with given standards or recorded MS/MS spectra in HMDB and
Metlin.