Mushrooms are known all over the world both due to the remarkable gastronomic value of some species
and for severe intoxications mediated by other species that are frequently difficult to distinguish from
the edible ones, by the common user. Therefore, it is important to develop strategies to discover
molecules that can identify mushroom species. In the present work, two GC–MS methodologies were
applied in the chemical characterization of 22 mushroom species (12 edible, 3 toxic and 7 potentially
toxic) – a multi-target procedure to simultaneously determine amino acids (AA), fatty acids (FA) and
sterols by previous derivatization procedure with MSTFA, and a Head Space-Solid Phase Microextraction
method to determine volatiles. For both methods, two approaches to data analysis were used:
(I) targeted analysis, to identify and quantify AA, FA sterols and volatiles; (II) untargeted analysis,
including Principal Component Analysis and Partial Least Square Discriminant Analysis, in order to
identify metabolites/metabolite pattern with potential species identification and/or differentiation.
Multi-target experiment allowed the identification and quantification of twenty one primary metabolites
(9 AA, 11 FA and 1 sterol). Furthermore, through untargeted data analysis, it was possible to identify a 5-
carbon sugar alcohol structure molecule, which was tentatively identified as xylitol or adonitol, with
potential to be a species-marker of the edible Suillus bovinus mushrooms. Volatile profiling studies
resulted in the identification of the main volatiles in mushrooms. Untargeted analysis allowed the
identification of 6 molecules that can be species- or genus-specific: one secondary metabolite specific to
the edible species Lycoperdon perlatum, an ester of hexanoic acid, tentatively identified as allyl or vinyl
caproate; and five other secondary metabolites, whose identification was not achieved, which were only
detected in Lactarius aurantiacus specimens (edibility/toxicity unknown).
