The FBMN workflow returned 83 matches with the GNPS speclibs collection, 54 unique spectra (46 unique compounds): seven candidates were validated by the IIMN, encompassing six distinct spectra associated with unique compounds: epicatechin, quercetin, and curcumin, as well as norethindrone, gestoden and a piperazine-derivative antihistamine: cyclizine. The annotation of these three latter compounds within the natural substance mixture is indeed surprising, considering that they are of synthetic origin. However, norethindrone and gestoden, two synthetic steroids, could be considered as natural product-like compounds when calculating their natural product likeness scores (NaPLeS = 1.8 and 2, respectively), in comparison to cyclizine (NaPLeS = -0.6). The more positive the score, the higher the NPlikeness. The most representative annotated chemical class were steroid (29%), diterpenoïd (23%), and flavonoid (17%), as shown in Fig. . B.