Fig. 3: Discovering OPEs at a repository scale.
From: A universal language for finding mass spectrometry data patterns
a, The general structure of OPEs and the MassQL query for the characteristic phosphate fragment. b, The molecular network of MassQL MS/MS in a repository scale query after clustering by Falcon30 (green, annotation by GNPS library; blue, annotation by an OPEs list curated by Ye et al.29; gray, unannotated). c, Summary of MS matching results (precursor m/z match with 20 ppm mass error) by the GNPS MS/MS library and the OPEs list by Ye et al.29. These putative identifications were based on precursor only (level 3 annotations). d, A molecular family shown containing alkyl-OPEs. OPEs reported by Ye et al. or in the MS/MS database search are indicated: tributyl phosphate and dimers (light orange and dark orange), and trioctyl phosphate and dimers (light blue and dark blue). Dibutyl phosphate (green) was not reported by Ye et al. or in the MS/MS database search. The structures displayed are illustrative of one possible isomer of the alkyl chain; the specific structure is beyond the scope of this report.
