Fig. 2: Insights from siderophores at a repository scale.

a, The MassQL query for iron-binding searches for the characteristic ⁵⁴Fe¹²C peak with 6.3% abundance relative to the ⁵⁶Fe¹²C peak. Peaks queried by MassQL are colored in red. b, The molecular network of MassQL spectra hits after clustering by MSCluster (gray, no MS/MS annotation by GNPS MS/MS library; orange, MS/MS annotation by GNPS MS/MS libraries). Singletons (no neighbors in the network) have been excluded from this molecular network. c, A spectral family of the molecular network containing desferrioxamines, including proton-bound and iron-bound desferrioxamines E, G and B, in addition to structurally related analogs. d, Less than <1% of clustered MS/MS are annotated as siderophores by GNPS libraries when masses associated with ethylenediaminetetraacetic acid (an anticoagulant added to MS samples) are removed from the network.