FIG. 2.

Anion-exchange HPLC analysis of legiobactin samples treated with iron. HPLC fractions containing legiobactin (i.e., both CAS-positive and bioassay-positive material) were pooled and reinjected into the HPLC following no addition of iron (left), addition of 0.67 mM FeCl₃ (middle), or addition of 1 mM FeCl₃ (right). Fractions were eluted with NaCl over a 120-min period. Shown here are those peaks eluted between 80 and 90 min, as detected at A₂₂₀ (top line) and A₂₅₄ (bottom line). The results presented are representative of at least two independent experiments. AU, arbitrary units.