FIG 5.

Binding of divalent transition metals stabilized VU0026921. (A to H) Absorbance was measured from 280 nm to 600 nm in 10-nm increments of 0 or 100 μM ‘921 combined with vehicle (A) or 500 μM CoCl₂ (B), CuSO₄ (C), FeSO₄ (D), MnCl₂ (E), ZnCl₂ (F), CaCl₂ (G), or MgCl₂ (H). Absorbance measurements were taken at 0, 5, 15, 30, 60, or 120 min after the addition of metals. The final absorbance spectra are ‘921 + metal with spectra for metal alone subtracted. Spectra displayed are representative of a single experiment that was performed three times. The spectrum of ‘921 at 0 min was included in each panel as a reference of the compound absorbance alone.