Galbinic acid is a depsidone lichen metabolite that has been found in U. undulata.1,2 It is active against the Gram-positive bacteria B. cereus, B. subtilis, and S. aureus, but not S. epidermidis (MICs = 62.5, 62.5, 250, and >250 ug/ml, respectively), as well as the Gram-negative bacterium E. coli, but not S. sonnei (MICs = 125 and >250 ug/ml, respectively).3