Roccellic acid is a lichen secondary metabolite that has been found in R. montagnei and has antibacterial and anticancer activities.1,2 It is active against the bacteria S. gordonii and P. gingivalis (MIC = 46.9 μg/ml for both).1 Roccellic acid (100 μg/ml) inhibits proliferation of MDA-MB-231, MCF-7, and DLD-1 cancer cells by 65.3, 75.8, and 87.9%, respectively.2