Norstictic acid is a lichen metabolite that has been found in R. farinacea and has antimicrobial and anticancer activities. It is active against A. hydrophilia, B. subtilis, L. monocytogenes, P. vulgaris, S. faecalis, C. albicans, and C. glabrata (MICs = 0.1-6.7 mM). Norstictic acid (1-100 μM) inhibits proliferation, migration, and invasion of MDA-MB-231 cells. In vivo, norstictic acid (15 mg/kg, i.p.) reduces tumor growth in an MDA-MB-231/GFP mouse xenograft model.
