Norstictic acid was first reported in 1934 as a metabolite produced by the lichen, Lobaria pulmonaria, along with two related
compounds. Norstictic acid has antioxidant, antimicrobial and antitumor activities. Norstictic acid treatment significantly
suppresses MDA-MB-231/GFP tumor growth of a breast cancer xenograft model in athymic nude mice.
