Atranorin is a depside lichen metabolite that has been found inS. alpinumand has diverse biological activities.^1,2,3,4It is active against the bacteriaB. cereus,B. subtilis,S. aureus,S. faecalis,P. vulgaris,L. monocytogenes, andA. hydrophila(MICs = 1.67, 0.38, 26.7, 13.4, 3.34, 9.83, and 1.67 mM, respectively), the fungiC. albicansandC. glabrata(MIC = 26.7 mM for both), as well as the mycobacteriumM. aurum(MIC = 250 µg/ml).^1,2Atranorin is cytotoxic to A270, HL-60, and Jurkat cancer cells (IC₅₀s = 197.9, 93.5, and 181.6 µM, respectively) but not HeLa, MCF-7, SK-BR-3, or HT-29 cancer cells (IC₅₀s = >200 µM).³It inhibits acetic acid-induced writhing in mice when administered orally at doses of 200 and 400 mg/kg.⁴Atranorin (200 and 400 mg/kg, p.o.) also reduces paw licking and biting in the second, but not first, phase of the formalin test when administered 30 minutes prior to formalin in mice.

1.IngÓlfsdÓttir, K., Chung, G.A., SkÚlason, V.G., et al.Antimycobacterial activity of lichen metabolites in vitroEur. J. Pharm. Sci.6(2)141-144(1998) 2.Yilmaz, M., TÜrk, A.O., Tay, T., et al.The antimicrobial activity of extracts of the lichen Cladonia foliacea and its (-)-usnic acid, atranorin, and fumarprotocetraric acid constituentsZ. Naturforsch. C. J. Biosci.59(3-4)249-254(2004) 3.Ba?korovÁ, M., Ba?kor, M., Mikeš, J., et al.Variable responses of different human cancer cells to the lichen compounds parietin, atranorin, usnic acid and gyrophoric acidToxicol. In Vitro25(1)37-44(2011) 4.Melo, M.G.D., AraÚjo, A.A.S., Rocha, C.P.L., et al.Purification, physicochemical properties, thermal analysis and antinociceptive effect of atranorin extracted from Cladina kalbiiBiol. Pharm. Bull.31(10)1977-1980(2008)