Atranorin is a depside lichen metabolite that has been found in S. alpinum and has diverse biological activities.1,2,3,4 It is active against the bacteria B. cereus, B. subtilis, S. aureus, S. faecalis, P. vulgaris, L. monocytogenes, and A. hydrophila (MICs = 1.67, 0.38, 26.7, 13.4, 3.34, 9.83, and 1.67 mM, respectively), the fungi C. albicans and C. glabrata (MIC = 26.7 mM for both), as well as the mycobacterium M. aurum (MIC = 250 µg/ml).1,2 Atranorin 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).3 It inhibits acetic acid-induced writhing in mice when administered orally at doses of 200 and 400 mg/kg.4 Atranorin (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)