Oosporein (Synonyms: NSC 88466)

Oosporein is a mycotoxin that has been found in Beauveria and has diverse biological activities.^1,2 It is cytotoxic to Sf9 and Sf21 insect cells with 50% cytotoxic concentration (CC₅₀) values of 4.23 and 10.43 µM, respectively.³ Oosporin induces lethality in day-old cockerels (LD₅₀ = 6.12 mg/kg).⁴ It inhibits Na⁺/K⁺-, Ca²⁺-, and Mg²⁺-ATPase activities by 27, 52, and 100%, respectively, in equine erythrocyte ghosts when used at a concentration of 200 µg/ml.² Oosporein inhibits herpes simplex 1 (HSV-1), but not HeLa cell or E. coli, DNA polymerase (IC₅₀s = 75, 610, and >700 µM, respectively).⁵ It is active against the bacterium S. pneumoniae (MIC = 32 µg/ml) and the plant pathogenic fungus P. infestans (MIC = 16 µM).^1,6

1.Wainwright, M., Betts, R.P., and Teale, D.M.Antibiotic activity of oosporein from Verticillium psalliotaeTrans. Br. Mycol. Soc.86(1)168-170(1986) 2.Jeffs, L.B., and Khachatourians, G.G.Toxic properties of Beauveria pigments on erythrocyte membranesToxicon. 35(8)1351-1356(1997) 3.Arboleda Valencia, J.W., GaitÁn Bustamante, A.L., JimÉnez, A.V., et al.Cytotoxic activity of fungal metabolites from the pathogenic fungus Beauveria bassiana: An intraspecific evaluation of beauvericin productionCurr. Microbiol.63(3)306-312(2011) 4.Cole, R.J., Kirksey, J.W., Cutler, H.G., et al.Toxic effects of oosporein from Chaetomium trilateraleJ. Agric. Food Chem.22(3)517-520(1974) 5.Terry, B.J., Liu, W.C., Cianci, C.W., et al.Inhibition of herpes simplex virus type 1 DNA polymerase by the natural product oosporeinJ. Antibiot. (Tokyo)45(2)286-288(1992) 6.Nagaoka, T., Nakata, K., Kouno, K., et al.Antifungal activity of oosporein from an antagonistic fungus against Phytophthora infestansZ. Naturforsch. C. J. Biosci.59(3-4)302-304(2004)