Bioactive Lipid Metabolites in Amanita Virosa.

Amanita fungi are the main lethal toadstool among the 1000 poisonous mushrooms known in the world. Thrombin is the key serine proteinase of the coagulation cascade and therefore a suitable target for inhibition of blood coagulation. An extract of Amanita virosa considerably inhibited thrombin (48%) and showed no inhibitory activity on trypsin. On the basis of inhibition selectivity between thrombin and trypsin and potency of thrombin inhibition, Amanita virosa constituted a good starting material for isolation of further compounds that are active against thrombin. In a preliminary study, 95 selected mushroom species have been screened in order to find novel specific non-peptidic thrombin inhibitors. The extract of Amanita virosa considerably inhibited thrombin (48% at concentration of 120 μg/mL). A bioassay oriented fractionation of the extract of Amanita virosa has led to the isolation of active compounds. On the basis of spectroscopic data, chemical reactions and GCMS analysis, complex mixtures of triglycerides, monoacylglycerols, free fatty acids and ergosterol have been isolated and identified.