An immunosuppressive mycotoxin which inhibits 20S proteasomal chymotrypsin activity (IC50 = 10 μM), preventing activation of NF-κB; induces apoptosis in monocytes and dendritic cells and reduces phagocytosis by neutrophils; inhibits geranylgeranyltransferase I and farnesyltransferase (IC50 = 17 and 80 μM, respectively); potently suppresses viral infection by Nipah and Hendra virus in vitro (IC50 = 149 and 579 nM, respectively).