A selective inhibitor of retrograde protein trafficking mediated by syntaxin-5; inhibits ebolavirus infection (EC50 = 12.2 μM) in HeLa cells; reduces ricin-induced toxicity in HeLa cells (20 μM); blocks JC polyomavirus, BK polyomavirus, and SV40 infection of Vero green monkey kidney epithelial cells in vitro (EC50s = 28.4, 61.2, and 58.6 μM, respectively); improves survival and reduces symptoms in mice infected with Shiga toxin-producing E. coli (100 mg/kg, i.p.); protects mice against ricin challenge when administered prophylactically (2 mg/kg),