Selenoesters and the selenium isostere of phthalic anhydride are bioactive selenium
compounds with a reported promising activity in cancer, both due to their cytotoxicity and capacity
to reverse multidrug resistance. Herein we evaluate the antiviral, the biofilm inhibitory, the
antibacterial and the antifungal activities of these compounds. The selenoanhydride and 7 out
of the 10 selenoesters were especially potent antiviral agents in Vero cells infected with herpes
simplex virus-2 (HSV-2). In addition, the tested selenium derivatives showed interesting antibiofilm
activity against Staphylococcus aureus and Salmonella enterica serovar Typhimurium, as well as a
moderate antifungal activity in resistant strains of Candida spp. They were inactive against anaerobes,
which may indicate that the mechanism of action of these derivatives depends on the presence of
oxygen. The capacity to inhibit the bacterial biofilm can be of particular interest in the treatment
of nosocomial infections and in the coating of surfaces of prostheses. Finally, the potent antiviral
activity observed converts these selenium derivatives into promising antiviral agents with potential
medical applications.
