16-epi Latrunculin B

16-epiLatrunculin B, a stereoisomer of the actin polymerization inhibitor latrunculin B, was initially isolated from the Red Sea sponge N. magnifica. At concentrations of 5-10 μg/ml, it disrupts microfilament activity in actin disruption assays and exhibits cytotoxic effects on mouse KA31T and NIH3T3 tumor cells, with GI50 values of 1 and 4 μg/ml, respectively. Furthermore, it shows antiviral activity against herpes simplex type 1 virus, with an ED50 of 1 μg/ml.