Abstract
The known metabolite heteronemin was isolated from the marine sponge Hyrtios reticulata Thiele, using a bioguided fractionation with the enzyme protein farnesyl transferase as a target (IC50 = 3 µM). In contrast, 12-epi-heteronemin, isolated from a related sponge, Hyrtios erecta Keller, did not show any noticeable inhibitory activity.