Jasplakinolide
Jasplakinolide is a naturally occurring cyclo-depsipeptide. It was first isolated from a species of marine sponge named Jaspis johnstoni. It is permeable to the cell membrane meaning that it is able to cross the membrane. Once it crosses the cell membrane, it is a potent inducer and stabilizer of actin filaments meaning that it rapidly stabilizes pre-existing filaments and polymerize the protein actin. It also inhibits the disassembly of theses filaments. When doing this, it competes with phalloidin making it unable to bind with F-actin.