Cytochalasin J is one of a family of potent mycotoxins produced by a range of fungi. All members of the class exhibit profound effects on cytoskeletal proteins, which give rise to pronounced morphogenic activity in animals and plants. Cytochalasin J is the deacetyl analogue of cytochalasin H and exhibits similar, though less potent, antibacterial, antifungal, nematocidal and antitumor activities.