Curvularin is a 12-membered macrocyclic lactone incorporating a resorcinyl moiety, produced by a number of fungal species including Curvularia, Penicillium and Alternaria. Curvularin exhibits a distinctly different biological profile to the structurally similar resorcylic acid lactones such as the zearalenones, radicicol and LL Z1640-2. Curvularin inhibits cell division by disrupting mitotic spindle formation and is known to be phytotoxic.