Trichothecenes are a group of sesquiterpenes produced by various Fusarium species like F. graminearum, F. sporotrichioides, F. poae or F. equiseti. The most important structural features causing the biological activities of trichothecenes are: the 12,13-epoxy ring, the presence of hydroxyl or acetyl groups at appropriate positions on the trichothecene nucleus and the structure and position of the side-chain. They are produced on many different grains like wheat, oats or maize.