The biosynthetic pathway as currently postulated for trichothecin, a model 12,13-epoxy-Δ9-trichothecene, involves the following sequence: 3 mevalonic acids → farnesyl pyrophosphate → trichodiene → trichodiol → 12,13-epoxytrichothec-9-ene → trichodermol → 12,13-epoxy,4β, 8a-dihydroxy-trichothec-9-ene → trichothecolone → trichothecin.