An organic heterotricyclic compound that consists of a 2,3,3a,8b-tetrahydro-<em>H</em>-benzo[<em>b</em>]cyclopenta[<em>d</em>]furan framework substituted by hydroxy groups at positions C-1 and C-8b, a methoxycarbonyl group at C-2, a phenyl group at C-3, a 4-methoxyphenyl group at C-3a, a methoxy group at C-8 and a 1,4-dioxan-2-yloxy group at position C-6 which in turn is substituted by a methoxy group at position 3 and a 1,2-dihydroxyethyl group at position 6. Isolated from <em>Aglaia silvestris</em>, it exhibits antineoplastic activity. ChEBI: Silvestrol is an organic heterotricyclic compound that consists of a 2,3,3a,8b-tetrahydro-H-benzo[b]cyclopenta[d]furan framework substituted by hydroxy groups at positions C-1 and C-8b, a methoxycarbonyl group at C-2, a phenyl group at C-3, a 4-methoxyphenyl group at C-3a, a methoxy group at C-8 and a 1,4-dioxan-2-yloxy group at position C-6 which in turn is substituted by a methoxy group at position 3 and a 1,2-dihydroxyethyl group at position 6. Isolated from Aglaia silvestris, it exhibits antineoplastic activity. It has a role as a metabolite and an antineoplastic agent. It is a methyl ester, an ether, an organic heterotricyclic compound and a member of dioxanes.