Benzo(d)xanthen-12-ol, 1,2,3,4,4a,5,6,7,7a,8-decahydro-9-methoxy-4,4,7,7a-tetramethyl-, (4aS,7S,7aR,13aS)-

Strongylin A is a sesquiterpenoid that is 1,2,3,4,4a,5,6,7,7a,8-decahydrobenzo[d]xanthene substituted by a hydroxy group at position 12, methyl groups at positions 4, 4, 7 and 7a and a methoxy group at position 9 (the 4aS,7S,7aR,13aS stereoisomer). Isolated from Strongylophora hartmani, it exhibits activity against the influenza virus. It has a role as a metabolite, an antineoplastic agent and an EC 3.2.1.18 (exo-alpha-sialidase) inhibitor. It is a sesquiterpenoid, a member of phenols, an aromatic ether and an organic heterotetracyclic compound.