Stachyflin and acetylstachyflin, novel anti-influenza A virus substances, produced by Stachybotrys sp. RF-7260. II. Synthesis and preliminary structure-activity relationships of stachyflin derivatives

Article abstract of DOI:10.7164/antibiotics.55.165

Stachyflin and acetylstachyflin, produced by Stachybotrys sp. RF-7260, were found to have potent anti-influenza A virus activity. Stachyflin is a new class of hemagglutinin fusion inhibitors of influenza A virus. Several derivatives were synthesized from acetylstachyflin and subjected to preliminary examination of their structure-activity relationships. Among them, the 3-oxo and 3,8′-dioxo derivatives showed potent antiviral activity similar to stachyflin. The 3-epi derivative was four times less active than stachyflin. Modification of the 6′-hydroxy group and the C-5′ position markedly diminished the antiviral activity.