Anti-Coxsackie Virus B3 Norsesquiterpenoids from the Roots of Phyllanthus emblica

Three new norsesquiterpenoid glycosides, 4′-hydroxyphyllaemblicin B (1) and phyllaemblicins E (2) and F (3), were isolated from the roots of Phyllanthus emblica, together with three known compounds, phyllaemblic acid (4), phyllaemblicin B (5), and phyllaemblicin C (6). Of these, 3 is a new norsesquiterpenoid dimer. The structures of 1−3 were established by spectroscopic data information and by acidic hydrolysis. The isolated compounds, together with two other known analogues, phyllaemblic acid methyl ester (7) and phyllaemblicin A (8), were evaluated for their antiviral activity toward coxsackie virus B3 (CVB3) by an in vitro cytopathic effect inhibitory assay. Compounds 5−7 exhibited strong anti-CVB3 activity.