Two novel antiviral terpenoids from the cultured Perovskia atriplicifolia

Two novel terpenoids, named norperovskatone (1), biperovskatone (2) were isolated from the cultured Perovskia atriplicifolia, together with five known compounds. Compound 1 was a novel C18 nor-diterpenoid featuring a unique seco-ring C. Compound 2 was an unusual dimer including two different diterpenoid units. The structures of the two novel compounds were established by comprehensive spectroscopic analysis, as well as by crystal X-ray diffractions. All of the isolates were evaluated for their anti-HBV activities. Compounds 1 and 2 were found to possess remarkable anti-HBV activity.