Claoxylones A–I, prenylbisabolane diterpenoids with anti-Coxsackie B virus activity from the branches and leaves of Claoxylon polot

Nine new prenylbisabolane diterpenoids, claoxylones A–I (1–9), were isolated from the branches and leaves of Claoxylon polot. This is the first example of prenylbisabolane diterpenoids with furan and tetrahydrofuran rings. Their structures and relative configurations were established by spectroscopic and conformational analysis, and the absolute configurations were determined by single-crystal X-ray diffraction and electronic circular dichroism (ECD) analysis. Compounds 1–9 exhibited antiviral activity against Coxsackie B3 virus, with IC50 values of 6.0–33.3 μM.