Anti-Hepatitis C Virus Dinorditerpenes from the Roots of <i>Flueggea virosa</i>

Along with four known terpenoids (1–4), eight new dinorditerpenes (5–12) were isolated and identified from the roots of Flueggea virosa. The absolute configurations of 4–6 were determined by the Mosher’s method, and that of 5 was confirmed by single-crystal X-ray diffraction analysis. Using the hepatitis C virus cell culture infection system, compounds 1, 3, 11, and 12 exhibited significant anti-HCV activity with EC50 values of 5.6, 5.0, 7.5, and 6.6 μM, respectively. Compounds 11 and 12 were nontoxic toward the tested Huh7.5 cell lines.