Chemical Constituents of the Roots of Phlomis betonicoides and Their Anti-Rotavirus Activity

Two new isobenzofuranone derivatives (1 and 2) together with six known compounds (3–8) were isolated from the roots of Phlomis betonicoides, a highly sweet plant in China. Their structures were determined by means of HR-ESI-MS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1–8 were tested for their anti-rotavirus activity. The results showed that compounds 1–8 exhibited potent anti-rotavirus activity with therapeutic index value 7.5–16.4.