Pentenyl Coumarins from the Roots and Stems of Nicotiana rustica and their Bioactivity

Two new pentenyl coumarins (1 and 2), together with three known pentenyl coumarins (3–5), were isolated from the roots and stems of Nicotiana rustica. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1–5 were tested for their anti-rotavirus activity. The results revealed that compounds 1–5 exhibited potent anti-rotavirus activity with therapeutic index (TI) value in the range of 11.1–15.7.