Isoquinoline Alkaloids from Whole Plants of Thalictrum cirrhosum and Their Antirotavirus Activity

Two new ( 1 and 2 ), together with two known ( 3 and 4 ), isoquinoline alkaloids were isolated from the whole plants of Thalictrum cirrhosum . Their structures were determined by means of HR-ESI-MS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1 – 4 were tested for their antirotavirus activity. The results revealed that compounds 2 exhibited high antirotavirus activity with a therapeutic index (TI) value of 19.3. This value is close to that of positive control (TI value 20.4). Compounds 1 , 3 , and 4 also exhibited potent antirotavirus activity with TI value above 10.