Nucleoside alkaloids with anti-platelet aggregation activity from the rhizomes of Ligusticum striatum

Two new (1-2) and six known (3-8) nucleoside alkaloids were isolated from the rhizomes of Ligusticum striatum DC. Compounds 1 and 2 (liguadenosines A and B) were unusual N-10 substituted adenosine derivatives. Their structures were elucidated by extensive spectroscopic analyses and ECD calculation. Most of them significantly inhibited the abnormal increase in platelet aggregation induced by ADP at concentrations of 50 and 100 mu M. Particularly, the inhibitory effect of 3 was equivalent to aspirin.