Steroidal alkaloids with anticoagulant activity from Veratrum nigrum L.

Chemical investigation of Veratrum nigrum L. (Melanthiaceae) resulted in the isolation of three previously undescribed steroidal alkaloids (1-3) and sixteen known analogues (4-19), including a solanidine-type steroidal alkaloid bearing a 3-O-β-D-glucosyl moiety (1) and a 15-hydroxylated jervine-type steroidal alkaloid (2). The absolute configurations of the undescribed compounds were determined by single-crystal X-ray diffraction, DP4+, and ECD calculations. Evaluation of the anticoagulant activity of all isolated compounds revealed that alkaloid 3 prolonged activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT) and moderately inhibited rabbit platelet aggregation induced by adenosine diphosphate (ADP) and arachidonic acid (AA).