Antiplatelet Aggregation Effects of Phenanthrenes from Calanthe arisanensis

Abstract

Three phenanthrenes (1–3), four indole alkaloids (4–7) and one steroid (8) were isolated from the leaves of Calanthe arisanensis for the first time. In the antiplatelet aggregation assay, phenanthrenes 1 and 2 showed potential antiplatelet activity. We have reported and discussed here the antiplatelet aggregation properties of the eleven naturally-occurring phenanthrenes (1–2 and 9–17) isolated from the underground part of the plant and eighteen chemically synthesized phenanthrenes (18–35). Overall, our data demonstrated that 1,4-phenanthrenequinones 20, 21 and 22 (collagen, IC50 0.2, 0.2, 0.1 μg/mL; thrombin, IC50 0.8, 1.0, 1.1 μg/mL, respectively) could be promising lead candidates for further cardiovascular disease studies.