Epiyangambin is a phytotoxic lignan, it shows inhibition of seed germination of Agrostis stolonifera cv. penncross (Poaceae) and inhibition of development of Lactuca sativa L. (Asteraceae) seedlings in a microassay using 24-well plates. Epiyangambin exhibits significant inhibition of the transformation of murine epidermal JB6 cells, with the IC50 value of 0.15 microg mL. (+)-Epiyangambin also has anti-platelet aggregation activity.