COMT inhibitor. Inhibits both brain and peripheral COMT. Also binds transthyretin (TTR) with high affinity (Kd1 and Kd2 values are 21 and 58 nM, respectively). Inhibits TTR aggregation in human plasma and prevents TTR-induced cytotoxicity in vitro. Stabilizes TTR in mice and humans in vivo. Orally bioavailable. Purity 99%. MW (observed): 273.24