Natural product isolated from the Garcinia hanburyi tree. Induces apoptosis in several tumor cell lines including T47D cells. Activates caspases with an EC50 value of 0.78 - 1.64 μM and competitively inhibits antiapoptotic Bcl-2 family proteins (IC50 values are 1.47, 1.21, 2.02, 0.66, 1.06 and 0.79 μM for Bcl-XL, Bcl-2, Bcl-W, Bcl-B, Bfl-1 and Mcl-1 respectively). Also blocks KIR2.1 channels (EC50 ≤ 100 nM).