A marine sponge alkaloid; an agonist of δ- and μ-opioid receptors (EC50s = 5.1 and 10.1 μM, respectively, in HEK293 cells expressing human recombinant receptors); a competitive antagonist of α-ARs (pA2s = 4.88 and 5.43, respectively, in isolated rabbit aorta and renal artery); inhibits growth of HeLa cervical cancer (IC50 = 15 μg/ml) and K562 leukemia (GI50 = 10 μM) cells; induces cell cycle arrest in the G2/M phase in K562 leukemia and MG63 osteosarcoma cells; inhibits chymotrypsin-, caspase-, and trypsin-like activity in a partially purified rat liver proteasome preparation (IC50s = 1.6, 2.7, and 18 μg/ml, respectively); dose-dependently activates p21 independent of p53 in MG63 cells from 20-50 μM; decreases immobility time in the forced swim test in mice at 40 mg/kg