Non-competitive guanylyl cyclase (GC) and adenylyl cyclase (AC) inhibitor. Downregulates cAMP and cGMP synthesis, and suppresses cGMP accumulation in a variety of cell lines (IC50 = 3.4 - 11.2 μM). Inhibits GC-stimulated Cl- transport in vitro and suppresses toxin-induced intestinal fluid accumulation in vivo.