IC50: 10.7 μM (Epac1), 66 μM (Epac2(B))

CE3F4 is a selective antagonist of Epac1, with IC ₅₀ s of 10.7 μM and 66 μM for Epac1 and Epac2(B), respectively. CE3F4 is more active on Epac1 than (S)-stereoisomer ((S)-CE3F4, IC ₅₀ , 56 μM), but less active than (R)-CE3F4 (IC ₅₀ , 5.8 μM). CE3F4 (50 μM) shows more inhibitory activities against GEF activity of Epac1, than that of Epac2(AB) or Epac2(B). CE3F4 reduces the exchange activity of Epac1 induced by 007, with IC ₅₀ of 23 ± 3 μM. CE3F4 (40 μM) specifically inhibits Epac1 guanine nucleotide exchange activity without interference with Rap1 activity or Epac1-Rap1 interaction. CE3F4 has no influence on PKA activity. CE3F4 (20 μM) inhibits Epac-induced Rap1 activation in living cultured HEK293 cells. CE3F4 (20 μM) significantly inhibits the late phase of ERK activation stimulated by glucose in INS-1 cells.

CE3F4 (1-3 mg/kg; through a catheter in the internal jugular vein) inhibits atrial fibrillation (AF) and CE3F4 (3 mg/kg; i.v.) inhibits ventricular arrhythmias.
CE3F4 (10 mg/kg; i.v.) improves cardiac function after myocardial infarction in mice.