IC50: 17.9 μM (HERG channel)

The effects of Guanfu base G is investigated in human embryonic kidney 293 (HEK293) cells transiently transfected with HERG complementary DNA using a whole-cell patch clamp technique. Guanfu base G inhibits HERG channel current in concentration-, voltage-, and time-dependent manners. Guanfu base G shifts the activation curve in a negative direction and accelerated channel inactivation but shows no effect on the inactivation curve. Moreover, Guanfu base G also accelerates channel recovery from inactivation.

Guanfu base G (5 mg/kg; intravenous injection; for 5-1200 minutes; rats) treatment in rats after 15 min could be detected the presence of Guanfu base A, about 10% of Guanfu base G in vivo could metabolize to Guanfu base A, which may be related to the metabolic enzymes in the body and its nature-related compounds, however, the substance in the body to eliminate more quickly, could be detected only around 240 min. The pharmacokinetic behavior of Guanfu base G is better in rats, the T _1/2 is 4.16 hours. These results indicate that Guanfu base G has a relatively suitable elimination half-life.