– l-Stephanine is a potent and highly selective alpha 1 adrenoceptor blocker, inhibits anococcygeus muscle contraction induced by phenylephrine with pA2 values of 6.76. Stephanine shows significant antiplasmodial activities with IC(50) ranged from 1.2 uM to 52.3 uM. Stephanine and crebanine have high inhibitory activity against gram-positive animal pathogenic bacteria, with MIC values of 0.078-0.312g/l, but low inhibitory activity against gram-negative animal pathogenic bacteria, they also inhibit hyphal growth of the plant pathogens Cercospora kaki.