Analgesic, sedative and antispastic effects of l-stepholidine

l-Stepholidine(St)(l-2,10-dihydroxy-3,9-dimethyloxy-tetra-hydropseu-doberberine) is an alkaloid isolated from Stephania longipes H.S.Lo. The intragastric LD50 in mice was 928(85-984) mg/kg.The ig ED50 on HAc-writhing of mice was 223(209-239) mg/kg. In the experiments of electric stimulation on mouse tail, the analgesic effect of St 50 mg/kg was weaker than that of morphine hydrochloride 25 mg/kg, and equivalent to that of l-tetrahydropalmatine. The inhibition of spontaneous activity of mice was measured by means of photocell, and ig ED50 was 258(239-279) mg/kg. St(8-40 micrg/mL)induced a dose-dependent inhibition on isolated intestine of rabbits.