Alkaloids of thalictrum. XX. Isolation, identification and structural elucidation of the alkaloids of the root of Thalictrum longistylum.

A study of the alkaloids of the roots of Thalictrum longistylum DC. resulted in the isolation of 12 alkaloids plus an artifact, 8-trichloromethyldihydroberberine. The 12 alkaloids were berberine, columbamine, jatrorrhizine, magnoflorine, methothalistyline, N-desmethylthalistyline, oxyberberine, palmatine, thalibrine, thalifendine, thaliglucinone, and thalistyline. Of these alkaloids, methothalistyline, N-desmethylthalistyline, and thalistyline are new compounds and with thaliglucinone possess hypotensive activity in dogs and rabbits. Methothalistyline, N-demethylthalistyline, thalistyline, and thalibrine were found to be active against Staphylococcus aureus and Mycobacterium smegmatis with with thalistyline being most active (50 microgram/ml).