Bioactive bisbenzylisoquinoline alkaloids from the roots of Stephania tetrandra.

Ten new bisbenzylisoquinoline alkaloids (1-10) and eight known analogues (11-18) were obtained from the roots of Stephania tetrandra. The structures of these compounds were determined by spectroscopic methods, single-crystal X-ray diffraction, electronic circular dichroism analyses, and chemical method. Compounds 1, 15, and 16 showed the better anti-inflammatory activities with IC₅₀ values of 15.26 ± 2.99, 6.12 ± 0.25, and 5.92 ± 1.89 μM, respectively. Compound 18 possessed cytotoxic activities against MCF-7, HCT-116, and HepG2 cell lines with IC₅₀ values of 2.81 ± 0.06, 3.66 ± 0.26, and 2.85 ± 0.15 μM, respectively.