Stephtetrandrine A-D, bisbenzylisoquinoline alkaloids from Stephania tetrandra

Four undescribed bisbenzylisoquinoline alkaloids, designated as Stephtetrandrine A-D, were isolated from the roots of Stephania tetrandra. Their structures were elucidated by IR, HRESIMS, ECD spectra, 1 D and 2 D NMR spectra and comparison with the literature data. Additional five known compounds (limacine, tetrandrine, N-trans-Feruloyltyramine, 2 '-N-chloromethyltetrandrine, 2,2'-N-N-dichloromethyltetrandrine) were also isolated. N-trans-Feruloyltyramine was isolated from Stephania tetrandra for the first time. The isolated compounds were tested for monoamine oxidase, acetylcholinesterase, phosphoinositide 3-kinase alpha and human hepatoma cell HepG2 inhibitory activities. Stephtetrandrine C showed obvious inhibitory effect on human hepatoma HepG2, with IC50 value of 16.2 mu M. Limacine and 2 '-N-chloromethyltetrandrine showed moderate monoamine oxidase inhibitory effect with the IC50 values of 37.7 and 29.2 mu M, respectively.

Automated summary

Four undescribed bisbenzylisoquinoline alkaloids were isolated and identified from the roots of Stephania tetrandra, along with the isolation of N-trans-Feruloyltyramine for the first time from this plant. Stephtetrandrine C exhibited significant inhibitory effect on human hepatoma cell HepG2, while Limacine and 2'-N-chloromethyltetrandrine showed moderate monoamine oxidase inhibitory effects.