Stephtetrandrine A-D, bisbenzylisoquinoline alkaloids from Stephania tetrandra

Abstract

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 α and human hepatoma cell HepG2 inhibitory activities. Stephtetrandrine C showed obvious inhibitory effect on human hepatoma HepG2, with IC₅₀ value of 16.2 μM. Limacine and 2′-N-chloromethyltetrandrine showed moderate monoamine oxidase inhibitory effect with the IC₅₀ values of 37.7 and 29.2 μM, respectively.

Graphical Abstract

Keywords:

• Stephania tetrandra
• Menispermaceae
• structure elucidation
• bisbenzylisoquinoline alkaloids
• enzyme inhibition
• Stephtetrandrine

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (grant number 21762027).