Cytotoxic effects of aporphine alkaloids from the stems and leaves of Stephania dielsiana YCWu

Phytochemical studies of the stems and leaves of Stephania dielsiana Y.C.Wu yielded two new aporphine alkaloids (1 and 5), along with six known alkaloids (2-4 and 6-8). Their structures were characterised based on analyses of spectroscopic data, including one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy and high-resolution electrospray ionisation mass spectrometry (HR-ESI-MS). The cytotoxic activities of the isolated compounds against a small panel of tumour cell lines were assessed by MTS assay. Interestingly, compound 2 exhibited particularly strong cytotoxic activities against HepG2, MCF7 and OVCAR8 cancer cell lines, with IC50 values of 3.20 & PLUSMN; 0.18, 3.10 & PLUSMN; 0.06 and 3.40 & PLUSMN; 0.007 & mu;M, respectively. Furthermore, molecular docking simulations were carried out to explore the interactions and binding mechanisms of the most active compound (compound 2) with proteins. Our results contribute to understanding the secondary metabolites produced by S. dielsiana and provide a scientific rationale for further investigations of cytotoxicity of this valuable medicinal plant.

Automated summary

Two new aporphine alkaloids (1 and 5) were discovered in the stems and leaves of Stephania dielsiana Y.C.Wu, along with six known alkaloids (2-4 and 6-8). Their structures were determined using spectroscopic techniques. Compound 2 showed strong cytotoxic activity against cancer cell lines HepG2, MCF7, and OVCAR8. Molecular docking simulations provided insights into the interactions and binding mechanisms of compound 2 with proteins. This study contributes to the understanding of secondary metabolites produced by S. dielsiana and provides a scientific basis for further investigation into the cytotoxicity of this medicinal plant.