Structurally diverse isobutylamides from Zanthoxylum nitidum.

Five pairs of new racemic alkamides (1a/1b and 4a/4b - 7a/7b) and two new achiral derivatives (2 – 3), as well as five known ones (8 – 12), were purified from the 95% EtOH extract of Zanthoxylum nitidum. Their structures were elucidated based on spectroscopic analyses (NMR and HR-ESI-MS), electronic circular dichroism (ECD) and NMR calculations. The enantiomeric separation was successfully achieved by chiral-phase HPLC-ECD measurements. Among all the isolates, compounds 2 , 3 , and 10 showed inhibitory effects against five human cancer cell lines, with IC 50 values in range of 18.51–48.03 μM. [Display omitted] • Seven new unsaturated alkylamide derivatives were isolated from Zanthoxylum nitidum. • The absolute configurations were determined by ECD calculation. • The enantiomeric separation was successfully achieved by chiral-phase HPLC-ECD measurements. • Compounds 2 , 3 , and 10 displayed moderate inhibitory effects against five human cancer cell lines. [ABSTRACT FROM AUTHOR]