A phytochemical investigation of the fruits of Solanum nigrum L. led to the isolation of 17 compounds including ten lignans (1-10) and seven amide alkaloids (11-17). Their structures were elucidated by extensive spectroscopic methods and comparison with literature data. All the compounds were isolated from S.nigrum, firstly. Besides, a plant network analysis of all isolated compounds was presented to demonstrate the chemotaxonomic significance. The research clarifies the chemotaxonomic significance, and it accordingly contributes to further knowledge of the chemical diversity of S. nigrum.