Thalfoetines A-D (1-4), unique hybrid aporphine alkaloids with a C-7 aromatic unit formed by a new C-C bond linking two building blocks, were isolated from Thalictrum foetidum. Their structures were elucidated by extensive spectroscopic and computational analysis. They inhibited bacteria significantly, and compound 1 damaged the cell structure of Staphylococcus aureus and inhibited its DNA synthesis.