Column chromatography of an ethanol extract from the whole plant of Berberis virgetorum resulted in the isolation of a novel benzylisoquinoline alkaloid, (—)-berbervirine [1], together with three known compounds, namely, berberine, jarrorrhizine, and noroxyhydrastinine. The structure of the new compound was determined as ',4'α-carbonyl-2'-carboxylbenzylisoquinoline by consideration of spectral and cd evidence. © 1995, American Chemical Society. All rights reserved.