Structural\nSimilarity in Natural Products Leading\nto Sample Misidentification: A Case Study of the Bisbenzylisoquinoline\nAlkaloids Oxyacanthine and Berbamine

The similar structures of natural compounds and the absence\nof\nNMR data for commercial products raise the risk of misidentification.\nThis work reports a case in which purchased samples labeled as “berbamine”\nfrom 14 suppliers are oxyacanthine (<b>1</b>). The NMR data\nof all purchased samples were consistent. The X-ray crystallography\ncharacterization of one sample revealed it to be <b>1</b>. The\nNMR data of <b>1</b> were fully assigned for the first time.\nBerbamine (<b>2</b>) was isolated from the roots of <i>Berberis sieboldii</i> Miq. The NMR data of <b>2</b> were\nassigned, and its crystal structure was reported for the first time.\nThe authors intend to raise awareness and support the academic/industrial\ncommunity through a study of this misidentification case.