Dysoverines G-K from the rhizome of Dysosma tonkinense and their cytotoxic activity.

Abstract

Phytochemical investigation of the 70% ethanol extract of Dysosma tonkinense rhizomes (Berberidaceae) led to the isolation of five new biflavonoids, dysoverines G-K (2-6), together with one known compound (dysoverine A, 1). The structures of the isolated compounds were elucidated by comprehensive spectroscopic analyses, including ultraviolet (UV), infrared (IR), one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy, high-resolution electrospray ionization tandem mass spectrometry (HR-ESI-MS/MS), and experimental and theoretical calculations of electronic circular dichroism (ECD). Compounds 1-6 were evaluated for their in vitro cytotoxic activities against seven human cancer cell lines using the MTT assay. All compounds exhibited promising cytotoxic activities, with IC50 values ranging from 1.75 to 10.24 μM. Among them, compounds 3 and 6 exhibited relatively strong cytotoxic activities across the tested cancer cell lines, with IC50 values ranging from 1.95 to 6.95 μM for compound 3 and from 1.75 to 5.73 μM for compound 6. These findings suggest that compounds 3 and 6 warrant further investigation for their potential anticancer activities.