Guided Isolation of Isopentenyl Flavonoids from Daphne giraldii Based on the Combination of GNPS and SMART

Six flavonoids (1–6), including 3 previously undescribed compounds (1–3), were isolated from the dried roots and stem skins of Daphne giraldii Nitsche. The strategy of LC-tandem mass spectrometry-based Global Natural Products Social Molecular Networking (GNPS) molecular network technology and NMR-based Small Molecule Accurate Recognition Technology (SMART) technology facilitated the precise separation of isopentenyl flavonoids in D. giraldii. The structures were determined through comprehensive spectroscopic analysis. Furthermore, all compounds were evaluated for their cytotoxic activity against Hep3B cells. Specifically, compounds 1 and 3 exhibited significant cytotoxicity with IC50 values of 5.52 ± 0.57 and 2.53 ± 0.49 μM, respectively, compared to the positive control sorafenib (IC50 = 7.08 ± 0.23 μM).