Non-alkaloid components with inhibitory activity against LPS induced NO production in RAW 264.7 cells isolated from the roots of Sophora flavescens

Sophora flavescens Aiton is a plant in the Leguminosae family. As a traditional Chinese medicine, it is used to treat eczema, bloody stool, skin pruritus, and so on. By studying non-alkaloid components in the roots of S. flavescens, we obtained a total of 49 compounds (1–49), including three undescribed flavonoids (13, 15 and 18), five undescribed isopentenyl flavonoids (32, 34, 38, 39 and 48), two known coumarins (1–2), three phenolic acids (3–5), one known isopentenyl flavonoids (19–31, 33, 35–37, 40–47 and 49). On the basis of chemical evidences and spectral data analysis (UV, ECD, Optical rotation data, 1D/2D-NMR and HR-ESI-MS), the structures of undescribed compounds were elucidated. The inhibitory effect of compounds 1–49 on LPS induced NO production in RAW 264.7 cells was detected. Compounds 11, 19, 21–24, and 28–30 showed significant inhibitory effects, and the IC₅₀ values of compounds 11 and 22 even reached 4.58 ± 0.66 and 4.53 ± 0.66 μM. This study suggests that flavonoids may be the main component that exerts anti-inflammatory effects in the non-alkaloid extraction layer of the extract from the roots of S. flavescens.