Constituents from Caragana jubata (Pall.) Poir. and their in vitro neuroprotective effects

The present study aimed to isolate compounds from Caragana jubata (Pall.) Poir. and evaluate their in vitro neuroprotective effects. The compounds were isolated by various column chromatographic techniques and semipreparative HPLC. The structures of the new compounds were elucidated using HR‒ESI‒MS, UV, IR, 1D and 2D NMR, and single X-ray diffraction data analysis. Furthermore, their absolute configurations were determined through ECD spectroscopic data analysis. An oxygen‒glucose deprivation/reperfusion (OGD/R)-induced PC12 cell model and LPS-induced NO release from a BV2 cell model were established to evaluate their in vitro neuroprotective effects. Four undescribed compounds (1‒4), comprising one rare rearranged isoflavanone derivative with a 6/6/6/6 four-ring system, one isoflavanone, and two isoflavones, together with 21 known compounds, were isolated from C. jubata. The steric configurations of compound 5 were determined for the first time. Compounds 1‒5, 7‒9, 11‒12, 14‒15, and 17‒21 showed protective effects against OGD/R-induced PC12 cells in a range of 3.125 to 25 µM. (‒)-Caraflavonoid B (2b) displayed the most prominent protective activity. In addition, compound 2b had antineuroinflammatory activity. Results of network pharmacology indicate compound 2b may exert anti-ischemic stroke (anti-IS) effect by modulating multiple targets and pathways.