Six undescribed protoberberine derivatives including two pairs of enantiomers, named yanhusanines G-L, along with fifteen reported protoberberine alkaloids, were isolated from the tubers of Corydalis yanhusuo. Among them, yanhusanines H-L feature a unique 13,13a-seco skeleton which is rare in nature. Their structural elucidations were achieved by extensive spectroscopic analysis and quantum chemistry calculations. A biogenetic route for yanhusanines H-L was proposed. Bioassay results showed that yanhusanine J exhibited potent inhibitory effect against the nitric oxide (NO) production in lipopolysaccharide (LPS) induced RAW 264.7 cells (IC50 = 2.25 +/- 1.32 mu M). Western blot analysis demonstrated that yanhusanine J exerted its anti-inflammatory effect via suppressing the nuclear factor kappa B (NF-kappa B) pathway, together with the decrease of the inflammatory factors TNF-alpha, IL-6 and IL-1 beta. Furthermore, molecular simulation docking indicated that yanhusanine J had strong interaction with the active site of the inducible nitric oxide synthase (iNOS) protein.
NSTL
Elsevier