Structurally diverse labdane diterpenoids from Leonurus japonicus and their anti-inflammatory properties in LPS-induced RAW264.7 cells. - GreenMedInfo Summary

A phytochemical study on the aerial parts ofled to the isolation and identification of 38 labdane diterpenoids, including 18 new (,,,,-,,-,,) and 20 known (-,-,,,-,,) analogues. Their structures were elucidated based on physical data analysis, including 1D and 2D NMR, HRMS, UV, IR, and X-ray diffraction. The structure of the known compoundwas confirmed by single-crystal X-ray diffraction data. These compounds can be divided into furanolabdane (-), tetrahydrofuranolabdane (-), lactonelabdane (-), labdane (-), and-labdane (-) type diterpenoids. All compounds were screened by lipopolysaccharide (LPS)-induced nitric acid (NO) production in RAW264.7 cells to evaluate anti-inflammatory effects. Compounds,,-,-,-, andinhibited NO production with ICvalues lower than 50μM, with compoundbeing the most active, with an ICvalue of 3.9± 1.7 μM. Further studies show that compoundinhibits pro-inflammatory cytokine production and IKKα/β phosphorylation and restores the IκB expression levels in the NF-κB signaling pathway.