A new phenylpropanoid-substituted epicatechin from the rhizome of Smilax china

A new phenylpropanoid-substituted epicatechin, (2 R,3S,9R)-methyl {2-(3,4-dihydroxyphenyl)-3,5,8a,4a-tetrahydroxy-3,4-dihydro-2H,12H-pyrano[2,3-α]xanthen-12-yl}acetate (1) was isolated from the rhizome of Smilax china, along with twelve known compounds (2 - 13), which were isolated from the Smilax genus for the first time. On the basis of chemical evidences and spectral data analysis (UV, ECD, 1 D and 2 D-NMR, HR-ESI-MS), the structures of compound 1 was elucidated. Furthermore, all compounds have been tested for their inhibitory effects on NO production in LPS-induced RAW 264.7 cells, and compounds 6, 7, 11 and 13 have obvious inhibitory effect, in which the IC₅₀ value of compound 7 reached 11.63 ± 1.29 μM. Through target screening and molecular docking, we can speculate that compound 7 may exert its anti-inflammatory effect by binding to MAPKAP kinase 2 and Leukocyte Proteases Cathepsin G & Chymase.