Two New 3,4;9,10-seco-Cycloartane Type Triterpenoids from Illicium difengpi and Their Anti-Inflammatory Activities

A pair of new 3,4;9,10-seco-cycloartane type triterpenoid stereoisomerides: 24R,25-dihydroxy-3,4;9,10-seco-4(28)-cycloarten-10,3-olide (1) named Illiciumolide A and 24S,25-dihydroxy-3,4;9,10-seco-4(28)-cycloarten-10,3-olide (2) named Illiciumolide B were isolated from the stem bark of Illicium difengpi, as well as five known biogenetically related triterpenoids, including sootepin E (3), betulinic acid (4), lupeol (5), (all-Z)-1,5,9,13,17,21-hexamethyl-1,5,9,13,17,21-cyclotertracosahexaene (6), and (all-E)-2,6,10,15,19,23-hexamethyl-2,6,10,14,18,22-tetracosahexaene (7). The structures of two new compounds were determined on the basis of spectroscopic analysis including 1D-, 2D-NMR, and MS techniques. Two assays were conducted: inhibition of tumor necrosis factor-alpha (TNF-α) and inhibition of nuclear factor kappa B (NF-κB) in RAW264. 7 cells induced by lipopolysaccharide (LPS). It was observed that compounds 1, 2 and 7 showed significant inhibition of TNF-α production and NF-κB release. The molecule docking results showed that compounds 1 and 2 got high fitness scores with dual specificity mitogen-activated protein kinase kinase 1 (MPKK1), whose activation plays a pivotal role between TNF-α and activation of NF-κB. The anti-HIV-1 potency of compounds 1–5 was also discussed, in addition to the results of computer-aided screening for targets.