Chemical Constituents of the Rare Cliff Plant Oresitrophe rupifraga and Their Antineuroinflammatory Activity

Four new ( 1 – 4 ) and thirteen known ( 5 – 17 ) compounds were isolated from a rare cliff plant, Oresitrophe rupifraga . Based on spectroscopic evidence, the new structures were established to be [(2 S ,3 R ,4 R )‐4‐(4‐methoxybenzyl)‐2‐(4‐methoxyphenyl)‐tetrahydrofuran‐3‐yl]methanol ( 1 ), (3 α )‐23‐(acetyloxy)‐3‐hydroxyolean‐12‐en‐29‐oic acid ( 2 ), 3 α ,23‐(isopropylidenedioxy)olean‐12‐en‐29‐oic acid ( 3 , artifact of isolation), and (3 β ,15 β )‐3‐hydroxycholest‐5‐en‐15‐yl β ‐ d ‐glucopyranoside ( 4 ), respectively. Among the isolates, compounds 1 , 4 , epieudesmin ( 7 ), and 1‐ O ‐(9 Z ,12 Z ,15 Z ‐octadecatrienoyl)glycerol ( 17 ) were found to show significant antineuroinflammatory effects by inhibiting the NO production in lipopolysaccharide ( LPS )‐stimulated murine BV ‐2 microglial cells, with IC 50 values of 7.21, 9.39, 4.96, and 8.51 μ m , respectively.