The NO inhibitory constituents from Illigera rhodantha

Sixteen compounds were isolated from the ethanol extract of Illigera rhodantha by silica gel, ODS, and Sephadex LH-20 column chromatographies. These compounds were identified as (2R,3R)-2,3-dihydroxy-2-methylbutane-1,4-diyldibenzoate (1), p-hydroxyphenethyl trans-ferulate (2), 4-O-benzoyl-2-C-methyl-D-erythritol (3), N-trans feruloyl-3-methyldopamine (4), tribulusamide A (5), cryptomeridiol (6), teuclatriol (7), oleanolic acid (8), icario A₂ (9), vanillic acid (10),p-hydroxybenzoic acid (11), gallic acid (12), ethyl gallate (13), chrysophanol (14), D-1-O-methyl-inositol (15), and hexadecanoic acid (16) based on their spectral data and physico-chemical properties. Compound 1 is an undescribed compound, of which its absolute configurations were determined by Mosher and ROESY methods; all the compounds except 10, 11 and 14 were isolated from Illigera genus for the first time. Compared with the positive control indomethacin, compounds 4-6, 8 and 9 inhibited significantly against the NO production in LPS-induced RAW 264.7 cells.