LIGNANS AND OTHER COMPOUNDS FROM THE LEAVES OF TRIADICA ROTUNDIFOLIA WITH INHIBITORY ACTIVITY ON NITRIC OXIDE PRODUCTION

Tóm tắt

By employing chromatographic techniques, six compounds (1–6) were successfully isolated from the leaves of Triadica rotundifolia (Hemsl.)  Esser. Their structures were elucidated to be (1S,2S)-2-(4-hydroxy-3,5-dimethoxyphenyl)-1-(4-hydroxy-3-methoxyphenyl)-1-methoxy propanol (1), (1S,2R)-2-(4-hydroxy-3,5-dimethoxyphenyl)-1-(4-hydroxy-3-methoxyphenyl)-1-methoxypropane-3-ol (2), syringaresinol (3), trimethyl-3,4-dihydrochebulate (4), methyl 3,4,5-trihydroxybenzoate (5), and 5-hydroxymethyl-2-furancarboxaldehyde (6), by detailed analysis of 1D, 2D NMR, and MS spectroscopic data as well as comparison with those reported. The absolute configurations of compounds 1, 2, and 4 were further confirmed using experimental circular dichroism (CD) spectroscopy. Several compounds were evaluated for their inhibitory activity against the production of nitric oxide (NO) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Compounds 1, 2, and 6 were found to reduce NO levels in murine macrophage cells, with IC₅₀ values ranging from 21.1 to 54.5 μM. This study represents the first report of compounds 1−6 isolated from T. rotundifolia.