Seven New 2-(2-Phenylethyl) Chromone Derivatives from Agarwood of Aquilaria Agallocha with Inhibitory Effects on Nitric Oxide Production

Seven new 2-(2-Phenethyl) chromone derivatives ( 1-7 ), including four 2-(2-Phenethyl) chromone s ( 1-4 ), one 6, 7, 8 trihydroxy-2-(2-Phenethyl) chromone ( 5 ), one acetylated 5, 6, 7, 8-tetrahydroxy-2-(2-Phenethyl) chromone ( 6 ), and one chlorine-containing 5, 6, 7, 8-tetrahydro-2-(2-Phenethyl) chromone ( 7 ), along with eight known compounds ( 8-15 ), were isolated from agarwood originating from Aquilaria agallocha Roxb.. Their structures were determined mainly by high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) and nuclear magnetic resonance (NMR) analysis. The absolute configurations of 3 - 7 were resolved by electronic circular dichroism (ECD) calculations. Nearly all compounds were evaluated for their anti-inflammatory activities in RAW264.7 cells. Compounds 1 and 7-11 displayed significant anti-inflammatory activities with IC 50 values ranging from 3.71 to 32.04 μM