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) chromones (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 IC50 values ranging from 3.71 to 32.04 μM.