2-(2-Phenylethyl)-4H-chromen-4-one Derivatives from the Resinous Wood of Aquilaria sinensis with Anti-Inflammatory Effects in LPS-Induced Macrophages.

The resinous wood of , known as agarwood ( in Chinese), is traditionally used for the treatment of abdominal pain, vomiting, circulatory disorders, and dyspnea. Four new 2-(2-phenylethyl)-4-chromen-4-one derivatives, namely 7-methoxy-2-[2-(4'-hydroxy-phenyl)ethyl]chromone (), 7-hydroxy-2-[2-(4'-methoxyphenyl)ethyl]chromone (), 5,6-dihydroxy- 2-[2-(3'-hydroxy-4'-methoxyphenyl)ethyl]chromone (), and 6-hydroxy-5-methoxy-2-(2-phenyl-ethyl)chromone (), have been isolated from the resinous wood of , together with nine known compounds. The structures of these compounds were determined through spectroscopic and MS analyses. Among the isolated compounds, neopetasan, 7-methoxy-2-(2-phenylethyl)-chromone, 6,7-dimethoxy-2-(2-phenylethyl)chromone, and 6,7-dimethoxy-2-[2-(4'-methoxy-phenyl)ethyl]chromone inhibited NF-κB activation in LPS-stimulated RAW 264.7 macrophages with relative luciferase activity values of 0.55 ± 0.09, 0.54 ± 0.03, 0.31 ± 0.05, and 0.38 ± 0.14, respectively, versus that of vehicle control (1.03 ± 0.02). In addition, 5,6-dihydroxy-2-[2-(3'-hydroxy-4'-methoxyphenyl)ethyl]chromone, 7-methoxy-2-(2-phenylethyl)chromone, 7-dimethoxy-2-(2-phenylethyl)chromone, and 6,7-dimethoxy-2-[2-(4'-methoxyphenyl)ethyl]chromone could suppress LPS-induced NO production in RAW 264.7 cells and did not induce cytotoxicity against RAW 264.7 cells after 24-h treatment.