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Twelve undescribed 2-(2-phenethyl)chromone dimers (1 − 12) were isolated from EtOAc extract of agarwood originating from Aquilaria filaria in the Philippines, guided by a UHPLC-MS analysis. Their structures were elucidated by 1D NMR, 2D NMR, and HR-ESI-MS spectra. The absolute configuration of 2-(2-phenylethyl)chromone dimers was determined by single-crystal X-ray diffraction analysis and comparison of the experimental and calculated ECD spectra. Compounds 1 , 2 , 5 and 9 − 12 exhibited potent to moderate anti-inflammatory activity with IC 50 values in the range of 22.43 ± 0.86 to 53.88 ± 4.06 μM. Phytochemical studies on agarwood of Aquilaria filaria led to identification of undescribed 2-(2-phenethyl)chromone dimers with significant anti-inflammatory activity. [Display omitted] • Twelve 2-(2-phenethyl)chromone dimers were isolated from agarwood of Aquilaria filaria. • All structures were elucidated by spectroscopic, X-ray crystallographic data, and ECD analyses. • Seven compounds showed inhibition effects on NO production in LPS-stimulated RAW264.7 cells. [ABSTRACT FROM AUTHOR]

Six new dimeric 2-(2-phenylethyl)chromones (1 – 6) were successfully isolated from the ethanol extract of agarwood of Aquilaria filaria from Philippines under HPLC-MS guidance. Compounds 1 – 6 are all dimers formed by linking 5,6,7,8-tetrahydro-2-(2-phenylethyl)chromone and flindersia 2-(2-phenylethyl)chromone via a single ether bond, and the linkage site (C5-O-C8′′) of compound 2 is extremely rare. A variety of spectroscopic methods were used to ascertain their structures, including extensive 1D and 2D NMR spectroscopic analysis, HRESIMS, and comparison with literature. The in vitro tyrosinase inhibitory and anti-inflammatory activities of each isolate were assessed. Among these compounds, compound 2 had a tyrosinase inhibition effect with an IC 50 value of 27.71 ± 2.60 μM, and compound 4 exhibited moderate inhibition of nitric oxide production in lipopolysaccharide-stimulated RAW264.7 cells with an IC 50 value of 35.40 ± 1.04 μM. [Display omitted] • Six new 2-(2-phenethyl)chromone dimers were isolated from agarwood of Aquilaria filaria. • Compound 2 had tyrosinase inhibition effect with an IC 50 value of 27.71 ± 2.60 μM. • Compound 4 exhibited anti-inflammatory activity with an IC 50 value of 35.40 ± 1.04 μM. [ABSTRACT FROM AUTHOR]

Four new 2-(2-phenethyl)chromone dimers (1–4) were isolated from EtOAc extract of agarwood originating from Aquilaria filaria from Philippines. Their structures were elucidated by spectroscopic analysis (1D and 2D NMR, and HRESIMS) and comparison of the experimental and computed ECD curves. Compounds 1–4 exhibited inhibition of nitric oxide production in lipopolysaccharide-stimulated RAW264.7 cells with IC 50 values in the range from 33.94 to 57.53 μM. [Display omitted] • Four new 2-(2-phenethyl)chromone dimers were isolated from agarwood of Aquilaria filaria from Philippines. • Compound 4 , whose unites A and B were linked via C5-O-C7″-ether bond, was a relative unusual 2-(2-phenethyl)chromone dimer. • Compounds 1–4 exhibited inhibition of nitric oxide production in lipopolysaccharide-stimulated RAW264.7 cells. [ABSTRACT FROM AUTHOR]