Chemical constituents from Maackia amurensis and their anti-inflammatory and antioxidant activities

A new flavonoid named (2S)-7,4'-dimethoxyl-6-(2″,3″-epoxy-3″-methylbutyl)flavanone (1), along with five known compounds (2-6), were isolated from the EtOAc-soluble extract of the stem bark of Maackia amurensis. Their structures were elucidated on the basis of spectroscopic methods. All compounds were evaluated for anti-inflammatory and antioxidant activities in vitro. Among them, compound 5 showed the highest inhibitory activity on NO production in RAW264.7 cells stimulated by LPS with IC50 value of 59.0 ± 1.5 µM. Meanwhile, compounds 1-6 exhibited varying antioxidant activities through DPPH, ABTS free radical-scavenging and FRAP assays.