Two new nimbolinin- and trichilin-class limonoids isolated from the fruits of Melia azedarach

Two new furan fragment isomerized limonoids, meliazedalides A and B (compounds 1 and 2 ), were isolated from the fruits of Melia azedarach Linn.. Their chemical structures were elucidated on the basis of HR-ESI-MS and 1D and 2D NMR data, which belonged to nimbolinin- and trichilin-class, respectively. Compound 2 exhibited weak inhibitory effect on NO production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages with IC₅₀ being 37.41 μmol·L^-1.