Anti-inflammation compounds from the seedpods of Pongamia pinnata (L.) Pierre guided by the bioactivity and UPLC-HRESIMS

Pongamia pinnata (Linn.) Pierre has anti-inflammatory activity and could significantly decrease serum tumor necrosis factor-α and IL-10 in arthritic rats. Previous research indicated the typical chemical constituent in P. pinnata is furanoflavone. Guided by anti-inflammatory active assay and UPLC-HRESIMS chromatography, 22 compounds were isolated from the ethanol extract of P. pinnata seedpods. One novel furanoflavone, 4′-hydroxypinnatin, was elucidated by HRESIMS, 1D- and 2D-NMR spectra. The 21 known compounds, including 9 furanoflavone, were identified by comparing their NMR data with the previous data in reference. In the known compounds, 5 were isolated for the first time from the species. The anti-inflammatory activities were assayed by assessing LPS-induced NO production in BV-2 cells. 12 compounds can inhibit the production of NO without cytotoxicity at concentration of 50 μM. Among them, compounds 4 can significantly inhibit the production of NO, with the IC 50 value of 31.36 μM.