A new neolignan and a new phenolic acid from the heartwood of Mansonia gagei JR Drumm

One new neolignan (1) and one new phenolic compound (2), together with four known compounds (3-6) were isolated from the heartwood of Mansonia gagei. Their structures were elucidated by extensive spectroscopic analyses, including 1D and 2D NMR and HRESIMS. The absolute configuration of 2 was established based on the DP4+ protocol and by comparison of experimental and calculated ECD spectra. All isolated compounds were evaluated by DPPH assay for antioxidant activity, while compounds 3-6 were assayed using the MTT-based colorimetric assay for cytotoxicity against lung cancer cell line A549. In terms of antioxidant activity, 1 and 3 exhibited stronger activity (IC50 14.91 +/- 1.10 and 17.46 +/- 0.16 mu M, respectively) than the positive control, ascorbic acid (IC50 30.20 +/- 0.47 mu M). Among the compounds tested for cytotoxicity, compound 3 showed the highest activity, with an IC50 value of 26.04 +/- 2.95 mu M.