Two new compounds, designated as knecorticosanones A–B (1–2), along with three known compounds (3–5) were isolated from the fruits of Knema globularia. Their structures were elucidated by extensive spectroscopy analysis, including 1D- and 2D-NMR, UV, IR, and HRESIMS and by comparison with the reported data in the literature. Compounds 1–5 were evaluated for their cytotoxicity. Knecorticosanone B (2) and malabaricone D (5) exhibited moderate cytotoxic effect against Hep-G2, MCF-7 and SK-LU-1 cell lines with IC50 values ranging from 8.76 ± 1.02 to 18.74 ± 1.75 μM while knecorticosanone A (1), virolane (3) and 7-hydroxy-3′,4′-methylenedioxyflavan (4) exhibited weak inhibitory effect against these cell lines with IC50 values ranging from 25.85 ± 2.75 to 66.75 ± 2.08 μM.