(24R)-3β-[6-O-(β-D-Glucopyranosyl)-β-D-glucopyranosyloxy]-24-[2-O,6-O-bis(β-D-glucopyranosyl)-β-D-glucopyranosyloxy]25-hydroxycucurbita-5-ene-11-one

11-oxo-mogroside V shows a higher scavenging effect on O ₂ - (concentration at which 50% of chemiluminescence intensity is inhibited [EC ₅₀ ] =4.79 μg/mL) and H ₂ O ₂ (EC ₅₀ =16.52 μg/mL) than those of mogroside V. It exhibits a remarkable inhibitory effect on *OH-induced DNA damage with EC ₅₀ =3.09 μg/mL.11-oxo-mogroside V, a natural sweetener, isolated from the fruits of Momordica grosvenori , exhibits strong inhibitory effect on the primary screening test indicated by the induction of Epstein-Barr virus early antigen (EBV-EA) by a tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA). 11-oxo-mogroside V exhibits strong inhibitory effect on EBV-EA induction (91.2, 50.9 and 21.3% inhibition at 1000, 500 and 100 mol ratio/TPA concentration, respectively).