Abstract: In this study, an ethanol extract of Ilex latifolia Thunb. was fractionated by successive solvent extraction, and the antioxidant, anti-complement and anti-cancer activity of the ethanol extract and its fractions were explored. Furthermore, the fractions with the highest bioactivity activity were further fractionated into monomers, which were subsequently identified. The antioxidant activity was measured by total reducing power, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity and superoxide anion scavenging capacity. The anti-complement activity was evaluated by hemolysis assay, and the inhibitory effect on the proliferation of MCF-7 cells was determined by MTT assay. The chemical structures of the purified monomers were identified by mass spectrometry (MS) and nuclear magnetic resonance (NMR). The results showed that the ethanol extract and its fractions all had good antioxidant effect. Among them, the ethyl acetate fraction not only had a strong antioxidant activity in the experimental concentration range, but also had a good anti-complement activity with an inhibition percentage of (79.67 ± 0.99)%. It could inhibit the proliferation of human breast cancer MCF-7 cells with an inhibition percentage of (54.8 ± 0.26)%. A total of 11 monomer compounds were isolated from the ethyl acetate fraction, and most of them were identified as phenols and flavonoids. In conclusion, the ethanol extract of I. latifolia Thunb. and its fractions have antioxidant and anti-complement activities and an inhibitory effect on the proliferation of MCF-7 cells, and the ethyl acetate fraction has the strongest biological activity.

Key words: Ilex latifolia Thunb.; compound; isolation and purification; activity evaluation; structural identification