Cayratia trifolia is a wild vines that grow a lot in different ecosystems in the Mekong Delta provinces in particular and in Vietnam in general. This is a rich source of raw materials, easy to find, but so far, the research works in the country and in the world on this plant are still limited. Therefore, the study was carried out to study the antioxidant-oriented chemical composition of the whole and fractional extracts (n-hexane, dichloromethane, ethyl acetate, n-butanol, water) from roots, stems, leaves and fruits of C. trifolia by DPPH (1,1-diphenyl-2-picrylhydrazyl) test with vitamin C as reference. The results of the study identified high antioxidant activity of ethyl acetate of C. trifolia root with the strongest antioxidant effect, with IC₅₀ = 51.27 µg/mL, followed by high ethyl acetate of C. trifolia stem, with IC₅₀ = 119.62 µg/mL, followed by high ethyl acetate of C. trifolia leaves, with IC₅₀ = 159.92 µg/mL and finally high ethyl acetate of C. trifolia fruit, with IC₅₀ = 268.11 µg/mL. Simultaneously, from the ethyl acetate fraction of C. trifolia roots, we isolated and recognized the structure of 3 compounds: 5-hydroxymethylfurfural (1), liquigitigenin (2), kaempferol-3-O-rhamnoside (3) . Among them, compounds (1) and (2) were found for the first time in C. trifolia roots compared with previous studies.

Keywords: Antioxidant, Cayratia trifolia (L.) Domino, compound, DPPH.