Antioxidant Activity of Compounds of Fractions from Cayratia trifolia Species

Cayratia trifolia (Vitaceae, commonly known as three-leaf cayratia), a wild vine abundant in the Mekong Delta, Vietnam, is traditionally used in folk medicine but underexplored scientifically. This study investigated the antioxidant-oriented chemical composition of whole and fractional extracts (n-hexane, dichloromethane, ethyl acetate, n-butanol, water) from roots, stems, leaves, and fruits of C. trifolia using the DPPH assay with vitamin C as a reference. The ethyl acetate fraction of C. trifolia roots exhibited the most potent antioxidant activity (IC50 = 51.27 µg/mL), followed by stems (IC50 = 119.62 µg/mL), leaves (IC50 = 159.92 µg/mL), and fruits (IC50 = 268.11 µg/mL). From the ethyl acetate fraction of roots, three compounds were isolated and identified as 5-hydroxymethylfurfural, liquiritigenin, and kaempferol-3-O-rhamnoside, with the first two reported in C. trifolia roots for the first time.