Murdannia bracteata is a wild plant in Can Tho City in particular and in Vietnam in general. This is a rich source of raw materials, easy to find, but up to now, domestic and world research on this plant is limited. Therefore, the project was carried out to study the chemical composition according to antioxidant orientation of total and fractional extracts (diethyl ether, ethyl acetate, n-butanol, water) from Murdannia bracteata using DPPH test (1,1-diphenyl-2-picrylhydrazyl) with vitamin C as reference. The results of the project have determined that the ethyl acetate fraction of Murdannia bracteata has the strongest antioxidant activity, with IC₅₀ = 881.66 µg/mL. From the ethyl acetate fraction of Murdannia bracteata, after repeated chromatography and purification, we have isolated and identified the structures of 4 compounds: apigenin (compound 1), kaempferol-3-O-rhamnoside (compound 2), pimaric acid (compound 3) and quercetin (compound 4). Compounds (2) and (3) were found for the first time in the species Murdannia bracteata grown in Can Tho City, Vietnam compared to previous studies. The results of this study provide a database for further research on biological effects in Murdannia bracteata.

Keywords: Antioxidant, Can Tho, DPPH, Murdannia bracteata, .