This research aims to determine the phenolic and flavonoid contents in the extracts of the
Sinapis alba L. parts and to calculate the free radical scavenging and antibacterial activity of
them. The highest phenolic content was 28.302 mg/g dry plant, the highest flavonoid content
was 2.072 mg/g dry plant in the methanolic flower extract. In interaction with diphenyl picryl
hydrazyl, the inhibitory concentrations of half of free radicals ranged from 2.836 mg/mL in the
methanolic fruit extract to 17.853 mg/mL in the chloroform flower extract. Methanolic extracts
showed a zone of inhibition against Staphylococcus aureus, the diameters of the inhibition zone
were 17.2 mm in leaf and fruit extracts, and 15 mm in flower extract at a concentration of 700
mg/mL. The study showed that the methanolic extracts of Sinapis alba L. have good phenolic
and flavonoid contents, good free radical scavenging activity and have antibacterial activity
against Staphylococcus aureus.