To our knowledge, this is the first work on the influence of species upon the bioactive molecules, antioxidant properties, and enzyme inhibitory capacities against tyrosinase and alpha-amylase ofOnosma polyanthaandO. mollis. The levels of phenolic compounds were from 6.55 to 10.37 mg gallic acid equivalent/g extract. The concentrations of total flavonoids varied from 2.71 to 10.78 mg quercetin equivalent/g extract. Twenty-five compounds were quantified via liquid chromatography - electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Significant differences were found between the two species. Chlorogenic acid, rosmarinic acid, hesperidin, and luteolin 7-glucoside were the major compounds in both species. Four antioxidant assays together with two enzyme tests confirmed thatO. polyanthaandO. mollisextracts exhibited remarkable antioxidant and enzyme inhibitory capacities. Statistical analyses confirmed that the biological activities depend on the synergism between phenolic compounds and radicals. The results proposedO. polyanthaandO. mollisspecies as potential sources of bioactive compounds for industrial application.