Evaluation of Anti-MRSA and Xanthine Oxidase Inhibition Activities of Phenolic Constituents fromPlumula nelumbinis
Isolation of metabolites fromPlumula nelumbinisled to the discovery of eleven compounds, including six flavonoids and five phenolderivatives. Their structures have been determined on the basis of chemical and spectroscopic data. Most of them, such as compounds1,4,6,8, and10,have shown inhibitory activity against hospital-acquired methicillin-resistantStaphylococcus aureus(HA-MRSA). MICs of compound8against SA-200195 and SA-300150 were 2 μg/mL and 8 μg/mL, respectively. And the antioxidant activity of isolated compounds was determined by checking the scavenging activity against three different radicals: 2,2-diphenyl-1-picrydrazyl (DPPH) radical, hydroxyl radical (OH∙), and superoxide anion (O2∙-), as well as xanthine oxidase inhibition. All flavonoids showed strong antioxidant activity. And compound6displayed the highest inhibitory effect against xanthine oxidase with IC50value of 8.2 μg/mL.