Identification of Secondary Metabolites with Antioxidant and Antimicrobial Activities from Artemisia iwayomogi and Chrysanthemum zawadskii

The present study describes the bioactive secondary metabolites of Artemisia iwayomogy and Chrysanthemum morifolium, a traditional medicinal plant widely distributed in Korea, through activity-monitored fractionation and isolation method. The aerial parts of plants were extracted with 80% ethyl alcohol, and an aqueous suspension of the extracts was partitioned successively with n-hexane, chloroform, ethylacetate, and n-butanol, leaving a residual water-soluble fraction. Secondary metabolites, compounds 1-12 were isolated from biologically active solvent-soluble fractions, and chemical structures were identified by high resolution mass spectroscopy and nuclear magnetic resonance spectroscopic analyses. All compounds were subjected to bioassay to evaluate their antioxidant and antimicrobial activities, as judged by scavenging stable 1,1-dipheny1-2-picrylhydrazyl free radicals and disk diffusion test with a minor modification of Institute of Clinical Laboratory Standards, respectively. Kaempferol (4), quercimeritrin (8), luteolin (10), and chlorogenic acid (12) were found to be antioxidants, and the concentrations at which resulted in 50% inhibition (IC50) were 105.16 +/- 0.09, 101.72 +/- 0.76, 91.96 +/- 0.06, and 85.31 +/- 0.14 mu M, respectively, and their activities compared favorably with those observed with the standards, ascorbic acid and BHA, which had IC50, values of 125.48 +/- 0.02 and 115.40 +/- 0.01 mu M, respectively. Leucodin (5) was isolated from A. iwayomogi for the first time as moderate antioxidant and antimicrobial naturals.