Phytotoxic Effect, DPPH Radical Scavenging Activity and Chlorogenic Acid Level of Methanol Extracts fromAerial Parts of Several Korean Salad Plants

Abstract

Aseries of aqueous or methanol extracts from four different Korean salad plants were assayed to determine theirallelopathy and antioxidant activity. The xtracts aplied on filter paper in a Petri-dish bioassay significantly inhibited rootgrowth of against alfalfa (Medicago sativa-1ofAster yomena was most phyto-toxic to alfalfa root growth, and folowed by that ofCirsium japonicum,Taraxacum oficinale,andIxeris dentate. Methanolextractsofplantsdose-dependentlyincreasedDPPHfreeradicalscavengingactivityinvitro. Antioxidantactivityofmethanolextracts from the same plant species was investigated, and the result showed high DPPH free radical scavenging activity inCirsiumjaponicum,Asteryomena,andIxeris dentate, however, inTaraxacumofficinalewasleastactivity.BymeansofHPLCanalysis, chlorogenic acid,p-1, respectively, showedthe highest amounts in methanol extracts fromCirsium japonicumleaves. These results suggestthat Compositae salad plantscontain water-soluble substances with allelopathic potential as wel as antioxidant activity.Key words- Alelopathy, Antioxidant activity, DPH radical scavenging activity, Plant parts, Extracts, Natural antioxidant