Screening of biologically active compounds from weeds.
Ninety-three weedy species were collected (in the Korea Republic) and screened for antimicrobial, antitumour, antioxidant and herbicidal activities. The results showed the following: few of them showed antifungal activities; however, Cuscuta japonica showed inhibitory activity against Alternaria mali; Ambrosia artemisiifolia and Geranium sibiricum showed inhibitory activity against Phytophthora capsici; and Aster yomema and Aster pilosus showed inhibitory activity against Phytophthora parasitica [Phytophthora nicotianae var. parasitica]. Ambrosia artemisiifolia, Artemisia princeps, Artemisia capillaris, Ludwigia prostrata, Chrysanthemum zawadskii, Bidens frondosa and G. sibiricum showed broad antibacterial activities. Carex chordorrhiza, Artemisia capillaris, Persicaria nodosa, Senecio koreanus, Panicum bisulcatum and G. sibiricum showed antiblebbing activity on human chronic leukaemia K562 cell, of which Persicaria nodosa had the greatest activity. Angelica decursiva, Equisetum arvense, Cimicifuga heracleifolia, Persicaria nodosa, G. sibiricum, Oenothera odorata and Cyperus sanguinolentus all showed antioxidant activities. Ludwigia prostrata and Peucedanum terebinthaceum showed strong herbicidal activities. A full list of weed species and microrganisms investigated during the trial is presented.