Antimicrobial activity of some coumarin containing herbal plants growing in Finland

Antimicrobial screening against selected Gram-positive and Gram-negative ba cteria, yeasts, mold, as Well as plant pathogenic fungi, with emphasis on m ethod optimization was carried out on methanol extracts prepared from seven plants grown in Finland. Sensitivity to the extracts was found to vary con siderably among the micro-organisms, the extract from Petroselinum crispum and Ruta graveolens showing the highest toxicity against Rhizoctonia solani . The growth Of Heterobasidium annosum was inhibited, whereas that of Phyto phtora (cactorum) was promoted by all the extracts. The antibacterial and a ntifungal activities of six natural coumarin compounds were weak, except fo r the inhibitory effect against Fusarium culmorum. (C) 2000 Elsevier Scienc e Ireland Ltd. All rights reserved.