New 2-phenylpyridazinones, analogs o f 4-chloro-5-methylamino-2-phenylpyridazin-3(2H)ones, were assayed for their phytotoxic activity to interfere with plant pigment formation. Six derivatives with — SCF3, — OCF2CH FCF3, — O CH F2, — CN, or — Br in meta position o f the phenyl ring exhibited similar or better bleaching activity than the m -CF3 analog (norflurazon). The activity is predominantly...

Semisolid olive-mill residues, pine chips, and mixtures of both residues contain phytotoxic components capable of inhibiting germination and vegetative growth in plants. Solid-state cultures of Phanerochate flavido-alba on pine chips or mixtures of both residues reduce these phytotoxic effects in fermented substrates. The phenol and lipid contents in cultures detoxified by this fungus also decr...

The neotropical bracken fern Pteridium arachnoideum (Kaulf.) Maxon. (Dennstaedtiaceae) is described as an aggressive pioneer plant species. It invades abandoned or newly burned areas and represents a management challenge at these invaded sites. Native to the Atlantic Forest and Cerrado (Tropical Savanna) Brazilian biomes, P. arachnoideum has nevertheless become very problematic in these conserv...

Tulasnein (1), a new metabolite with strong antimicrobial and weaker cytotoxic and phytotoxic activity, was isolated from culture filtrates of three strains of the xylariaceous coprophilous fungus Podosordaria tulasnei. The producing strains were identified by their rhizomorphs and by ITS rDNA sequence analysis. A second new metabolite, podospirone (2), was also produced by all three strains wh...

Artemisinin, a secondary metabolite produced in Artemisia plant species, besides having antimalarial properties is also phytotoxic. Although, the phytotoxic activity of the compound has been long recognized, no information is available on the mechanism of action of the compound on photosynthetic activity of the plant. In this report, we have evaluated the effect of artemisinin on photoelectron ...

Systematic bioassay-guided fractionation of the methylene chloride extract of the roots from Ligularia macrophylla was performed to identify both phytotoxic and antifungal compounds. Four phytotoxic eremophilanes (furanoeremophilan-14beta,6alpha-olide, 6beta-angeloyloxy-10beta-hydroxyfuranoeremophilane, eremophil-7(11)-ene-12,8alpha;14beta,6alpha-diolide, and 3alpha-angeloyloxybakkenolide A) an...

The furanoeremophilanes 6 beta-angeloyloxy-1,10-dehydrofuranoeremophilan-9-one (1), 6 beta-hydroxy-1,10-dehydrofuranoeremophilan-9-one (2) and 6 beta-propionyloxy-1,10-dehydrofuranoeremophilan-9-one (3) were isolated from Senecio otites, their structures elucidated by spectral analyses, and their insecticidal and phytotoxic properties evaluated. Compounds 1-3 proved to be effective aphid antife...