| Abstract
| - Myrothecium verrucaria and Fusarium compactum were isolated from diseased Orobanche ramosaplants collected in southern Italy to find potential biocontrol agents of this parasitic weed. Both fungigrown in liquid culture produced metabolites that inhibited the germination of O. ramosa seeds at1−10 μM. Eight metabolites were isolated from M. verrucaria culture extracts. The main metabolitewas identified as verrucarin E, a disubstituted pyrrole not belonging to the trichothecene group. Sevencompounds were identified by spectroscopic methods as macrocyclic trichothecenes, namely,verrucarins A, B, M, and L acetate, roridin A, isotrichoverrin B, and trichoverrol B. The main metaboliteproduced by F. compactum was neosoloaniol monoacetate, a trichothecene. All the trichothecenesproved to be potent inhibitors of O. ramosa seed germination and possess strong zootoxic activitywhen assayed on Artemia salina brine shrimps. Verrucarin E is inactive on both seed germinationand zootoxic assay. Keywords: Orobanche ramosa; Myrothecium verrucaria; Fusarium compactum; phytotoxins; trichothecenes; seed germination inhibitors
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