Phytotoxic metabolites from a fungal pathogen of in Iran.

Two phytotoxic furan derivatives were isolated, together with the well-known fungal and plant phytotoxin tyrosol, from the culture filtrates of . This fungal pathogen isolated from trees induced wood necrosis and decline symptoms on the host plant in Iran. The two furan derivatives, isolated for the first time from , were identified by spectroscopic methods (essentially 1 D and 2 D H and C NMR and ESIMS spectroscopy) as 5-hydroxymethylfuraldehyde and 2,5-dihydroxymethylfuran. The phytotoxic activity of the three metabolites was evaluated by leaf puncture assay on holm oak ( L.) and tomato ( L.) leaves. All compounds induced necrosis on holm oak leaves while very low toxicity was showed against tomato leaves. The two furan derivatives were more toxic than tyrosol and particularly 5-hydroxymethylfuraldehyde was the most phytotoxic compound.