Phytotoxic metabolites from Stilbocrea macrostoma, a fungal pathogen of Quercus brantii in Iran

Abstract

Two phytotoxic furan derivatives were isolated, together with the well-known fungal and plant phytotoxin tyrosol, from the culture filtrates of Stilbocrea macrostoma. This fungal pathogen isolated from Quercus brantii trees induced wood necrosis and decline symptoms on the host plant in Iran. The two furan derivatives, isolated for the first time from Stilbocrea macrostoma, were identified by spectroscopic methods (essentially 1 D and 2 D ¹H and ¹³C 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 (Quercus ilex L.) and tomato (Lycopersicon esculentum 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.

Graphical Abstract

Keywords:

• Stilbocrea macrostoma
• oak trees
• Quercus brantii
• phytotoxins
• furan derivatives
• 5-hydroxymethyl-2-furaldehyde and 2,5-dihyroxymetylfuran

Disclosure statement

No potential conflict of interest was reported by the author(s).

ORCID

Marco Masi http://orcid.org/0000-0003-0609-8902

Angela Tuzi http://orcid.org/0000-0002-2523-5039

Jafar Abdollahzadeh htpp://orcid.org/0000-0001-8642-1401

Antonio Evidente htpp://orcid.org/0000-0001-9110-1656

Additional information

Funding

Samaneh Bashiri was supported by the University of Kurdistan, Sanandaj, Iran and received a grant from the Ministry of Science, Research and Technology, Tehran, Iran.