Antifungal effects of metabolites from Arthrinium sp. 2-65 and identification of main active ingredients

Using microbes and their metabolites as material to develop new biological fungicides is still vital for pesticide development. Our preliminary study found that the endophytic fungi Arthrinium sp. 2-65 of Thymus mongolicus (Ronniger) Ronniger showed a certain inhibitory effect on pathogenic fungi.

In this study, the antifungal activity of Arthrinium sp. 2-65 was evaluated. The ethyl acetate extract of Arthrinium sp. 2-65 exhibited significant inhibitory activity against pathogenic fungi, especially Botrytis cinerea. The main compounds of Arthrinium sp. 2-65 metabolites were isolated and purified, and the two compounds were identified by infrared spectroscopy (IR), high-performance liquid chromatography (HPLC), ¹H nuclear magnetic resonance (NMR), ¹³C NMR, and high-resolution mass spectrometry (HRMS) as 2-hexyl-3-methylmaleic anhydride (A) and 2-carboxymethyl-3-n-hexylmaleic acid anhydride (B).

The main compounds (A and B) isolated and characterised from the fermentation broth of Arthrinium sp. 2-65 showed satisfactory inhibitory effects against pathogenic fungi, especially B. cinerea. These compounds could be used as potential molecules for the development of novel pesticides to control grey mould.