Bioactive Metabolites from the Endophytic Fungus <em>Aspergillus sp. </em>SPH2

• DOI: 10.20944/preprints202012.0407.v1
• Publication Date: 2020-12-17T07:58:53Z
• Authors: Viridiana Morales...; Carmen E. Díaz; Elena Trujillo; Rubén Muñoz; A. Sonia Olmeda; Felix Valcarcel; Maria Fe Andrés; Azucena Gonzalez-...
• Keywords: 0301 basic medicine; Antifungals; neoaspergillic acid; QH301-705.5; 3109 Ciencias Veterinarias; Mellein; Endophyte; Ixodicidal; Article; Aspergillus ochraceous; <i>Aspergillus ochraceous</i>; 03 medical and health sciences; anatomy_morphology; Biology (General); Veterinaria; endophyte; ixodicidal; antifungal; mellein; Neoaspergillic acid

In the current study, an ethyl acetate extract from the endophytic fungus Aspergillus ochraceus SPH2 isolated from the stem parts of the endemic plant Bethencourtia palmensis was screened for its biocontrol properties against plant pathogens (Fusarium moniliforme, Alternaria alternata and Botrytis cinerea), insect pests (Spodoptera littoralis, Myzus persicae, Rhopalosiphum padi), plant parasites (Meloidogyne javanica) and ticks (Hyalomma lusitanicum). SPH2 gave extracts with strong fungicidal and ixodicidal effects at different fermentation times. The bioguided isolation of these extracts gave compounds 1-3. Mellein (1) showed strong ixodicidal effects and was also fungicidal. This is the first report on the ixodicidal effects of 1. Neoaspergillic acid (2) showed potent antifungal effects. Compound 2 appeared during the exponential phase of the fungal growth while neohydroxyaspergillic acid (3) appeared during the stationary phase, suggesting that 2 is the biosynthetic precursor of 3. Additional molecular ions compatible with pyrazynes that were detected during the exponential phase included flavacol, and aspergilliamide while ochramide A was mostly detected during the stationary phase of the fermentation. Moreover, polyketids were also detected during the sationaty phase of the fermentation curve (dihydroaspyrone, aspyrone, asperlactone) and the alkaloid circumdatin H. Ochratoxin A was not detected. Therefore, SPH2 could be a potential biotechnological tool for the production of ixodicidal mellein.